POSITRON CORP
SB-2, 2000-02-14
ELECTROMEDICAL & ELECTROTHERAPEUTIC APPARATUS
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AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 14, 2000
                                                    REGISTRATION NO. 333-

===============================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM SB-2
             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                              POSITRON CORPORATION

            TEXAS                     3845                      76-0083622
(State or other jurisdiction    (Primary Standard            (I.R.S. Employer
    of incorporation or            Industrial             Identification Number)
    other organization)       Classification Code)


            1304 LANGHAM CREEK DRIVE, SUITE 300, HOUSTON, TEXAS 77084
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

                            GARY H. BROOKS, PRESIDENT
            1304 LANGHAM CREEK DRIVE, SUITE 300, HOUSTON, TEXAS 77084
                           (NAME OF AGENT FOR SERVICE)
                      ------------------------------------
                                   COPIES TO:
                                 ROGER S. MERTZ
                   ALLEN, MATKINS, LECK, GAMBLE & MALLORY LLP
                                 333 BUSH STREET
                         SAN FRANCISCO, CALIFORNIA 94104
                            TELEPHONE: (415) 837-1515
                            FACSIMILE: (415) 837-1516
                      ------------------------------------
                  APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED
              SALE TO THE PUBLIC: AS SOON AS PRACTICABLE AFTER THE
                 EFFECTIVE DATE OF THIS REGISTRATION STATEMENT.
                      ------------------------------------

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous  basis  pursuant to Rule 415 under the Securities Act of
1933, check the following box. [X]

     If this Form is filed to  register  additional  securities  for an offering
pursuant to Rule 462(b) under the  Securities  Act of 1933,  check the following
box and list the Securities  Act  registration  number of the earlier  effective
registration statement for the same offering. [_]

     If this Form is a  post-effective  amendment  filed pursuant to Rule 462(c)
under  the  Securities  Act of  1933,  check  the  following  box and  list  the
Securities  Act  registration   statement   number  of  the  earlier   effective
registration statement for the same offering. [_]

     If this form is a  post-effective  amendment  filed pursuant to Rule 462(d)
under  the  Securities  Act of  1933,  check  the  following  box and  list  the
Securities  Act  registration   statement   number  of  the  earlier   effective
registration statement for the same offering. [_]

     If delivery of the  prospectus is expected to be made pursuant to Rule 434,
please check the following box: [_]

                      ------------------------------------

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
====================================================================================================================

          TITLE OF SECURITIES                              PROPOSED MAXIMUM   PROPOSED MAXIMUM
           TO BE REGISTERED               AMOUNT TO BE      OFFERING PRICE       AGGREGATE          AMOUNT OF
                                           REGISTERED        PER SHARE(1)      OFFERING PRICE    REGISTRATION FEE
- --------------------------------------------------------------------------------------------------------------------
<S>           <C>                           <C>                  <C>             <C>                   <C>
Common Stock, $0.01 par value               51,172,990           $0.53           $27,121,684           $7,160
- --------------------------------------------------------------------------------------------------------------------
Common Stock Underlying Warrants            27,560,000(2)        $0.53           $14,606,800           $3,856
====================================================================================================================
Total                                       78,732,990           $0.53           $41,728,484          $11,016
====================================================================================================================
</TABLE>
<PAGE>

(1) Estimated solely for the purpose of computing the amount of registration fee
pursuant to Rule 457(c)  under the  Securities  Act of 1933 based on the average
high and low sale prices of  registrant's  common stock on February 9, 2000.

(2) The warrants may be exercised to purchase  shares of common stock.  Pursuant
to  Rule  416  under  the  Securities  Act of  1933,  as  amended,  we are  also
registering such  indeterminable  number of additional shares of common stock as
may be  saleable  upon  conversion  of some of these  warrants  pursuant  to the
warrant provisions governing conversion price.

      THE REGISTRANT HEREBY AMENDS THIS  REGISTRATION  STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER  AMENDMENT  WHICH  SPECIFICALLY  STATES  THAT  THIS  REGISTRATION
STATEMENT SHALL  THEREAFTER  BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES  ACT OF 1933 OR UNTIL THIS  REGISTRATION  STATEMENT  SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION,  ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.

- --------------------------------------------------------------------------------


<PAGE>


                 SUBJECT TO COMPLETION, DATED February 14, 2000

PROSPECTUS

                            POSITRON CORPORATION

                                [LOGO] POSITRON

                                78,732,990 SHARES
                                  COMMON STOCK


The selling  stockholders  identified in this prospectus are offering 78,732,990
shares of common stock, 27,560,000 of which underlie warrants to purchase common
stock  which  have  not yet been  exercised.  All  these  securities  are  being
registered  for resale only.  Positron will not receive any of the proceeds from
the sale of shares by the selling stockholders.

Positron's  common  stock is traded on the  over-the-counter  securities  market
("pink sheets"),  and quoted on the NASD's  Electronic  Bulletin Board under the
symbol  "POSC.OB"  On February 9, 2000,  the last  reported  sales price for the
common stock on the Electronic Bulletin Board was $0.56 per share.


INVESTING IN OUR COMMON STOCK INVOLVES A HIGH DEGREE OF RISK. SEE "RISK FACTORS"
BEGINNING ON PAGE 5.

                             ----------------------

NEITHER  THE  SECURITIES  AND  EXCHANGE  COMMISSION  NOR  ANY  STATE  SECURITIES
COMMISSION HAS APPROVED OR  DISAPPROVED  OF THESE  SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.



                        ---------------------------------


                The date of this Prospectus is February 14, 2000.


      You may rely on the information contained in this prospectus.  We have not
authorized anyone to provide  information  different from that contained in this
prospectus.  Neither the  delivery of this  prospectus  nor sale of common stock
means that information contained in this prospectus is correct after the date of
this  prospectus.  This prospectus is not an offer to sell or solicitation of an
offer to buy these shares of common stock in any  circumstances  under which the
solicitation is unlawful.

<PAGE>

                               TABLE OF CONTENTS

                                                                        Page No.

Summary Information ..................................................      3
Risk Factors .........................................................      6
Use of Proceeds ......................................................     17
Selling Stockholders .................................................     17
Plan of Distribution .................................................     19
Legal Proceedings ....................................................     20
Directors, Executive Officers, Promoters and Control Persons .........     21
Security Ownership of Certain Beneficial Owners and Management .......     22
Description of Securities ............................................     24
Interest of Named Experts and Counsel ................................     25
Disclosure of Commission Position on
  Indemnification for Securities Act Liabilities .....................     26
Description of Business ..............................................     26
Management's Discussion and  Analysis of Plan of Operation ...........     29
Description of Property ..............................................     35
Certain Relationships and Related Transactions .......................     35
Market for Common Equity and Related Stockholder Matters .............     36
Executive Compensation ...............................................     38
Changes in and Disagreements With Accountants on
  Accounting and Financial Disclosure ................................     42
Legal Matters ........................................................     44
Where You Can Find More Information ..................................     44
Consolidated Financial Statements ....................................    F-1


                                      2
<PAGE>


                               SUMMARY INFORMATION

TO  UNDERSTAND  THIS  OFFERING  FULLY,  WE  ENCOURAGE  YOU TO READ  THIS  ENTIRE
PROSPECTUS  CAREFULLY,  INCLUDING THE FINANCIAL  STATEMENTS AND THE NOTES TO THE
CONSOLIDATED  FINANCIAL  STATEMENTS OF THE COMPANY  APPEARING  ELSEWHERE IN THIS
PROSPECTUS.

REFERENCES  IN THIS  DOCUMENT  TO  "WE,"  "US,"  AND  "OUR"  REFER  TO  POSITRON
CORPORATION.

THIS PROSPECTUS CONTAINS FORWARD-LOOKING  STATEMENTS.  THE OUTCOME OF THE EVENTS
DESCRIBED  IN THESE  FORWARD-LOOKING  STATEMENTS  IS SUBJECT TO RISKS AND ACTUAL
RESULTS  COULD  DIFFER   MATERIALLY.   THE  SECTIONS  ENTITLED  "RISK  FACTORS,"
"MANAGEMENT'S  DISCUSSION  AND  ANALYSIS OF FINANCIAL  CONDITION  AND RESULTS OF
OPERATIONS"  AND  "BUSINESS,"  AS WELL AS  OTHER  SECTIONS  IN THIS  PROSPECTUS,
CONTAIN A  DISCUSSION  OF SOME OF THE  FACTORS  THAT COULD  CONTRIBUTE  TO THOSE
DIFFERENCES.


                                   THE COMPANY

Positron  Corporation  (the "Company") was incorporated in the State of Texas on
December 20, 1983,  and  commenced  commercial  operations  in 1986.  We design,
manufacture,  market and service  advanced  medical  imaging  devices  utilizing
positron emission tomography ("PET") technology under the trade-name POSICAM(TM)
systems1. Unlike other currently available imaging technologies,  PET technology
permits the  measurement  of the  biological  processes of organs and tissues as
well as producing  anatomical  and structural  images.  POSICAM  systems,  which
incorporate patented and proprietary  technology,  enable physicians to diagnose
and treat patients in the area of cardiology, neurology and oncology.

The Food and Drug Administration ("FDA") approved the initial POSICAM system for
marketing in 1985. As of October 31, 1999, we have sold sixteen POSICAM systems,
of which thirteen are in leading  medical  facilities in the United States,  two
are  installed  in  international  medical  institutions,  and  one is  awaiting
installation  at a major medical  institution  in Japan.  The Company  presently
markets its POSICAM systems at list prices of up to $2.0 million  depending upon
the configuration and equipment options of the particular system.

PET technology is an advanced imaging  technique,  which permits the measurement
of the  biological  processes  of  organs  and  tissues  as  well  as  producing
anatomical and structural  images.  Other advanced imaging  techniques,  such as
magnetic  resonance  imaging  ("MRI") and computed  tomography  ("CT"),  produce
anatomical  and  structural  images,  but do not  image  or  measure  biological
processes. The ability to measure biological abnormalities in tissues and organs
allows physicians to detect disease at an early stage, and provides  information
which would  otherwise be unavailable to diagnose and treat disease.  We believe
that our PET  technology  can lower the total  cost of  diagnosing  and  tracing
certain diseases by providing a means for early diagnosis and reducing expensive
invasive or unnecessary  procedures,  such as angiograms or biopsies  which,  in
addition to being costly and painful, may not be necessary or appropriate.

Commercialization  of PET technology  commenced in the mid-1980s and the Company
is one of several commercial  manufacturers of PET imaging systems in the United
States.  Although the other  manufacturers are substantially  larger, we believe
that  our  POSICAM   systems  have   proprietary   operational  and  performance
characteristics,  which  may give  certain  performance  advantages  over  other
commercially available PET systems. Such advantages include: (i) high

- ----------

1 POSICAM(TM)  is a registered  trademark of Positron.  All other brand names or
trademarks  appearing in this  prospectus  are the property of their  respective
holders.


                                      3
<PAGE>


count-rate sensitivity which results in faster imaging; (ii) enhanced ability to
use certain types of radio pharmaceuticals which reduces reliance on a cyclotron
and enhances patient  throughput;  (iii) ability to minimize patient exposure to
radiation;  and (iv)  ability to  minimize  false  positive  and false  negative
diagnosis of disease. The medical imaging industry,  in which we are engaged, is
subject to rapid and significant technological change. There can be no assurance
that the POSICAM  systems can be upgraded to meet future  innovations in the PET
industry or that new technologies will not emerge, or existing technologies will
not be improved, which would render our products obsolete or non-competitive.

Our primary focus to date has been on the clinical cardiology market,  where our
POSICAM  systems  have been used to assess the  presence  and extent of coronary
heart disease,  such as the effect of arterial blockages and heart damage due to
heart attacks. In 1994 and 1995, we made technological advances which allowed us
to market our products to the neurological and oncological markets. Neurological
applications of POSICAM systems  include  diagnoses of certain brain  disorders,
such as  epileptic  seizures,  dementia,  stroke,  Alzheimer's  disease,  Pick's
disease and Parkinson's  disease.  In oncology,  POSICAM systems are used in the
diagnosis and  evaluation of melanoma and tumors of the bone and various  organs
and tissues such as the brain, liver, colon, breasts and lymphatic system.

We have set forth below, in tabular form for convenience, some summary financial
information  regarding  the Company for the years  ended  December  31, 1997 and
1998,  and for the three months and nine months ended  September 30, 1999.  This
information is only a summary. You should read it together with our consolidated
financial statements and notes beginning on page F-1.

                       SUMMARY CONSOLIDATED FINANCIAL DATA
                      (IN THOUSANDS, EXCEPT PER SHARE DATA)

<TABLE>
<CAPTION>
                                                    YEAR ENDED DECEMBER 31,        THREE             NINE
                                                    -----------------------     MONTHS ENDED     MONTHS ENDED
SELECTED RESULTS OF OPERATIONS:                      1997           1998           9/30/99         9/30/99
                                                    -------        ------       ------------    ------------
<S>                                                <C>            <C>            <C>               <C>
REVENUES
    System sales                                   $  1,129       $   --         $   --            $   --
    Fee per scan                                        602            455           --                 137
    Service and component                             1,795          1,553            385             1,088
                                                   --------       --------       --------          --------
  Total Revenues                                      3,526          2,008            385             1,225
                                                   --------       --------       --------          --------
COST OF REVENUES
    System sales                                        698           --             --                  49
    Fee per scan                                        156            118           --                --
    Service, warranty and component                     465            402            171               418
    Provision for inventory obsolescence              1,224           --             --                --
                                                   --------       --------       --------          --------
  Total cost of revenues                              2,543            520            171               467
                                                   --------       --------       --------          --------
GROSS PROFIT                                            983          1,488            214               759
                                                                                                   --------
TOTAL OPERATING EXPENSES                              3,609          1,700            384               749
                                                                                                   --------
INCOME/LOSS FROM OPERATIONS                          (3,931)          (212)          (170)               10
                                                                                                   --------
Income Interest (Expense)                              (524)          (512)            55               (45)
Income (Loss) before extraordinary item              (4,455)          (724)          (115)              (35)
Extraordinary Item, Gain on Foregiveness of Debt       --             --              143               143
                                                   --------       --------       --------          --------
Net Loss                                             (4,455)          (724)           (28)             (108)
                                                   ========       ========       ========          ========
PER SHARE DATA
                                                                                                   --------
Basic and diluted net loss per common share           (0.91)         (0.14)          0.00              0.00
Weighted average number of
  basic shares outstanding (1)                        4,885          5,150         40,278            23,792
</TABLE>

(1)   See  Note  1 to  the  financial  statements  for  an  explanation  of  the
      determination of the number of shares used in computing per share data.


                                      4
<PAGE>


              SELECTED BALANCE SHEET DATA
                                                  December 31,    September 30,
                                                      1998            1999
                                                    ------          ------
Assets
   Cash and cash equivalents                        $    8          $8,606
   Accounts receivable                                  99             210
   Inventories                                         391             636
   Prepaid expenses                                     58             103
                                                    ------          ------
      Total current assets                             556           9,555
   Note receivable                                                      30
   Plant and equipment - net                           130             108
                                                    ------          ------
      Total assets                                     686           9,693
                                                    ======          ======
Liabilities
   Notes payable to affiliate                          792               0
   Accounts payable and accrued liabilities          4,723           3,696
   Unearned revenue                                    142              74
   Long term debt to affiliate                         600               0
   Other liabilities                                    68              51
                                                    ------          ------
      Total liabilities                              6,325           3,821
                                                    ------          ------
Stockholders deficit
   Series A and B Preferred stock                    1,582           1,035
   Common stock                                         52             521
   Additional paid in capital                       42,426          53,907
   Accumulated deficit                              (49,684)        (49,576)
   Treasury stock, 60,156 shares at cost                15             (15)
                                                    ------          ------
      Total shareholders equity                     (5,639)         (5,872)
                                                    ------          ------
      Total liabilities and shareholders equity        686           9,693
                                                    ======          ======



                                       5
<PAGE>

                                  THE OFFERING

Securities offered for resale by certain stockholders of our Company

      - up to 51,172,990 shares of Common stock

      - up to 27,560,000 shares of Common Stock underlying warrants

We will not receive  any of the  proceeds  from the resale of these  securities,
although if all the warrants are  exercised,  we could  receive up to $6,138,000
from the exercise of the warrants.


                                  RISK FACTORS

YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED BELOW BEFORE MAKING A DECISION
TO BUY OUR COMMON STOCK. THE RISKS AND UNCERTAINTIES DESCRIBED BELOW ARE NOT THE
ONLY ONES WE FACE.  ADDITIONAL RISKS AND UNCERTAINTIES NOT PRESENTLY KNOWN TO US
OR THAT WE CURRENTLY  DEEM  IMMATERIAL MAY ALSO  MATERIALLY  IMPAIR OUR BUSINESS
OPERATIONS.

IF ANY OF THE FOLLOWING RISKS ACTUALLY OCCUR, OUR BUSINESS,  FINANCIAL CONDITION
OR RESULTS OF OPERATIONS COULD BE MATERIALLY  ADVERSELY AFFECTED.  IN SUCH CASE,
THE TRADING  PRICE OF OUR COMMON  STOCK COULD  DECLINE,  AND YOU MAY LOSE ALL OR
PART OF YOUR  INVESTMENT.  YOU SHOULD  ALSO REFER TO THE OTHER  INFORMATION  SET
FORTH IN THIS  PROSPECTUS,  INCLUDING OUR FINANCIAL  STATEMENTS  AND THE RELATED
NOTES.


IF WE  CONTINUE TO  EXPERIENCE  LOSSES IN THE FUTURE,  OUR  BUSINESS,  FINANCIAL
CONDITION AND GROWTH PROSPECTS COULD BE MATERIALLY ADVERSELY AFFECTED.

We have had net losses in each fiscal year since we started  operations in 1986.
We expect to continue to incur losses on an operating  basis for the foreseeable
future on both an  annual  and


                                      6
<PAGE>


quarterly  basis  Losses to date have  occurred  primarily  because we have been
unable to sell POSICAM  systems in sufficient  quantities to be  profitable.  In
addition,  and because the price of each POSICAM system is so  significant,  our
revenues  fluctuate  significantly  from quarter to quarter and year to year. We
are not able to assure that we will ever achieve the level of operating revenues
needed to be profitable  in the future or, if we are able to become  profitable,
that we will be able to remain  profitable.  Because of these expected losses we
may not be able to implement our business  plans,  and our  business,  financial
condition and growth prospects could be materially adversely affected.

As of  December  31,  1998,  we  had an  accumulated  deficit  of  approximately
$49,684,000  as the result of our history of net losses.  We received new equity
capital in July and August 1999 through a private  placement  involving the sale
of stock and warrants for cash.  Nonetheless,  we believe that it is likely that
we will continue to experience  operating losses and accumulate deficits for the
foreseeable future. For the two most recent fiscal years, our year-end financial
statements  have  contained a  qualification  from our  independent  accountants
regarding the uncertainty of our ability to continue as a going concern.


IF OUR NEW  MANAGEMENT  IS NOT ABLE TO IMPROVE  AND EXPAND OUR  OPERATIONS,  OUR
BUSINESS AND RESULTS OF OPERATIONS COULD SUFFER.

Effective  January  22,  1999 we employed  Gary H.  Brooks as  president  of the
Company on a part-time basis and thereafter, on September 1, 1999 on a full-time
basis.  While Mr. Brooks is a very  experienced  senior executive in the medical
imaging  field,  he has assumed  operating  responsibility  with a very  limited
management team. If he is not able  simultaneously  to stabilize our operations,
expand  our  staff,   and  improve  and  expand  our   operations   quickly  and
dramatically, our financial condition,  profitability and growth prospects could
be materially adversely affected.


IF WE ARE UNABLE TO RETAIN AND ATTRACT QUALIFIED  PERSONNEL,  OUR BUSINESS COULD
SUFFER.

Our ability to grow and our future  success  depend on our ability to  identify,
attract,  hire,  train,  retain and  motivate  other highly  skilled  technical,
managerial,  sales and marketing,  customer service and professional  personnel.
Competition for such employees is intense, particularly with the technical skill
set we  require,  and  there  can be no  assurance  that  we  will  be  able  to
successfully attract, assimilate or retain sufficiently qualified personnel. Our
failure to retain and attract the  necessary  technical,  managerial,  sales and
marketing, customer service personnel and experienced professionals could have a
material  adverse  effect on our  business,  financial  condition and results of
operations.


IF THE MEDICAL  COMMUNITY  DOES NOT EMBRACE OUR  TECHNOLOGY,  OUR  BUSINESS  AND
GROWTH PROSPECTS WILL BE MATERIALLY ADVERSELY AFFECTED.

PET  Imaging  is an  accurate  non-invasive  method to  diagnose  or assess  the
severity of coronary  artery  disease.  Unlike other imaging  technologies,  PET
technology  allows a  physician  to  determine  whether  blood flow to the heart
muscle is normal,  thereby identifying  narrowed coronary arteries,  and whether
damaged  heart  muscle is viable and may benefit from  treatment


                                       7
<PAGE>


such as bypass surgery or angioplasty. Nonetheless, there are other non-invasive
methods  available to make such  diagnoses.  We believe that  acceptance  of our
products and services will depend on several factors, including:

         o  cost

         o  reliability

         o  availability of proprietary upgrades

         o  reimbursement  of PET diagnostic  procedures by healthcare  insurers
            and/or the federal Medicare system

         o  cost and reliability of maintenance

         o  ability to incorporate non-proprietary enhancements

We  cannot  assure  you that our  technology  will gain  wide  acceptance  among
physicians,   medical   groups  and  hospitals  or  that  medical   groups  will
significantly  increase  their use of the  technology  for  diagnosis  and other
medical  applications.  If the market fails to continue to develop,  or develops
more slowly than  expected,  our business,  results of operations  and financial
condition  will  be  adversely  affected.  In  addition  we may be  unable,  for
technical  or  other   reasons,   to  develop  and  introduce  new  services  or
enhancements  of existing  technology and services in a timely manner,  and such
services and  enhancements  may not gain widespread  market  acceptance.  Any of
these things could have a material  adverse  affect on our business,  results of
operations and financial condition.


IF THERE IS A DECREASE IN THE DEMAND FOR MEDICAL  DIAGNOSTIC  IMAGING  EQUIPMENT
AND SERVICES OF ALL TYPES, OUR BUSINESS COULD SUFFER.

Demand for high-end  medical  diagnostic  imaging  procedures and devices can be
adversely  affected by periods of economic slowdown or recession when the public
tends  to seek  less  expensive  medical  services  perceived  to be  almost  as
effective as those which are superior but more expensive.


IF WE ARE UNABLE TO  DIFFERENTIATE  OURSELVES FROM  COMPETITION IN OUR INDUSTRY,
OUR BUSINESS AND GROWTH PROSPECTS COULD BE HARMED.

We face competition from three other commercial manufacturers of PET systems and
from other imaging technologies,  primarily Single Photon Emission CT ("SPECT").
While we do not  believe  that  MRI and CT scan  imaging  represent  significant
competing  technologies  (PET,  MRI and CT scans each  provide  information  not
available from the others),  we cannot assure that the medical community and our
other clients will continue to agree.

In addition,  our current primary  competition from commercial  manufacturers of
PET systems comes from General Electric Company ("GE"), Siemens Medical Systems,
Inc. in a joint venture with CTI, Inc. of Knoxville,  Tennessee  ("CTI/Siemens")
and ADAC Medical Systems ("ADAC").  GE,  CTI/Siemens and ADAC have substantially
greater financial, technological and personnel resources than we do.

Moreover, two Japanese  manufacturers,  Hitachi and Shimadzu,  have manufactured
and  sold  PET  scanners  in  Japan  but not  yet in the  United  States.  These
manufacturers   represent   additional


                                       8
<PAGE>


sources of competition which have substantially greater financial, technological
and personnel resources than do we.

The primary  competing  technology  in the nuclear  medicine  industry is SPECT,
which costs substantially less than our systems.  While we believe our system is
a better  diagnostic tool than SPECT imaging,  we cannot assure that the medical
community will make its decisions on that basis.

High field MRI  technology,  an advanced  version of MRI, is in the  development
stage,  but is a potential  competitor to PET in certain  neurology and oncology
applications.  We cannot presently  predict the future  competitiveness  of high
field MRI.

Several  manufacturers  of SPECT  systems are now offering  multi-head  systems,
which  have been  modified  to  operate in  coincidence  mode,  similar to a PET
scanner.  These  systems  achieve  spatial  resolutions  similar  to that of PET
scanners, but their sensitivity and count rate are only a small fraction of that
achieved by true PET  scanners.  While we believe  these  systems are useful for
only a very limited  class of clinical PET  studies,  we cannot  assure that the
medical community will adopt that position.


IF  THIRD  PARTY  REIMBURSEMENT  IS  NOT  EXPANDED  OR IS  OTHERWISE  NEGATIVELY
AFFECTED, IT WILL SEVERELY AFFECT OUR FINANCIAL POSITION.

Our systems are  purchased or leased  primarily by medical  institutions,  which
provide health care services to their  patients.  Such  institutions or patients
typically bill or seek  reimbursement  from various  third-party  payors such as
Medicare,  Medicaid,  other governmental programs and private insurance carriers
for the charges  associated with the provided  healthcare  services.  We believe
that the market success of PET imaging depends largely upon obtaining  favorable
coverage and reimbursement policies from such programs and carriers.

Prior to March 1995, Medicare and Medicaid did not provide reimbursement for PET
imaging.  Since then  Medicare and Medicaid  reimbursement  for PET imaging have
been, and we believe may continue to be, very  restrictive.  We further  believe
that  restrictive  reimbursement  policies have had a very  significant  adverse
affect on widespread use of PET imaging and have, therefore,  adversely affected
our business, financial condition, results of operations and cash flows.

In recent  years,  certain  procedures  have been  approved  for  reimbursement.
Whether additional reimbursable procedures will be approved for reimbursement by
appropriate  regulators,  whether  insurers  will  follow,  and/or  whether  the
procedure reimbursement level will be sufficient to stimulate the PET market are
unknown at this time.

Many insurance  carriers currently consider PET imaging to be an investigational
procedure and do not reimburse for procedures involving PET imaging.

If  third-party  coverage for PET  procedures  using the POSICAM  system remains
unavailable,  it will likely  have a material  adverse  effect on the  Company's
business,  financial condition,  results


                                       9
<PAGE>


of operations and cash flows. We cannot assure that  reimbursement  policies for
these procedures will change.


IF WE ARE NOT ABLE TO KEEP UP WITH TECHNOLOGICAL CHANGE, IT WILL HAVE A MATERIAL
NEGATIVE EFFECT ON OUR BUSINESS.

The  industry  in which we are  engaged  is  subject  to rapid  and  significant
technological  change.  There can be no assurance  that  POSICAM  systems can be
upgraded to meet future innovations in the PET industry or that new technologies
will not emerge,  or existing  technologies  will not be  improved,  which would
render our products obsolete or  non-competitive.  Our competitors in the United
States, as described above, have  significantly  greater financial and technical
resources and  production  and marketing  capabilities  than we do. In addition,
there can be no assurance that other established medical imaging companies,  any
of which would  likely  have  greater  resources  than we do, will not enter the
market. We also face competition from other imaging  technologies which are more
firmly established and have a greater market acceptance, including single-photon
emission computed tomography (SPECT).  There can be no assurance that we will be
able to compete successfully against any of our competitors.


IF WE ARE  NOT  ABLE TO  FIRMLY  ESTABLISH  MARKET  ACCEPTANCE,  IT WILL  HAVE A
MATERIAL NEGATIVE EFFECT ON OUR BUSINESS.

The POSICAM systems  involve new technology that competes with more  established
diagnostic techniques.  The purchase and installation of a PET system involves a
significant  capital  expenditure  on the  part of the  purchaser.  A  potential
purchaser  of a PET system  must have an  available  patient  base that is large
enough  to  provide  the  utilization   rate  needed  to  justify  such  capital
expenditure.  There  can be no  assurance  that PET  technology  or our  POSICAM
systems will be accepted by the target  markets or that the  Company's  sales of
POSICAM systems will increase or that we will ever be profitable.


IF OUR PHYSICAL  FACILITIES ARE INADEQUATE TO OUR  MANUFACTURING  NEEDS, IT WILL
HAVE A MATERIAL  NEGATIVE EFFECT ON OUR ABILITY TO MANUFACTURE AND  CONSEQUENTLY
SELL OUR PRIMARY PRODUCT.

We believe we currently  have the ability to assemble our scanners in a discrete
area of our corporate facility located in Houston, Texas. Scanners are generally
produced by assembling parts furnished to us by outside suppliers. We believe we
can assemble a typical system in two to three months,  with an additional  month
required  for  testing  before  delivery.  We  cannot  assure  however  that our
facilities will remain adequate.


IF OUR SUPPLY OF ESSENTIAL  PARTS AND MATERIALS IS SEVERELY  INTERRUPTED,  OR IF
THESE  PRODUCTS  FAIL TO  CONTINUE  TO MEET OUR  NEEDS,  IT WILL HAVE A MATERIAL
ADVERSE EFFECT ON OUR BUSINESS.

There are  several  essential  components  of our  systems  which we obtain from
limited or sole sources,  including bismuth germinate oxide (BGO) crystals which
detect positron emissions,  and photo-multiplier  tubes, which convert the light
energy  emitted by the crystals  into  electrical  impulses for use in the image
reconstruction  process.  While we attempt to make alternate supply arrangements
in the event  that the  supply of either  component  is  interrupted,  we cannot
assure


                                       10
<PAGE>


that those  arrangements can be made and will provide  sufficient  quantities of
those components on a timely or uninterrupted  basis.  Further, we cannot assure
that the cost of supplies will not rise  significantly  or that  components from
alternate  suppliers  will  continue  to meet  our  needs  and  quality  control
requirements.


IF OUR  PATENTS  AND OTHER  PROPRIETARY  TECHNOLOGY  FAIL TO PROVIDE  MEANINGFUL
PROTECTION  FROM  COMPETITORS,  IT COULD HAVE A MATERIAL  ADVERSE  EFFECT ON OUR
BUSINESS.

We hold certain  patent and trade secret rights  relating to various  aspects of
our PET  technology,  which  are of  material  importance  to us and our  future
prospects.  There can be no  assurance,  however,  that our patents will provide
meaningful protection from competitors.  Even if a competitor's products were to
infringe  on the  patents  we hold,  it would be costly  for us to  enforce  our
rights,  and efforts at  enforcement  would divert funds and resources  from our
operations.  Furthermore,  there can be no assurance  that our products will not
infringe on any patents of others.

In  addition,  we  require  each  employee  and/or  consultant  to enter  into a
confidentiality  agreement  designed  to assist in  protecting  our  proprietary
rights.  There can be no assurance that these agreements will provide meaningful
protection or adequate remedies for our trade secrets or proprietary know-how in
the event of unauthorized use or disclosure of such information,  or that others
will not independently develop substantially  equivalent proprietary information
and  techniques or otherwise  gain access to our trade  secrets and  proprietary
know-how.


IF WE ARE UNABLE TO CONTINUE TO CONDUCT AND SUPPORT RESEARCH AND DEVELOPMENT, IT
WILL HAVE A MATERIAL  ADVERSE  AFFECT ON OUR  ABILITY TO DEVELOP AND IMPROVE OUR
SYSTEMS.

Our systems  are based on  proprietary  technology  initially  developed  at the
University of Texas Health Science Center under a multi-million  dollar research
program begun in 1979.  Since that time,  we have funded the  necessary  further
product  development and  commercialization  of the system.  These are expensive
activities  which are critical to our ability to develop and  maintain  improved
systems.  During fiscal years 1997, 1998 and the first half of fiscal year 1999,
we did not have sufficient funds to conduct substantial research and development
activities.  There  can be no  assurance  that our  inability  to  conduct  such
activities  during that period will not have an adverse effect on our ability to
do so in the future, or that any continuing inability to conduct such activities
will  not have a  material  adverse  affect  on our  business  as a whole in the
future.


IF OUR  MARKETING  STRATEGY  IS  UNSUCCESSFUL,  IT WILL HAVE A MATERIAL  ADVERSE
AFFECT ON OUR BUSINESS.

Our initial marketing strategy targeted clinical cardiology based on the initial
research  conducted at the  University  of Texas.  With the  development  of the
POSICAM  HZ and  POSICAM  HZL  series  of  machines,  we are  pursuing  the full
oncology,  cardiology and neurology related PET application  markets.  To market
our systems in all these  markets,  we rely primarily on referrals from users of
our  existing  installed  scanners,   clinical   presentations  at  professional
conferences,  and articles in trade journals.  There is no assurance that such a
strategy is sufficiently  aggressive to compete  against  larger,  better funded
competitors.


                                       11
<PAGE>


IF WE ARE UNABLE TO SUCCESSFULLY RECRUIT AND RETAINING QUALIFIED  PERSONNEL,  IT
WILL HAVE A MATERIAL ADVERSE AFFECT ON OUR BUSINESS.

Our success  depends to a  significant  degree upon the efforts of our executive
officers and key employees. The loss or unavailability of the services of any of
our key personnel could have a material  adverse effect on our  operations.  Our
success also depends upon our ability to attract and retain qualified  personnel
in all areas of our business, particularly management,  research, marketing, and
engineering.  There can be no assurance that we will be able to continue to hire
and  retain a  sufficient  number of  qualified  personnel.  If we are unable to
retain and attract such qualified personnel, our business, operating results and
cash flows could be adversely affected.


IF WE ARE UNABLE TO MEET  GOVERNMENT  REGULATORY  REQUIREMENTS,  AND/OR IF THOSE
REQUIREMENTS BECOME SUBSTANTIALLY MORE DIFFICULT TO MEET, IT MAY HAVE A MATERIAL
ADVERSE EFFECT ON OUR ABILITY TO MARKET AND SELL OUR PRODUCTS.

Various aspects of testing,  manufacturing,  labeling, selling, distributing and
promoting our systems and the radiopharmaceuticals used with them are subject to
regulation   on  the  federal   level  by  the  United   States  Food  and  Drug
Administration  ("FDA") and in Texas by the Texas Department of Health and other
similar state agencies. In addition, sales of medical devices outside the United
States may be subject to foreign  regulatory  requirements that vary widely from
country to country.  The FDA  regulates  medical  devices  based on their device
classification.  Our device is listed as a Class II medical device, whose safety
and effectiveness are regulated by the use of special controls such as published
performance standards.  To date, the FDA has not published performance standards
for PET systems. If the FDA does publish performance  standards for PET systems,
there can be no assurance that the standards will not have a potentially adverse
effect  on  our  product,  including  substantial  delays  in  manufacturing  or
disrupting our marketing activities.  Other FDA controls, reporting requirements
and  regulations  also apply to  manufacturers  of medical  devices,  including:
reporting of adverse events and injuries,  and the mandatory compliance with the
Quality System Regulations commonly known as Good Manufacturing Practices.

In addition to the regulatory  requirements  affecting the day to day operations
of our  product,  the  FDA  requires  medical  device  manufacturers  to  submit
pre-market  clearance  information  about proposed new devices  and/or  proposed
significant  changes to their existing device prior to their  introduction  into
the  stream  of  commerce.  This  process,  commonly  referred  to  as a  510(k)
Clearance,   is  an  extensive  written  summary  of  performance   information,
comparative   information  with  existing  medical  devices,   product  labeling
information,  safetyt and effectiveness  information,  intended use information,
and the like.  Until the FDA has had the  opportunity  to thoroughly  review and
"clear" the submission,  commercial  distribution of the product is specifically
disallowed.   Although  the  FDA  is  required  to  respond  to  all  pre-market
notifications  within ninety days of receiving  them, the FDA often takes longer
to respond.  One the FDA has cleared the device, it notifies the manufacturer in
terms  of  a  "substantial  equivalence"  letter.  The  manufacturer  may  begin
marketing  the  new  or  modified   device  when  it  receives  the  substantial
equivalence letter. If the FDA requires  additional  information or has specific
questions,  or if the company is notified that the device is not  "substantially
equivalent"  to a device  which has already been  cleared,  it may not begin the
market the device. A non-


                                       12
<PAGE>


substantial equivalence  determination or requests for additional information of
a new or significantly  modified  product could materially  affect our financial
results and operations.

Moreover,  the FDA routinely inspects medical device  manufacturers to determine
compliance  with  Quality  System  Regulations,  and  conducted  such a  routine
inspection of the Company's  operations in July 1999. The inspection resulted in
issuance   of  four   inspectional   observations,   identifying   light   minor
discrepancies to the Company's internal operation  procedures for collection and
analysis of service records,  data input of information for software testing and
the review of a quality report. We have instituted  adequate corrective measures
for these  inspectional  observations  and have provided that information to the
FDA.

In addition to complying with federal requirements,  we are required under Texas
state  law to  register  with  the  state  Department  Health  with  respect  to
maintaining   radiopharmaceuticals   on  premises  for  testing,   research  and
development  purposes.  While in the past we have received  notice of only minor
violations which were promptly and easily  corrected,  and while we believe that
we have taken  adequate  measures to prevent the  recurrence of any  violations,
there is no assurance that violations may not occur in future,  which could have
a material adverse effect on our operations.

Further,  sales of medical devices outside the country may be subject to foreign
regulatory requirements. These requirements vary widely from country to country.
There is no assurance  that the time and effort  required to meet those  varying
requirements  may not adversely  affect our ability to distribute our systems in
some countries.

If we are  unsuccessful in minimizing the negative  effect of prolonged  working
capital  deficiencies,  it will have a material  adverse  effect on our business
going forward.

Particularly  during fiscal years 1997,  1998 and the first half of 1999, we had
minimal amounts of working  capital,  and were unable to timely meet some of our
obligations  as they came due.  As a result,  we were in  arrears to many of our
vendors and  supplier.  We also  deferred  paying  salaries  and  certain  other
benefits to certain  management level employees.  While we have remedied many of
those arrearages, and adopted a program to meet all of our obligations, there is
no assurance  that everyone to whom payments are still owed will  cooperate with
this  program.  Such  failure to cooperate  could have an adverse  affect on our
ability to implement the program in an orderly fashion.


IF WE ARE UNABLE TO RETURN TO  ELIGIBILITY  FOR  LISTING ON THE NASDAQ  SMALLCAP
MARKET, THE MARKET PRICE OF OUR STOCK COULD BE ADVERSELY AFFECTED.

Our common stock was listed previously on the NASDAQ SmallCap Market.  There are
certain  standards  regarding capital and surplus for the continued listing of a
security on the NASDAQ SmallCap Market. In 1997 we failed to maintain our NASDAQ
stock market listing, and may not meet the relisting  requirements for some time
in the future. There can be no assurances that we will ever meet the capital and
surplus  requirements  needed to be re-listed  under the NASDAQ  SmallCap Market
System.

Trading of our Common  Stock is  currently  conducted  on the NASD's  Electronic
Bulletin  Board.  Trading  in the Common  Stock is covered by rules  promulgated
under the Exchange Act for non-


                                       13
<PAGE>


NASDAQ and non-exchange listed securities.  Under such rules, broker/dealers who
recommend  such  securities  to persons  other than  established  customers  and
accredited  investors must make a special written suitability  determination for
the purchaser  and receive the  purchaser's  written  agreement to a transaction
prior to sale.  Securities are exempt from these rules if the market price is at
least $5.00 per share. As of September 30, 1999, the closing price of our Common
Stock was less than $1.00.  In addition,  the SEC has adopted  regulations  that
generally define a penny stock to be any equity security that has a market price
of less than $5.00 per share, subject to certain exceptions. Our common stock is
currently  subject  to such penny  stock  rules.  The  regulations  require  the
delivery,  prior to any  transaction  involving a penny  stock,  of a disclosure
schedule  explaining the penny stock market and the risks associated  therewith.
As a penny stock, the market liquidity for our Common Stock is severely affected
due to the limitations  placed on  broker/dealers  that sell the Common Stock in
the public market.


IF WE ARE UNABLE TO DEVELOP  BENEFICIAL  FINANCING  ARRANGEMENTS,  IT MAY HAVE A
NEGATIVE EFFECT ON OUR FINANCIAL POSITION GOING FORWARD.

In order to sell our POSICAM  systems,  we have found it necessary  from time to
time to  participate  in ventures  with certain  customers  or otherwise  assist
customers in their  financing  arrangements.  These  venture  arrangements  have
involved  lower cash  prices for our systems in exchange  for  interests  in the
venture.  These  arrangements  expose us to the attendant  business risks of the
ventures.  In  certain  instances,   we  have  sold  our  systems  to  financial
intermediaries,  which have, in turn,  leased the SYSTEM.  Such transactions may
not give rise to the same economic  benefit as would have occurred had we made a
direct cash sale at our regular market price on normal sales terms. There can be
no assurance that we will not find it necessary to enter similar transactions to
effect  future  sales.  Moreover,  the nature and extent of our interest in such
ventures or the existence of remarketing or similar obligations could require us
to account for such transactions as financing  arrangements  rather than "sales"
for  financial  reporting  purposes.  Such  treatment  could  have the effect of
delaying the  recognition of revenue on such  TRANSACTIONS  and may increase the
volatility of our financial results.


IF WE ARE SUBJECT TO SUBSTANTIAL THIRD PARTY LIABILITY  CLAIMS,  PARTICULARLY IF
THE CLAIMS EXCEED OUR INSURANCE COVERAGE, IT WILL HAVE A MATERIAL ADVERSE EFFECT
ON OUR BUSINESS.

The use of our products entails certain risks of product liability. There can be
no assurance that product  liability  claims will not be  successfully  asserted
against us. While we maintain  liability  insurance coverage in the amount of $1
million per occurrence and an annual aggregate maximum of $2 million,  there can
be no assurance  that we will be able to maintain  such  insurance in the future
or, if maintained, that such insurance will be sufficient in amount to cover any
successful  product  liability  claims.  Any  uninsured  liability  could have a
material adverse effect is our financial position and operation.


BECAUSE WE HAVE NEVER PAID CASH  DIVIDENDS ON OUR COMMON STOCK AND DO NOT INTEND
TO DO SO IN THE  FORESEEABLE  FUTURE,  THE PRICE OF OUR COMMON  STOCK MAY REMAIN
VOLATILE.

We have never paid cash  dividends  on our common stock and do not intend to pay
cash  dividends  on our common  stock in the  foreseeable  future.  The Series A
Preferred Stock


                                       14
<PAGE>


Statement of Designation  prohibits the payment of common stock  dividends until
all required  dividends  have been paid on the Series A preferred  stock.  As of
December 31, 1998,  approximately  $561,000 of preferred  stock  dividends  were
undeclared and unpaid.


IF OUR QUARTERLY  REVENUES AND OPERATING  RESULTS FLUCTUATE  SIGNIFICANTLY,  THE
PRICE OF OUR COMMON STOCK IS LIKELY TO BE MORE VOLATILE.

Due to the  substantial  price  of  each  system,  our  quarterly  revenues  and
operating results are likely to vary substantially from quarter to quarter. This
in turn may cause the price of our common  stock to be volatile.  A  substantial
decline  in our  stock  price is  possible  at any  time.  We  believe  that the
following  factors,   among  others,  could  affect  our  quarterly  results:

         o  fluctuations in sale of systems

         o  the introduction of new products and services by our competitors;

         o  the level of consumer  interest and  confidence  in our products and
            services;

         o  the introduction of new products and services by us; o the timing of
            our release of enhancements to our products and services;

         o  our  ability to upgrade  and  develop  our  information  systems and
            operational infrastructure to accommodate growth;

         o  the timing and rate at which we  increase  our  expenses  to support
            projected growth;

         o  the cost of compliance  with federal and state  government  laws and
            regulations,   including  any  changes  in  our  historic   business
            practices that could result from legal interpretations;

         o  any dispute involving our proprietary software;

         o  our announcement of new marketing initiatives;

         o  technical difficulties or service interruptions;

         o  changes  in  our   operating   expenses   and   investment   in  our
            infrastructure;

         o  general  economic  conditions  in the  United  States  and  economic
            conditions;

         o  changes  in  estimates  of  our  future  financial   performance  by
            securities analysts;

         o  additions or departures of key executives  and operating  personnel;
            and

         o  sales of our common stock or other securities in the open market.

Accordingly,  we believe  period-to-period  comparisons of our operating results
are not  meaningful  and the results for any period should not be relied upon as
an indication of future performance.  Our operating results may fail to meet our
expectations  or those of analysts who follow us. Any such  failure  could cause
the price of our stock to decline substantially.


                                       15
<PAGE>


IF WE ARE UNABLE TO  SUCCESSFULLY  ADDRESS ANY LINGERING  YEAR 2000 ISSUES,  OUR
BUSINESS COULD BE MATERIALLY ADVERSELY AFFECTED.

We have  completed  the process of  identifying  and  modifying or replacing any
computer systems and software  products to ensure that they will function in the
year 2000 and thereafter.  We have identified two systems with modest continuing
problems.  We can not be sure however that our efforts to address  internal year
2000 compliance  have been entirely  successful.  In addition,  while it appears
that the computer  systems and software of other companies on whom we depend are
2000  compliant,  if we or any of these other companies fail to remain year 2000
compliant,  or otherwise develop additional  problems related to that issue, our
systems and  operations  could be disrupted and our  operating  results could be
materially adversely affected.

For this  reason,  although the  financial  impact of  implementing  the systems
changes  necessary to become year 2000  compliant  has not been  material to our
financial position or results of operations, our expectations about future costs
associated  with year 2000  compliance are subject to  uncertainties  that could
cause actual results to differ  materially from our  expectations.  Factors that
could  influence the amount and timing of future costs  include:  our success in
having  accurately  identified  systems  and  programs  that are not  year  2000
compliant,  the nature and amount of programming  required to upgrade or replace
each of the affected programs;  the availability,  rate and magnitude of related
labor and consulting  costs; and the success of our business  partners,  vendors
and clients in addressing the Y2K issue.


IF PREVIOUSLY  UNREGISTERED SHARES OF OUR COMMON STOCK ARE SOLD INTO THE MARKET,
IT COULD CAUSE THE MARKET PRICE OF OUR COMMON STOCK TO DROP.

The  market  price of our  common  stock  could drop as a result of sales of the
shares covered by this prospectus in the market after the offering, or the price
could  remain  lower  because of the belief that such sales might  occur.  These
factors  could  make it more  difficult  for us to raise  funds  through  future
offerings of common stock.

As of June 30, 1999,  Positron had 15,211,758  shares of common stock issued and
outstanding.  Following this offering and assuming all outstanding  warrants are
exercised prior to their expiration,  85,338,540 shares will be freely tradable,
and  additional  unregistered  shares  will be  tradable  under  SEC Rule 144 by
persons other than affiliates of Positron.

We have  reserved an aggregate of  6,572,678  shares for issuance to  employees,
officers,  directors and consultants under the 1994 and 1999 Stock Option Plans,
the 1999  Non-Employee  Directors'  Stock  Option  Plan,  the 1999  Stock  Bonus
Incentive  Plan, and the 1999 Employee Stock Purchase Plan. To date,  options to
purchase  1,367,678  shares have been granted under such plans and are currently
outstanding. Positron intends to file a Form S-8 registration statement covering
the shares  issued and  issuable  pursuant to the 1999 Stock  Option Plan and to
each of the other employee and non-employee  director benefit plans. Further, we
have  reserved an  additional  22,936,245  shares for issuance  upon exercise of
outstanding  Warrants to purchase  Common  Stock,  most of which are included in
this registration statement.

This  registration  statement  covers all of the shares subject to  registration
rights which could not otherwise  currently be sold pursuant to Rule 144. We are
not  aware  of  any  pending  or  threatened


                                       16
<PAGE>


actions  by the  holders  of any  registration  rights  seeking  damages  due to
Positron's  failure to  register  the shares that they hold.  We face  potential
liability,  however,  from damage  claims from such  stockholders.  The costs of
defending against such claims and potential adverse outcomes of the claims could
have a material adverse effect on our business,  financial condition and results
of operations.

As part of the private placement which closed in August, 1999 Positron agreed to
use its best efforts to register the resale of the shares sold within 90 days of
closing.


                SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS


THIS  PROSPECTUS  CONTAINS  FORWARD-LOOKING  STATEMENTS  THAT INVOLVE  RISKS AND
UNCERTAINTIES.  YOU SHOULD NOT RELY ON THESE FORWARD-LOOKING  STATEMENTS.  WORDS
SUCH AS "ANTICIPATE,"  "BELIEVE," "PLAN," "EXPECT,"  "FUTURE," "INTEND," "COULD"
AND SIMILAR  EXPRESSIONS  INDICATE  FORWARD-LOOKING  STATEMENTS.  YOU SHOULD NOT
PLACE  UNDUE  RELIANCE ON THESE  FORWARD-LOOKING  STATEMENTS.  THESE  STATEMENTS
INVOLVE A NUMBER OF RISKS AND  UNCERTAINTIES AND OUR ACTUAL RESULTS COULD DIFFER
MATERIALLY FROM THOSE ANTICIPATED IN THESE  FORWARD-LOOKING  STATEMENTS FOR MANY
REASONS,   INCLUDING  THE  FACTORS  DESCRIBED  IN  "PROSPECTUS  SUMMARY,"  "RISK
FACTORS,"  "MANAGEMENT'S  DISCUSSION  AND  ANALYSIS OF FINANCIAL  CONDITION  AND
RESULTS OF  OPERATIONS"  AND  "BUSINESS"  AND ELSEWHERE IN THIS  PROSPECTUS.  WE
CAUTION YOU NOT TO PLACE UNDUE  RELIANCE  ON THESE  FORWARD-LOOKING  STATEMENTS.
SUCH  FORWARD-LOOKING  STATEMENTS  SPEAK ONLY AS OF TODAY'S DATE AND WE DISCLAIM
ANY OBLIGATION TO UPDATE FORWARD-LOOKING STATEMENTS.

                                 USE OF PROCEEDS

We will not receive any  proceeds  from the sale of common  stock by the selling
stockholders except for the exercise price of the warrants.  If the warrants are
exercised in full,  we will receive  approximately  $4,240,750,  although we can
neither assure nor predict that any or all or the warrants will be exercised. We
intend  to use any  proceeds  from the  exercise  of the  warrants  for  general
corporate purposes.

                              SELLING STOCKHOLDERS

The following table sets forth (i) the number of outstanding  shares,  including
shares  issuable  within 60 days of  October  31,  1999  pursuant  to options or
warrants,  beneficially  owned  and  the  percentage  ownership  of the  selling
stockholders prior to the offering,  (ii) the aggregate number of shares offered
by each such  stockholder  pursuant to this  prospectus  and (iii) the number of
shares  beneficially  owned  by each  selling  stockholder  and  the  percentage
ownership  assuming  the  sale  of  all of  the  shares  offered  by  each  such
stockholder pursuant to this prospectus.


                                       17
<PAGE>

<TABLE>
<CAPTION>
                                                                SHARES BENEFICIALLY OWNED                      SHARES BENEFICIALLY
                                                                    PRIOR TO OFFERING                          OWNED AFTER OFFERING
                                                          -------------------------------------                   ---------------
                                                                       NUMBER OF SHARES
                                                           NUMBER OF   ISSUABLE WITHIN             SHARES
                                                          OUTSTANDING     60 DAYS OF             OFFERED IN
                         NAME                                SHARES    OCTOBER 31, 1999      %    OFFERING        NUMBER       %
                         ----                             -----------  ----------------     ---  ----------       ------      ---
<S>                                                        <C>              <C>             <C>   <C>             <C>          <C>
Adams, Thomas G.                                             100,000                                100,000
Akane International, Inc. .............................      333,333               --         *     333,333           --       *
Almeida, Manuel Serzedelo de ..........................      500,000               --         *     500,000           --       *
Almeida, Miguel A. S. Ferreira ........................    1,000,000               --       1.7   1,000,000           --       *
Amorim Dessenvolvimento, S.G.P.S., S.A ................    2,900,000               --       3.0   2,900,000           --       *
Andrasko, Gary ........................................      100,000               --         *     100,000           --       *
Asano, Isao ...........................................      333,333               --         *     333,333           --       *
Balbi, Armando Rinaldi ................................      300,000               --         *     300,000           --       *
Banco Privado Portuges ................................    5,000,000               --       8.7   5,000,000           --       *
Bloch, Raymond E ......................................       30,000               --         *      30,000           --       *
Borges, Joal Vierira ..................................      500,000               --         *     500,000           --       *
Bridlespur Partners, L.P. .............................      105,000               --         *     105,000           --       *
Brooks, Gary H (1) ....................................       50,000        3,000,000       5.0   3,000,000       50,000       *
Brunton, Craig S ......................................       20,000               --         *      20,000           --       *
Buzga, Joseph .........................................       10,000               --         *      10,000           --       *
Condado, Filipe Alfonso ...............................           --        2,500,000       4.2   2,500,000           --       *
Daffodil Overseas Corp. ...............................      500,000               --         *     500,000           --       *
Dapicod Investments Co. Lt ............................    5,000,000               --       8.7   5,000,000           --       *
D'Orey, Monica Albuquerque ............................           --        2,650,000       4.4   2,650,000           --       *
Dorion ................................................    2,100,000               --       3.6   2,100,000           --       *
D. Rich, Inc. .........................................      666,666               --       1.2     666,666           --       *
ESAF/Espirito Santo Fundos de Pensoes .................    4,000,000               --       6.9   4,000,000(2)        --       *
ESAF International Management .........................    1,728,666               --       3.0   1,666,666       62,000       *
Garcao, Jose Caefano Salema ...........................           --        2,500,000       4.2   2,500,000           --       *
Garcao, Jose Maria Salema .............................    2,500,000               --       4.3   2,500,000           --       *
Garcao, Sofia Salema ..................................           --        2,500,000       4.2   2,500,000(3)        --       *
Gomes, Jose Osvaldo ...................................    1,333,333               --       2.3   1,333,333           --       *
Goreton Holding Ltd. ..................................      333,333               --         *     333,333           --       *
Gould, K. Lance (4) ...................................      168,000               --               168,000           --       *
Guedes, Jose Filipe ...................................    1,000,000               --       1.7   1,000,000           --       *
Herring, Jack L .......................................       30,000               --                30,000           --       *
Imatron ...............................................    9,000,000               --      15.6   9,000,000           --       *
Katz, Dean ............................................       20,000               --         *      20,000           --       *
Kambayashi, Kazuo .....................................      333,333               --         *     333,333           --       *
Kawaguchi, Noriko .....................................      333,333               --         *     333,333           --       *
Kelley, Cynthia A .....................................       40,000               --         *      40,000           --       *
Kelley, Nancy E .......................................       70,000               --         *      70,000           --       *
Kiehl, Samuel J.III ...................................      250,000               --         *     200,000       50,000       *
Kinoshita, Sachiko ....................................    1,333,333               --       2.3   1,333,333           --       *
Martins, Francisco Carvalho ...........................    1,000,000               --       1.7   1,000,000           --       *
Martins, Jose Diego Ferreira ..........................    1,000,000        1,500,000       4.2   2,500,000           --       *
Marques, Richard ......................................      333,333               --         *     333,333           --       *
Mendia, Eduardo Guedes ................................    1,000,000               --       1.7   1,000,000           --       *
Mertz, Roger ..........................................      333,333               --         *     333,333           --       *
Meyer, S. Lewis (1) ...................................       79,000        1,500,000       2.7   1,500,000       79,000       *
Molnar, Anthony R .....................................       30,000                                 30,000           --       *
Morris Holdings Ltd. ..................................                     3,000,000       5.0   3,000,000           --       *
Ohbayashi, Atsuo ......................................      333,333               --         *     333,333           --       *
Okamura, S ............................................                       160,000               160,000           --       *
Paulo, Cazrlos Sao ....................................           --        2,650,000       4.4   2,650,000           --       *
Pimentel, Maria Madalena ..............................           --        1,000,000       1.7   1,000,000           --       *
Pipo, James E .........................................       10,000               --         *      10,000           --       *
Politzer, Dave ........................................       50,000               --         *      50,000           --       *
Profutures Bridge Capital Fund Ltd. ...................           --        1,500,000             1,500,000           --       *
Redman, Kenneth C .....................................       10,000               --         *      10,000           --       *
Sako Corporation ......................................    2,333,333               --       4.0   2,333,333           --       *
Seitz, Tadd C .........................................      105,000                                100,000           --       *
Serras, Luis ..........................................    1,000,000               --       1.7   1,000,000           --       *
Silva, Manuel Telles da ...............................    1,000,000               --       1.7   1,000,000           --       *
Steitz, Timothy C .....................................      100,000               --         *     100,000           --       *
Substitute ............................................           --                        3.9   3,000,000           --       *
TAG Limited Inc. ......................................      100,000               --         *     100,000           --       *
TTPK Company Limited Partnership ......................       70,000               --         *      70,000           --       *
Uro-Tech, Inc.(1) .....................................      388,787          316,671         *     100,000      605,458       *
Violante, Manuel Luidda Silva .........................      500,000               --         *     500,000           --       *
Vistula Finance Limited ...............................                     3,000,000       5.0   3,000,000           --       *
Wintersteller, C. Jeffrey .............................       10,000               --         *      10,000           --       *
TOTAL .................................................   51,297,782       27,776,671            78,732,990
</TABLE>


                                       18
<PAGE>


(1)   See SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT.

(2)   Includes the security  holdings of 12 separate funds,  divided as follows:
      Fundo  de  Pensoes  Ford  Lusitana  (150,000);  Fundo  de  Pensoes  Pfizer
      (50,000);  Fundo de Pensoes SIBS (300,000);  Fundo de Pensoes Cahora Bassa
      (100,000);  Fundo de  Pensoes  Rank  Xerox  (150,000);  Fundo  de  Pensoes
      Tranquilidade   (500,000);    Fundo   de   Pensoes   Administratdores   Da
      Tranquilidade (100,000);  Fundo de Pensoes TDP (100,000); Fundo de Pensoes
      Eurospuma (50,000); Fundo de Pensoes Petrogal (500,000);  Fundo de Pensoes
      EDP (1,700,000); and Fundo de Pensoes GES (300,000)

(3)   Sofia Salema Garcao holds two warrants for the  following two values:  (1)
      1,000,000, (2) 1,500,000.

(4)   Served as director until 1998.


                              PLAN OF DISTRIBUTION

The selling  stockholders may offer their shares at various times in one or more
of the  following  transactions:

         o  in the over-the-counter market;

         o  on any exchange on which the shares may hereafter be listed;

         o  in negotiated transactions other than on such exchanges;

         o  by pledge to secure debts and other obligations;

         o  in  connection  with the writing of non-traded  and  exchange-traded
            call  options,  in  hedge   transactions,   in  covering  previously
            established short positions and in settlement of other  transactions
            in standardized or over-the-counter options; or

         o  in a combination of any of the above transactions.

The selling  stockholders  may sell their shares at market prices  prevailing at
the time of sale,  at  prices  related  to such  prevailing  market  prices,  at
negotiated  prices  or  at  fixed  prices.  The  selling  stockholders  may  use
broker-dealers  to sell their shares.  The  broker-dealers  will either  receive
discounts or  commissions  from the selling  stockholders,  or they will receive
commissions  from  purchasers  of  shares.  In  addition,  some  of the  Selling
Shareholders  may be eligible  and may elect to sell some or all of their shares
pursuant  to  additional  exemptions  to the  registration  requirements  of the
Securities  Act,  including  but not limited to Rule 144  promulgated  under the
Securities Act, rather than pursuant to this Registration Statement.

Under certain circumstances the selling stockholders and any broker-dealers that
participate in the  distribution may be deemed to be  "underwriters"  within the
meaning of the Securities Act. Any commissions  received by such  broker-dealers
and any  profits  realized  on the  resale of  shares by them may be  considered
underwriting  discounts and  commissions  under the Securities  Act. The selling
stockholders  may  agree  to  indemnify  such  broker-dealers   against  certain
liabilities,  including  liabilities  under the  Securities  Act.  In  addition,
Positron has agreed to indemnify  the selling  stockholders  with respect to the
shares offered hereby against certain liabilities, including certain liabilities
under the Securities Act.

Under the rules and  regulations  of the Exchange Act, any person engaged in the
distribution  of the  resale of shares may not  simultaneously  engage in market
making  activities  with respect to Positron's  common stock for a period of two
business  days  prior to the  commencement  of such  distribution.  The  selling
stockholders  will also be subject to applicable  provisions of the


                                       19
<PAGE>


Exchange Act and  regulations  under the Exchange Act which may limit the timing
of  purchases  and sales of shares of  Positron's  common  stock by the  selling
stockholders.

The selling  stockholders  will pay all  commissions,  transfer taxes, and other
expenses  associated  with the sale of  securities by them.  The shares  offered
hereby are being registered pursuant to contractual obligations of Positron, and
Positron has paid the expenses of the  preparation of this  prospectus.  We have
not  made any  underwriting  arrangements  with  respect  to the sale of  shares
offered hereby.

                                LEGAL PROCEEDINGS

The City of Houston,  Katy Independent  School District (KISD) and Harris County
together brought a consolidated action against us for delinquent taxes and other
assessments  relating to tax years 1995 through  1997. In February 1998 judgment
was entered against us in the amount of approximately $240,000. In November 1998
we negotiated a payment  schedule with the city,  county and school  district to
retire the judgment as to each entity and to cover  assessments for the 1998 tax
year. We have  maintained  the payment  schedule for current and prior tax years
and are  reducing  the  judgment in monthly  increments.  Based on payment,  the
County recently dismissed its action.

In January 1996 we entered  into an  employment  agreement  with Werner J. Haas,
Ph.D, for Dr. Haas to serve as our President and Chief Executive Officer for two
years.  In February  1997 Dr. Haas  informed  the Board that he  considered  his
contract to have been constructively  terminated for failure to pay the February
15, 1997 payroll to any of our management employees and specifically to him. Dr.
Haas  resigned as an employee and member of the Board and  demanded  that we pay
him all past due salary as well as nine months severance pay. We replied that we
believed no amounts were due under his employment  agreement.  Dr. Haas recently
filed an action in state court claiming other and additional demands for payment
for an  aggregate  demand of  approximately  $250,000.  We intend to  vigorously
defend our  position and have not recorded  any  additional  liability  for this
claim. There can be no assurance however,  that the claim will not result in our
incurring a liability.

We acquired  the  know-how  and patent  rights for  positron  imaging from three
entities  --the  Clayton  Foundation,  K. Lance Gould  (formerly a director) and
Nizar A. Mullani (also formerly a director.) Pursuant to agreements with each of
them,  we were  obligated  to pay  royalties  of 4.5% in the  aggregate of gross
revenues  from  sales,  uses,  leases,  licensing  or  rentals  of the  relevant
technology. In 1993 each royalty holder agreed to reduced royalty payments to 3%
in the  aggregate  in exchange for  receiving  certain  loans and entering  into
certain consulting  agreements.  The consulting  agreements  provided that if we
defaulted in our obligations under those  agreements,  Dr. Gould and Mr. Mullani
would be entitled to reinstatement of their earlier royalties.  In April 1998 we
received a demand letter from Mr. Mullani alleging defaults under his consulting
agreement.  We  believe  that such  defaults,  if any,  may also  have  occurred
regarding Dr. Gould's  agreement,  although he has made no formal demand.  Since
that  time,  we have  reached  agreement  with Dr.  Gould  regarding  payment of
royalties in the past and in the future,  as well as several  other  issues.  We
have had similar  discussions with Clayton Foundation and Mr. Mullani,  although
no agreements have been reached with these parties.


                                       20
<PAGE>


                    DIRECTORS, EXECUTIVE OFFICERS, PROMOTERS
                              AND CONTROL PERSONS.


EXECUTIVE OFFICERS AND DIRECTORS

The  following  table  sets  forth  certain  information   regarding  Positron's
executive officers and directors as of October 31, 1999.

NAME                   AGE      EXECUTIVE POSITION
- ----                   ---      ------------------

Gary H. Brooks         51       Director, President, Chief Financial Officer
                                (Acting) & Secretary

S. Lewis Meyer         55       Director

Gary B. Wood, Ph.D.    50       Director

John J. Ariatti        53       Vice President, Sales and Marketing

      Mr.  Meyer was  appointed  to the Board on January 22, 1999 in  connection
with a series of agreements entered into by Company and Imatron Inc. ("Imatron")
in May 1998,  pursuant  to which in January  1999  Imatron  purchased  9,000,000
shares of Company common stock,  representing a majority of the Company's common
stock at the time  ("Imatron  Transaction.").  Positron  received a nominal cash
amount from  Imatron in payment for the shares.  Imatron  began  making  working
capital  advances  available to Positron in order to enable it to meet a portion
of its current  obligations.  As of  December  31, 1998  Positron  had  borrowed
$600,000 from Imatron pursuant to a promissory note bearing interest at one-half
percent  over prime and  secured by all of the  Company's  assets.  The loan was
retired in September,  1999. In addition to providing  limited  working  capital
financing,  Imatron agreed to support Positron's marketing program by seeking to
cause the  placement  of ten POSICAM  systems  with third  parties over the next
three  years,  and also by using its best  efforts  to  arrange  for  additional
third-party equity financing in an aggregate amount of not less than $8,000,000.
As  part  of the  consummation  of the  transaction  in  January  1999,  all the
Company's  directors and officers except for Dr. Wood resigned and Mr. Meyer and
Gary H. Brooks were nominated by Imatron to fill those vacancies.

      Also on January 22, 1999 Mr. Meyer was appointed as Chairman of the Board.
While the Chairman of its Board of  Directors,  Mr. Meyer is neither an employee
nor an  executive of the  Company.  Mr.  Meyer also  continues to serve as Chief
Executive  Officer of Imatron,  which  position he has held since June 23, 1993.
From April 1991 until  joining  Imatron,  he was Vice  President,  Operations of
Otsuka Electronics  (U.S.A.),  Inc., Fort Collins,  Colorado,  a manufacturer of
clinical MR systems and analytical NMR spectrometers.  From August 1990 to April
1991 he was a founding partner of Medical Capital Management,  a company engaged
in providing  consulting  services to medical equipment  manufacturers,  imaging
services  providers  and related  medical  professionals.  Prior  thereto he was
Founder,  President  and Chief  Executive  Officer of American  Health  Services
Corp.,  (now Insight  Health  Services) a developer  and operator of  diagnostic
imaging and  treatment  centers.  Mr.  Meyer is a director  of  Imatron,  and of
FiNet.com,  Inc.  and the  Chairman of its  Compensation  Committee.  Mr.  Meyer
received  his B.S.  degree  in  Physics  from  the  University  of the  Pacific,
Stockton, California in 1966, an M.S.


                                       21
<PAGE>


degree in Physics from Purdue  University  in 1968,  and a Ph.D. in Physics from
Purdue University in 1971.

      Mr. Brooks has served as a director since January 22, 1999, appointed also
in connection  with the Imatron  Transaction.  (SEE ABOVE.) Also on that date he
was appointed as President, Secretary and Treasurer of the Company and served in
those  capacities on a part-time  basis until September 1, 1999, when he assumed
those  responsibilities  on a full-time basis. Prior to joining the Company on a
full-time   basis,   Mr.  Brooks  served  as  Vice   President  of  Finance  and
Administration, Chief Financial Officer and Secretary for Imatron since December
1993.  Prior to joining Imatron he was Chief Financial  Officer and Director for
five years at Avocet, a privately-held  sports electronics  manufacturer located
in Palo  Alto,  CA. Mr.  Brooks  received  his B.A.  in Zoology in 1971 from the
University of California,  Berkeley,  and an M.B.A. in Finance and Accounting in
1973 from the University of California, Los Angeles.

      Dr. Wood has served as a director  from April 1990 to the present,  and as
its Chairman until January 1999.  From October 1, 1994 to December 31, 1995 when
Dr. Werner Haas was appointed to those positions, he also acted as President and
Chief  Executive  Officer of the Company.  He assumed  those  offices again from
February  1997 when Dr. Haas  resigned  until  January 1999 when Mr.  Brooks was
appointed   President.   Dr.  Wood  is  also  President  of  Concorde  Financial
Corporation,  a private  investment,  management  and  consulting  firm which he
founded in 1981 and is the  founder,  chairman  and a principal  shareholder  of
OmniMed Corporation,  a venture capital investment firm founded in 1986. OmniMed
specializes in investing in the  biotechnology  and health care industries.  Dr.
Wood holds a BS and MS in  Electrical  Engineering  (with  special  emphasis  in
biomedical  instrumentation)  and an  interdisciplinary  Doctorate of Philosophy
from Texas Tech University.  Certain of the entities  controlled by Dr. Wood are
principal shareholders of Positron.

      John J. Ariatti was appointed as our Vice President,  Sales and Marketing,
effective  September  27,  1999,  with  over 20  years of  sales  and  marketing
experience  in the medical  imaging  industry.  During the last five years,  Mr.
Ariatti has served as Vice  President of Marketing and then as Vice President of
Sales for Toshiba America  Medical  Systems from 1995 through 1998,  Director of
Sales and  Marketing  for Elscint from  January to August 1995,  and Director of
Sales,  Marketing  and Customer  Support for Otsuka  Electronics  from June 1991
until he joined Elscint.

                          SECURITY OWNERSHIP OF CERTAIN
                        BENEFICIAL OWNERS AND MANAGEMENT

The  following  tables,  based in part upon  information  supplied by  officers,
directors and principal  shareholders,  set forth certain information  regarding
the ownership of the Company's  voting  securities as of October 31, 1999 by (i)
all those known by the Company to be beneficial owners of more than five percent
of any class of the Company's voting securities;  (ii) each director; (iii) each
named executive  officer;  and (iv) all executive  officers and directors of the
Company as a group.  Unless  otherwise  indicated,  each of the shareholders has
sole voting and investment power with respect to the shares  beneficially owned,
subject to community property laws where applicable.


                                       22
<PAGE>


SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS(a)

<TABLE>
<CAPTION>
- --------------------------------------------------------------------------------------------------------------------
                                  |                 |                       |                    |                  |
 Name and Address of Beneficial   |    Number of    |   % of Outstanding    | Number of Shares   | % of Outstanding |
              Owner               |    Shares of    |     Common Stock      |    of Series A     |     Series A     |
                                  |  Common Stock   |                       |  Preferred Stock   |  Preferred Stock |
- ----------------------------------|-----------------|-----------------------|--------------------|------------------|
<S>                                <C>               <C>                     <C>                  <C>
                                  |                 |                       |                    |                  |
Uro-Tech Ltd.(b)                  |      1,690,188  |         2.8%          |        433,329     |       44.2%      |
- ----------------------------------|-----------------|-----------------------|--------------------|------------------|
                                  |                 |                       |                    |                  |
Imatron Inc.(c)                   |      9,000,000  |        15.6%          |                    |                  |
- ----------------------------------|-----------------|-----------------------|--------------------|------------------|
                                  |                 |                       |                    |                  |
Banco Privado Portuges(d)         |      5,000,000  |         8.7%          |                    |                  |
- ----------------------------------|-----------------|-----------------------|--------------------|------------------|
                                  |                 |                       |                    |                  |
Amorim Dessenvolvimento,          |      2,900,000  |         5.0%          |                    |                  |
S.G.P.S., S.A.(e)                 |                 |                       |                    |                  |
- ----------------------------------|-----------------|-----------------------|--------------------|------------------|
                                  |                 |                       |                    |                  |
Dapicod Investments Co., Ltd.(f)  |     5,000,000   |        8.7%           |                    |                  |
- -------------------------------------------------------------------------------------------------------------------
</TABLE>

- ----------

(a)   Security  ownership  information  for  beneficial  owners  is  taken  from
      statements filed with the Securities and Exchange  Commission  pursuant to
      Sections 13(d), 13(g) and 16(a) and information made known to the company.

(b)   Includes  388,787 shares of common stock owned by Uro-Tech,  Ltd., a Texas
      limited  partnership,  the general partner of which is OmniMed Corporation
      ("OmniMed").  Includes  984,730  shares  of  common  stock  issuable  upon
      conversion  of  433,329  shares  of  Series  A 8%  cumulative  convertible
      redeemable  preferred stock, and 216,671 warrants to purchase common stock
      acquired upon  conversion of $650,000 in principal  amount of the Uro-Tech
      loan.  Also includes  100,000 shares  issuable upon conversion of warrants
      acquired in connection  with extending and retiring the Uro-Tech loan. Dr.
      Wood is a director and beneficially  owns 63.7% of the outstanding  voting
      securities of OmniMed.

(c)   Represents   all   securities   purchased  in   connection   with  Imatron
      Transaction. See DIRECTORS, OFFICERS, PROMOTERS AND CONTROL PERSONS above.
      The headquarters offices of Imatron are located at 389 Oyster Point blvd.,
      So. San Francisco, CA 94080.

(d)   R. Muezinho da Silveira, 12, 1250 Lisbon, Portugal.

(e)   Edificio  Amorim,  Rua de Melandas No. 380 (Apartado 20), 4536 Mozelos VFR
      Codex, Portugal.

(f)   Edificio  Peninsula,  Praca do Bom Sucesso  127/131 - 7th,  ESC.  702, Ap.
      551236EC Galiza, 4051-401 Porto, Portugal.



                                       23
<PAGE>



SECURITY OWNERSHIP OF DIRECTORS AND EXECUTIVE OFFICERS

The table below presents the security  ownership of the Company's  Directors and
Named Executive Officers.


                                              AMOUNT AND NATURE
                                                OF BENEFICIAL       PERCENT
TITLE OF CLASS    NAME OF BENEFICIAL OWNER      OWNERSHIP(aa)      OF CLASS(bb)
- --------------    ------------------------    -----------------    ------------

Common            Gary H. Brooks                  3,050,000(cc)      5.0%

Common            S. Lewis Meyer                  1,579,000(dd)      2.7%

Common            Gary B. Wood, Ph.D                 65,513(ee)       *

Common            John J. Ariatti                    40,625(ff)       *

Common            All Directors and Executive     4,735,138          7.7%
                  Officers as a Group

- ----------

*     Does not exceed 1% of the referenced class of securities.

(aa)  Ownership is direct unless indicated otherwise.

(bb)  Calculation  based on 57,534,660  common shares  outstanding as of October
      31, 1999.

(cc)  Includes  50,000 shares owned directly and 3,000,000  shares issuable upon
      the exercise of warrants  that are  exercisable  as of October 31, 1999 or
      that will become exercisable within 60 days thereafter.

(dd)  Includes  79,000 shares owned directly and 1,500,000  shares issuable upon
      the exercise of warrants  that are  exercisable  as of October 31, 1999 or
      that will become exercisable within 60 days thereafter.

(ee)  Includes  7,304 shares of common stock issuable upon exercise of a warrant
      held by Dr. Wood and 50,000 shares of common stock  issuable upon exercise
      of options granted to Dr. Wood in March 1995, 7,000 shares of common stock
      issuable  upon  exercise  of options  granted to Dr. Wood in June 1994 and
      1,209 shares of common stock issuable upon exercise of options  granted to
      Dr. Wood in June 1995.

(ff)  Mr.  Ariatti was granted an option to  purchase  650,000  shares of common
      stock in connection with his employment,  40,625 of which will vest within
      60 days of October 31, 1999.

                            DESCRIPTION OF SECURITIES

The  authorized  capital  stock of Positron  consists of  100,000,000  shares of
common  stock,  $0.01 par value per share,  and  10,000,000  shares of Preferred
Stock,  $0.01 par value per share. As of October 31, 1999,  57,534,660 shares of
common stock, and 980,948 shares of preferred stock were issued and outstanding.

COMMON STOCK

Subject to preferences  that may apply to shares of preferred stock  outstanding
at the time, the holders of  outstanding  shares of common stock are entitled to
receive dividends out of assets legally available therefore at such times and in
such amounts as the Board may from time to time determine.  Each  stockholder is
entitled  to one  vote  for  each  share of  common  stock  held on all  matters
submitted  to a vote of  stockholders.  Cumulative  voting for the  election  of
directors is not provided for in Positron's Amended and Restated  Certificate of
Incorporation,  which means that the  holders of a majority of the shares  voted
can elect all of the directors  then standing for election.  The common stock is
not  entitled  to  preemptive  rights  and  is  not  subject  to  conversion  or
redemption.  Upon a liquidation,  dissolution or winding-up of the Company,  the
assets legally  available for  distribution  to stockholders  are  distributable
ratably  among the holders of the common stock and any  participating  preferred
stock outstanding at that time after payment of



                                       24
<PAGE>


liquidation preferences,  if any, on any outstanding preferred stock and payment
of other claims of creditors.

PREFERRED STOCK

Positron  is  authorized,  subject to  limitations  prescribed  by Texas law, to
provide for the issuance of preferred stock in one or more series,  to establish
from time to time the number of shares to be  included in each such  series,  to
fix the rights, preferences and privileges of the shares of each wholly unissued
series and any  qualifications,  limitations  or  restrictions  thereon,  and to
increase or decrease  the number of shares of any such series (but not below the
number of shares of such series then  outstanding)  without any further  vote or
action by the  stockholders.  The Board may  authorize the issuance of preferred
stock with voting or conversion  rights that could  adversely  affect the voting
power or other  rights of the  holders  of the common  stock.  The  issuance  of
preferred  stock,  while  providing  flexibility  in  connection  with  possible
acquisitions and other corporate  purposes,  could, among other things, have the
effect of delaying,  deferring or preventing a change in control of Positron and
may  adversely  affect the market  price of the common  stock and the voting and
other rights of the holders of common stock. Positron currently has one class of
preferred stock outstanding.

Currently  there is one series of preferred stock  outstanding,  the Series A 8%
Cumulative  Convertible  Redeemable  Preferred  Stock.  Each  share of  Series A
Preferred  Stock is convertible  into one share of Common Stock.  The conversion
price at which the Series A Preferred Stock is convertible  into Common Stock is
subject to adjustment on certain factors.  The Company may declare eight percent
dividends  on the  Series A  Preferred  Stock in its  discretion.  The  Series A
Preferred Stock is senior to the Company's Common Stock on liquidation;  holders
may vote on an as if converted basis on any matter requiring  shareholder  vote;
and while the Series A Preferred  Stock is outstanding  or any dividends  remain
unpaid, the Company may not pay or declare dividends on its Common Stock.

REGISTRATION RIGHTS

We are registering the shares being sold by the selling stockholders pursuant to
contractual obligations to the selling stockholders. Other than the shares being
offered hereby, Positron is under no obligation to register any of its shares.

WARRANTS

As of October 31,  1999,  we had  outstanding  warrants  to purchase  28,868,845
shares of common  stock at  exercise  prices  ranging  from $0.05 to $ 4.125 and
expiring between February 7, 2000 and June 15, 2009.

                      INTEREST OF NAMED EXPERTS AND COUNSEL

The  Consolidated  Financial  Statements  of Positron  for the fiscal year ended
December 31, 1998 appearing in the  Registration  Statement have been audited by
Ham,  Langston and Brezina,  independent  certified public  accountants,  as set
forth in their report appearing  elsewhere herein,  and are included in reliance
upon such report given upon the  authority of said firm as experts in accounting
and auditing.


                                       25
<PAGE>

The  validity of the common  stock being  offered  hereby will be passed upon by
Allen Matkins Leck Gamble & Mallory LLP, San Francisco, California. A partner of
Allen Matkins holds shares of Positron's  common stock,  representing  less than
0.1% of Positron's outstanding common stock.

                      DISCLOSURE OF COMMISSION POSITION ON
                 INDEMNIFICATION FOR SECURITIES ACT LIABILITIES

Pursuant to the Texas Business Corporation Law (the "BCL"),  Positron's Articles
of Incorporation  exclude personal liability on the part of its directors to the
Company for monetary  damages based upon any violation of their fiduciary duties
as directors, provided the director acted in good faith, reasonably believed the
conduct  was in the best  interests  of the  corporation  and had no  reason  to
believe the conduct was unlawful.  Positron's  Articles of Incorporation and its
Bylaws  require  indemnification  of directors and officers of the registrant to
the  fullest  extent  permitted  by the TBCL for  claims  against  them in their
official capacities, including stockholders' derivative actions.

Insofar as indemnification  for liabilities arising under the Securities Act may
be  permitted to  directors,  officers  and  controlling  persons of the Company
pursuant to the foregoing provisions, or otherwise, we have been advised that in
the  opinion  of the SEC,  such  indemnification  is  against  public  policy as
expressed in the Securities Act and is, therefore, unenforceable.

                             DESCRIPTION OF BUSINESS

BUSINESS AND BUSINESS DEVELOPMENT.

Positron  Corporation  (the "Company") was incorporated in the State of Texas on
December 20, 1983,  and  commenced  commercial  operations  in 1986.  We design,
manufacture,  market and service  advanced  medical  imaging  devices  utilizing
positron   emission   tomography   ("PET")   technology   under  the  trade-name
POSICAM((TM))  systems2.  Unlike other currently available imaging technologies,
PET technology permits the measurement of the biological processes of organs and
tissues as well as producing anatomical and structural images.  POSICAM systems,
which  incorporate  patented and proprietary  technology,  enable  physicians to
diagnose and treat patients in the area of cardiology, neurology and oncology.

The Food and Drug Administration ("FDA") approved the initial POSICAM system for
marketing in 1985. As of October 31, 1999, we have sold sixteen POSICAM systems,
of which thirteen are in leading  medical  facilities in the United States,  two
are  installed  in  international  medical  institutions,  and  one is  awaiting
installation  at a major medical  institution  in Japan.  The company  presently
markets its POSICAM systems at list prices of up to $2.0 million  depending upon
the configuration and equipment options of the particular system.

PET technology is an advanced imaging  technique,  which permits the measurement
of the  biological  processes  of  organs  and  tissues  as  well  as  producing
anatomical and structural  images.  Other advanced imaging  techniques,  such as
magnetic  resonance  imaging  ("MRI") and computed

- ----------

2 POSICAM is the  registered  trademark  of  Positron.  All other brand names or
trademarks  appearing in this  prospectus  are the property of their  respective
holders.


                                       26
<PAGE>

tomography ("CT"), produce anatomical and structural images, but do not image or
measure biological processes. The ability to measure biological abnormalities in
tissues and organs allows  physicians to detect  disease at an early stage,  and
provides  information which would otherwise be unavailable to diagnose and treat
disease.  We  believe  that our PET  technology  can  lower  the  total  cost of
diagnosing  and  treating  certain  diseases  by  providing  a means  for  early
diagnosis and reducing  expensive  invasive or unnecessary  procedures,  such as
angiograms or biopsies which,  in addition to being costly and painful,  may not
be necessary or appropriate.

Commercialization  of PET technology  commenced in the mid-1980s and the Company
is one of several commercial  manufacturers of PET imaging systems in the United
States.  Although the other  manufacturers are substantially  larger, we believe
that  our  POSICAM   systems  have   proprietary   operational  and  performance
characteristics,  which  may give  certain  performance  advantages  over  other
commercially available PET systems. Such advantages include: (i) high count-rate
sensitivity  which  results  in faster  imaging;  (ii)  enhanced  ability to use
certain types of radio pharmaceuticals which reduces reliance on a cyclotron and
enhances  patient  throughput;  (iii)  ability to minimize  patient  exposure to
radiation;  and (iv)  ability to  minimize  false  positive  and false  negative
diagnosis of disease. The medical imaging industry,  in which we are engaged, is
subject to rapid and significant technological change. There can be no assurance
that the POSICAM((TM)) systems can be upgraded to meet future innovations in the
PET industry or that new technologies will not emerge, or existing  technologies
will  not  be   improved,   which  would   render  our   products   obsolete  or
non-competitive.

Our primary focus to date has been on the clinical cardiology market,  where our
POSICAM  systems  have been used to assess the  presence  and extent of coronary
heart disease,  such as the effect of arterial blockages and heart damage due to
heart attacks. In 1994 and 1995, we made technological advances which allowed us
to market our products to the neurological and oncological markets. Neurological
applications of POSICAM systems  include  diagnoses of certain brain  disorders,
such as  epileptic  seizures,  dementia,  stroke,  Alzheimer's  disease,  Pick's
disease and Parkinson's  disease.  In oncology,  POSICAM systems are used in the
diagnosis and  evaluation of melanoma and tumors of the bone and various  organs
and tissues such as the brain, liver, colon, breasts and lymphatic system.

COMPETITION

We face competition from three (3) other commercial manufacturers of PET systems
and from  other  imaging  technologies,  primarily  Single  Photon  Emission  CT
(SPECT).  We do not believe that MRI and CAT scan imaging represent  significant
competing technologies,  but rather complementary  technologies to PET. PET, MRI
and CAT scans each provides information not available from the others.

Our primary competition from commercial  manufacturers of PET systems comes from
General Electric Company ("GE") and Siemens Medical Systems,  Inc. and ADAC in a
joint  venture with CTI, Inc. of Knoxville,  Tennessee  ("CTI/Siemens").  GE and
CTI/Siemens and ADAC all have substantially greater financial, technological and
personnel resources than we do. See "Summary - The Company -Risk Factors").


                                       27
<PAGE>

In  addition,   two  Japanese   manufacturers,   Hitachi  and  Shimadzeu,   have
manufactured  and sold PET  scanners in Japan but not yet in the United  States.
These  manufacturers  represent  additional  sources of  competition  which have
substantially  greater financial,  technological and personnel resources than we
do.

The primary  competing  technology in the nuclear medicine industry is SPECT. We
believe that the primary  reason  SPECT  competes  successfully  with PET is the
lower cost of the SPECT  systems,  which cost  between  $175,000 and $750,000 as
compared  with up to $2.0  million  (depending  on  configuation  and  equipment
options) for our systems.  We believe however that our  POSICAM(TM)  system is a
better  diagnostic  tool in that our systems  are able to create  more  accurate
images than SPECT imaging.  Unlike SPECT, the radioactive substances used by our
system are based on naturally occurring substances within the body and allow our
systems to directly measure the metabolic processes and changes occurring within
the  scanned  organ,  thus  providing  a  more  accurate  image  and  functional
assessment.

High field MRI  technology,  an advanced  version of MRI, is in the  development
stage,  but is a potential  competitor to PET in certain  neurology and oncology
applications.  Presently,  high  field MRI may be useful in  performing  certain
research  (non-clinical)  applications  such as blood  flow  studies  to perform
"brain mapping" to localize the portions of the brain associated with individual
functions (such as motor activities and vision.) We cannot presently predict the
future competitiveness of high field MRI.

Several  manufacturers  of SPECT  systems are now offering  multi-head  systems,
which  have been  modified  to  operate in  coincidence  mode,  similar to a PET
scanner.  These  systems  achieve  spatial  resolutions  similar  to that of PET
scanners, but their sensitivity and count rate are only a small fraction of that
achieved by true PET scanners,  making the images  "noisy" and more difficult to
interpret.  We believe these systems are useful for only a very limited class of
clinical  PET  studies  using  only  the FDG  radiotracer.  In  addition,  SPECT
coincidence systems offer limited,  if any,  corrections for patient attenuation
and scatter, which affects the accuracy of diagnosis.

INTELLECTUAL PROPERTY

Trademarks and other proprietary  rights are extremely  important to our success
and our competitive position. We currently hold a number of trademarks,  service
marks,  patents and  copyrights.  Although we seek to protect our trademarks and
other  proprietary  rights  through a variety  of means,  we may not have  taken
adequate steps to protect these rights. We will continue to license content from
third  parties in the future and it is possible  that we could be  subjected  to
infringement  actions based upon the content  licensed from these third parties.
Any claims brought against us, regardless of their merit, could result in costly
litigation  and the  diversion of its  financial  resources  and  technical  and
management  personnel.  Further,  if  such  claims  are  proved  valid,  through
litigation  or otherwise,  we may be required to change our  trademarks or other
proprietary  marks and pay financial  damages,  which could adversely affect our
business.

We  typically  enter  into   confidentiality  or  license  agreements  with  our
employees,  consultants and corporate partners,  and generally control access to
and  distribution  of our  technologies,  documentation  and  other  proprietary
information.  Despite  our  efforts  to  protect  our  proprietary


                                       28
<PAGE>

rights from  unauthorized  use or  disclosure,  parties may attempt to disclose,
obtain or use our  proprietary  rights.  The steps we have taken may not prevent
misappropriation  of our proprietary  rights,  particularly in foreign countries
where laws or law enforcement  practices may not protect our proprietary  rights
as fully as in the United States.

EMPLOYEES

As of November 30, 1999, we employed 21 people, of whom all are full-time.  None
of our employees is  represented  by a union.  We believe our relations with our
employees are good.

                           MANAGEMENT'S DISCUSSION AND
                          ANALYSIS OF PLAN OF OPERATION

The following  discussion and analysis of the financial condition and results of
operations  of  Positron  should be read in  conjunction  with our  Consolidated
Financial Statements (including notes) that appear elsewhere in this prospectus.


GENERAL

We were  incorporated  in December 1983 and commenced  commercial  operations in
1986.  Since that time, we have generated  revenues  primarily from the sale and
service  contract  revenues  derived  from our POSICAM  system,  13 of which are
currently in operation in certain medical  facilities in the United States.  The
Company has never been able to sell its POSICAM systems in sufficient quantities
to achieve profitability

In May 1998,  we entered into a series of  agreements  with Imatron  Inc., a New
Jersey  corporation  and  technology-based  company  engaged  principally in the
business of designing,  manufacturing and marketing a high performance  computed
tomography  pursuant to which on January 22,  1999,  Imatron  acquired  majority
ownership of the  Company.  In  conjunction  with the  execution  of  definitive
agreements in May, 1998, Imatron began making working capital advances available
to us of up to  $500,000  in order to enable us to meet a portion of our current
obligations. As of December 31, 1998, we had borrowed $600,000 pursuant to those
agreements.  The loan  agreement  was  thereafter  amended by oral  agreement to
increase the working  capital  advances  available  under the Agreement up to an
additional $100,000. The loan bore interest at 1/2% over the prime rate, was due
March 1, 2000 (with interest being payable  monthly),  and was secured by all of
Positron's assets.

Pursuant to the agreement, Imatron acquired 9,000,000 shares of our Common Stock
on January  22,  1999,  representing  at that time a majority  ownership  of the
outstanding  common  stock of Positron  on a  full-diluted  and  as-if-converted
basis, excluding  out-of-the-money warrants and options determined at that time.
Positron  received a nominal cash acquisition  price from Imatron in payment for
the shares plus a series of affirmative commitments.

Imatron,  in addition to providing limited working capital financing,  agreed to
support our marketing program  particularly with regard to Imatron's  affiliate,
Imatron  Japan,  Inc.  by  agreeing  to take,  after  the  share  purchase,  all
reasonable  efforts to cause the  placement of 10 POSICAM  systems over the next
three years.  Imatron also agreed to help  facilitate  the  recapitalization  of


                                       29
<PAGE>

Positron to support its re-entry  into the medical  imaging  market by using its
best efforts to arrange for additional third-party equity financing for Positron
over  an  eighteen-month  period  in  an  aggregate  amount  of  not  less  than
$8,000,000.  Consummation  of the issuance of shares to Imatron was  conditioned
upon,  among other things (a) the  resignation of each officer of Positron,  (b)
the  resignation  of at  least  three  of the four  Positron  directors  and the
appointment  of  Imatron's  nominees to fill such  vacancies,  and (c)  Positron
shareholder  approval of an amendment to Positron's Articles of Incorporation to
increase its authorized common stock to 100,000,000  shares of common stock. All
of those  conditions  were met,  and the shares were issued on January 22, 1999.
Through Imatron's efforts, private placements were concluded in August resulting
in an equity infusion of approximately $11.4 million net to Positron.

In  connection  with the above  transactions,  Positron,  Imatron and two of the
lenders to  Positron,  Uro-Tech,  Ltd.  and  ProFutures,  entered  into  certain
agreements  whereby (a)  ProFutures  waived all past  defaults  and extended the
maturity of its loan (with a balance of approximately  $570,000 at September 30,
1998) to  December 5, 1998,  in return for a $50,000  payment,  the  issuance of
warrants to purchase  1,150,000  shares of  Positron  common  stock at $0.25 per
share (in  addition to the  issuance of  previously  bargained  for  warrants to
purchase an  additional  100,000  shares of Positron  common  stock at $0.25 per
share),  and minimum loan repayments of $50,000 for each of the months of April,
May,  June and July 1998,  $100,000 for the month of August 1998 and $50,000 for
each of the months of September,  October, and November 1998, (b) Imatron agreed
to  subordinate  its loan to  ProFutures'  loan,  (c) Uro-Tech,  Ltd.  agreed to
subordinate  its loan (with a balance of  approximately  $767,000  plus  accrued
interest payable of  approximately  $286,000 at September 30, 1998) to Imatron's
loan,  and (d)  ProFutures  and Imatron  agreed that all amounts above the first
$1,000,000  of any  third-party  equity  financing  obtained by Imatron would be
applied  equally  to reduce  Positron's  debt to both  ProFutures  and  Imatron.
Consistent  with  the  amendment  to the  Imatron  Agreement,  the  Company  and
ProFutures  amended  their  agreements  to provide  further  waivers of any past
defaults and further extended the maturity of the ProFutures Loan to December 5,
1998 and minimum loan repayments of $50,000 for each of the months of September,
October,  November 1998.  Imatron agreed to continue to subordinate  its loan to
the  ProFutures  Loan,  and Uro-Tech,  Ltd.  agreed to  subordinate  its loan to
Imatron's loan.

The  ProFutures  loan was fully paid and retired in December  1998, in part from
proceeds received from the sale of the system being leased by Buffalo Cardiology
and Pulmonary Associates. Since then the Imatron loan and the Uro-Tech loan have
also been repaid and retired,  in part from  proceeds  received from the private
placement that concluded in August 1999.


                      COMPARISON OF YEAR ENDED 1998 TO 1997


RESULTS OF OPERATIONS

During the year ended  December 31, 1998,  the Company  continued to  experience
deterioration  in its  financial  condition;  however,  the  Company's  net loss
decreased to $724,000 in 1998 from  $4,455,000 in 1997. The decrease in net loss
is primarily the result of significant  staff  reductions and efforts to curtail
costs. Further analysis follows:


                                       30
<PAGE>

REVENUES:  System sales  decreased to $0 in 1998 from  $1,129,000  in 1997.  The
Company sold no systems in 1998 and only one POSICAM(TM) system in 1997. Fee per
scan revenues decreased to $455,000 in 1998 from $602,000 in 1997 as a result of
the sale of the  previously  leased  system to Buffalo  Cardiology  &  Pulmonary
Associates. Service and component revenue decreased by $242,000 to $1,553,000 in
1998 as compared to  $1,795,000  in 1997,  due  primarily to a conversion of one
system from full service contract to "time and material contract".

COST OF SALES AND  SERVICES:  Cost of system sales  decreased to $0 in 1998 from
$698,000  in 1997 due to the fact  that no  POSICAM  systems  were sold in 1998.
Costs of fee per scan decreased to $118,000 in 1998 from $156,000 in 1997 due to
lower maintenance  costs on the Company's only fee per scan system.  The primary
cost  associated  with  fee per scan is  depreciation  expense,  which  remained
constant.  Service, warranty and component cost decreased $63,000 to $402,000 in
1998 from  $465,000 in 1997 due primarily to the  corresponding  drop in service
revenues.   The  Company   recognized  a  $1,224,000   provision  for  inventory
obsolescence   during  the  fourth  quarter  of  1997  based  upon  management's
assessment that improvements would need to be made to the Company's  POSICAM(TM)
systems  in  order  to meet  current  technological  requirements  by  potential
customers.

OPERATING  EXPENSES:  Research and development  expenses decreased to $0 in 1998
from  $1,305,000 in 1997 due to diversion of R&D staff time to customer  service
support.  The company continued to reduce personnel levels significantly in 1998
as  liquidity  problems  squeezed  Company  resources.   Selling,   general  and
administrative  expenses  declined to $1,700,000 in 1998 from $3,609,000 in 1997
also due to staff reductions.

OTHER EXPENSES:  Interest expense increased to $525,000 in 1998 from $334,000 in
1997 due primarily to interest  expense  associated with the Company's loan from
ProFutures (the "ProFutures  Loan"). The ProFutures Loan was initially funded in
November 1996 and had a balance in excess of $1,000,000 throughout much of 1997.
The interest rate on the  ProFutures  Loan increased from 12% to 18% during 1997
and that increase in interest  rate  combined  with a higher  average debt level
resulted in a significant  increase in interest expense.  The Company retired in
full the  ProFutures  loan in December 1998 in part with proceeds  received from
the sale of the  machine  being  leased  to  Buffalo  Cardiology  and  Pulmonary
Associates (see "Imatron Transaction" section above).

NET OPERATING LOSS CARRY FORWARDS: The Company has accumulated a significant net
operating  loss carry  forward  which may be used to reduce  taxable  income and
related  income taxes in future years.  On the other hand,  since the closing of
the Company's 1993 initial public offering, the sale in February,  March and May
of 1996 of 3,075,318 shares of Series A Convertible Preferred Stock and the sale
of 9,000,000  shares to Imatron,  each resulted in more than a 50% change in the
ownership  percentages  of  shareholders.  The  provisions of Section 382 of the
Internal Revenue Code severely limit the annual utilization of the net operating
loss carry forwards. In addition, the utilization of the losses to reduce future
income taxes is dependent upon the generation of sufficient taxable income prior
to the expiration of the net operating loss carry  forwards.  The carry forwards
will begin to expire in the year 1999.

LIQUIDITY AND CAPITAL RESERVES:  Since its inception the Company has been unable
to  sell  POSICAM(TM)  systems  at  quantities   sufficient  to  be  profitable.
Consequently,  the Company has


                                       31
<PAGE>

sustained  substantial  losses. Net losses for the years ended December 31, 1998
and 1997 were $724,000 and $4,455,000,  respectively.  At December 31, 1998, the
Company had an  accumulated  deficit of  approximately  $49,684,000.  Due to the
sizable  prices of the Company's  systems and the limited number of systems sold
or  placed  in  service  each  year,  the  Company's  revenues  have  fluctuated
significantly year to year.

At December 31, 1998, the Company had cash and cash equivalents in the amount of
$8,000  compared to $160,000 at December 31, 1997.  Throughout  much of 1997 and
1998,  the Company has been unable to meet  certain of its  obligations  as they
came  due.  As a result of the  Company's  liquidity  problem,  the  payment  of
salaries and other  benefits to certain  management  level  employees  (totaling
approximately  $700,000) were deferred at December 31, 1997 and remained  unpaid
at  December  31,1998.  Additionally,  the  Company is in arrears to many of its
vendors and suppliers.  As of December 31, 1998, such amount owed to vendors and
suppliers totaled approximately  $1,327,000.  This amount does not include fully
the demand made by Dr. Haas. See comments in section EMPLOYEES above.

Even though the Company  successfully  retired Profutures Loan in December 1998,
on an  on-going  basis  the  Company  will  require  additional  debt or  equity
financing  to sustain  its  operations.  The  Company  is  relying on  Imatron's
undertaking  to use its best  efforts to arrange  additional  third party equity
financing for the Company to fulfill its current  financing needs.  There are no
assurances that Imatron will be successful in arranging  additional  third party
equity financing for the Company or, if such equity financing is obtained,  that
the terms of such  equity  financing  will be  favorable  to the  Company or its
shareholders.

As a result of the Company's liquidity problems,  its auditors,  Ham, Langston &
Brezina,  L.L.P.,  added  an  explanatory  paragraph  to  their  opinion  on the
Company's  financial  statements for the year ended December 31, 1998 indicating
that substantial doubt exists about the Company's ability to continue as a going
concern.


                     COMPARISON OF THE RESULTS OF OPERATIONS
              FOR THE THREE MONTHS ENDED SEPTEMBER 30, 1999 & 1998.

The company  generated a profit of $28,000 for the three months ended  September
30, 1999 compared to a loss of $744,000 for the three months ended September 30,
1998.  This  turnaround  was primarily the result of  improvements  in operating
expenses and cost cutting.

The Company generated no revenue from system sales during the three months ended
September  30, 1999 or 1998.  Fee per scan revenue  decreased to zero during the
three  months of 1999 from  $147,000 for the three months of 1998 due to Buffalo
Cardiology's  purchase of their  leased  scanner  from the Company in the fourth
quarter of 1998.  Upgrade  revenue  for the quarter was $0 in 1999 versus $0 for
1998. In addition,  service and component  sales revenue  increased  $232,000 to
$385,000 in 1999 from  $153,000  during the same  period  1998 due to  increased
service work. This increase is attributable to normal fluctuations in service.

Gross profit for the three months ended September 30, 1999 was $214,000 compared
to $163,000  for the three  months in 1998.  This  increase  in gross  profit of
$51,000 was due


                                       32
<PAGE>

primarily  the loss of revenue  and gross  margin on the  Buffalo  fee per scan,
offset by the increased margin on service.

Total  operating  expense  decreased  $456,000 to $384,000  for the three months
ended September 30, 1999 from $840,000 for 1998. The decrease  primarily results
from  significant  staff  reductions  and related  reductions in  administrative
overhead costs, offset by back pay and bonuses of $132,000 paid in the quarter.

Interest income was $55,000 for the three months ended September 30, 1999 versus
interest  expense of $67,000 for the same three months 1998 due primarily to the
reduction in the Company's debt level compared to 1998 resulting from the payoff
of the Profutures  loan in the fourth quarter of 1998, the payoff of the Imatron
and  Uro-Tech  loans in August of 1999 and the  interest  in the  quarter on the
equity capital.

The Company  recognized  extraordinary  income in the quarter of $142,000 on the
partial  forgiveness of accrued  interest on the Uro-Tech note.  This note, plus
the remaining accrued interest, were paid in full during the third quarter.


                     COMPARISON OF THE RESULTS OF OPERATIONS
              FOR THE NINE MONTHS ENDED SEPTEMBER 30, 1999 & 1998.

The company  generated a profit of $108,000 for the nine months ended  September
30,  1999  compared  to a loss  of  $984,000  for the  nine  months  1998.  This
turnaround was primarily the result of  improvements  in operating  expenses and
cost cutting and the reversal of certain  reserves due to collection of accounts
receivable previously deemed uncollectable.

The Company  generated no revenue from system sales during the nine months ended
September  30, 1999 or 1998.  Fee per scan revenue  decreased to zero during the
first  nine  months of 1999  from  $454,000  for the nine  months of 1998 due to
Buffalo Cardiology having purchased their leased scanner from the company in the
fourth  quarter of 1998.  Upgrade  revenue for the first nine months of 1999 was
$137,000 versus zero for 1998. In addition,  there was a increase in service and
component  sales revenue of $155,000 during 1999 versus 1998 due to more service
work performed  during the nine months ended  September 30, 1999. This change in
service work is attributable to normal fluctuations in service.

Gross profit during the nine months of 1999 was $759,000  compared to $1,012,000
for the nine months ended  September 30, 1998.  This decrease in gross profit of
$253,000 is due primarily to the loss of revenue and gross margin on the Buffalo
fee per scan.

Total  operating  expense  decreased  $1,019,000 to $749,000 for the nine months
ended  September 30, 1999 from $1,768,000 for the nine months 1998. The decrease
primarily  results from significant  staff reductions and related  reductions in
administrative  overhead  costs and the  reversal  of  certain  reserves  due to
collection of accounts  receivable  previously deemed  uncollectable,  offset by
back pay and bonuses of $132,000 paid in the quarter.

Interest expense decreased to of $45,000 for the nine months ended September 30,
1999 from  $228,000 for the nine months 1998 due  primarily to the  reduction in
the  Company's  debt level in


                                       33
<PAGE>

the  first  nine  months  of 1999 as  compared  to the  nine  months  of 1998
resulting  from the  payoff of the  Profutures,  the payoff of the  Imatron  and
Uro-Tech loans in August of 1999,  and the interest  income in third quarter for
the quarter on the equity capital.

The Company  recognized  extraordinary  income in the quarter of $142,000 on the
partial forgiveness of accrued interest on the Uro-Tech note. This note plus the
remaining accrued interest were paid in full during third quarter.


                               FINANCIAL CONDITION

During 1998 and the three quarters of 1999,  management  took certain actions to
improve operating expenses, reduce costs and collect certain accounts receivable
previously deemed uncollectable.  As a result, the company experienced its first
three quarterly profits since going public.

Net income for the nine months ended  September 30, 1999 was  $117,000.  Despite
this profit, Positron previously has been unable to sell its POSICAM(TM) systems
in  sufficient  quantities  to be  profitable.  Consequently,  the  Company  has
sustained substantial  accumulated losses. Due to the sizeable selling prices of
the  Company's  systems  and the  limited  number of  systems  sold or placed in
service each year, the Company's revenues have fluctuated  significantly year to
year.  The Company has an  accumulated  deficit of  $49,576,000 at September 30,
1999.


IMPACT OF THE YEAR 2000

The Year 2000 ("Y2K") issue results from computer  programs  having been written
using two digits  rather  than four to define the  applicable  year.  Any of the
Company's  computer  programs that have time sensitive  software may recognize a
date using "00" as the year 1900 rather than the year 2000. This could result in
a system failure or miscalculation causing a disruption of business activities.

The Company  performed an assessment of the Y2K issue using a broad overview and
management's  current  understanding  of  its  information  and  non-information
systems and its informal  understanding  of the information and  non-information
systems of its significant suppliers and major customers.

Based on the assessment,  the Company believes that with the exception of two of
its systems, it did not need significant  modifications to its computer software
or  hardware  and that its  existing  computer  systems  (including  information
systems,  non-information  systems using date  sensitive  embedded chips and its
POSICAM(TM)  systems) will  function  properly with respect to dates in the year
2000 and  thereafter.  Based upon such  assessment,  the Company also  currently
believes  that costs to modify the  Company's  existing  computer  hardware  and
software  systems in regard to the Y2K issue will not be significant  and should
not exceed $10,000. However, the Y2K issue is extremely complex and the costs to
properly assess its impact on the Company and to correct associated problems may
be very significant.

Based  on  the  Company's  assessment  of  its  relationships  with  significant
suppliers and major  customers to understand  the extent to which the Company is
vulnerable  to any  failure  by third


                                       34
<PAGE>

parties to remedy  their own Y2K issues,  management  believes  that the Company
does not have significant exposure with respect to third parties.

                             DESCRIPTION OF PROPERTY

We are  headquartered in Houston,  Texas where we currently lease  approximately
5,400 square feet of space.  The facility  includes area for system assembly and
testing, a computer room for hardware and software design, and office space. The
facility is leased month to month at a rate of  approximately  $2,700 per month.
We estimate the space to be sufficient for the current fiscal year.

                 CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

S. Lewis Meyer,  pursuant to authorization  of the Board of Directors,  borrowed
$10,000 from the Company in June 1999 pursuant to a promissory note bearing 7.0%
simple interest,  with interest payable quarterly beginning October 1, 1999. The
purpose  of the loan was to enable  Mr.  Meyer to  purchase  1,500,000  warrants
granted to him at that time.

Gary H. Brooks,  pursuant to authorization  of the Board of Directors,  borrowed
$20,000 from the Company in June 1999 pursuant to a promissory note bearing 7.0%
simple interest,  with interest payable quarterly beginning October 1, 1999. The
purpose  of the loan was to enable Mr.  Brooks to  purchase  3,000,000  warrants
granted to him at that time.

In January  1995 the  Company  and Dr.  Wood  extended  an  existing  Consulting
Agreement whereby Dr. Wood continued to provide certain  managerial,  financial,
marketing and organization services to the Company. The Company incurred fees of
approximately  $80,000 in each of 1996 and 1997 pursuant to the  Agreement,  and
fees of  approximately  $80,000 in 1998 as payment  for Dr.  Wood's  services as
Chief Executive Officer during that year. By its terms, the Agreement expired as
of  December  31, 1998 and was not  renewed.  We paid Dr. Wood fees of $6,667 in
1999 for his  services  as  President  and  Chief  Executive  Officer  until the
appointment of Gary Brooks as President on January 22, 1999.

During 1995 and 1996, in order to fund its  activities,  the Company  borrowed a
total of $1,313,000 from Uro-Tech, Ltd., an affiliate of the Company and a Texas
limited partnership.  The general partner of Uro-Tech is OmniMed Corporation, of
which Dr. Wood beneficially owns 63.7% of the outstanding stock. As of March 31,
1996, $650,000 of the note was converted to 433,329 shares of Series A Preferred
Stock and 216,671 Redeemable Stock Purchase Warrants. In addition, in connection
with the loan, Uro-Tech was granted warrants to purchase 67,500 shares of common
stock  exercisable  at $2.00 until  February 7, 2001.  The loan bore interest at
13.8% per  year,  matured  on April  30,  1997 and was  thereafter  extended  in
connection with the Imatron Transaction. The Uro-Tech loan was collateralized by
liens and security  interests  encumbering most of the Company's  assets,  which
security interest was thereafter  subordinated to a loan from Imatron as part of
the Imatron Transaction.

The Company  fully  retired the  Uro-Tech  Loan,  including  all  principal  and
interest  due, in September  1999 and in  connection  therewith  and  Uro-Tech's
forgiveness  of certain  sums of interest  due it by the  Company,  replaced and
cancelled the warrant to purchase  67,500 common


                                       35
<PAGE>

shares at an exercise  price of $2.00 with a warrant to purchase  100,000 common
shares at an exercise  price of $1.00.  The  replacement  warrant is exercisable
through September 20, 2001.

The Company and Mr. Brooks entered into an Employment Agreement,  effective with
his  appointment  as President on January 22, 1999  pursuant to which Mr. Brooks
agreed to be employed by the  Company on a  part-time  basis from the  effective
date through  August 31, 1999 and  thereafter on a full time basis.  Mr. Brooks'
initial  appointment  is as  President.  Pursuant to the  Agreement,  which runs
initially  through  June  15,  2000  and  then  on  a  rolling  six-month  basis
thereafter,  the gross amount of Mr. Brooks' base salary was $1,000 monthly from
January 22, 1999 to June 15, 1999,  $3,416.67 monthly from June 15, 1999 through
August 31, 1999, and $185,000 on an annualized  basis on and after  September 1,
1999.  Mr.  Brooks  is also  entitled  to  reimbursement  for up to  $20,000  of
relocation  expenses to  relocate  his  residence  to  Houston,  Texas,  an auto
allowance  of $500 per month,  the right to  purchase  for  $20,000 a warrant to
purchase up to three million shares of the Company's common stock exercisable at
$0.30 per share,  participation  in the Company's  benefit plans consistent with
other  executives,  and severance on termination  without cause in the amount of
the  greater of the base  salary he would have  earned to the end of the term or
six months.  The  warrants  Mr.  Brooks can purchase  vest  immediately  but are
subject to the Company's  right of  repurchase,  which right lapses 25% on grant
and the  remainder  quarterly  over the  next  three  years.  In the  event  his
employment is terminated by the Company without cause or on a change of control,
the Company's  repurchase  right  regarding his warrants lapses entirely and any
other equity participation he may have in company securities vests immediately.

            MARKET FOR COMMON EQUITY AND RELATED STOCKHOLDER MATTERS

In December 1993, the Company  completed an initial public offering of 1,750,000
shares of Common  Stock  and  1,946,775  redeemable  warrants  (the  "Redeemable
Warrants") to purchase  Common Stock (the "Initial Public  Offering").  Prior to
the Initial  Public  Offering  there was no public market for  Company's  Common
Stock.  The Redeemable  Warrants  expired in December 1998. The Company's Common
Stock is currently traded in the over-the-counter  securities market, and quoted
on the NASD's Electronic Bulletin Board under the symbol POSC.OB.  The Company's
Common  Stock and,  prior to their  expiration,  the  Redeemable  Warrants  were
previously  traded on the  NASDAQ  SmallCap  Market  but were  delisted  in 1997
because the Company was unable to comply with various  financial and  compliance
requirements for continued inclusion on the NASDAQ SmallCap Market. See "Item 1.
Description of Business - Risks Associated with Business Activities."

The  following  range of the high and low reported  closing sales prices for the
Company's  Common Stock for each  quarter in 1998 and 1997,  and the first three
quarters of 1999, all as reported on the NASDAQ OTC Bulletin Board or the NASDAQ
SmallCap Market. On January 10, 2000, the last reported sale price of our common
stock on the NASD Electronic Bulletin Board was $ 0.5625.


                                       36
<PAGE>

                       1997                    1998                    1999
                  --------------          --------------          -------------
                  HIGH       LOW          HIGH       LOW          HIGH      LOW
                  ----       ---          ----       ---          ----      ---
First Quarter    $3.375    $1.250        $0.625    $0.266        $0.438   $0.120
Second Quarter   $1.938    $0.375        $0.609    $0.188        $0.700   $0.120
Third Quarter    $1.438    $0.422        $0.453    $0.213        $1.094   $0.469
Fourth Quarter   $0.953    $0.172        $0.500    $0.040        $0.906   $0.375

There  were  approximately  295  shareholders  of record  of Common  Stock as of
October 31, 1999, including  broker-dealers holding shares beneficially owned by
their customers.

The Company has never paid cash dividends on its Common Stock.  The Company does
not intend to pay cash dividends on its Common Stock in the foreseeable  future.
The Series A Preferred Stock  Statement of Designation  prohibits the payment of
Common Stock dividends until all required dividends have been paid on the series
of  preferred  stock.  As of  September  30,  1999,  approximately  $373,000  of
preferred stock dividends are undeclared and unpaid by the Company.


                                       37
<PAGE>


                             EXECUTIVE COMPENSATION


SUMMARY COMPENSATION OF NAMED EXECUTIVES

         The Summary Compensation Table shows certain  compensation  information
for each person who served as Chief  Executive  Officer  during the year and the
other most highly compensated  executive  officers whose aggregate  compensation
exceeded  $100,000 for services  rendered in all  capacities  during fiscal year
1998 and for the first 10 months of fiscal year 1999  (collectively  referred to
as the "Named Executive  Officers").  Compensation  data is shown for the fiscal
years  ended  December  31, 1998 and 1997 and for the first ten months of fiscal
year 1999. This  information  includes the dollar value of base salaries,  bonus
awards, the number of stock options granted, and certain other compensation,  if
any, whether paid or deferred.


                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>
                                                                          LONG TERM
                                                    ANNUAL               COMPENSATION        ALL OTHER
                                                 COMPENSATION               AWARDS        COMPENSATION(b)
                                          -------------------------      ------------     --------------
           NAME AND
      PRINCIPAL POSITION         YEAR     SALARY($)(a)        BONUS      OPTIONS/ SARS
      ------------------         ----     ---------           -----      -------------
<S>                              <C>        <C>                 <C>        <C>                <C>
Gary H. Brooks, President        1999       $48,375(c)         -0-              -0-               -0-

Gary B. Wood, Ph.D., President   1999         6,667            -0-              -0-               -0-
and Chief Executive Officer      1998        93,333            -0-              -0-
(2/1/97 to 1/22/99)              1997        33,333            -0-              -0-

John J. Ariatti                  1999       $15,801(d)         -0-         650,000(d)

Howard Baker                     1998      $163,027(e)         -0-              -0-           $1,986
                                 1997       $91,000            -0-              -0-
</TABLE>

- ----------

(a)   Amounts shown include cash and non-cash  compensation  earned with respect
      to the year shown above.

(b)   Represents the Company's matching contributions to its 401(k) plan.

(c)   Mr. Brooks served as President on a part-time  basis from January 22, 1999
      until September 1, 1999, and thereafter on a full-time basis.  This number
      reflects  compensation  paid through  10/31/99.  Mr.  Brooks also received
      $20,000 in reimbursement of relocation expenses in 1999.

(d)   Mr. Ariatti was appointed Vice  President,  Sales and Marketing  effective
      September 27, 1999. This number reflects  compensation  paid him from that
      date through  10/31/99.  In connection  with his employment he was granted
      options to purchase 650,000 shares of Positron common stock exercisable at
      $0.47,  the market price of the stock on the grant date.  The options vest
      quarterly  over the first  four  years  from the date of grant.  40,625 of
      these options are exercisable within 60 days of October 31, 1999.

(e)   Mr.  Baker  served  as EVP,  Sales  and  Marketing  during  1997 and until
      December 1998 when he resigned.


                                       38
<PAGE>


OPTION GRANTS IN LAST FISCAL YEAR

      The following  table sets forth the options granted during the last fiscal
year to each of the named executive officers of the Company:


                      OPTION/SAR GRANTS IN FISCAL YEAR 1998

<TABLE>
<CAPTION>
====================================================================================================================

                          Individual Grants                           Potential Realizable Value at
                                                                   Assumed Annual Rates of Stock Price
                                                                      Appreciation For Option Term
====================================================================================================================
                     NUMBER OF      % OF TOTAL
                     SECURITIES       OPTIONS
                       UNDER        GRANTED TO      EXERCISE OR
                      OPTIONS      EMPLOYEES IN     BASE PRICE     MARKET      EXPIRATION       0%($)     5%($)(b)
NAME                 GRANTED (#)  FISCAL YEAR(a)      ($/SH)        PRICE         DATE
- ----                 -----------  --------------    -----------    ------      ----------       -----     --------
<S>                    <C>              <C>             <C>          <C>           <C>            <C>        <C>
Gary B. Wood           -0-              -0-             -0-          -0-           -0-            -0-        -0-
</TABLE>

(a)   No options were granted to any  employee,  including  executive  officers,
      during the last fiscal year.

(b)   Based on 5-year  option  term and  annual  compounding;  results  in total
      appreciation of 27.6% (at 5% per year) and 61.1% (at 10% per year).

OPTION EXERCISES IN LAST FISCAL YEAR AND YEAR-END OPTION VALUES

      The  following  table sets  forth the  options  exercised  during the last
fiscal year by Named Executive Officers of the Company:


       AGGREGATED OPTIONS EXERCISED AND OPTION VALUES IN FISCAL YEAR 1998

<TABLE>
<CAPTION>
                                                     Number of securities        Value of unexercised
                                                    underlying unexercised      In-the-Money options at
               Shares acquired       Value         options at year-end (#)     year-end ($)exercisable/
NAME           ON EXERCISE (#)    REALIZED ($)    EXERCISABLE/UNEXERCISABLE          UNEXERCISABLE
- ----           ---------------    ------------    -------------------------    ------------------------
<S>                  <C>              <C>                    <C>                          <C>
Gary B. Wood         -0-              -0-                    -0-                          -0-
</TABLE>


BOARD COMPENSATION

We reimburse  directors for their reasonable  expenses associated with attending
meetings of the Board of Directors.  Directors  who are  full-time  employees of
Positron  Corporation  are not separately  compensated  for their service on the
Board.  Until January 22, 1999  non-employee  directors were eligible to receive
$12,500  annually for their services and  attendance at regular Board  meetings,
and $500 for each additional Board or committee meeting attended,  not to exceed
an  additional  $2,500 per year.  The  Chairman  of the Board also  received  an
additional annual retainer of $2,000 per year. Due to the financial  constraints
facing the Company  during 1997 and 1998,  non-employee  directors were not paid
fees for their  services as director.  Since  January 22, 1999 and until further
notice, non-employee directors are not separately


                                       39
<PAGE>


compensated  for  their  services  on the Board  although  they  continue  to be
reimbursed for their  reasonable  expenses  associated  with attending board and
committee meetings.

On and after October 6, 1999, each non-employee  director is eligible to receive
an option to  purchase  25,000  shares of common  stock  under  Positron's  1999
Non-employee Directors' Stock Option Plan. The exercise price is equal to 85% of
the fair market value of the common stock on the date of grant. In addition,  so
long as the Plan is in effect and there are  shares  available  for grant,  each
director in service on January 1 of each year  (provided the director has served
continuously  for at least the  preceding  30 days) is  eligible  to  receive an
option to purchase  25,000 shares of common stock at an exercise  price equal to
85% of the fair market value of the common  stock on the date of grant.  Initial
options as well as annual  options  granted under the Plan are subject to one or
two  schedules,  either  vesting over four years or vesting fully on the date of
grant.  In the latter  event,  the common stock  acquired  upon exercise of such
options are subject to a right of repurchase  in favor of Positron  which lapses
in four equal annual  installments,  beginning on the first  anniversary  of the
date of grant.

The 1999 Non-Employee Directors' Plan replaces portions of the 1994 Stock Option
Plan,  pursuant to which both employee and non-employee  directors were eligible
to receive stock option  grants.  Pursuant to the 1994 Plan,  each  non-employee
director was  automatically  granted a one time stock option to purchase  10,500
shares of common stock at the time of election,  and on  reelection an option to
purchase that number of shares equal to the quotient derived by dividing $15,000
by the fair  market  value of the  common  stock on the date of  grant.  160,000
shares had been reserved for issuance to  non-employee  directors under the 1994
Plan, of which 113,724 non-statutory options had been granted as of December 31,
1998. No additional  option grants were made to non-employee  directors in 1999,
and the Plan was terminated by the Board of Directors  effective October 6, 1999
simultaneous with the adoption by the Board of the 1999 Non-Employee  Directors'
Plan.


COMPENSATION ARRANGEMENTS

Effective January 22, 1999 the Company entered into an employment agreement with
Gary H.  Brooks.  Pursuant  to the  Agreement,  he was  appointed  initially  as
President of the Company with an initial  employment  term ending June 15, 2000,
with a rolling six month basis thereafter.  From January 22, 1999 until June 15,
1999 and then from June 15,  1999  through  August 31,  1999 his base salary was
$1,000 and $3,416.67 per month respectively,  reflecting his less than full-time
commitments to the office during these periods.  Effective September 1, 1999 and
his full-time  assignment with the Company,  his salary increased to $185,000 on
an annualized basis. In addition to participation in the Company's group benefit
plans and a monthly automobile  allowance,  Mr. Brooks was given the opportunity
to purchase for $20,000 a warrant to purchase  3,000,000 shares of the Company's
common stock  exercisable  at $0.30 per share.  The warrant,  and the underlying
common stock, are subject to the Company's  repurchase  right,  which lapses 25%
immediately and the remainder quarterly over the next three years. The Board can
terminate Mr.  Brooks'  employment  without cause on thirty days' written notice
and the payment of base salary for the remainder of the  employment  term or six
months, whichever is greater.


                                       40
<PAGE>


COMPENSATION PLANS

EMPLOYEE STOCK OPTION PLAN

Positron has had several  employee  stock option  plans,  most recently the 1994
Stock Option Plan, which was terminated by the Board effective  October 6, 1999,
and the 1999  Employee  Stock  Option  Plan,  which  was  adopted  by the  Board
effective  June 15,  1999.  The 1994 Plan  provided  for the grant of options to
officers, directors, key employees and consultants of the Company. The 1999 Plan
provides for the grant of options to  officers,  employees  (including  employee
directors)  and  consultants.   Both  the  1994  Plan  and  the  1999  Plan  are
administered  by the Board of  Directors.  The  administrator  is  authorized to
determine the terms of each option granted under the plans, including the number
of shares,  exercise price, term and  exercisability.  Options granted under the
plans may be incentive stock options or nonqualified stock options. The exercise
price of  incentive  stock  options may not be less than 100% of the fair market
value of the common stock as of the date of grant (110% of the fair market value
in the case of an optionee owns more than 10% of the total combined voting power
of all classes of Positron  capital  stock).  Options may not be exercised  more
than  ten  years  after  the  date  of  grant  (five  years  in the  case of 10%
stockholders).

Upon  termination  of employment  for any reason other than death or disability,
each  option  may be  exercised  for a period  of 90 days,  to the  extent it is
exercisable  on the date of  termination.  In the case of a  termination  due to
death or disability, an option will remain exercisable for a period of one year,
to the extent it is  exercisable on the date of  termination.  As of October 31,
1999, there were 3,205,000 shares available for grant under the plans.

NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN

The 1999 Non-employee  Directors' Stock Option Plan, described elsewhere in this
Prospectus,  provides for the  automatic  grant of an option to purchase  25,000
shares  of  common  stock to  non-employee  directors  upon  their  election  or
appointment  to the Board,  and  subsequent  annual grants also in the amount of
25,000 shares of common stock.  The exercise  price of the options is 85% of the
fair market value of the common stock on the date of grant.  The Directors' Plan
is administered  by the Board.  Options granted under the Directors' Plan become
exercisable  in one of two  ways:  either  in four  equal  annual  installments,
commencing on the first  anniversary of the date of grant,  or  immediately  but
subject to the Company's right to repurchase,  which  repurchase right lapses in
four equal annual installments,  commencing on the first anniversary of the date
of grant..  To the extent that an option is not  exercisable  on the date that a
director  ceases to be a director  of the  company,  the  unexercisable  portion
terminates.

1999 STOCK BONUS INCENTIVE PLAN

In October 1999 the Board adopted an Employee Stock Bonus Incentive Plan,  which
provides  for  the  grant  of  bonus  shares  to any of  Positron  employee.  or
consultant to recognize  exceptional service and performance  beyond.the service
recognized  by  the  employee's  salary  or  consultant's  fee.  The  Board  has
authorized  up to an aggregate of 1,000,000  shares of common stock for issuance
as bonus  awards  under the Stock Bonus Plan.  The Stock Bonus Plan is currently
administered by the Board. Each grant of bonus shares is in an amount determined
by the Board,


                                       41
<PAGE>


up to a maximum of the  participant's  salary.  The shares  becomes  exercisable
according to a schedule to be established by the Board at the time of grant.

1999 EMPLOYEE STOCK PURCHASE PLAN

A total of 500,000  shares of common stock has been reserved for issuance  under
Positron's Employee Stock Purchase Plan (the "Purchase Plan"), none of which has
as yet been issued.  The Purchase  Plan permits  eligible  employees to purchase
Common Stock at a discount through payroll deductions during offering periods of
up to 27 months.  Offering periods generally will begin on the first trading day
of a calendar quarter. The initial offering period began on January 1, 2000. The
price at which stock is purchased  under the Purchase  Plan will be equal to 85%
of the  fair  market  value  of  common  stock  on the  first or last day of the
offering period, whichever is lower.

401(K) PLAN

The Company has a 401(k)  Retirement  Plan and Trust (the  "401(k)  Plan") which
became  effective  as of January  1, 1989.  Employees  of the  Company  who have
completed  one-quarter  year of service and have attained age 21 are eligible to
participate  in the 401(k) Plan.  Subject to certain  statutory  limitations,  a
participant may elect to have his or her  compensation  reduced by up to 20% and
have the Company contribute such amounts to the 401(k) Plan on his or her behalf
("Deferral  Contributions").  The Company makes contributions in an amount equal
to  25%  of  the  participant's  Deferral  Contributions  up to 6% of his or her
compensation ("Employer Contributions"). Additionally, the Company may make such
additional contributions as it shall determine each year in its discretion.  All
Deferral  and  Employer  Contributions  made  on  behalf  of a  participant  are
allocated to his or her individual accounts and such participant is permitted to
direct the investment of such accounts.

A participant is fully vested in the current value of that portion of his or her
accounts  attributable to Deferral  Contributions.  A participant's  interest in
that portion of his or her accounts  attributable to Employer  Contributions  is
generally fully vested after five years of employment.  Distributions  under the
401(k) Plan are made upon termination of employment,  retirement, disability and
death.  In addition,  participants  may make  withdrawals in the event of severe
hardship or after the  participant  attains age  fifty-nine  and  one-half.  The
401(k)  Plan is  intended  to qualify  under  Section  401 of the Code,  so that
contributions  made under the 401(k) Plan,  and income earned on  contributions,
are not taxable to participants until withdrawal from the 401(k) Plan.

                        CHANGES IN AND DISAGREEMENTS WITH
               ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

On April 7, 1998, Coopers & Lybrand L.L.P. ("Coopers & Lybrand"),  by means of a
letter  addressed  to the Chairman of the Board and Chief  Executive  Officer of
Positron  Corporation informed the Company that it had resigned as the Company's
independent  auditors.  The resignation arose from Coopers & Lybrand's desire to
terminate  its  relationship  with the  Company  because of the  Company's  then
current financial condition.


                                       42
<PAGE>


The report of Coopers & Lybrand  for either of the of the past two years did not
contain an opinion or disclaimer of opinion, or qualification or modification as
to uncertainty,  audit scope, or accounting  principles,  except:  (i) Coopers &
Lybrand's  report on the  financial  statements of the Company as of and for the
years ended December 31, 1996,  contained a separate paragraph stating that "the
Company has  suffered  recurring  losses from  operations  and has a net capital
deficiency  that  raises  substantial  doubt  about its ability to continue as a
going concern.  Management's plans in regard to these matters are also described
in Note 1. The financial  statements do not include any  adjustments  that might
result from the outcome of this uncertainty";  and (ii) The financial statements
as of and for the fiscal year ended December 31, 1997 have not been audited.

This  decision to resign was made by Coopers & Lybrand and was neither  approved
nor disapproved by the Company's Board of Directors.

During the two most recent fiscal  periods ended  December 31, 1998 and December
31,  1997  and  from  December  31,  1997 to the  date of  Coopers  &  Lybrand's
resignation,  there were: (i) no disagreements between the Company and Coopers &
Lybrand on any matter of accounting principles or practice,  financial statement
disclosure, or auditing scope or procedure,  which disagreements if not resolved
to the  satisfaction of Coopers & Lybrand would have caused it to make reference
thereto in its report;  and (ii) no  reportable  events as defined in  paragraph
304(a)(1)(iv) of Regulation S-B.

Coopers & Lybrand has provided the  Securities  and Exchange  Commission  with a
letter agreeing to the disclosure contained herein.

Coopers and Lybrand was replaced by Ham, Langston & Brezina,  L.L.P. on June 26,
1998. Prior to the engagement of Ham, Langston & Brezina,  L.L.P. as independent
auditors,  the Company had not  consulted  them  regarding  the  application  of
accounting principles to a specified transaction,  either completed or proposed;
or the type of audit opinion that might be rendered on the  Company's  financial
statements or any other  financial  presentation  whatsoever.  No  disagreements
exist between the Company and Ham, Langston & Brezina,  L.L.P. on any matters of
accounting principles or practices,  financial statement disclosure, or auditing
scope or procedure.

ANTI-TAKEOVER PROVISIONS

Positron  is  governed  by Part 13 of the Texas  Business  Corporation  Law.  In
general,  this  article  restricts a  corporation  from  entering  into  certain
business  combinations with an affiliated  stockholder (defined as any person or
entity that is the beneficial  owner of at least 20% of a  corporation's  voting
stock)  or its  affiliates  for a period  of three  years  after the date of the
transaction in which the person became an interested  stockholder unless (i) the
transaction  is approved by the board of directors of the  corporation  prior to
the shareholder's acquisition date, (ii) the business combination is approved by
the  affirmative  vote of the holders of at least  two-thirds of the outstanding
voting shares not beneficially owned by the affiliated  shareholder at a meeting
of  shareholders  and not by written  consent,  called for that purpose not less
than six months  after the  affiliated  shareholder's  share  acquisition  date.
"Business combinations" include mergers, asset sales, share exchanges, and other
transactions resulting in a financial benefit to the


                                       43
<PAGE>

interested  stockholder.  A Texas  corporation may "opt out" of these provisions
with an express  provision  in its  original  articles  of  incorporation  or an
express  provision in its articles of  incorporation  or bylaws resulting from a
stockholders'  amendment  approved  by at least  two-thirds  of the  outstanding
voting  shares,  and after a waiting period of 18 months after the vote has been
taken.  Positron has not "opted out" of the  provisions  of Part  Thirteen.  The
statute could prohibit or delay mergers or other  takeover or  change-in-control
attempts with respect to the Company and,  accordingly,  may discourage attempts
to acquire the Company.

                                  LEGAL MATTERS

The validity of the common stock  offered  hereby will be passed on for Positron
by Allen Matkins Leck Gamble & Mallory LLP, San Francisco, California.

                       WHERE YOU CAN FIND MORE INFORMATION

We file annual,  quarterly,  and special  reports,  proxy  statements  and other
information with the Securities and Exchange  Commission.  You may read and copy
any reports,  statements or other information on file at the Commission's public
reference  room in Washington,  D.C. You can request copies of those  documents,
upon payment of a duplicating fee, by writing to the Commission.

We have filed a registration  statement on Form SB-2 with the  Commission.  This
prospectus,  which forms a part of that registration statement, does not contain
all the information set forth in the registration statement. Certain information
is omitted and you should refer to the registration  statement and its exhibits.
Statements  contained in this  prospectus  as to the  contents of any  contract,
agreement or other  document  referred to are not  necessarily  complete and you
should refer in each instance to the copy of such  contract,  agreement or other
document filed as an exhibit to the registration Statement, each statement being
qualified  in all respects by such  reference.  You may read and copy all or any
portion  of the  registration  statement  or any  reports,  statements  or other
information we file with the  Commission at the  Commission's  public  reference
room at 450 Fifth Street, N.W., Washington,  D.C. 20549, and at the Commission's
following  regional  offices:  Northeast  Regional Office, 7 World Trade Center,
Suite 1300,  New York, New York 10048;  and Midwest  Regional  Office,  Citicorp
Center, 500 West Madison Street, Suite 1400, Chicago, Illinois 60661.

Our SEC filings and the registration statement can also be reviewed by accessing
the Commission's Internet site at http://www.sec.gov.

Positron  will provide  without  charge to each person to whom a  prospectus  is
delivered  upon written or oral  request of such person,  a copy of any document
incorporated  herein by reference (not  including  exhibits to the document that
have been  incorporated  by  reference  unless such  exhibits  are  specifically
incorporated by reference in the document which this  prospectus  incorporates).
Requests should be directed to: Chief Financial Officer,  Positron  Corporation,
1304 Langham Creek Drive, Suite 300, Houston, Texas 77084.


                                       44
<PAGE>


                                    APPENDIX

Report of Independent Accountants



Board of Directors and Stockholders
Positron Corporation


We have audited the  accompanying  balance sheet of Positron  Corporation  as of
December  31,  1998 and the  related  statements  of  operations,  stockholders'
deficit and cash flows for each of the two years in the period then ended. These
financial  statements are the  responsibility of the Company's  management.  Our
responsibility  is to express an opinion on these financial  statements based on
our audits.

We  conducted  our  audits  in  accordance  with  generally   accepted  auditing
standards. Those standards require that we plan and perform the audits to obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements.  An audit also includes
assessing the  accounting  principles  used and  significant  estimates  made by
management,  as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.

In our opinion,  the financial  statements  referred to above present fairly, in
all material  respects,  the financial  position of Positron  Corporation  as of
December 31, 1998, and the results of its operations and its cash flows for each
of the two years in the period then ended in conformity with generally  accepted
accounting principles.

The  accompanying  financial  statements  have been  prepared  assuming that the
Company  will  continue  as a  going  concern.  As  discussed  in  Note 1 to the
financial statements,  the Company has suffered recurring losses from operations
and has a net capital deficiency that raises substantial doubt about its ability
to continue has a going concern. Management's plan with regard to this matter is
also  described  in  Note  1.  The  financial  statements  do  not  include  any
adjustments that might result from the outcome of this uncertainty.

                                       /s/ Ham, Langston & Brezina, L.L.P.
                                       -----------------------------------
                                       Ham, Langston & Brezina, L.L.P.

Houston, Texas
March 26, 1999


                                      F-1
<PAGE>


                                  BALANCE SHEET
                              POSITRON CORPORATION
                             AS OF DECEMBER 31, 1998
                    (AMOUNTS IN THOUSANDS, EXCEPT SHARE DATA)


                                     ASSETS
                                     ------

Current Assets:
    Cash and cash equivalents                                   $      8
    Accounts receivable, net                                          99
    Inventories                                                      391
    Prepaid expenses                                                  58
                                                                --------

        Total current assets                                         556

Plant and equipment net                                              130
                                                                --------

        Total assets                                            $    686
                                                                ========


                      LIABILITIES AND STOCKHOLDERS' DEFICIT
                      -------------------------------------

Current liabilities:
    Notes payable                                               $    792
    Accounts payable and accrued liabilities                       4,723
    Unearned revenue                                                 142
                                                                --------

        Total current liabilities                                  5,657

Long-term Debt                                                       600

Other liabilities                                                     68
                                                                --------

        Total Liabilities                                          6,325
                                                                --------

Stockholders' deficit:
    Series A Preferred Stock: $1.00 par value; 8%
        cumulative, convertible, redeemable; 5,450,000
        shares authorized; 1,557,403 shares issued
        outstanding at December 31, 1998                           1,557
    Series B Preferred Stock: $1.00 par value, 8%
        cumulative, convertible, redeemable; 25,000
        shares authorized, issued and outstanding at
        December 31, 1998                                             25
    Common stock: $0.04 par value; 100,000,000 shares
        authorized 5,166,542 shares Issued and 5,106,386
        and 5,068,834 shares outstanding at December 31, 1998         52

    Additional paid-in capital                                    42,426
    Accumulated deficit                                          (49,684)
    Treasury stock:  60,156 shares at cost                           (15)
                                                                --------

        Total stockholders' deficit                               (5,639)
                                                                --------

         Total liabilities and stockholders' deficit            $    686
                                                                ========

                        See Notes to Financial Statements


                                      F-2
<PAGE>


                              POSITRON CORPORATION
                            STATEMENTS OF OPERATIONS
                 FOR THE YEARS ENDED DECEMBER 31, 1998 AND 1997
                    (AMOUNTS IN THOUSANDS, EXCEPT SHARE DATA)

                                                          1998           1997
Revenues:
     System sales                                      $    --        $   1,129
     Fee per scan                                            455            602
     Service and component                                 1,553          1,795
                                                       ---------      ---------

Total revenues                                             2,008          3,526
                                                       ---------      ---------

     Costs of sales and services:
     System sales                                           --              698
     Fee per scan                                            118            156
     Service, warranty and component                         402            465
     Provision for inventory obsolescence                   --            1,224
                                                       ---------      ---------

Total costs of sales and service                             520          2,543
                                                       ---------      ---------

Gross profit                                               1,488            983
                                                       ---------      ---------

Operating expenses:
     Research and development                               --            1,305
     Selling, general and administrative                   1,700          3,609
                                                       ---------      ---------

Total operating costs                                      1,700          4,914
                                                       ---------      ---------

Loss from operations                                        (212)        (3,931)
                                                       ---------      ---------

Other expenses:
     Interest expense                                       (525)          (334)
     Gain on disposal of property and equipment               29           --
     Other expense                                           (16)          (190)
                                                       ---------      ---------

Total other expense, net                                    (512)          (524)
                                                       ---------      ---------

Net loss                                               $    (724)     $  (4,455)
                                                       ---------      ---------

Basic and dilutive net loss per common share           $   (0.14)     $   (0.91)
                                                       ---------      ---------

Weighted average common shares outstanding             5,150,131      4,884,870
                                                       ---------      ---------

                       See notes to financial statements.


                                      F-3
<PAGE>


                              POSITRON CORPORATION
                       STATEMENT OF STOCKHOLDERS' DEFICIT
                 FOR THE YEARS ENDED DECEMBER 31, 1998 AND 1997
                    (AMOUNTS IN THOUSANDS, EXCEPT SHARE DATA)

<TABLE>
<CAPTION>
                             SERIES A            SERIES B          ADDITIONAL
                          PREFERRED STOCK     PREFERRED STOCK     COMMON STOCK              ACCUMUL-   TREAS-
                          ---------------     ---------------     ------------     PAID-IN    ATED      URY
                         SHARES      AMOUNT   SHARES  AMOUNT     SHARES    AMOUNT  CAPITAL   DEFICIT   STOCK   TOTAL
                         ------      ------   ------  ------     ------    ------  -------   -------   ------  -----
<S>                     <C>           <C>     <C>         <C>  <C>             <C> <C>      <C>          <C>    <C>
Balance at              2,404,624     $2,405  25,000      $25  4,312,182       $43 $41,374  $(44,505)    $--    $(658)
January 1, 1997

Net Loss                       --         --      --       --         --        --      --    (4,455)     --   (4,455)

Conversion of
Series A Preferred
Stock to Common Stock    (809,625)      (810)     --       --    809,625         8     802        --      --       --

Conversion of
Warrants to Common
Stock                          --         --      --       --      7,183        --      15        --      --       15

Treasury Stock
received upon
settlement of note
receivable                                                                                               (15)     (15)
                        ---------     ------  ------      ---  ---------       --- -------  --------    ----  -------
Balance at              1,594,999      1,595  25,000       25  5,128,990        51  42,191   (48,960)    (15)    5113)
                        ---------     ------  ------      ---  ---------       --- -------  --------    ----  -------
December 31, 1997

Net Loss                       --         --      --       --         --        --      --      (724)     --     (724)

Conversion of             (37,552)       (38)     --       --     37,552         1      37        --      --       --
Series A Preferred
Stock to Common Stock

Warrants issued for
note extension
(1,150,000 shares)                                                                     198                        198
                        ---------     ------  ------      ---  ---------       --- -------  --------    ----  -------

Balance at
December 31, 1998       1,557,447     $1,557  25,000      $25  5,166,542       $52 $42,426  $(49,684)   $(15) $(5,639)
                        =========     ======  ======      ===  =========       === =======  ========    ====  =======
</TABLE>

                       See notes to financial statements.


                                      F-4
<PAGE>


                              POSITRON CORPORATION
                             STATEMENTS OF CASH FLOW
                  FOR THE YEAR ENDED DECEMBER 31, 1998 AND 1997
                             (AMOUNTS IN THOUSANDS)

                                                        1998       1997
                                                      --------   --------
Cash flows from operating activities:
Net loss                                              $  (724)   $(4,455)
Adjustment to reconcile net loss to net cash
provided by (used in) operating activities:
    Depreciation                                          250        255
    Warrants issued for interest expense                  198       --
    Provision for doubtful accounts
        and notes receivable                             --          456
    Provision for obsolescence of inventory              --        1,224
    Net gain from sale and disposal of
        property and equipment                            (29)      --
    Provision to reduce intangible assets
        to net realizable value                          --           81
    Amortization of intangible assets                    --           25
    Change in assets and liabilities, operating:
         Decrease in accounts receivable                  154        120
         Decrease in inventories                           17      1,001
         Decrease in prepaid expenses                      73         28
         Decrease in other current assets                --          426
         Increase (decrease) in accounts payable
            and accrued liabilities                       (30)     1,011
         Decrease in revolving line of credit            --          (75)
         Increase (decrease) in other liabilities        (177)       177
         Increase (decrease) in unearned revenue           82       (207)
                                                      -------    -------

            Net cash provided by (used in)
                operating activities                     (186)        67
                                                      -------    -------

Cash flows from investing activities:
    Proceeds from sale of equipment                       364       --
    Capital expenditures                                 --           (3)
                                                      -------    -------

Net cash provided by (used in) investing activities       364         (3)
                                                      -------    -------

Cash flows from financing activities:
     Proceeds from note payable to an affiliate           600        104
     Repayment of other notes payable                    (930)      (405)
     Proceeds from conversion of warrants
        to common stock                                  --           15
                                                      -------    -------

       Net cash used in financing activities             (330)      (286)
                                                      -------    -------

Net decrease in cash and cash equivalents             $  (152)   $  (222)

Cash and cash equivalents, beginning of year              160        382
                                                      -------    -------

Cash and cash equivalents, end of year                $     8    $   160
                                                      =======    =======

                       See notes to financial statements.


                                      F-5
<PAGE>


                              Positron Corporation
                          Notes to Financial Statements

1.    DESCRIPTION OF BUSINESS

      Positron Corporation (the "Company") was incorporated on December 20, 1983
      in the state of Texas and commenced commercial operations during 1986. The
      Company designs, manufacturers, markets and services its POSICAM(TM)
      system advanced medical imaging devices, utilizing positron emission
      tomography ("PET") technology. These systems utilize the Company's
      patented and proprietary technology, an imaging technique which assesses
      the biochemistry, cellular metabolism and physiology of organs and
      tissues, as well as producing anatomical and structural images. Targeted
      markets include medical facilities and diagnostic centers located
      throughout the world. POSICAM(TM) systems are used by physicians as
      diagnostic and treatment evaluation tools in the areas of cardiology,
      neurology and oncology. The Company faces competition principally from two
      other companies which specialize in advanced medical imaging equipment.
      Since its inception the Company has been unable to sell its POSICAM(TM)
      systems in sufficient quantities to be profitable. Consequently, the
      Company has sustained substantial losses. Net losses for the years ended
      December 31, 1998 and 1997 were $749,000 and $4,455,000, respectively, and
      at December 31, 1998 the Company has an accumulated deficit of
      $49,709,000. The magnitude of the selling prices of the Company's systems
      and the limited number of systems sold or placed in service each year has
      caused the Company's revenues to fluctuate significantly from year to
      year.

      At December 31, 1998, the Company had cash and cash equivalents of only
      $8,000 compared to $160,000 at December 31, 1997. During both 1998 and
      1997, the Company was unable to meet certain obligations as they came due
      and the Company's liquidity problems have become critical. As a result of
      the Company's severe liquidity problem, salary payments owed to certain
      management level employees totaling approximately $700,000 and dating back
      more than a year were unpaid at December 31, 1998. Additionally, the
      Company is subject to certain unasserted claims which have not been
      resolved.

      To deal with its critical liquidity problem, during January 1999 the
      Company completed an agreement (the "Imatron Transaction") with Imatron,
      Inc. ("Imatron"), whereby in Imatron acquired a majority ownership in the
      Company and plans to raise capital for continued operation of the Company
      (See Note 14). If Imatron is unsuccessful in its efforts to raise capital
      for the Company, management believes that the Company will be unable to
      continue as a going concern and that the Company's assets will be seized
      by its secured creditors..


                                      F-6
<PAGE>


2.    SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

      CASH AND CASH EQUIVALENTS

      Cash and cash equivalents include all cash balances and highly liquid
      investments with an original maturity of three months or less.

      INVENTORY

      Inventories are stated at the lower of cost or market and include
      material, labor and overhead. Cost is determined using the first-in,
      first-out (FIFO) method of inventory valuation.

      PLANT AND EQUIPMENT

      Plant and equipment are recorded at cost and depreciated for financial
      statement purposes using the straight-line method over estimated useful
      lives of three to seven years. Gains or losses on dispositions are
      included in the statement of operations in the period incurred.
      Maintenance and repair costs are charged to expense as incurred.

      IMPAIRMENT OF LONG-LIVED ASSETS

      Periodically, the Company evaluates the carrying value of its plant and
      equipment, and long-lived assets, which includes patents and other
      intangible assets, by comparing the anticipated future net cash flows
      associated with those assets to the related net book value. If an
      impairment is indicated as a result of such reviews, the Company would
      remove the impairment based on the fair market value of the assets, using
      techniques such as projected future discounted cash flows or third party
      valuations. As of December 31, 1998 an adjustment to intangible assets was
      indicated and recorded.

      REVENUE RECOGNITION

      Revenues from POSICAM(TM) system contracts are recognized when all
      significant costs have been incurred and the system has been shipped to
      the customer. Revenues from fee per scan contracts are recognized upon
      performance of patient scans. Revenues from maintenance contracts are
      recognized over the term of the contract. Service revenues are recognized
      upon performance of the services.

      RESEARCH AND DEVELOPMENT EXPENSES

      All costs related to research and development are charged to expense as
      incurred.

      WARRANTY COSTS

      The Company accrues for the cost of product warranty on POSICAM(TM)
      systems at the time of shipment. Warranty periods generally range up to a
      maximum of one year but may extend for longer periods. Actual results
      could differ from the amounts estimated.


                                      F-7
<PAGE>


      NET LOSS PER COMMON SHARE

      Basic and dilutive net loss per common share for the years ended December
      31, 1998 and 1997 have been computed by dividing net loss by the weighted
      average number of shares of common stock outstanding during these periods.
      All common stock equivalents were antidilutive.

      ESTIMATES

      The preparation of financial statements in conformity with generally
      accepted accounting principles requires management to make estimates and
      assumptions that affect the reported amounts of assets and liabilities and
      disclosure of contingent assets and liabilities at the date of the
      financial statements and the reported amounts of revenues and expenses
      during the reporting period. Actual results could differ from those
      estimates.

      FAIR VALUE OF FINANCIAL INSTRUMENTS

      The Company includes fair value information in the notes to the financial
      statements when the fair value of its financial instruments is different
      from the book value. When the book value approximates fair value, no
      additional disclosure is made.

      RECLASSIFICATIONS

      Certain amounts presented in the Company's December 31, 1997 financial
      statements have been reclassified in order to conform to current year
      presentation.

      COMPREHENSIVE INCOME

      Effective January 1, 1998, the Company adopted Statement of Financial
      Accounting Standards ( "SFAS") No. 130, "Reporting Comprehensive Income".
      Comprehensive income includes such items as unrealized gains or losses on
      certain investment securities and certain foreign currency translation
      adjustments. The Company's financial statements include none of the
      additional elements that affect comprehensive income. Accordingly,
      comprehensive income and net income are identical.

      SEGMENT INFORMATION

      Effective January 1, 1998 the Company adopted SFAS 131, "Disclosures About
      Segments of an Enterprise and Related Information". SFAS 131 requires a
      company to disclose financial and other information, as defined by the
      statement, about its business segments, their products and services,
      geographic areas, major customers, revenues, profits, assets and other
      information. The Company believes that it operates in only one business
      segment and does not have geographically diversified business operations.
      Accordingly, the adoption of SFAS 131 did not have a significant impact on
      the Company (See Note 15).


                                      F-8
<PAGE>


3.    ACCOUNTS RECEIVABLE

      Accounts receivable at December 31, 1998 consisted of the following:
      (dollars in thousands)

      Accounts receivable - equipment sales                       $ 1,011
      Accounts receivable - maintenance                                99
                                                                  -------

                                                                    1,110
      Less allowance for doubtful accounts                         (1,011)
                                                                  $    99
                                                                  -------

4.    INVENTORIES

      Inventories at December 31, 1998 consisted of the following: (dollars in
      thousands)

      Raw materials                                               $ 1,126
      Finished goods                                                  438
                                                                  -------
                                                                    1,564
      Less reserve for obsolescence                                (1,173)
                                                                  -------
      Net Inventory                                               $   391
                                                                  -------

      Due to improvements in technology that will slow movement of the Company's
      inventory, the Company recorded a reserve for obsolescence of $1,224,000
      at December 31, 1997 to reduce inventories to their estimated net
      realizable value.

5.    PLANT AND EQUIPMENT

      Plant and equipment at December 31, 1998 consisted of the following:
      (dollars in thousands)

      Furniture and fixtures                                      $    86
      Computers and peripherals                                        93
      Leasehold improvements                                           17
      Machinery and equipment                                         203
                                                                  -------
                                                                      399
      Less accumulated depreciation                                  (269)
                                                                  -------
                                                                  $   130
                                                                  =======

      During the year ended December 31, 1998, the Company sold certain leased
      assets and disposed of various assets not in use. The net effect of these
      sales and dispositions resulted in the Company reporting $29,000 gain in
      the accompanying statement of operations.


                                      F-9
<PAGE>


6.    ACCOUNTS PAYABLE AND ACCRUED LIABILITIES

      Accrued liabilities at December 31, 1998 consisted of the following:
      (dollars in thousands)

      Trade                                                       $   677
      Rent                                                            282
      Interest                                                        370
      Professional fees                                               229
      Property tax                                                    347
      Warranty                                                      1,337
      Compensation                                                    980
      Royalties                                                       384
      Other                                                           117
                                                                  $ 4,723

7.    NOTES PAYABLE AND LONG-TERM DEBT TO AFFILIATES

      Notes payable and long-term debt at December 31, 1998 consisted of the
      following (dollars in thousands):

      Notes payable to Uro-Tech, Ltd (the "Uro-Tech Loan")
      bearing interest at 13.8% per year and due July 31,
      1998, (based upon extensions granted in connection
      with the Imatron Transaction). This note is
      collateralized by liens and security interests
      encumbering substantially all of the Company's assets,
      including the Company's know-how, patents and
      proprietary rights pertaining to its PET technology.
      This note is subordinated to the Imatron Note
      described below and was not paid upon maturity.             $ 792


      Note payable to Imatron, Inc. (the "Imatron Loan")
      bearing interest at prime (7.75% at December 31,
      1998) plus 1/2 percent per year and due March 1, 2000.
      Interest is due monthly on this note and is
      collateralized by liens and security interest
      encumbering substantially all the Company's assets,
      including the Company's know-how, patents and
      proprietary rights pertaining to its PET technology            600
                                                                  ------
                                                                   1,392
      Less current portion                                           792
                                                                  ------
                                                                  $  600
                                                                  ======

      In connection with the Uro-Tech Loan, the Company granted Uro-Tech, Ltd.
      Warrants to purchase 67,500 shares of common stock at an exercise price of
      $2.00 per share, exercisable through February 7, 2001.

      All notes payable and long-term debt outstanding at December 31, 1998 are
      due during the years ending December 31, 1999 and 2000.

8.    COMMON STOCK-OPTIONS AND WARRANTS

      OPTIONS

      In 1987, the Company established a common stock option plan (the "1987
      Plan") covering directors, officers and other key employees. In November
      1993, the Company canceled all options outstanding under the 1987 Plan. In
      connection with such cancellations, the board of directors authorized the
      reissuance of 38,522 options to purchase shares of common stock at 75
      percent of the IPO price following the closing of an initial public
      offering. Such options vested and became exercisable on January 3,


                                      F-10
<PAGE>


      1995. In addition, in February 1994, the board of directors authorized the
      issuance of an additional 150,000 options at the same exercise price.
      Options granted under the 1987 Plan expired on the earlier of three months
      after termination of employment or ten years from the grant date.

      Effective June 3, 1994, the shareholders of the Company approved the 1994
      Incentive and Nonstatutory Option Plan (the "1994 Plan"). The 1994 Plan as
      amended, provides for the issuance of an aggregate of 601,833 Common Stock
      options to key employees, directors, and certain consultants and advisors
      of the Company. The 1994 Plan also provides that the exercise price of
      Incentive Options shall not be less than the fair market value of the
      shares on the date of the grant. The exercise price per share of
      Nonstatutory options shall not be less than the par value of the Common
      Stock or 50% of the fair market value of the common stock on the date of
      grant. The 1994 Plan is administered by the Compensation Committee o f the
      Board of Directors. The committee has the authority to determine the
      individuals to whom awards will be made, the amount of the awards, and all
      other terms and conditions of the awards. As of December 31, 1998, options
      to purchase an aggregate of 144,389 shares of common stock at a range of
      $2.626 - $4.125 per share, have been granted to certain key employees.

      The 1994 Plan also provides that each non-employee director automatically
      receives options to purchase 10,500 shares of common stock at the date
      such individual becomes a non-employee director. Each non-employee
      director who is a director on the first business day following each Annual
      Shareholder Meeting also receives an option to purchase a number of shares
      of common stock having a value of $15,000 as determined by the fair market
      value of the common stock at the date of grant. As of December 31, 1998,
      options to purchase an aggregate of 163,724 shares of common stock at a
      range of $2.625-$4.125 per share had been granted to non-employee
      directors. All 1994 Plan options expire within ten years of the date of
      the grant.

      There were no stock option grants, exercises or forfeitures during the
      years ended December 31, 1998 or 1997. At December 31, 1998, 1997 and 1996
      the Company had $572,678 stock options outstanding at a weighted average
      exercise price of $2.80 per share.

      The Company has elected to apply the disclosure only provisions of
      STATEMENT OF FINANCIAL ACCOUNTING NO. 123, ACCOUNTING FOR STOCK-BASED
      COMPENSATION ("SFAS 123") which, if fully adopted by the Company, would
      change the method the Company applies in recognizing the cost of the Plan.
      Adoption of the cost recognition provisions of SFAS 123 is optional and
      the Company has decided not to elect those provisions. As a result, the
      Company continues to apply ACCOUNTING PRINCIPLES BOARD OPINION NO. 25
      ("APB 25") and related interpretations in accounting for the measurement
      and recognition of the Plan's cost.

      The shares exercisable for vested options and the corresponding weighted
      average exercise price was 435,436 shares and $2.80 per share at December
      31, 1998 and 1997.


                                      F-11
<PAGE>


      Following is a summary of stock options outstanding at December 31, 1998.

                         OPTIONS OUTSTANDING     OPTIONS EXERCISABLE
                        ---------------------   --------------------
                                   WEIGHTED
                                    AVERAGE     WEIGHTED                WEIGHTED
                                   REMAINING    AVERAGE                 AVERAGE
         RANGE OF                    TERM       EXERCISE                EXERCISE
      EXERCISE PRICE     SHARES    (IN YEARS)     PRICE      SHARES       PRICE
      --------------    -------    ----------   --------     -------    --------
      $2.625 - $3.375   492,980       6.20         2.63      376,194       2.63
      $3.376 - $4.125    79,698       6.66         3.91       59,242       3.92
      $2.625 - $4.125   572,678       6.27         2.80      435,436      $2.80
                        =======                              =======

      The Company did not grant or reprice any options during the year ended
      December 31, 1998 or 1997.

      Under SFAS 123, compensation cost is measured at the grant date based on
      the fair value of the awards and is recognized over the service period,
      which is usually the vesting period. The fair value of options granted
      during 1998 and 1997 was estimated on the date of grant using the Black
      Scholes option-pricing model with the following assumptions used to
      calculate fair value of options awarded in 1998 and 1997: (i)average
      dividend yield of 0.00%; (ii) expected volatility of 83.36%; (iii)
      expected life of five (5) years; and (iv) estimated risk-free interest
      rate, which is different for grants awarded on different grant dates,
      ranging from 5.66% to 7.15%. The pro forma disclosures as if the Company
      adopted the cost recognition requirements of SFAS 123 are as follows (in
      thousands):

                                         1998                    1997
                               ----------------------  -----------------------
                               AS REPORTED  PRO FORMA  AS REPORTED   PRO FORMA
                               -----------  ---------  -----------   ---------

      Net loss                    $ (749)     $ (749)    $(4,455)     $(4,485)

      Earnings per common share   $(0.15)     $(0.15)    $ (0.91)     $ (0.93)


      The effects of applying SFAS 123 in this proforma disclosure are not
      indicative of future results. SFAS 123 does not apply to awards prior to
      1995. Additional awards in future years are not anticipated by the
      Company.

      WARRANTS

      Prior to the Company's initial public offering, the Company issued
      warrants to the purchasers of the then outstanding Series E Preferred
      Stock (the "1993 Warrants"). Subject to adjustment for certain
      transactions, the 1993 Warrants as originally issued, were exercisable for
      an aggregate of 353,531 shares of Common Stock at an exercise price of
      $9.90. Because of certain specified anti-dilution provisions, the 1993
      Warrants were exercisable for an aggregate of 519,394 shares of Common
      Stock at a purchase price of $5.60 per share as of December 31, 1997. The
      1993 Warrants expired November 30,1998.

      In connection with its initial public offering, the Company issued
      3,898,550 Redeemable Warrants (the "Redeemable Warrants"). The Redeemable
      Warrants as originally issued


                                      F-12
<PAGE>


      were exercisable for an aggregate of 3,893,550 shares of Common Stock at
      an exercise price of $8.25 per share. Because of the anti-dilution
      provisions the Redeemable Warrants were exercisable for an aggregate of
      5,646,798 shares of Common Stock at a purchase price of $5.60 per share at
      December 21, 1997. The Redeemable Warrants expired December 31, 1998.

      In April 1998, in connection with the Imatron transaction, the Company
      granted ProFuturesBridge Capital, L.P. ("ProFutures") warrants to purchase
      1,150,000 shares of the Company's common stock at $0.25 per share in
      return for the extension of a loan agreement (See Note 14). During 1998
      the Company recognized interest expense of $198,000 related to the value
      of these 1,150,000 warrants.

      A summary of warrant activity is as follows:

                                            # of Shares    Exercise Price
                                            -----------    ---------------

      Balance at December 31, 1996            7,799,720    $2.00-$3,572.27

      Warrants issued in connection
         with the ProFutures Loan               100,000    $          1.84
      Warrants converted to Common Stock         (7,183)
                                             ----------    ---------------

      Balance at December 31, 1997            7,892,537    $1.84-$3,572.27

      Warrants issued in connection with
         the ProFutures Loan 1993 warrants
         anti-dilution provisions             1,150,000    $          0.25
      Expired                                (6,166,192)   $          5.60
                                             ----------    ---------------

      Balance at December 31, 1998            2,876,345    $0.25-$3,572.27
                                             ==========    ===============

      No compensation expense related to options and warrants was recognized by
      the Company in the accompanying statement of operations during the years
      ended December 31, 1998 or 1997.

9.    PREFERRED STOCK

      The Company's Articles of Incorporation authorize the board of directors
      to issue 10,000,000 shares of preferred stock from time to time in one or
      more series. The board of directors is authorized to determine, prior to
      issuing any such series of preferred stock and without any vote or action
      by the shareholders, the rights, preferences, privileges and restrictions
      of the shares of such series, including dividend rights, voting rights,
      terms of redemption, the provisions of any purchase, retirement or sinking
      fund to be provided for the shares of any series, conversion and exchange
      rights, the preferences upon any distribution of the assets of the
      Company, including in the event of voluntary or involuntary liquidation,
      dissolution or winding up of the Company, and the preferences and relative
      rights among each series of preferred stock.


                                      F-13
<PAGE>


      SERIES A PREFERRED STOCK

      In February, March and May of 1996, the Company issued 3,075,318 shares of
      Series A 8% Cumulative Convertible Redeemable Preferred Stock $1.00 par
      value ("Series A Preferred Stock") and Redeemable Common Stock Purchase
      Warrants to purchase 1,537,696 shares of the Company's Common Stock. The
      net proceeds of the private placement were approximately $2,972,000. Each
      share of the Series A Preferred Stock is immediately convertible into one
      share of Common Stock. Each Redeemable Common Stock Purchase Warrant is
      exercisable at a price of $2.00 per share of Common Stock. Eight percent
      (8%) dividends on the Series A Preferred Stock may be paid in cash or in
      Series A Preferred Stock at the discretion of the Company. The Series A
      Preferred Stock is senior to the Company's Series B Preferred Stock and
      Common Stock in liquidation. Holders of the Series A Preferred stock may
      vote on an as if converted basis on any matter requiring shareholder vote.
      While the Series A Preferred Stock is outstanding or any dividends thereon
      remain unpaid, no Common Stock dividends may be paid or declared by the
      Company. The Series A Preferred Stock may be redeemed in whole or in part,
      at the option of the Company, at any time subsequent to March 1998 at a
      price of $1.46 per share plus any undeclared and/or unpaid dividends to
      the date of redemption. Redemption requires at least 30 days advanced
      notice and notice may only be given if the Company's common stock has
      closed above $2.00 per share for the twenty consecutive trading days prior
      to the notice.

      In conjunction with the issuance of the aforementioned Series A Preferred
      Stock, Uro-Tech converted amounts receivable from the Company totaling
      $650,000 into 433,329 shares of Series A Preferred Stock and 216,671
      Redeemable Stock Purchase Warrants.

      SERIES B PREFERRED STOCK

      In July 1996, the Company issued 25,000 shares of Series B 8% Cumulative
      Convertible Redeemable Preferred stock $1.00 par value ("Series B
      Preferred Stock") and Common Stock Purchase Warrants to purchase up to
      100,000 shares of its Common stock, par value $.01 per share. The Series B
      Preferred Stock plus Common Stock Purchase Warrants sold for approximately
      $50.00 per share of Series B Preferred stock. Subject to adjustment for
      certain antidilution events, each share of Series B Preferred Stock is
      initially convertible into 25 shares of Common Stock and each Common Stock
      Purchase Warrant is exercisable for one share of Common Stock at an
      exercise price of $2.00 per share. Eight percent (8%) dividends on the
      Company's Series B Preferred Stock may be paid in cash or in Series B
      Preferred Stock, at the discretion of the Company. The Series B Preferred
      Stock is junior to the Series A Preferred Stock, but senior to the
      Company's Common Stock in liquidation. The Series B Preferred Stock has no
      voting rights other than those afforded by law. As a class, however, the
      holders of the Series B Preferred Stock may vote on matters directly
      affecting the Series B Preferred Stock or mergers and/or consolidations of
      the Company with another company. The Series B Preferred Stock may be
      redeemed in whole or in part, at the option of the Company, at any time
      subsequent to July 1998 at a price of $50 per share plus any undeclared
      and/or unpaid dividends to the date of redemption. Redemption requires at
      least 30 days


                                      F-14
<PAGE>


      advanced notice and notice may only be given if the Company's common stock
      has closed above $2.00 per share for the twenty consecutive trading days
      prior to the notice.

      Dividends may not be paid or declared on the Company's Common stock while
      any unpaid dividends are outstanding on the Series B Preferred Stock. The
      Series B Preferred Stock and the Common Stock Purchase Warrants are not
      convertible or exercisable until such time as the Company's shareholders
      approve an amendment to its Articles of Incorporation increasing the
      number of the authorized shares of Common Stock by at least 2,500,000
      shares.

      As of December 31, 1998, stated dividends that are undeclared and unpaid
      on the Series A and Series B Preferred Stocks are as follows: (in
      thousands)

      Series A                                                    $   311
      Series B                                                        250
                                                                  -------

      Total                                                       $   561
                                                                  =======

      The Company anticipates that such dividends, when declared, will be paid
      in the shares of Series A and Series B Preferred Stock.

12.   INCOME TAXES

      The Company has incurred losses since its inception and, therefore, has
      not been subject to federal income taxes. As of December 31, 1998, the
      Company had net operating loss ("NOL") carryforwards for income tax
      purposes of approximately $43,500,000 which expire in 1999 through 2018.
      Under the provisions of Section 382 of the Internal Revenue Code the
      greater than 50% ownership change in the Company in connection with the
      Imatron Transaction severely limits the Company's ability to utilize the
      NOL carryforward to reduce future taxable income and related tax
      liabilities. Additionally, because United States tax laws limit the time
      during which NOL carryforwards may be applied against future taxable
      income, the Company will not be able to take full advantage of its NOL for
      federal income tax purposes should the Company generate taxable income.

      The composition of deferred tax assets and the related tax effects at
      December 31, 1998 as follows: (amounts in thousands)

      Deferred tax assets:
           Net operating losses                                   $14,807
           Allowance for doubtful accounts
              and notes receivable                                    343
           Inventory basis difference                                 767
           Accrued liabilities and reserves                           584
           Valuation allowance                                    (16,517)
                                                                  -------

           Total deferred tax assets                                   16
                                                                  -------

      Deferred tax liabilities:
           Property and equipment                                      16
           Other                                                       --
                                                                  -------

           Total deferred tax liability                                16
                                                                  -------

      Net deferred tax asset (liability)                              $--
                                                                  =======


                                      F-15
<PAGE>


      The difference between the income tax benefit in the accompanying
      statement of operations and the amount that would result if the U.S.
      Federal statutory rate of 34% were applied to pre-tax loss is as follows:
      (amounts in thousands)


                                              1998              1997
                                        ---------------   ----------------
                                        Amount      %     Amount       %
                                        ------    -----   -------    -----

      Benefit for income tax at
         federal statutory rate          $ 246     34.0   $ 1,514     34.0
      Non-deductible expenses              (64)    (9.0)       --       --
      Increase in valuation allowance     (182)   (25.0)   (1,514)   (34.0)
                                         -----    -----   -------    -----

      Total tax benefit                  $  --       --   $    --       --
                                         =====    =====   =======    =====


13.   401(K) PLAN

      The Positron Corporation 401(k) Plan and Trust (the "Plan") covers all of
      the Company's employees who are United States citizens, at least 21 years
      of age and have completed at least one quarter of service with the
      Company. Pursuant to the Plan, employees may elect to reduce their current
      compensation by up to the statutorily prescribed annual limit and have the
      amount of such reduction contributed to the Plan. The Plan provides for
      the Company to make contributions in an amount equal to 25 percent of the
      participant's deferral contributions, up to 6 percent of the employee's
      compensation, as defined in the Plan agreement. The Company's contribution
      expense was approximately $6,000 and $12,000 in 1998 and 1997,
      respectively. The board of directors of the Company may authorize
      additional discretionary contribution, although, no additional Company
      contributions have been made as of December 31, 1998.

14.   RELATED PARTY TRANSACTIONS

      The Company has an incentive compensation plan for certain key employees
      and its former Chairman. The incentive compensation plan provides for
      annual bonus payments based upon achievement of certain corporate
      objectives as determined by the Company's compensation committee, subject
      to the approval of the board of directors. To date, the Company has not
      paid any bonuses pursuant to the incentive compensation plan.

      Pursuant to agreements entered into in November 1993, the Company extended
      loans to a current board member and a former board members in order to
      provide each of them with funds to satisfy their respective personal
      income tax liability arising out of the conversion of certain Positron
      Corporation Promissory Notes into Common Stock. Such agreements were
      entered into by the Company in connection with the IPO and in
      consideration of certain concessions made by the board member and former
      board member concerning the conversion terms under their respective Notes.
      Pursuant to the agreements, each of the


                                      F-16
<PAGE>


      loans were made on substantially the following terms: (i) limited to a
      principal amount not to exceed $175,000, (ii) interest payable at a rate
      of six percent per year, (iii) an initial term of three years with the
      principal balance being due and payable upon the expiration of the term,
      (iv) limited recourse against the borrower, and (v) collateralized by
      Positron Corporation Common Stock owned by the borrower. In accordance
      with such agreements, on April 15, 1994, the Company extended a $165,817
      loan to a current board member and a $158,552 loan to the former board
      member.

      Both of the notes receivable matured in April 1997 but were not repaid by
      the debtors and, accordingly, 60,156 shares of the Company's common stock
      reverted back to the Company and are included in treasury stock at
      December 31, 1998. In connection with this transaction, the Company
      recognized bad debt expense of $309,000 during 1997.

      The Company formerly had certain consulting agreements with its Chairman
      and a member of its board. Each agreement provided for monthly consulting
      payments of $6,667 and expired in 1998.

13.   COMMITMENTS AND CONTINGENCIES

      EMPLOYMENT AGREEMENT WITH FORMER EMPLOYEE

      On January 1, 1996, the Company entered into an employment agreement with
      Werner J. Haas, Ph.D. pursuant to which Dr. Haas agreed to serve as
      President and Chief Executive Officer of the Company for a term of two
      years. The employment agreement provided for the payment of an annual base
      salary of $200,000, bonuses in an amount to be determined at the
      discretion of the Board of Directors of the Company, and participation in
      any employee benefit plan adopted by the Company for its employees.

      On February 18, 1997, Dr. Haas informed the Board of Directors of the
      Company that he considered his contract to have been terminated by the
      Company without cause as a result of the Company's failure to pay the
      February 15, 1997 payroll to any of its management level employees and
      specifically to him. Additionally, Dr. Haas resigned as a member of the
      Company's Board of Directors. Dr. Haas has demanded that the Company pay
      him all past due salary as well as the nine months severance pay specified
      in his employment agreement if his contract is determined to have been
      terminated without cause. The Company's maximum exposure with regard to
      Dr. Haas' employment agreement is approximately $175,000 should Dr. Haas
      establish that he was terminated without cause. The Company believes, and
      has indicated to Dr. Haas, that no amounts are due him under his
      employment agreement. Accordingly, the Company's potential loss with
      regard to this matter should fall within a range up to $175,000. As of
      December 31, 1998, the Company is unable to predict the outcome of the
      disagreement between Dr. Haas and the Company.

      ROYALTY AGREEMENTS

      The Company is obligated to pay royalties of 3% of the gross revenue from
      sales, uses, leases, licensing or rentals of POSICAM systems, 1% each to
      two former directors of the


                                      F-17
<PAGE>


      Company and two other unrelated entities. During the years ended December
      31, 1998 and 1997 the Company incurred royalties of $16,000 and $42,000,
      respectively.

      The Company's royalties were reduced to the 3% level based upon
      consideration, provided to two of the payees, under consulting agreements
      and promissory notes. However, the consulting agreements provide that if
      the Company defaults in its payment obligations thereunder, then the
      payees would be entitled to receive regrant of the royalties that they
      previously released. In April 1998, the Company received a demand letter
      from one of the payees alleging default under his consulting agreement in
      1997 and demanding regrant of an additional 1% royalty interest. Although
      the Company has not received a demand from the second payee, the Company
      believes that a payment default may have occurred under his consulting
      agreement and that as a result thereof, he may be entitled to the regrant
      of an additional 0.5% royalty interest. The Company has accrued
      approximately $100,000 in recognition of the additional roylaties due. In
      December 1998, the Company reached an agreement in principle regarding
      payment of back royalties, waiver of demand rights regarding defaults
      under a consulting contract and retaining the reduced royalty payment
      level going forward. If the parties fail to reach a settlement, with the
      other payee such payee will be entitled to receive an aggregate 2% royalty
      resulting in an increase of the Company's royalty obligations from 3% to
      4%. Such increase in royalty obligations could have a material adverse
      effect on the Company's future financial performance.

      LEASE AGREEMENTS

      During 1997, the Company leased its office and manufacturing facility and
      certain office equipment under noncancelable operating leases with
      unexpired terms ranging from one to four years. In March 1998, the
      Company, under severe cash flow constraints, was forced to leave its
      long-term office and manufacturing facility lease and move its operations
      to a facility with significantly reduced space and a more affordable lease
      payment. The Company entered into a series of six-month leases at a
      monthly rate of $2,671 and the Company's current lease expires in August
      1998. However, the Company was unable to obtain a release from its
      original lease and has been notified by its former landlord that all
      delinquent amounts due under its original lease are currently payable.
      Company management believes that the landlord has leased its space to new
      tenants at favorable lease rates and that its exposure is limited to any
      shortfall in lease payments experienced by the former landlord. The
      Company believes that its maximum exposure related to the lease with its
      former landlord is $950,000, based on the remaining future payments due at
      the date the lease was abandoned. However, the Company believes that the
      amounts due the landlord will be offset by payments from the current
      tenant and should not exceed $75,000. Accordingly, the company's potential
      loss falls in a range from $75,000 to $950,000 and the Company has accrued
      approximately $250,000 related to this matter. As of December 31, 1998,
      the Company is unable to predict the outcome of this disagreement with its
      former landlord.


                                      F-18
<PAGE>


      Rental expense for operating leases amounted to approximately $110,000 and
      $256,000 for the years ended December 31, 1998 and 1997, respectively.
      Future minimum lease payments due under noncancelable operating leases
      with original lease terms of greater than one year and expiration dates
      subsequent to December 31, 1998, are summarized as follows: (amounts in
      thousands)

      1998                                                        $ 361
      1999                                                          421
      2000                                                          210
                                                                  -----

      Total minimum lease payments                                $ 992
                                                                  =====

      The above lease payment schedule consists primarily of payments due under
      the Company's lease with its former landlord.

      IMPACT OF YEAR 2000

      The Year 2000 issue is the result of computer programs being written using
      two digits rather than four to define the applicable year. Any of the
      Company's computer programs that have time sensitive software may
      recognize a date using "00" as the year 1900 rather than the year 2000.
      This could result in a system failure or miscalculation causing a
      disruption of business activities.

      The Company has performed only a preliminary assessment of the Year 2000
      issue using a broad overview and management's current understanding of its
      information and non-information systems and its informal understanding of
      the information and non-information systems of its significant suppliers
      and major customers. None of the details tasks necessary to properly
      assess the Year 2000 issue (such as direct coordination with vendors,
      customers and manufacturers) have been performed.

      Based on a preliminary assessment, the Company believes that no
      significant modifications to its computer software or hardware will be
      required and that its existing computer systems (including information
      systems, non-information systems using date sensitive embedded chips and
      its POSICAM(TM) systems) will function properly with respect to dates in
      the year 2000 and thereafter. Based upon such preliminary assessment, the
      Company also currently believes that costs to modify the Company's
      existing computer hardware and software systems in regard to the Year 2000
      issue will not be significant and should not exceed $10,000. However, the
      Year 2000 issue is extremely complex and the costs to properly assess its
      impact on the Company and to correct associated problems may be
      significant.

      Based on the Company's preliminary assessment of its relationships with
      significant suppliers and major customers to understand the extent to
      which the Company is vulnerable to any failure by third parties to remedy
      their own Year 2000 issues, management believes that the Company does not
      have significant exposure with respect to third parties. However, the
      Company's preliminary assessments indicated that the worst case scenario
      with regard to the Year 2000 issue would be delays in receiving parts and
      materials needed for manufacturing and delays by customers in making
      payments for fee-per-scan and maintenance services. In the Company's
      current financial position, such circumstances could threaten the
      Company's continued existence.


                                      F-19
<PAGE>


      Due to the Company's current severe liquidity problems, the Company has
      not had the financial resources to perform a complete assessment of Year
      2000 issues, assess the potential cost or develop any contingency plan
      with regard to Year 2000 issues that may arise. The Company is unable to
      predict at the current time, when and to what extent it may further pursue
      its assessment of potential Year 2000 issues and the development of any
      contingency plans in respect thereof. If the Company is able to obtain
      necessary financial resources, a complete assessment of the Year 2000
      issues facing the Company will likely be completed in the third quarter of
      1999.

      PAST DUE PROPERTY TAXES

      In February 1998, certain taxing authorities filed legal actions against
      the Company to collect certain past due property taxes, penalty and
      interest totaling $241,307. In connection with such legal actions, the
      taxing authorities filed liens covering substantially all inventory,
      furniture, fixtures and equipment of the Company. The Company has accrued
      all past due property taxes and is currently operating under a payment
      agreement with the taxing authorities.

      DISPUTE REGARDING POSICAM(TM) SYSTEM

      Arbitration procedures have been initiated against the Company by a
      Chinese Company ("Complainant") regarding purchase of POSICAM(TM) system
      ("System"). In September 1996 the Company contracted with Complainant to
      supply a System, with Complainant providing a down payment of
      approximately $300,000 and a commitment to provide a letter of credit for
      the remaining purchase price, fundable upon shipment of the System. The
      Company used the down payment to purchase the beginning inventory for and
      begin construction of the System. Complainant failed to provide the Letter
      of Credit, and the Company was not able to complete and deliver the
      System. Complainant demanded return of its deposit and initiated
      arbitration in September 1998 with the China International Economic and
      Trade Arbitration Commission in Shanghai. The Company believes that the
      claims raised are without merit, and intends to vigorously defend its
      interests. It is not possible at present to predict the outcome of this
      proceeding, although an unfavorable ruling could have a material adverse
      effect on the Company's business and financial performance.

14.   IMATRON AGREEMENT

      In May 1998, the Company entered into an agreement (the "Imatron
      Transaction") with Imatron Inc. ("Imatron"), pursuant to which in January
      1999, Imatron acquired a majority ownership of the Company. In conjunction
      with the Imatron Transaction, Imatron has made working capital advances to
      the Company of $600,000 to enable the Company to meet a portion of its
      current obligations.

      Upon consummation of the Imatron Transaction in January 1999, Imatron
      acquired a majority ownership of the outstanding common stock of the
      Company on a fully-diluted and as-if-converted basis( excluding
      out-of-the-money warrants and options determined


                                      F-20
<PAGE>


      at the time of issuance of the shares of Imatron) and was issued nine
      million of the Company's common stock in return for a nominal cash payment
      in the amount of $100.

      Imatron, in addition to providing limited working capital financing, has
      agreed to support the Company's marketing program particularly with regard
      to Imatron's affiliate, Imatron Japan, Inc. by agreeing to make all
      reasonable efforts to cause the placement of 10 POSICAM(TM) systems over
      the next three years. During 1998 the Company shipped a POSICAM(TM) system
      to Imatron Japan as the first delivery under a three-year distribution
      agreement entered into during 1997. Imatron Japan, an affiliate of
      Imatron, is a major distributor for Imatron's Ultrafast CT and for the
      products of certain other high technology companies. Imatron owns a 24
      percent minority interest in Imatron Japan.

      Imatron has also agreed to help facilitate the recapitalization of the
      Company and to support its re-entry into the medical imaging market by
      using its best efforts, after the share issuance closing date, to arrange
      for additional third-party equity financing for the Company over an
      eighteen-month period in an aggregate amount of at least $8,000,000. There
      can be no assurances, however, that any such sales will actually be
      consummated or that Imatron will be able to successfully assist the
      Company in raising additional capital.

      In connection with the Imatron Transaction, the Company, Imatron and two
      current lenders to the Company, Uro-Tech and ProFutures, entered into
      certain agreements whereby (a) ProFutures waived all past defaults and
      extended the maturity of the ProFutures Loan in return for a $50,000
      payment and the issuance of warrants to purchase 1,150,000 shares of the
      Company's common stock at $0.25 per share. The ProFutures Loan was
      subsequently repaid in November 1998; (b) Imatron agreed to subordinate
      its loan to the ProFutures Loan, (c) Uro-Tech agreed to subordinate its
      loan (with a current balance of approximately $792,000 plus accrued
      interest payable of approximately $272,000 at December 31, 1998) to
      Imatron's loan

      If Imatron is unsuccessful in its efforts to raise capital for the
      Company, management believes that the Company will be unable to continue
      as a going concern and that the Company's assets will be seized by its
      secured creditors.

15.   SEGMENT INFORMATION AND MAJOR CUSTOMERS

      As discussed in Note 1, the Company believes that all of its material
      operations are conducted in the servicing and sales of medical imaging
      devices and it currently reports as a single segment.

      During the years ended December 31, 1998 and 1997 the Company had a
      limited number of customers as follows:

                                                          ---------- ----------
      Total number of customers                              1998       1997
                                                          ---------- ----------

      Customers accounting for more than 10% revenues         12         12
                                                               2         2
      Percent of revenues derived from largest customer       23%        32%


                                      F-21
<PAGE>


17.   SUPPLEMENTAL CASH FLOW DATA

      Supplemental disclosure of cash flow information.

                                                          ---------- ----------
                                                             1998       1997
                                                          ---------- ----------

      Cash paid for interest                                $ 163      $ 277
                                                          ========== ==========


                                      F-22
<PAGE>


                              POSITRON CORPORATION
                                 BALANCE SHEETS
                        (IN THOUSANDS, EXCEPT SHARE DATA)

                                                    September 30,   December 31,
                                                        1999           1998
                                  ASSETS             (UNAUDITED)      (NOTE)
                                  ------             -----------    -----------
Current assets:
    Cash and cash equivalents                        $   8,606      $       8
    Accounts receivable, net                               210             99
    Inventories                                            636            391
    Prepaid expenses                                       103             58
                                                     ---------      ---------

        Total current assets                             9,555            556

    Note Receivable                                         30             --
    Plant and equipment, net                               108            130
                                                     ---------      ---------

        Total assets                                 $   9,693      $     686
                                                     =========      =========


                   LIABILITIES AND STOCKHOLDERS' DEFICIT
                   -------------------------------------

Current liabilities:
    Accounts payable, trade and accrued liabilities      3,696          4,723
    Note payable to an affiliate                            --            792
    Unearned revenue                                        74            142
                                                     ---------      ---------

        Total current liabilities                        3,770          5,657

Long term debt to an affiliate                              --            600
Other liabilities                                           51             68
                                                     ---------      ---------

        Total liabilities                                3,821          6,325
                                                     =========      =========

Stockholders' equity:

Series A Preferred Stock: $1.00 par value; 8%
    cumulative, convertible, redeemable; $1.00 par
    value; 5,450,000 shares authorized; 1,035,448
    and 1,557,403 shares issued and outstanding at
    September 30, 1999 and December 31, 1998,
    respectively                                         1,035          1,557

Series B Preferred Stock: $1.00 par value, 8%
    cumulative, convertible, redeemable; 25,000
    shares authorized, 25,000 Issued, and
    outstanding at September 30, 1999 and December
    31, 1998, respectively                                  --             25

Common Stock: $0.01 par value; 100,000,000 shares
    authorized; 52,146,877 and 5,166,542 shares
    issued on September 30,1999 and December 31,
    1998, respectively                                     521             52

    Additional paid-in capital                          53,907         42,426
    Accumulated deficit                                (49,576)       (49,684)
    Treasury Stock:  60,156 shares at cost                 (15)           (15)
                                                     ---------      ---------

        Total stockholders' equity                       5,872         (5,639)
                                                     ---------      ---------

            Total liabilities and
                stockholders' equity                 $   9,693      $     686
                                                     =========      =========


                                      F-23
<PAGE>


Note:   The consolidated balance sheet at December 31, 1998 has been derived
        from the audited financial statements at that date but does not include
        all of the information and footnotes required by generally accepted
        accounting principles for complete financial statements. See
        accompanying notes.


                                      F-24
<PAGE>


                              POSITRON CORPORATION
                            STATEMENTS OF OPERATIONS
                        (IN THOUSANDS, EXCEPT SHARE DATA)
                                   (UNAUDITED)

                                          THREE MONTHS ENDED   NINE MONTHS ENDED
                                          ------------------   -----------------
                                             September 30,       September 30,
                                           ----------------    ----------------
                                            1999      1998      1999      1998
                                           ------    ------    ------    ------
Revenues:
     Fee per scan                             $--    $  147    $   --    $  454
     Upgrades                                  --        --       137        --
     Service and component                    385       153     1,088       933
                                           ------    ------    ------    ------

         Total Revenue:                       385       300     1,225     1,387
                                           ------    ------    ------    ------

Costs of sales and services:
     Fee per scan                              --        29        --        89
     Upgrades                                  --        --        49        --
     Service, warranty and component          171       108       418       286
                                           ------    ------    ------    ------

         Total costs of revenues              171       137       467       375
                                           ------    ------    ------    ------

         Gross profit                         214       163       759     1,012

Operating expenses:
    Research and development                  140        --       269        18
    Selling and marketing                      60        --        60        16
    General and administrative                184       840       420     1,734
                                           ======    ======    ======    ======

        Total operating expenses              384       840       749     1,768
                                           ------    ------    ------    ------

        Income (loss) from operations        (170)     (677)       10      (756)

Interest income/(expense)                      55       (67)      (45)     (228)
                                           ------    ------    ------    ------

Loss before extraordinary item               (115)     (744)      (35)     (984)

Extraordinary item, gain on
    forgiveness of debt                       143        --       143        --
                                           ------    ------    ------    ------

Net income (loss)                          $   28    $ (744)   $  108    $ (984)
                                           ======    ======    ======    ======

Basic and diluted earnings
    (loss) per common share
    including extraordinary item           $ 0.00    $(0.14)   $ 0.00    $(0.19)
                                           ======    ======    ======    ======

Weighted average number of basic
    Common shares outstanding              40,278     5,144    23,792     5,139
                                           ======    ======    ======    ======


Weighted average number of diluted
    Common shares outstanding              50,880     5,144    27,691     5,139
                                           ======    ======    ======    ======


                             See accompanying notes


                                      F-25
<PAGE>


                              POSITRON CORPORATION
                       CONDENSED STATEMENTS OF CASH FLOWS
                             (AMOUNTS IN THOUSANDS)
                                   (UNAUDITED)

                                          THREE MONTHS ENDED  NINE MONTHS ENDED
                                          ------------------  -----------------
                                             September 30,      September 30,
                                           ----------------    ---------------
                                            1999      1998      1999     1998
                                           ------    ------    ------    -----
Cash flows from operating activities:
    Net income (loss)                      $   28    $ (744)   $  108    $(984)
    Adjustment to reconcile net income
        (loss) to net cash provided
        (used) in operating activities         --        --        --      763
        Depreciation                           (2)      126        13       --
    Changes in operating assets and
        liabilities:
        Accounts receivable                     9       216      (111)      --
        Inventory                            (251)       --      (245)      --
        Prepaid expenses                      (45)      173       (45)      --
        Notes Receivable                      (30)       --       (30)      --
        Accrued liabilities                (1,000)      260    (1,017)      --
        Unearned revenue                      (98)       60       (68)      --
        Other liabilities
                                              (17)      (16)      (17)      --
                                           ------    ------    ------    -----

             Net cash used in
                 operating activities      (1,412)   (1,406)       75     (221)
                                           ------    ------    ------    -----

Cash flows from financing activities:
    Proceeds from sale of common stock     11,402        --    11,402       --
    Repayment of other notes payable       (1,392)       --    (1,392)    (206)
                                           ------    ------    ------    -----

             Net cash used in
                 financing activities      10,010        --    10,010     (206)
                                           ------    ------    ------    -----

Net decrease in cash and cash equivalents  $8,604    $   75    $8,598    $ (15)

Cash and cash equivalents, beginning
        of period                               2        70         8      160
                                           ------    ------    ------    -----

Cash and cash equivalents, end of period   $8,606    $  145    $8,606    $ 145


                             See accompanying notes


                                      F-26
<PAGE>


                              POSITRON CORPORATION
                     SELECTED NOTES TO FINANCIAL STATEMENTS

1.    BASIS OF PRESENTATION

      The accompanying unaudited interim financial statements have been prepared
      in accordance with generally accepted accounting principles and the rules
      of the U.S. Securities and Exchange Commission, and should be read in
      conjunction with the audited financial statements and notes thereto
      contained in the Company's Annual Report of Form 10-KSB for the year ended
      December 31, 1998. In the opinion of management, all adjustments,
      consisting of normal recurring adjustments, necessary for a fair
      presentation of financial position and the results of operations for the
      interim periods presented have been reflected herein. The results of
      operations for interim periods are not necessarily indicative of the
      results to be expected for the full year. Notes to the financial
      statements which would substantially duplicate the disclosure contained in
      the audited financial statements for the most recent fiscal year ended
      December 31, 1998, as reported in the Form 10-KSB, have been omitted.

2.    COMPREHENSIVE INCOME

      Effective January 1, 1998, the Company adopted Statement of Financial
      Accounting Standard ("SFAS") No. 130, "Reporting Comprehensive Income."
      Comprehensive income includes such items as unrealized gains or losses on
      certain investment securities and certain foreign currency translation
      adjustments. The Company's financial statements include none of the
      additional elements that affect comprehensive income. Accordingly,
      comprehensive income and net income are identical.

3.    EARNINGS PER SHARE

      Basic earnings per common share are based on the weighted average number
      of common shares outstanding in each year and after preferred stock
      dividend requirements. Diluted earnings per common share assume that any
      dilutive convertible preferred shares outstanding at the beginning of each
      year were converted at those dates, with related interest, preferred stock
      dividend requirements and outstanding common shares adjusted accordingly.
      It also assumes that outstanding common shares were increased by shares
      issuable upon exercise of those stock options for which market price
      exceeds exercise price, less shares which could have been purchased by the
      Company with related proceeds. The convertible preferred stock and
      outstanding stock options and warrants were not included in the
      computation of diluted earnings per common share for 1998 since it would
      have resulted in an antidilutive effect.

      The following table sets forth the computation of diluted weighted average
      shares outstanding (Shares in thousands):


                                      F-27
<PAGE>


                                          THREE MONTHS ENDED  NINE MONTHS ENDED
                                          ------------------  -----------------
                                             September 30,      September 30,
                                            ---------------    ---------------
                                             1999     1998      1999     1998
                                            ------    -----    ------    -----

Denominator:
    Denominator for basic earnings
        per Share-weighted average
        shares                              40,278    5,144    23,792    5,139

    Effect of dilutive securities:
        Convertible Series A
            preferred stock                    670       --       670       --
    Dilutive potential common shares         9,932       --     3,229       --
    Denominator for diluted earnings
        per Share-adjusted weighted
        Average shares and assumed
            Conversions                     50,880    4,885    27,691    4,885
                                            ======    =====    ======    =====

4.    INCOME TAX

      The difference between the Federal statutory income tax rate and the
      Company's effective income tax rate is primarily attributable to increases
      in valuation allowances for deferred tax assets relating to net operating
      losses.

5.    IMATRON TRANSACTION

      In May 1998, the Company entered into an agreement (the "Imatron
      Transaction") with Imatron Inc. ("Imatron"), pursuant to which in January
      1999, Imatron acquired a majority ownership of the Company. In conjunction
      with the Imatron Transaction, Imatron made working capital advances to the
      Company of $600,000 to enable the Company to meet a portion of its current
      obligations.

      Upon consummation of the Imatron Transaction in January 1999, Imatron
      acquired a majority ownership of the outstanding common stock of the
      Company on a fully-diluted and as-if-converted basis (excluding
      out-of-the-money warrants and options determined at the time of issuance
      of the shares of Imatron) and was issued nine million of the Company's
      common stock in return for a nominal cash payment in the amount of $100.

      Imatron, in addition to providing limited working capital financing,
      agreed to support the Company's marketing program particularly with regard
      to Imatron's affiliate, Imatron Japan, Inc. by agreeing to make all
      reasonable efforts to cause the placement of 10 POSICAM(TM) systems over
      the next three years. During 1998 the Company shipped a POSICAM(TM) system
      to Imatron Japan as the first delivery under a three-year distribution
      agreement entered into during 1997. Imatron Japan, an affiliate of
      Imatron, is a major distributor for Imatron's Ultrafast CT and for the
      products of certain other high technology companies. Imatron owns a 24
      percent minority interest in Imatron Japan.

      Imatron has also agreed to help facilitate the recapitalization of the
      Company and to support its re-entry into the medical imaging market by
      using its best efforts, after the share issuance closing date, to arrange
      for additional third-party equity financing for the Company over an
      eighteen-month period in an aggregate amount of at least $8,000,000. There
      can be no assurances, however, that any such sales will actually be
      consummated


                                      F-28
<PAGE>


      or that Imatron will be able to successfully assist the Company in raising
      additional capital.

      In connection with the Imatron Transaction, the Company, Imatron, and two,
      then current lenders, to the Company, Uro-Tech and ProFutures, entered
      into certain agreements whereby (a) ProFutures waived all past defaults
      and extended the maturity of the ProFutures Loan in return for a $50,000
      payment and the issuance of warrants to purchase 1,150,000 shares of the
      Company's common stock at $0.25 per share. The ProFutures Loan was
      subsequently repaid in November 1998; (b) Imatron agreed to subordinate
      its loan to the ProFutures Loan, (c) Uro-Tech agreed to subordinate its
      loan (with a current balance of approximately $792,000 plus accrued
      interest payable of approximately $272,000 at December 31, 1998) to
      Imatron's loan.

      In August of 1999, Imatron successfully completed raising a net $11.4
      million of equity capital for the Company. This reduced Imatron's current
      ownership in the company to approximately 16%. Consistent with the
      completion of the financing, the Company has repaid the Imatron bridge
      loan plus interest and paid the Uro-tech loan plus interest. The Company's
      President has resigned as Imatron's CFO and Imatron no longer has
      operating or voting control of the company.


                                      F-29
<PAGE>


                                                              78,732,990 Shares







                                                                 Common Stock





                                                                 ------------

                                                                  PROSPECTUS
                                                                 ------------










                                                              February 14, 2000

<PAGE>


                                     PART II


                     INFORMATION NOT REQUIRED IN PROSPECTUS


                    INDEMNIFICATION OF DIRECTORS AND OFFICERS

Pursuant  to  the  Texas  Business  Corporation  Act  (Art.2.02-1),   Positron's
Certificate  of  Incorporation  excludes  personal  liability on the part of its
directors to the Company for monetary  damages based upon any violation of their
fiduciary duties as directors, except as to liability for any breach of the duty
of loyalty,  acts or omissions  not in good faith or which  involve  intentional
misconduct or a knowing  violation of law,  acts set forth in Art.  2.02-1(B) of
the Business  Corporation Act, or any transaction from which a director receives
an improper  personal  benefit.  This  exclusion of liability does not limit any
right which a director may have to be indemnified.

Positron's  Certificate of Incorporation and its Bylaws require  indemnification
of directors and officers of the Company to the fullest extent  permitted by the
Business  Corporation Law for claims against them in their official  capacities,
including stockholders' derivative actions.


                   OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

The following table sets forth the costs and expenses,  other than  underwriting
discounts and commissions, payable by the registrant in connection with the sale
of the common stock being  registered.  All amounts are estimated except the SEC
Registration Fee..

      SEC Registration Fee                                        $ 11,016
      Blue Sky Qualification Fees and Expenses                      20,000
      Accounting Fees and Expenses                                   2,500
      Legal Fees and Expenses                                       50,000
      Printing and Engraving                                        20,000
      Miscellaneous                                                  1,000
                                                                  --------
      Total                                                       $104,516

                     RECENT SALES OF UNREGISTERED SECURITIES

      During the past three years, the registrant has issued the securities set
forth below which were not registered under the Securities Act of 1933.

      Warrants were issued to ProFutures Bridge Capital Fund, Ltd. in connection
with the execution of a loan to the Company in 1996 and subsequent extensions of
credit in 1997 and 1998. A total of 1,500,000 warrants have been issued to
ProFutures during this period, 250,000 of which were initially exerciseable at
$2.40 per share (which price was later adjusted) and 1,250,000 of which are
exercisable at $0.25 per share. To date, none of the warrants has been
exercised, and the shares underlying the warrants are being registered in this
registration statement. Pursuant to anti-dilution provisions contained in the
warrants, the number of shares underlying the warrants may be greater than
1,500,000.

      Warrants were issued to Uro-Tech Ltd., a Texas limited partnership, in
connection with extensions or conversions of a loan originally made to the
Company in November 1995. The general partner of Uro-Tech Ltd. is OmniMed
Corporation, the founder, chairman and principal


                                      II-1
<PAGE>


shareholder of which is Dr. Gary B. Wood, a member of the Company's board of
directors. Initially, a warrant to purchase 67,500 shares of common stock was
issued to Uro-Tech, Ltd. in connection with the original extension of credit. In
September 1999 that warrant was exchanged for a warrant to purchase 100,000
common shares in connection with the extension and retirement of the loan. The
shares underlying the replacement warrant are being registered in this
registration statement. In addition, 216,671 warrants to purchase common stock
were issued to Uro-Tech in 1997 upon conversion of $650,000 in the principal
amount of the loan.

      Effective January 22, 1999, the Company sold to Gary H. Brooks and S.
Lewis Meyer respectively warrants to purchase 3,000,000 shares and 1,500,000
shares respectively of Positron common stock. Mr. Brooks is the Company's
President and Mr. Meyer is Chairman of the Board. See SECURITY OWNERSHIP OF
DIRECTORS AND EXECUTIVE OFFICERS of this statement. The shares underlying these
warrants are being registered pursuant to this registration statement.

      In August 1999 the Company concluded a private placement of 42,166,664
shares of Positron common stock for a total price of $12,700,000. In connection
with the private placement, Positron also issued 21,460,000 five-year warrants.
The common shares and the shares underlying these warrants are being registered
pursuant to this registration statement.

      In November 1999, the Company negotiated a resolution regarding all open
issues with K. Lance Gould, a former director and royalty holder. See LEGAL
PROCEEDINGS of this Statement. In connection with the settlement and release
negotiated with Dr. Gould, the Company issued to Dr. Gould 168,000 shares of
Positron common stock. These common shares are being registered pursuant to this
registration statement.

                                ITEM 27: EXHIBITS

3.1     Articles of Incorporation of the Registrant (incorporated herein by
        reference to Exhibit 3.1 to the Company's Registration Statement on Form
        SB-2 (File No. 33-68722)).

3.2     By-laws of the Registrant, as amended (incorporated herein by reference
        to Exhibit 3.2 to the Company's Registration Statement on Form SB-2
        (File No. 33-68722)).

4.1     Specimen Stock Certificate (incorporated herein by reference to Exhibit
        4.1 of the Company's Annual Report on Form 10-KSB for the year ended
        December 31, 1994).

4.2     Form of Redeemable Warrant (included as part of Exhibit 4.5)

4.3     Statement of Designation Establishing Series A 8% Cumulative Convertible
        Redeemable Preferred Stock of Positron Corporation, dated February 28,
        1996 (incorporated herein by reference to Exhibit 4.3 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

4.4     Warrant Agreement dated as of February 29, 1996, between Positron
        Corporation and Continental Stock Transfer & Trust Company (incorporated
        herein by reference to Exhibit 4.4 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

4.5     Specimen Redeemable Warrant Certificate to Purchase Shares of Common
        Stock (incorporated herein by reference to Exhibit 4.5 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).


                                      II-2
<PAGE>


4.6     Stock Purchase Warrant dated as of February 7, 1996 issued by Positron
        Corporation to Boston Financial & Equity Corporation (incorporated
        herein by reference to Exhibit 4.6 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

4.7     Statement of Designation Establishing Series B 8% Cumulative Convertible
        Redeemable Preferred Stock of Positron Corporation, dated July 9, 1996.

4.8     Form of Warrant Agreement dated as of July 10, 1996, between Positron
        Corporation and Brooks Industries Profit Sharing Plan.

4.9*    Warrant Agreement dated as of June 15, 1999 between Positron Corporation
        and Gary Brooks.

4.10*   Stock Purchase Warrant dated as of June 15, 1999 issued by Positron
        Corporation to Gary H. Brooks.

4.11*   Warrant Agreement dated as of June 15, 1999 between Positron Corporation
        and S. Lewis Meyer

4.12*   Stock Purchase Warrant dated as of June 15, 1999 issued by Positron
        Corporation to S. Lewis Meyer

4.13*   Stock Purchase Warrant dated as of September 20, 1999 issued by Positron
        Corporation to Uro-Tech, Ltd. as replacement for 1995 Warrant.

4.14    Form of Stock Purchase Agreement executed in connection with July 1999
        Private Placement (incorporated by reference to Exhibit 5.1 to the
        Company's Report on 8-K dated August 18, 1999.)

4.15    Form of Common Stock Purchase Warrant in connection with July 1999
        Private Placement (incorporated by reference to Exhibit 5.2 to the
        Company's Report on 8-K dated August 18, 1999.)

5.1*    Opinion of Allen Matkins Leck Gamble & Mallory LLP

10.1    Lease Agreement dated as of July 1, 1991, by and between Lincoln
        National Pension Insurance Company and Positron Corporation
        (incorporated herein by reference to Exhibit 10.1 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.2    Agreement dated as of March 1, 1993, by and between Positron Corporation
        and Oxford Instruments (UK) Limited (incorporated herein by reference to
        Exhibit 10.2 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.3    International Distribution Agreement dated as of November 1, 1992, by
        and between Positron Corporation and Batec International , Inc.
        (incorporated herein by reference to Exhibit 10.3 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.4+   1994 Incentive and Nonstatutory Option Plan.

10.5+   Amended and Restated 1987 Stock Option Plan (incorporated herein by
        reference to Exhibit 10.5 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.6+   Retirement Plan and Trust (incorporated herein by reference to Exhibit
        10.6 to the Company's Registration Statement on Form SB-2 (File No.
        33-68722)).


                                      II-3
<PAGE>


10.7    Amended and Restated License Agreement dated as of June 30, 1987, by and
        among The Clayton Foundation for Research, Positron Corporation, K.
        Lance Gould, M.D., and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.7 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.8    Clarification Agreement to Exhibit 10.7 (incorporated herein by
        reference to Exhibit 10.8 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.9    Royalty Assignment dated as of December 22, 1988, by and between K.
        Lance Gould and Positron Corporation (incorporated herein by reference
        to Exhibit 10.10 to the Company's Registration Statement on Form SB-2
        (File No. 33-68722)).

10.10   Royalty Assignment dated as of December 22, 1988, by and between Nizar
        A. Mullani and Positron Corporation (incorporated herein by reference to
        Exhibit 10.11 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.11   Royalty Assignment dated as of December 22, 1988, by and between The
        Clayton Foundation and Positron Corporation (incorporated herein by
        reference to Exhibit 10.12 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.12+  Stock Purchase Warrant dated October 31, 1993, issued to Gary B. Wood
        (incorporated herein by reference to Exhibit 10.15 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.13   Amendment No. 1 to Exhibit 10.22 (incorporated herein by reference to
        Exhibit 10.23 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.14+  Consulting Agreement dated as of January 15, 1993, by and between
        Positron Corporation and K. Lance Gould, M.D. (incorporated herein by
        reference to Exhibit 10.24 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.15   Stock Purchase Warrant dated February 25, 1993, issued to K. Lance Gould
        (incorporated herein by reference to Exhibit 10.26 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.16+  Consulting Agreement dated February 23, 1995, effective December 15,
        1994, by and between Positron Corporation and F. David Rollo, M.D.
        Ph.D., FACNP.

10.17+  Consulting Agreement dated as of January 15, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.31 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.18+  Consulting Agreement dated as of November 12, 1993, by and between
        Positron Corporation and OmniMed Corporation (incorporated herein by
        reference to Exhibit 10.35 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.19   Contract No. 1318 dated as of December 30, 1991, by and between Positron
        Corporation and The University of Texas Health Science Center at Houston
        (incorporated herein by reference to Exhibit 10.39 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).


                                      II-4
<PAGE>


10.20+  Letter Agreement dated July 30, 1993 between Positron Corporation and
        Howard Baker (incorporated herein by reference to Exhibit 10.52 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.21   Technology Transfer Agreement dated as of September 17, 1990, by and
        between Positron Corporation and Clayton Foundation for Research
        (incorporated herein by reference to Exhibit 10.54 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.22   Stock Purchase Warrant dated as of October 31, 1993 issued to Gerald
        Hillman (incorporated herein by reference to Exhibit 10.56 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.23   Stock Purchase Warrant dated as of October 31, 1993 issued to The Dover
        Group (incorporated herein by reference to Exhibit 10.57 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.24   Stock Purchase Warrant dated as of October 31, 1993 issued to John
        Wilson (incorporated herein by reference to Exhibit 10.63 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.25+  Stock Purchase Warrant dated as of October 31, 1993 issued to Robert
        Guezuraga (incorporated herein by reference to Exhibit 10.64 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.26   Stock Purchase Warrant dated as of October 31, 1993 issued to Richard
        Ronchetti (incorporated herein by reference to Exhibit 10.65 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.27   Form of Amended and Restated Registration Rights Agreement dated as of
        November 3, 1993, by and among Positron and the other signatories
        thereto (1993 Private Placement) (incorporated herein by reference to
        Exhibit 10.73 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722).

10.28   Registration Rights Agreement dated as of July 31, 1993, by and among
        Positron and the other signatories thereto (other than the 1993 Private
        Placement) (incorporated herein by reference to Exhibit 10.74 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.29   Software Licenses dated as of March 1, 1993, by and between Positron
        Corporation and Oxford Instruments (UK) Limited (incorporated herein by
        reference to Exhibit 10.81 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.30   Distribution Agreement dated as of June 1, 1993, by and between Positron
        Corporation and Elscint, Ltd. (incorporated herein by reference to
        Exhibit 10.82 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.31+  Employment Agreement dated as of August 19, 1993, by and between
        Positron Corporation and Richard E. Hitchens (incorporated herein by
        reference to Exhibit 10.83 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).


                                      II-5
<PAGE>


10.32+  Employment Agreement dated as of August 19, 1993, by and between
        Positron Corporation and Howard R. Baker (incorporated herein by
        reference to Exhibit 10.84 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.33   Amended and Restated Warrant Agreement dated as of April 14, 1994, by
        and between Positron Corporation and Continental Stock Transfer and
        Trust Company (including form of Warrant Certificate).

10.34   First Amendment to Amended and Restated Registration Rights Agreement,
        dated as of November 19, 1993, by and among Positron Corporation and the
        other signatories thereto (incorporated herein by reference to Exhibit
        10.91 to the Company's Registration Statement on Form SB-2 (File No.
        33-68722)).

10.35   Agreement made and entered into as of October 31, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.97 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.36   Agreement made and entered into as of October 31, 1993, by and between
        Positron Corporation and K. Lance Gould (incorporated herein by
        reference to Exhibit 10.98 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.37   Agreement made and entered into as of November 15, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.100 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.38   Agreement made and entered into as of November 15, 1993, by and between
        Positron Corporation and K. Lance Gould (incorporated herein by
        reference to Exhibit 10.101 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.39   First Amendment made and entered as of January 25, 1994, by and between
        Emory University d/b/a Crawford Long Hospital and Positron Corporation
        (incorporated herein by reference to Exhibit 10.102 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1993).

10.40+  Employment Agreement dated January 1, 1996 by and between Werner J.
        Haas, Ph.D. and Positron Corporation (incorporated herein by reference
        to Exhibit 10.40 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.41   Loan and Security Agreement made as of November 14, 1995, between
        Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.41 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.42   First Modification and Extension Agreement made as of January 3, 1996,
        by Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.42 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.43   Second Modification and Extension Agreement made as of February 26, 1996
        by Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.43 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).


                                      II-6
<PAGE>


10.44   Uro-Tech Loan Conversion Agreement dated as of November 14, 1995,
        between Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.44 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.45   Promissory Note dated September 14, 1995, in the principal amount of
        $1,500,000 payable to Uro-Tech, Ltd. (incorporated herein by reference
        to Exhibit 10.45 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.46   Promissory Note dated September 14, 1995, in the principal amount of
        $1,000,000 payable to Uro-Tech, Ltd. (incorporated herein by reference
        to Exhibit 10.46 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.47   Revolving Finance agreement with Boston Financial & Equity Corporation
        (incorporated herein by reference to Exhibit 10.47 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

10.48   Security Agreement Boston Financial & Equity Corporation (incorporated
        herein by reference to Exhibit 10.48 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

10.49   Supplement to Security Agreement Security Interest in Inventory
        (incorporated herein by reference to Exhibit 10.49 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

10.50   Inter-Creditor Agreement (incorporated herein by reference to Exhibit
        10.50 of the Company's Annual Report on Form 10-KSB for the year ended
        December 31, 1995).

10.51   Loan Agreement between Positron Corporation and ProFutures Bridge
        Capital Fund, L.P. dated November 1, 1996.

10.52   Promissory Note dated November 14, 1996, in the principal amount of
        $1,400,000 payable to ProFutures Bridge Capital Fund, L.P.

10.53   InterCreditor Agreement dated November 14, 1996 among Uro-Tech, Ltd.,
        Boston Financial & Equity Corporation and ProFutures Bridge Capital
        Fund, L.P.

10.54   Amendment to BF&E loan

10.55   Amendment to Uro-Tech loan

10.56   Acquisition Agreement between General Electric Company and Positron
        Corporation dated July 15, 1996.

10.57   Loan Agreement between Positron Corporation and Imatron, Inc..

10.58   Sales and Marketing Agreement With Beijing Chang Feng Medical.

10.59   Stock Purchase Agreement between Positron Corporation and Imatron, Inc.

10.60   Promissory Note from Positron Corporation to Imatron, Inc.

10.61*+ Employment Agreement dated as of January 22, 1999 by and between
        Positron Corporation and Gary H. Brooks

10.62*  Agreement and Release dated as of November 30, 1999 by and among
        Positron Corporation, K. Lance Gould and University of Texas Medical
        Center

10.63*+ 1999 Stock Option Plan


                                      II-7
<PAGE>


10.64*+ 1999 Non-Employee Directors' Stock Option Plan

10.65*+ 1999 Stock Bonus Incentive Plan

10.66*+ 1999 Employee Stock Purchase Plan

10.67*  Stock Purchase Warrant dated September 1, 1999 issued by Positron to S.
        Okamura and Associates, Inc.

10.68*  Stock Purchase Warrant dated August 18, 1999 issued by Positron to
        Morris Holdings Ltd.

10.69*  Stock Purchase Warrant dated January 20, 2000 issued by Positron to
        Vistula Finance Limited

23.1*   Consent of Ham, Langston & Brezina

24.1    Powers of Attorney (included on signature page hereto)


*       Filed herewith

+       Management contract or compensatory plan or arrangement identified
        pursuant to Item 13(a).

                              ITEM 28: UNDERTAKINGS

      A.    The undersigned registrant hereby undertakes:

      (1)   To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement:

            (i)   To include any prospectus required by section 10(a)(3) of the
Securities Act of 1933, as amended;

            (ii)  To reflect in the prospectus any facts or events arising after
the effective date of the Registration Statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in the Registration
Statement. Notwithstanding the foregoing, any increase or decrease in volume of
securities offered (if the total dollar value of securities offered would not
exceed that which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of prospectus
filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in
the volume and price represent no more than a 20% change in the maximum
aggregate offering price set forth in the "Calculation of the Registration Fee"
table in the effective Registration Statement; and

            (iii) To include any material information with respect to the plan
of distribution not previously disclosed in the Registration Statement or any
material change to such information in the Registration Statement.

      (2)   That, for the purpose of determining any liability under the
Securities Act of 1933, as amended, each such post-effective amendment shall be
deemed to be a new registration


                                      II-8
<PAGE>


statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

      (3)   To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

      B.    Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the provisions described in Item 14 above,
or otherwise, the registrant has been advised that in the opinion of the
Securities and Exchange Commission such indemnification is against public policy
as expressed in the Securities Act and is, therefore, unenforceable. In the
event that a claim for indemnification against such liabilities (other than the
payment by the registrant of expenses incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question of whether
such indemnification by it is against public policy as expressed in the Act and
will be governed by the final adjudication of such issue.

      C.    The undersigned registrant hereby undertakes that:

            (1)   For purposes of determining any liability under the Securities
Act of 1933, the information omitted from the form of prospectus filed as part
of this registration statement in reliance upon Rule 430A and contained in a
form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or
497(h) under the Securities Act of 1933 shall be deemed to be part of this
registration statement as of the time it was declared effective.

            (2)   For purposes of determining any liability under the Securities
Act, each post-effective amendment that contains a form of prospectus shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.


                                    SIGNATURE

Pursuant to the  requirements  of the  Securities  Act of 1933,  the  registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing on Form  SB-2 and has duly  caused  this  Registration
Statement on Form SB-2 to be signed on its behalf by the undersigned,  thereunto
duly authorized, in the City of Houston, Texas on February 14, 2000.


                                            POSITRON CORPORATION


                                        By: /s/GARY H. BROOKS
                                            -----------------
                                            Gary H. Brooks
                                            President


                                      II-9
<PAGE>


                                POWER OF ATTORNEY

Each person whose  signature  appears  below  constitutes  and appoints S. Lewis
Meyer and Gary H. Brooks his true and lawful  attorneys-in-fact and agents, each
acting alone, with full power of substitution and resubstitution, for him and in
his  name,  place  and  stead,  in any and all  capacities,  to sign  any or all
amendments (including post-effective  amendments) to the Registration Statement,
and to sign any  registration  statement for the same  offering  covered by this
Registration  Statement  that is to be  effective  upon filing  pursuant to Rule
462(b) under the  Securities  Act of 1933,  as amended,  and all  post-effective
amendments  thereto,  and to file the same, with all exhibits  thereto,  and all
documents in connection therewith,  with the Securities and Exchange Commission,
granting unto said  attorneys-in-fact and agents, full power and authority to do
and perform each and every act and thing  requisite  and necessary to be done in
and about the  premises,  as fully to all  intents  and  purposes as he might or
could  do  in  person,   hereby   ratifying   and   confirming   all  that  said
attorneys-in-fact   and  agents,   each  acting  alone,  or  his  substitute  or
substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the  requirements of the Securities Act of 1933,  this  Registration
Statement  on  Form  SB-2  has  been  signed  by the  following  persons  in the
capacities and on the dates indicated.



SIGNATURE                      OFFICE                                   DATE

S. Lewis Meyer                 Director                         January 24, 2000

Gary H. Brooks                 Director, President Chief        February 7, 2000
                               Financial Officer
                               (Acting) and Secretary

Gary B. Wood, Ph.D.            Director                         February 1, 2000

Antonio P. Falcao              Director                         February 2, 2000


<PAGE>


                                 EXHIBIT INDEX

3.1     Articles of Incorporation of the Registrant (incorporated herein by
        reference to Exhibit 3.1 to the Company's Registration Statement on Form
        SB-2 (File No. 33-68722)).

3.2     By-laws of the Registrant, as amended (incorporated herein by reference
        to Exhibit 3.2 to the Company's Registration Statement on Form SB-2
        (File No. 33-68722)).

4.1     Specimen Stock Certificate (incorporated herein by reference to Exhibit
        4.1 of the Company's Annual Report on Form 10-KSB for the year ended
        December 31, 1994).

4.2     Form of Redeemable Warrant (included as part of Exhibit 4.5)

4.3     Statement of Designation Establishing Series A 8% Cumulative Convertible
        Redeemable Preferred Stock of Positron Corporation, dated February 28,
        1996 (incorporated herein by reference to Exhibit 4.3 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

4.4     Warrant Agreement dated as of February 29, 1996, between Positron
        Corporation and Continental Stock Transfer & Trust Company (incorporated
        herein by reference to Exhibit 4.4 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

4.5     Specimen Redeemable Warrant Certificate to Purchase Shares of Common
        Stock (incorporated herein by reference to Exhibit 4.5 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).


                                     1
<PAGE>


4.6     Stock Purchase Warrant dated as of February 7, 1996 issued by Positron
        Corporation to Boston Financial & Equity Corporation (incorporated
        herein by reference to Exhibit 4.6 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

4.7     Statement of Designation Establishing Series B 8% Cumulative Convertible
        Redeemable Preferred Stock of Positron Corporation, dated July 9, 1996.

4.8     Form of Warrant Agreement dated as of July 10, 1996, between Positron
        Corporation and Brooks Industries Profit Sharing Plan.

4.9*    Warrant Agreement dated as of June 15, 1999 between Positron Corporation
        and Gary Brooks.

4.10*   Stock Purchase Warrant dated as of June 15, 1999 issued by Positron
        Corporation to Gary H. Brooks.

4.11*   Warrant Agreement dated as of June 15, 1999 between Positron Corporation
        and S. Lewis Meyer

4.12*   Stock Purchase Warrant dated as of June 15, 1999 issued by Positron
        Corporation to S. Lewis Meyer

4.13*   Stock Purchase Warrant dated as of September 20, 1999 issued by Positron
        Corporation to Uro-Tech, Ltd. as replacement for 1996 Warrant.

4.14    Form of Stock Purchase Agreement executed in connection with July 1999
        Private Placement (incorporated by reference to Exhibit 5.1 to the
        Company's Report on 8-K dated August 18, 1999.)

4.15    Form of Common Stock Purchase Warrant in connection with July 1999
        Private Placement (incorporated by reference to Exhibit 5.2 to the
        Company's Report on 8-K dated August 18, 1999.)

5.1     Opinion of Allen Matkins Leck Gamble & Mallory LLP

10.1    Lease Agreement dated as of July 1, 1991, by and between Lincoln
        National Pension Insurance Company and Positron Corporation
        (incorporated herein by reference to Exhibit 10.1 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.2    Agreement dated as of March 1, 1993, by and between Positron Corporation
        and Oxford Instruments (UK) Limited (incorporated herein by reference to
        Exhibit 10.2 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.3    International Distribution Agreement dated as of November 1, 1992, by
        and between Positron Corporation and Batec International , Inc.
        (incorporated herein by reference to Exhibit 10.3 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.4+   1994 Incentive and Nonstatutory Option Plan.

10.5+   Amended and Restated 1987 Stock Option Plan (incorporated herein by
        reference to Exhibit 10.5 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.6+   Retirement Plan and Trust (incorporated herein by reference to Exhibit
        10.6 to the Company's Registration Statement on Form SB-2 (File No.
        33-68722)).


                                        2
<PAGE>


10.7    Amended and Restated License Agreement dated as of June 30, 1987, by and
        among The Clayton Foundation for Research, Positron Corporation, K.
        Lance Gould, M.D., and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.7 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.8    Clarification Agreement to Exhibit 10.7 (incorporated herein by
        reference to Exhibit 10.8 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.9    Royalty Assignment dated as of December 22, 1988, by and between K.
        Lance Gould and Positron Corporation (incorporated herein by reference
        to Exhibit 10.10 to the Company's Registration Statement on Form SB-2
        (File No. 33-68722)).

10.10   Royalty Assignment dated as of December 22, 1988, by and between Nizar
        A. Mullani and Positron Corporation (incorporated herein by reference to
        Exhibit 10.11 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.11   Royalty Assignment dated as of December 22, 1988, by and between The
        Clayton Foundation and Positron Corporation (incorporated herein by
        reference to Exhibit 10.12 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.12+  Stock Purchase Warrant dated October 31, 1993, issued to Gary B. Wood
        (incorporated herein by reference to Exhibit 10.15 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.13   Amendment No. 1 to Exhibit 10.22 (incorporated herein by reference to
        Exhibit 10.23 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.14+  Consulting Agreement dated as of January 15, 1993, by and between
        Positron Corporation and K. Lance Gould, M.D. (incorporated herein by
        reference to Exhibit 10.24 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.15   Stock Purchase Warrant dated February 25, 1993, issued to K. Lance Gould
        (incorporated herein by reference to Exhibit 10.26 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.16+  Consulting Agreement dated February 23, 1995, effective December 15,
        1994, by and between Positron Corporation and F. David Rollo, M.D.
        Ph.D., FACNP.

10.17+  Consulting Agreement dated as of January 15, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.31 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.18+  Consulting Agreement dated as of November 12, 1993, by and between
        Positron Corporation and OmniMed Corporation (incorporated herein by
        reference to Exhibit 10.35 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.19   Contract No. 1318 dated as of December 30, 1991, by and between Positron
        Corporation and The University of Texas Health Science Center at Houston
        (incorporated herein by reference to Exhibit 10.39 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).


                                       3
<PAGE>


10.20+  Letter Agreement dated July 30, 1993 between Positron Corporation and
        Howard Baker (incorporated herein by reference to Exhibit 10.52 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.21   Technology Transfer Agreement dated as of September 17, 1990, by and
        between Positron Corporation and Clayton Foundation for Research
        (incorporated herein by reference to Exhibit 10.54 to the Company's
        Registration Statement on Form SB-2 (File No. 33-68722)).

10.22   Stock Purchase Warrant dated as of October 31, 1993 issued to Gerald
        Hillman (incorporated herein by reference to Exhibit 10.56 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.23   Stock Purchase Warrant dated as of October 31, 1993 issued to The Dover
        Group (incorporated herein by reference to Exhibit 10.57 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.24   Stock Purchase Warrant dated as of October 31, 1993 issued to John
        Wilson (incorporated herein by reference to Exhibit 10.63 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.25+  Stock Purchase Warrant dated as of October 31, 1993 issued to Robert
        Guezuraga (incorporated herein by reference to Exhibit 10.64 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.26   Stock Purchase Warrant dated as of October 31, 1993 issued to Richard
        Ronchetti (incorporated herein by reference to Exhibit 10.65 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.27   Form of Amended and Restated Registration Rights Agreement dated as of
        November 3, 1993, by and among Positron and the other signatories
        thereto (1993 Private Placement) (incorporated herein by reference to
        Exhibit 10.73 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722).

10.28   Registration Rights Agreement dated as of July 31, 1993, by and among
        Positron and the other signatories thereto (other than the 1993 Private
        Placement) (incorporated herein by reference to Exhibit 10.74 to the
        Company's Registration Statement on Form SB-2 (File No. 33-68722)).

10.29   Software Licenses dated as of March 1, 1993, by and between Positron
        Corporation and Oxford Instruments (UK) Limited (incorporated herein by
        reference to Exhibit 10.81 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.30   Distribution Agreement dated as of June 1, 1993, by and between Positron
        Corporation and Elscint, Ltd. (incorporated herein by reference to
        Exhibit 10.82 to the Company's Registration Statement on Form SB-2 (File
        No. 33-68722)).

10.31+  Employment Agreement dated as of August 19, 1993, by and between
        Positron Corporation and Richard E. Hitchens (incorporated herein by
        reference to Exhibit 10.83 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).


                                        4
<PAGE>


10.32+  Employment Agreement dated as of August 19, 1993, by and between
        Positron Corporation and Howard R. Baker (incorporated herein by
        reference to Exhibit 10.84 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.33   Amended and Restated Warrant Agreement dated as of April 14, 1994, by
        and between Positron Corporation and Continental Stock Transfer and
        Trust Company (including form of Warrant Certificate).

10.34   First Amendment to Amended and Restated Registration Rights Agreement,
        dated as of November 19, 1993, by and among Positron Corporation and the
        other signatories thereto (incorporated herein by reference to Exhibit
        10.91 to the Company's Registration Statement on Form SB-2 (File No.
        33-68722)).

10.35   Agreement made and entered into as of October 31, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.97 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.36   Agreement made and entered into as of October 31, 1993, by and between
        Positron Corporation and K. Lance Gould (incorporated herein by
        reference to Exhibit 10.98 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.37   Agreement made and entered into as of November 15, 1993, by and between
        Positron Corporation and Nizar A. Mullani (incorporated herein by
        reference to Exhibit 10.100 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.38   Agreement made and entered into as of November 15, 1993, by and between
        Positron Corporation and K. Lance Gould (incorporated herein by
        reference to Exhibit 10.101 to the Company's Registration Statement on
        Form SB-2 (File No. 33-68722)).

10.39   First Amendment made and entered as of January 25, 1994, by and between
        Emory University d/b/a Crawford Long Hospital and Positron Corporation
        (incorporated herein by reference to Exhibit 10.102 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1993).

10.40+  Employment Agreement dated January 1, 1996 by and between Werner J.
        Haas, Ph.D. and Positron Corporation (incorporated herein by reference
        to Exhibit 10.40 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.41   Loan and Security Agreement made as of November 14, 1995, between
        Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.41 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.42   First Modification and Extension Agreement made as of January 3, 1996,
        by Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.42 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.43   Second Modification and Extension Agreement made as of February 26, 1996
        by Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.43 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).


                                        5
<PAGE>


10.44   Uro-Tech Loan Conversion Agreement dated as of November 14, 1995,
        between Positron Corporation and Uro-Tech, Ltd. (incorporated herein by
        reference to Exhibit 10.44 of the Company's Annual Report on Form 10-KSB
        for the year ended December 31, 1995).

10.45   Promissory Note dated September 14, 1995, in the principal amount of
        $1,500,000 payable to Uro-Tech, Ltd. (incorporated herein by reference
        to Exhibit 10.45 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.46   Promissory Note dated September 14, 1995, in the principal amount of
        $1,000,000 payable to Uro-Tech, Ltd. (incorporated herein by reference
        to Exhibit 10.46 of the Company's Annual Report on Form 10-KSB for the
        year ended December 31, 1995).

10.47   Revolving Finance agreement with Boston Financial & Equity Corporation
        (incorporated herein by reference to Exhibit 10.47 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

10.48   Security Agreement Boston Financial & Equity Corporation (incorporated
        herein by reference to Exhibit 10.48 of the Company's Annual Report on
        Form 10-KSB for the year ended December 31, 1995).

10.49   Supplement to Security Agreement Security Interest in Inventory
        (incorporated herein by reference to Exhibit 10.49 of the Company's
        Annual Report on Form 10-KSB for the year ended December 31, 1995).

10.50   Inter-Creditor Agreement (incorporated herein by reference to Exhibit
        10.50 of the Company's Annual Report on Form 10-KSB for the year ended
        December 31, 1995).

10.51   Loan Agreement between Positron Corporation and ProFutures Bridge
        Capital Fund, L.P. dated November 1, 1996.

10.52   Promissory Note dated November 14, 1996, in the principal amount of
        $1,400,000 payable to ProFutures Bridge Capital Fund, L.P.

10.53   InterCreditor Agreement dated November 14, 1996 among Uro-Tech, Ltd.,
        Boston Financial & Equity Corporation and ProFutures Bridge Capital
        Fund, L.P.

10.54   Amendment to BF&E loan

10.55   Amendment to Uro-Tech loan

10.56   Acquisition Agreement between General Electric Company and Positron
        Corporation dated July 15, 1996.

10.57   Loan Agreement between Positron Corporation and Imatron, Inc..

10.58   Sales and Marketing Agreement With Beijing Chang Feng Medical.

10.59   Stock Purchase Agreement between Positron Corporation and Imatron, Inc.

10.60   Promissory Note from Positron Corporation to Imatron, Inc.

10.61*+ Employment Agreement dated as of January 22, 1999 by and between
        Positron Corporation and Gary H. Brooks

10.62*  Agreement and Release dated as of November 30, 1999 by and among
        Positron Corporation, K. Lance Gould and University of Texas Medical
        Center

10.63*+ 1999 Stock Option Plan


                                       6
<PAGE>


10.64*+ 1999 Non-Employee Directors' Stock Option Plan

10.65*+ 1999 Stock Bonus Incentive Plan

10.66*+ 1999 Employee Stock Purchase Plan

10.67*  Stock Purchase Warrant dated September 1, 1999 issued by Positron to S.
        Okamura and Associates, Inc.

10.68   Stock Purchase Warrant dated August 18, 1999 issued by Positron to
        Morris Holdings Ltd.

10.69   Stock Purchase Warrant dated January 20, 2000 issued by Positron to
        Vistula Finance Limited

23.1*   Consent of Ham, Langston & Brezina

24.1    Powers of Attorney (included on signature page hereto)


*       Filed herewith

**      To be filed by amendment

+       Management contract or compensatory plan or arrangement identified
        pursuant to Item 13(a).


                                       7



                                   EXHIBIT 4.9


                           WARRANT PURCHASE AGREEMENT


       THIS WARRANT  PURCHASE  AGREEMENT (the  "Agreement")  is made and entered
into this 15th day of June, 1999 by and between  POSITRON  CORPORATION,  a Texas
corporation (the "Company") and GARY H. BROOKS (the "Investor").


                                R E C I T A L S :
                                 - - - - - - - -


       WHEREAS,  the  Company  desires  to issue to  Investor  and the  Investor
desires to  purchase  from the  Company a warrant  (the  "Warrant")  to purchase
3,000,000  shares of the Company's  common stock (the "Shares") all on the terms
and conditions  hereinafter  provided.  The Warrant and the Shares are hereafter
collectively referred to as the "Securities".

       NOW, THEREFORE, IT IS AGREED AS FOLLOWS:

       1.     ISSUANCE OF WARRANT;  REPURCHASE  RIGHT.  For a purchase  price of
$0.0067 per warrant (the "Per Warrant Purchase Price") representing an aggregate
purchase  price of $20,000  ("Aggregate  Purchase  Price")  payable in cash upon
execution hereof, the Company agrees to issue to Investor the Warrant,  the form
of which is  attached  hereto as Exhibit A. The  Company  reserves to itself the
right  to  repurchase  any  portion  of the  Warrant  issued  pursuant  to  this
Agreement,  and the right to  repurchase  any stock issued upon  exercise of any
portion of the  Warrant  ("Repurchase  Right"),  as of a date 90 days  following
termination  for any  reason or for no reason of  Investor's  employment  by the
Company. The price of repurchase will be equal to the Per Warrant Purchase Price
regarding  any portion of the Warrant that remains  unexercised  at the time the
Company  exercises its Repurchase Right, or the purchase price of the underlying
stock (i.e.  the  exercise  price of the Warrant)  regarding  any portion of the
Warrant that has already been  exercised at the time the Company  exercises  its
Repurchase Right. The Repurchase Right shall lapse as follows:  immediately upon
issuance as to 750,000 shares;  as to an additional  187,500 shares on September
15, 1999; and as to an additional 187,500 shares quarterly  thereafter until the
Company's Repurchase Right shall have lapsed as to all shares.

       2.     INVESTOR REPRESENTATIONS.  Investor hereby represents and warrants
to the Company as follows:

              (a)    The Investor understands that: (i)The offer and sale of the
Securities  by the  Company  to  Investor  has not  been  registered  under  the
Securities Act of 1933 (the "Securities  Act"), in reliance on an exemption from
such  registration   available  under  the  Securities  Act  and  rules  adopted
thereunder;  (ii)The  Investor  must hold the  Warrant  indefinitely  unless the
Securities are  subsequently  registered  under the Securities Act and qualified
under

<PAGE>


applicable state securities laws, or unless an exemption from such  registration
and qualification is available.

              (b)    The Investor is acquiring the Securities for his or her own
account, for investment,  and not with a view to any sale or distribution of any
interest therein.

              (c)    The Investor has such knowledge and experience in financial
and business  matters as to be capable of evaluating  the merits and risks of an
investment  in the  Securities,  and the  Investor is able to bear the  economic
risks of such an investment.

              (d)    All statements  made,  and  information  furnished,  by the
Investor in this certificate and all other information furnished by the Investor
to the Company, are true and complete, to the best of the Investor's knowledge.

       3.     RESTRICTIONS ON TRANSFER. The Investor agrees that:

              (a)    The Investor will not attempt to transfer the Securities in
violation of the restrictions set forth in this Agreement.

              (b)    The Company may note such  restrictions  on transfer in its
records and refuse to recognize any transfer  which  violates this  agreement or
for which the Company has not received an acceptable  opinion of counsel stating
that such transfer will not violate such restrictions.

              (c)    One or more legends indicating a lack of registration under
the Securities Act and a lack of qualification  under state securities laws will
be imprinted on the  Securities.  One such legend  shall read  substantially  as
follows:

       THE SECURITIES  HAVE NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE
COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND ANY SALE, TRANSFER,
PLEDGE OR OTHER DISPOSITION THEREOF MAY BE MADE ONLY (i) IN A REGISTRATION UNDER
SAID ACT OR (ii) IF AN EXEMPTION FROM  REGISTRATION  UNDER SAID ACT IS AVAILABLE
AND THE  COMPANY HAS  RECEIVED  AN OPINION OF COUNSEL TO THAT EFFECT  REASONABLY
SATISFACTORY TO IT.

       4.     BINDING ON SUCCESSORS;  INDEMNIFICATION.  The Investor agrees that
the  above   representations  and  warranties  are  binding  on  the  Investor's
successors and assigns and are made for the benefit of the Company and any other
persons who may become liable for violations of federal or state securities laws
as a  result  of  the  falsity  of  any of  the  Investor's  representations  or
warranties.  The Investor  agrees to indemnify,  defend,  and hold harmless such
persons from any  liability  arising  from the falsity of any of the  Investor's
representations  or  warranties  or from the breach of any  covenant of Investor
contained herein.

       5.     REGISTRATION  RIGHTS.  The Company  hereby  grants to Investor the
following registration rights with respect to the Shares:

              (a)    Definitions.


                                      -2-
<PAGE>


              "Commission" shall mean the Securities and Exchange  Commission or
any other federal  agency at the time  administering  the Securities Act of 1933
(the "Securities Act").

              "Register,"   "registered,"   and   "registration"   refer   to  a
registration  effected  by  preparing  and filing a  registration  statement  in
compliance  with the Securities Act of 1933, and the  declaration or ordering of
the effectiveness of such registration statement.

              "Registration  Expenses"  shall mean all expenses  incurred by the
Company in compliance with the provisions of this Section 5, including,  without
limitation,  all  registration  and filing  fees,  printing  expenses,  fees and
disbursements  of counsel for the Company,  blue sky fees and expenses,  and the
expenses of any special audits incident to or required by any such  registration
(but excluding the compensation of regular employees of the Company, which shall
be paid in any event by the Company).

              "Selling  Expenses"  shall  mean all  underwriting  discounts  and
selling  commissions  applicable  to  the  sale  of  Shares  and  all  fees  and
disbursements of counsel to Investor.

              "Shares"   means  the  shares  of  the   Company's   common  stock
exercisable  upon  exercise  of the  Warrant  and any common  stock  issued with
respect thereto (e.g. upon a stock split or stock dividend.

              "Investor"  means the  person  set forth  above and any  permitted
assignee.

              (b)    COMPANY REGISTRATION.

                     (i)    NOTICE OF  REGISTRATION.  If, at any time  after the
date hereof,  the Company  shall  determine  to register  any of its  securities
either  for its own  account  or the  account  of a  security  holder or holders
exercising  their  respective   demand   registration   rights,   other  than  a
registration  relating  solely to  employee  benefit  plans,  or a  registration
relating solely to a Commission Rule 145  transaction,  or a registration on any
registration form which does not permit secondary sales, the Company will:

                            a)     promptly  give  to  Investor  written  notice
thereof  (which shall include a list of the  jurisdictions  in which the Company
intends to attempt to qualify such  securities  under the applicable blue sky or
other state securities laws); and

                            b)     include in such registration (and any related
qualification under blue sky laws or other compliance),  and in any underwriting
involved  therein,  all the Shares  specified in a written  request or requests,
made by Investor  within  fifteen (15) days after receipt of the written  notice
from the Company  described  in this clause (i),  except as set forth in Section
5(b)(ii) below.

                     (ii)   UNDERWRITING.  If  the  registration  of  which  the
Company  gives  notice  is  for  a  registered  public  offering   involving  an
underwriting: the Company shall so advise Investor as part of the written notice
given pursuant to Section 5(b) hereof.  In such event,  the right of Investor to
registration  pursuant to this Section 5 shall be  conditioned  upon  Investor's
participation in such underwriting and the inclusion of Investor's Shares in the
underwriting to


                                      -3-
<PAGE>


the extent  provided  herein.  Investor shall  (together  with the Company,  its
directors and officers, and any other shareholders distributing their securities
through such  underwriting)  enter into an  underwriting  agreement in customary
form with the  underwriter  or  underwriters  selected for  underwriting  by the
Company.

       Notwithstanding any other provision of this Section 5, if the underwriter
determines  that marketing  factors require a limitation on the number of shares
to be  underwritten,  the  underwriter  may exclude from such  registration  and
underwriting  some or all of the Shares which would  otherwise  be  underwritten
pursuant hereto.  Any securities so excluded shall be apportioned pro rata among
Investor and any other  shareholders  distributing their securities through such
underwriting  according to the total amount of securities  otherwise entitled to
be included therein owned by such  shareholders or in such other  proportions as
shall mutually be agreed upon.

       If Investor  disapproves  of the terms of any such  underwriting,  it may
elect  to  withdraw   therefrom  by  written  notice  to  the  Company  and  the
underwriter.  Any Shares excluded or withdrawn from such  underwriting  shall be
withdrawn from such registration.

       The Company shall bear all Registration  Expenses  incurred in connection
with any  registration,  qualification and compliance by the Company pursuant to
this Section  5(b).  All Selling  Expenses  shall be borne by the holders of the
securities so registered  pro rata on the basis of the number of their shares so
registered.

                     (iii)  REGISTRATION PROCEDURES. In the case of registration
effected  by the  Company  pursuant to this  Agreement,  the  Company  will keep
Investor  advised in writing as to the initiation of registration  and as to the
completion thereof. At its expense, the Company will:

                            a)     keep such registration effective for a period
of one year or until  Investor has completed the  distribution  described in the
registration statement relating thereto, whichever first occurs;

                            b)     furnish such number of prospectuses and other
documents incident thereto as Investor from time to time may reasonably request;
and

                            c)     use its best  efforts to  register or qualify
the  Shares  under  the  securities  or blue sky laws of such  jurisdictions  as
Investor may request; provided, however, that the Company shall not be obligated
to register or qualify such Shares in any particular  jurisdiction  in which the
Company would be required to execute a general  consent to service of process in
order to effect such  registration,  qualification,  or  compliance,  unless the
Company is already subject to service in such  jurisdiction and except as may be
required by the Securities Act or applicable rules or regulations thereunder.

                            d)     Notify the  holder of Shares  covered by such
registration  statement  at any  time  when a  prospectus  relating  thereto  is
required to be delivered under the Act of the happening of any event as a result
of which the  prospectus  included in such  registration  statement,  as then in
effect,  includes  an untrue  statement  of a material  fact or omits to state a
material fact required to be stated  therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.


                             4-
<PAGE>

       (c)    INDEMNIFICATION.

              (i)    The  Company  will  indemnify  the  Investor,  each  of its
officers,  directors and  partners,  and each person  controlling  such Investor
within the  meaning of Section 15 of the  Securities  Act or the 1934 Act,  with
respect to which  registration,  qualification  or compliance  has been effected
pursuant to this Agreement,  and each  underwriter,  if any, and each person who
controls any underwriter  within the meaning of Section 15 of the Securities Act
or the 1934 Act, against all expenses,  claims,  losses,  damages or liabilities
(or actions in respect  thereof),  including  any of the  foregoing  incurred in
settlement of any litigation,  commenced or threatened,  arising out of or based
on any untrue  statement  (or  alleged  untrue  statement)  of a  material  fact
contained in any registration statement,  prospectus, offering circular or other
document,  or  any  amendment  or  supplement  thereto,  incident  to  any  such
registration,  qualification or compliance, or based on any omission (or alleged
omission)  to state  therein a material  fact  required to be stated  therein or
necessary to make the statements  therein,  in the light of the circumstances in
which they were made,  not  misleading,  or any  violation by the Company of the
Securities Act, or the 1934 Act, or any rule or regulation promulgated under the
Securities  Act,  or the 1934 Act,  or under any state  securities  law or under
common law,  applicable to the Company in connection with any such registration,
qualification or compliance,  and the Company will reimburse the Investor,  each
of its  officers,  directors  and  partners,  and each  person  controlling  the
Investor,   each  such  underwriter  and  each  person  who  controls  any  such
underwriter,  for any legal and any other expenses reasonably incurred,  as such
expenses are incurred, in connection with investigating,  preparing or defending
any such claim, loss, damage, liability or action;  provided,  however, that the
Company will not be liable (i) for amounts paid in  settlement of any such loss,
claim,  damage,  liability or action if such settlement is effected  without the
consent of the Company  (which consent shall not be  unreasonably  withheld) and
(ii) in any such case to the extent that any such claim, loss, damage, liability
or expense  arises out of or is based on any untrue  statement  or  omission  or
alleged  untrue  statement or omission,  made in reliance upon and in conformity
with written information furnished to the Company by an instrument duly executed
by the Investor, controlling person or underwriter and stated to be specifically
for use therein.

              (ii)   The  Investor  will,  if Shares  held by the  Investor  are
included  in the  securities  as to which such  registration,  qualification  or
compliance is being effected,  indemnify the Company,  each of its directors and
officers, each underwriter,  if any, of the Company's securities covered by such
a  registration  statement,  each  person  who  controls  the  Company  or  such
underwriter  within the meaning of Section 15 of the  Securities Act against all
claims,  losses, damages and liabilities (or actions in respect thereof) arising
out of or based on any untrue  statement  (or  alleged  untrue  statement)  of a
material fact contained in any such registration statement, prospectus, offering
circular or other  document,  or any  omission  (or alleged  omission)  to state
therein a material fact  required to be stated  therein or necessary to make the
statements  therein  not  misleading,  and  will  reimburse  the  Company,  such
directors,  officers, persons,  underwriters or control persons for any legal or
any other  expenses  reasonably  incurred in connection  with  investigating  or
defending any such claim, loss, damage, liability or action, in each case to the
extent,  but only to the extent,  that such untrue  statement (or alleged untrue
statement)  or  omission  (or  alleged  omission)  is made in such  registration
statement,  prospectus, offering circular or other document in reliance upon and
in conformity with written


                                      -5-
<PAGE>

information  furnished  to the  Company by an  instrument  duly  executed by the
Investor  and stated to be  specifically  for use therein.  Notwithstanding  the
foregoing,  the liability of the Investor under this subsection  shall not apply
to amounts paid in  settlement  of any such loss,  claim,  damage,  liability or
action if such settlement is effected without the consent of the Investor (which
consent  shall not be  unreasonably  withheld),  and (ii) shall be limited in an
amount equal to the  aggregate  net proceeds of the shares sold by the Investor,
except  to the  extent  such  liability  arises  out of or is based  on  willful
misconduct by the Investor.

              (iii)  Each party entitled to  indemnification  under this Section
5(d) (the  "Indemnified  Party")  shall  give  notice to the party  required  to
provide   indemnification   (the  "Indemnifying   Party")  promptly  after  such
Indemnified Party has actual knowledge of any claim as to which indemnity may be
sought,  and shall  permit the  Indemnifying  Party to assume the defense of any
such claim or any litigation resulting therefrom,  provided that counsel for the
Indemnifying  Party,  who shall conduct the defense of such claim or litigation,
shall  be  approved  by  the   Indemnified   Party  (whose  approval  shall  not
unreasonably  be withheld),  and the  Indemnified  Party may participate in such
defense at such party's  expense,  and provided  further that the failure of any
Indemnified  Party to give  notice as  provided  herein  shall not  relieve  the
Indemnifying  Party of its obligations under this Agreement except to the extent
that  the  failure  to  give  such  notice  is  materially   prejudicial  to  an
Indemnifying  Party's ability to defend such action and provided  further,  that
the  Indemnifying  Party  shall not assume the  defense  for matters as to which
there is a conflict of interest or separate and  different  defenses,  but shall
pay the fees and expenses of one separate  counsel  retained by the  Indemnified
Party in the event of such conflict of interest.  No Indemnifying  Party, in the
defense of any such claim or litigation,  shall, except with the consent of each
Indemnified Party, consent to entry of any judgment or enter into any settlement
which  does not  include  as an  unconditional  term  thereof  the giving by the
claimant or plaintiff to such Indemnified  Party of a release from all liability
in respect to such claim or litigation.

              (iv)   If the indemnification provided for in this Section 5(d) is
held by a court of competent  jurisdiction  to be  unavailable to an indemnified
party with respect to any loss, liability, claim, damage, or expense referred to
therein,  then the Indemnifying  Party, in lieu of indemnifying such Indemnified
Party  hereunder,  shall  contribute  to the  amount  paid  or  payable  by such
Indemnified Party as a result of such loss, liability, claim, damage, or expense
in such  proportion  as is  appropriate  to reflect  the  relative  fault of the
Indemnifying  Party on the one hand and of the Indemnified Party on the other in
connection  with  the  statements  or  omissions  that  resulted  in such  loss,
liability,  claim,  damage,  or expense as well as any other relevant  equitable
considerations.  The  relative  fault  of  the  Indemnifying  Party  and  of the
Indemnified  Party shall be  determined  by reference  to,  among other  things,
whether  the  untrue or  alleged  untrue  statement  of a  material  fact or the
omission  to state a  material  fact  relates  to  information  supplied  by the
indemnifying party or by the indemnified party and the parties' relative intent,
knowledge,  access to  information,  and  opportunity to correct or prevent such
statement or omission.

              (v)    The  obligations of the Company and the Investor under this
Section  5(d)  shall  survive  the  completion  of any  offering  of Shares in a
registration statement under this Section 5 and otherwise.


                                      -6-
<PAGE>

              (vi)   INFORMATION BY INVESTOR. The Investor of Shares included in
any  registration  shall  furnish  to the  Company  such  information  regarding
Investor,  the Shares held by it and the distribution  proposed by such Investor
as the Company  may  reasonably  request in writing  and as shall be  reasonably
required  in  connection  with any  registration,  qualification  or  compliance
referred to in this Agreement.

              (vii)  TRANSFER OF  REGISTRATION  RIGHTS.  The rights to cause the
Company to register  securities  granted Holders under Section 5 may be assigned
to a transferee  or assignee in  connection  with any transfer or  assignment of
Shares by a Holder provided that: (i) such transfer may otherwise be effected in
accordance with applicable  securities laws and (ii) such assignee or transferee
becomes a party to this  Agreement  and  assumes all of the  obligations  of the
transferring Holder under Section 5.

       6.     GOVERNING LAW. This  Agreement  shall be governed by and construed
in accordance with the laws of the State of Texas.

       7.     COUNTERPARTS.  This  Agreement  may be  executed  in any number of
counterparts,  each of which  shall be an  original,  but all of which  together
shall constitute one instrument.

       IN WITNESS  WHEREOF,  the  undersigned  purchasers of securities  and the
Company have executed this Agreement as of the day and year first above written.


                                       POSITRON CORPORATION


                                       By: /s/ S. Lewis Meyer
                                          --------------------------------------
                                                       Its: Chairman


                                       INVESTOR

                                       /s/ Gary H. Brooks
                                       -----------------------------------------
                                                       Gary H. Brooks



                                      -7-



                                  EXHIBIT 4.10

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (I) IN A  REGISTRATION  UNDER SAID ACT OR
(II) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.

                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                  TO PURCHASE 3,000,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                       This Warrant Expires June 15, 2009


Warrant No. 99-1                                                3,000,000 Shares


      THIS CERTIFIES that,  subject to the terms and conditions herein set forth
in this  warrant,  GARY H. BROOKS (the  "Holder")  is entitled to purchase  from
Positron Corporation, a Texas corporation ("Company"),  at any time or from time
to time during the Exercise  Period (defined in Section 12 below) and subject to
the provisions  regarding  Exercise of Warrant (as set forth in Section 6 below)
the  number of fully  paid and  non-assessable  shares  of  common  stock of the
Company (the "Shares") as provided  herein upon surrender of this Warrant at the
principal  office of the  Company,  and, at the  election  of the  Holder,  upon
payment of the purchase price at said office in cash or by cashier's check or by
the wire transfer of funds in a dollar amount equal to the purchase price of the
Shares for which the consideration is being given.

      This Warrant shall be  exercisable  for that number of Shares as set forth
above,  in minimum  units of  100,000  shares.

      1.    PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share of  Common  Stock  (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall be Thirty Cents ($0.30).

      2.    ADJUSTMENT  OF WARRANT  PRICE AND  NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:


                                      -1-
<PAGE>


            (a)   ADJUSTMENT FOR DIVIDENDS IN STOCK.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other  securities at the time  receivable  upon the exercise of this
Warrant)  shall have  received,  or, on or after the  record  date fixed for the
determination of eligible  stockholders,  shall have become entitled to receive,
without  payment  therefor,  other or additional  stock of the Company by way of
dividend  (other than as provided for in Section  2(b) below),  then and in each
such case,  upon the exercise of this  Warrant,  the Holder shall be entitled to
receive,  in addition to the number of shares of Common  Stock  receivable,  and
without  payment of any additional  consideration  therefor,  the amount of such
other or  additional  stock of the Company which the Holder would receive on the
date of such  exercise  had it been the holder of record of such Common Stock on
the date  hereof and had  thereafter,  during the period from the date hereof to
and including the date of such  exercise,  retained such shares and/or all other
additional  stock  receivable  by it as  aforesaid  during such period and given
effect to all adjustments called for during such period by this Section 2.

            (b)   ADJUSTMENT  FOR  CHANGES  IN  COMMON  STOCK.  In the  event of
changes in the  outstanding  Common Stock of the Company by reason of split-ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.

      3.    NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

      4.    NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a stockholder of the Company prior to its exercise.

      5.    RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.

      6.    EXERCISE  OF  WARRANT;  REPURCHASE  RIGHT.  Subject to the terms and
conditions  hereof,  this  Warrant may be  exercised  by the holder  hereof then
registered  on the books of the  Company  any time on or after  granting  of the
Warrant,  subject  however to the Company's  right to repurchase  any portion of
this  Warrant,  and/or any  portion of any stock  issued  upon  exercise  of the
Warrant ("Repurchase Right"), as of a date 90 days following termination for any
reason


                                      -2-
<PAGE>


or for no reason of the  employment  by the Company of the initial  holder.  The
Company's Repurchase Right shall lapse as follows:  immediately upon issuance as
to 750,000 shares; as to an additional 187,500 shares on September 15, 1999; and
as to an additional  187,500  shares  quarterly  thereafter  until the Company's
Repurchase  Right shall have lapsed as to all shares.  Subject to the foregoing,
this Warrant may be exercised by the Holder or its registered  assigns, in whole
or in part and in minimum  units of 100,000  shares,  by the  surrender  of this
Warrant at the principal office of the Company,  together with the attached form
of subscription  duly executed,  accompanied by payment in full of the amount of
the Warrant Price in the form described in this Warrant.  Upon partial  exercise
of this  Warrant,  a new  warrant  or  warrants  containing  the  same  date and
provisions  as this  Warrant  shall be issued by the  Company to the  registered
holder  for the  number of shares of Common  Stock  with  respect  to which this
Warrant  shall not have been  exercised.  A Warrant shall be deemed to have been
exercised  immediately  prior  to the  close  of  business  on the  date  of its
surrender for exercise as provided above, and the person entitled to receive the
shares of Common  Stock  issuable  upon such  exercise  shall be treated for all
purposes  as the holder of such  shares of record as of the close of business on
such date. As promptly as  practicable  on or after such date, the Company shall
issue and deliver to the person or persons  entitled  to receive  the shares,  a
certificate  or  certificates  for the  number of full  shares  of Common  Stock
issuable  upon such  exercise,  together  with cash in lieu of any fraction of a
share as provided above.

      7.    CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

      8.    COMPLIANCE WITH  SECURITIES  ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm  in  writing  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

      9.    SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants  of like  tenor and date  representing  in the  aggregate  the right to
purchase  such number of shares of such Common Stock as shall be  designated  by
such holder at the time of such surrender; provided, however, that the Company's
obligations to subdivide  securities  under this Section shall be subject to and
conditioned  upon the compliance of any such  subdivision  with applicable state
securities laws and with the Securities Act.

      10.   LOSS, THEFT, DESTRUCTION,  OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this


                                      -3-
<PAGE>


Warrant,  and in the  case of loss,  theft,  or  destruction,  of  indemnity  or
security  reasonably  satisfactory to it and reimbursement to the Company of all
reasonable  expenses  incidental  thereto,  in the case of mutilation,  and upon
surrender and  cancellation  of this Warrant the Company will make and deliver a
new  Warrant  of like tenor and dates as of such  cancellation,  in lieu of this
Warrant.

      11.   MISCELLANEOUS.  This  Warrant  shall be  governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference  only,  and shall not be deemed to  constitute a part of this Warrant.
Neither this Warrant nor any term included may be changed,  waived,  discharged,
or terminated  orally but only by an instrument in writing signed by the Company
and the Holder.  All notices  and other  communications  from the Company to the
Holder  shall  be by  telecopy  or  expedited  courier  service  to the  address
furnished to the Company in writing by the last holder of this Warrant who shall
have  furnished  an address to the  Company in  writing.  This  Warrant has been
issued pursuant to a Warrant  Purchase  Agreement dated as of June 15, 1999, the
terms of which, including certain repurchase provisions, are incorporated herein
by reference.  A copy of such Warrant Purchase Agreement may be inspected at the
office of the Company during normal business hours.

      12.   EXERCISE   PERIOD.   The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on June 15, 2009.

      ISSUED this 15th day of June, 1999.


                                            POSITRON CORPORATION

                                            By: /s/ S. Lewis Meyer
                                               ---------------------------------
                                            Its: Chairman

ATTEST:


- -------------------------

                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION


      FOR VALUE RECEIVED the undersigned registered owner of this warrant hereby
sells, assigns, and transfers unto the Assignee named below all of the rights of
the undersigned  under the within Warrant,  with respect to the number of shares
of Common Stock set forth below.

             Name of Assignee:

             --------------------------


             Address:

             --------------------------

             --------------------------



             Number of Shares

             --------------------------

and does hereby  irrevocably  constitute and appoint  __________________________
Attorney to make such transfer on the books of POSITRON  CORPORATION  maintained
for the purpose, with full power of substitution in the premises.

Dated:
      ----------------------

                                               ---------------------------------
                                               Name of Warrant Holder


                                               ---------------------------------
                                               Signature



Witness:
        --------------------

<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)

      The undersigned  registered  owner of this Warrant  irrevocably  exercises
this  Warrant  for and  purchases  ________________  of the  number of shares of
Common Stock of POSITRON CORPORATION purchasable with this Warrant, and herewith
makes  payment  therefor,  all at the  price  and on the  terms  and  conditions
specified in this Warrant.

Dated:
      ---------------------

                                        ----------------------------------------
                                        Signature of Registered Owner

                                        ----------------------------------------
                                        Street Address

                                        ----------------------------------------
                                        City                State    Zip Code




                                  EXHIBIT 4.11


                           WARRANT PURCHASE AGREEMENT


      THIS WARRANT PURCHASE AGREEMENT (the "Agreement") is made and entered into
this  15th  day of  June,  1999 by and  between  POSITRON  CORPORATION,  a Texas
corporation (the "Company") and S. LEWIS MEYER (the "Investor").


                                R E C I T A L S :
                                 - - - - - - - -


      WHEREAS, the Company desires to issue to Investor and the Investor desires
to purchase  from the Company a warrant (the  "Warrant")  to purchase  1,500,000
shares  of the  Company's  common  stock  (the  "Shares")  all on the  terms and
conditions  hereinafter  provided.  The  Warrant  and the Shares  are  hereafter
collectively referred to as the "Securities".

      NOW, THEREFORE, IT IS AGREED AS FOLLOWS:

      1.    ISSUANCE  OF  WARRANT;  REPURCHASE  RIGHT.  For a purchase  price of
$0.0067 per warrant (the "Per Warrant Purchase Price") representing an aggregate
purchase  price of $10,000  ("Aggregate  Purchase  Price")  payable in cash upon
execution hereof, the Company agrees to issue to Investor the Warrant,  the form
of which is  attached  hereto as Exhibit A. The  Company  reserves to itself the
right  to  repurchase  any  portion  of the  Warrant  issued  pursuant  to  this
Agreement,  and the right to  repurchase  any stock issued upon  exercise of any
portion of the  Warrant  ("Repurchase  Right"),  as of a date 90 days  following
termination  for  any  reason  or for no  reason  of  Investor's  service  to or
affiliation  with the Company.  The price of repurchase will be equal to the Per
Warrant  Purchase  Price  regarding  any  portion of the  Warrant  that  remains
unexercised  at the time the Company  exercises  its  Repurchase  Right,  or the
purchase price of the underlying  stock (i.e. the exercise price of the Warrant)
regarding any portion of the Warrant that has already been exercised at the time
the Company  exercises its Repurchase Right. The Repurchase Right shall lapse as
follows:  immediately  upon issuance as to 375,000  shares;  as to an additional
93,750  shares on September  15, 1999;  and as to an  additional  93,750  shares
quarterly  thereafter until the Company's  Repurchase Right shall have lapsed as
to all shares.

      2.    INVESTOR REPRESENTATIONS. Investor hereby represents and warrants to
the Company as follows:

            (a)   The Investor  understands  that:  (i)The offer and sale of the
Securities  by the  Company  to  Investor  has not  been  registered  under  the
Securities Act of 1933 (the "Securities  Act"), in reliance on an exemption from
such  registration   available  under  the  Securities  Act  and  rules  adopted
thereunder;  (ii)The  Investor  must hold the  Warrant  indefinitely  unless the
Securities are  subsequently  registered  under the Securities Act and qualified
under

<PAGE>


applicable state securities laws, or unless an exemption from such  registration
and qualification is available.

            (b)   The Investor is acquiring  the  Securities  for his or her own
account, for investment,  and not with a view to any sale or distribution of any
interest therein.

            (c)   The Investor has such  knowledge  and  experience in financial
and business  matters as to be capable of evaluating  the merits and risks of an
investment  in the  Securities,  and the  Investor is able to bear the  economic
risks of such an investment.

            (d)   All  statements  made,  and  information  furnished,   by  the
Investor in this certificate and all other information furnished by the Investor
to the Company, are true and complete, to the best of the Investor's knowledge.

      3.    RESTRICTIONS ON TRANSFER. The Investor agrees that:

            (a)   The Investor  will not attempt to transfer the  Securities  in
violation of the restrictions set forth in this Agreement.

            (b)   The  Company  may note such  restrictions  on  transfer in its
records and refuse to recognize any transfer  which  violates this  agreement or
for which the Company has not received an acceptable  opinion of counsel stating
that such transfer will not violate such restrictions.

            (c)   One or more legends  indicating a lack of  registration  under
the Securities Act and a lack of qualification  under state securities laws will
be imprinted on the  Securities.  One such legend  shall read  substantially  as
follows:

      THE SECURITIES  HAVE NOT BEEN  REGISTERED WITH THE SECURITIES AND EXCHANGE
COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND ANY SALE, TRANSFER,
PLEDGE OR OTHER DISPOSITION THEREOF MAY BE MADE ONLY (i) IN A REGISTRATION UNDER
SAID ACT OR (ii) IF AN EXEMPTION FROM  REGISTRATION  UNDER SAID ACT IS AVAILABLE
AND THE  COMPANY HAS  RECEIVED  AN OPINION OF COUNSEL TO THAT EFFECT  REASONABLY
SATISFACTORY TO IT.

      4.    BINDING ON SUCCESSORS; INDEMNIFICATION. The Investor agrees that the
above  representations  and warranties are binding on the Investor's  successors
and assigns  and are made for the  benefit of the Company and any other  persons
who may become liable for  violations of federal or state  securities  laws as a
result of the falsity of any of the  Investor's  representations  or warranties.
The Investor  agrees to indemnify,  defend,  and hold harmless such persons from
any liability arising from the falsity of any of the Investor's  representations
or warranties or from the breach of any covenant of Investor contained herein.

      5.    REGISTRATION  RIGHTS.  The Company  hereby  grants to  Investor  the
following registration rights with respect to the Shares:

            (a)   Definitions.


                                      -2-
<PAGE>

            "Commission"  shall mean the Securities  and Exchange  Commission or
any other federal  agency at the time  administering  the Securities Act of 1933
(the "Securities Act").

            "Register," "registered," and "registration" refer to a registration
effected by preparing and filing a registration statement in compliance with the
Securities Act of 1933, and the declaration or ordering of the  effectiveness of
such registration statement.

            "Registration  Expenses"  shall mean all  expenses  incurred  by the
Company in compliance with the provisions of this Section 5, including,  without
limitation,  all  registration  and filing  fees,  printing  expenses,  fees and
disbursements  of counsel for the Company,  blue sky fees and expenses,  and the
expenses of any special audits incident to or required by any such  registration
(but excluding the compensation of regular employees of the Company, which shall
be paid in any event by the Company).

            "Selling Expenses" shall mean all underwriting discounts and selling
commissions  applicable to the sale of Shares and all fees and  disbursements of
counsel to Investor.

            "Shares" means the shares of the Company's common stock  exercisable
upon  exercise of the Warrant and any common stock  issued with respect  thereto
(e.g. upon a stock split or stock dividend.

            "Investor"  means  the  person  set forth  above  and any  permitted
assignee.

            (b)   COMPANY REGISTRATION.

                  (i)   NOTICE OF  REGISTRATION.  If, at any time after the date
hereof, the Company shall determine to register any of its securities either for
its own account or the account of a security holder or holders  exercising their
respective demand registration rights, other than a registration relating solely
to employee  benefit plans,  or a registration  relating  solely to a Commission
Rule 145 transaction,  or a registration on any registration form which does not
permit secondary sales, the Company will:

            a)    promptly give to Investor  written notice thereof (which shall
include a list of the  jurisdictions  in which the Company intends to attempt to
qualify such securities  under the applicable blue sky or other state securities
laws); and

            b)    include in such  registration  (and any related  qualification
under  blue sky  laws or other  compliance),  and in any  underwriting  involved
therein,  all the Shares  specified in a written  request or  requests,  made by
Investor  within  fifteen (15) days after receipt of the written notice from the
Company  described in this clause (i),  except as set forth in Section  5(b)(ii)
below.

                  (ii)  UNDERWRITING.  If the  registration of which the Company
gives notice is for a registered public offering involving an underwriting:  the
Company shall so advise Investor as part of the written notice given pursuant to
Section  5(b)  hereof.  In such event,  the right of  Investor  to  registration
pursuant to this Section 5 shall be conditioned upon Investor's participation in
such underwriting and the inclusion of Investor's Shares in the underwriting to


                                      -3-
<PAGE>

the extent  provided  herein.  Investor shall  (together  with the Company,  its
directors and officers, and any other shareholders distributing their securities
through such  underwriting)  enter into an  underwriting  agreement in customary
form with the  underwriter  or  underwriters  selected for  underwriting  by the
Company.

      Notwithstanding  any other provision of this Section 5, if the underwriter
determines  that marketing  factors require a limitation on the number of shares
to be  underwritten,  the  underwriter  may exclude from such  registration  and
underwriting  some or all of the Shares which would  otherwise  be  underwritten
pursuant hereto.  Any securities so excluded shall be apportioned pro rata among
Investor and any other  shareholders  distributing their securities through such
underwriting  according to the total amount of securities  otherwise entitled to
be included therein owned by such  shareholders or in such other  proportions as
shall mutually be agreed upon.

      If  Investor  disapproves  of the terms of any such  underwriting,  it may
elect  to  withdraw   therefrom  by  written  notice  to  the  Company  and  the
underwriter.  Any Shares excluded or withdrawn from such  underwriting  shall be
withdrawn from such registration.

      The Company shall bear all  Registration  Expenses  incurred in connection
with any  registration,  qualification and compliance by the Company pursuant to
this Section  5(b).  All Selling  Expenses  shall be borne by the holders of the
securities so registered  pro rata on the basis of the number of their shares so
registered.

                  (iii) REGISTRATION  PROCEDURES.  In the  case of  registration
effected  by the  Company  pursuant to this  Agreement,  the  Company  will keep
Investor  advised in writing as to the initiation of registration  and as to the
completion thereof. At its expense, the Company will:

                        a)    keep such  registration  effective for a period of
one year or until  Investor  has  completed  the  distribution  described in the
registration statement relating thereto, whichever first occurs;

                        b)    furnish  such  number  of  prospectuses  and other
documents incident thereto as Investor from time to time may reasonably request;
and

                        c)    use its best  efforts to  register  or qualify the
Shares under the securities or blue sky laws of such  jurisdictions  as Investor
may  request;  provided,  however,  that the Company  shall not be  obligated to
register or qualify  such  Shares in any  particular  jurisdiction  in which the
Company would be required to execute a general  consent to service of process in
order to effect such  registration,  qualification,  or  compliance,  unless the
Company is already subject to service in such  jurisdiction and except as may be
required by the Securities Act or applicable rules or regulations thereunder.

                        d)    Notify  the  holder  of  Shares  covered  by  such
registration  statement  at any  time  when a  prospectus  relating  thereto  is
required to be delivered under the Act of the happening of any event as a result
of which the  prospectus  included in such  registration  statement,  as then in
effect,  includes  an untrue  statement  of a material  fact or omits to state a
material fact required to be stated  therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.


                                      -4-
<PAGE>

            (c)   INDEMNIFICATION.

                  (i)   The Company will  indemnify  the  Investor,  each of its
officers,  directors and  partners,  and each person  controlling  such Investor
within the  meaning of Section 15 of the  Securities  Act or the 1934 Act,  with
respect to which  registration,  qualification  or compliance  has been effected
pursuant to this Agreement,  and each  underwriter,  if any, and each person who
controls any underwriter  within the meaning of Section 15 of the Securities Act
or the 1934 Act, against all expenses,  claims,  losses,  damages or liabilities
(or actions in respect  thereof),  including  any of the  foregoing  incurred in
settlement of any litigation,  commenced or threatened,  arising out of or based
on any untrue  statement  (or  alleged  untrue  statement)  of a  material  fact
contained in any registration statement,  prospectus, offering circular or other
document,  or  any  amendment  or  supplement  thereto,  incident  to  any  such
registration,  qualification or compliance, or based on any omission (or alleged
omission)  to state  therein a material  fact  required to be stated  therein or
necessary to make the statements  therein,  in the light of the circumstances in
which they were made,  not  misleading,  or any  violation by the Company of the
Securities Act, or the 1934 Act, or any rule or regulation promulgated under the
Securities  Act,  or the 1934 Act,  or under any state  securities  law or under
common law,  applicable to the Company in connection with any such registration,
qualification or compliance,  and the Company will reimburse the Investor,  each
of its  officers,  directors  and  partners,  and each  person  controlling  the
Investor,   each  such  underwriter  and  each  person  who  controls  any  such
underwriter,  for any legal and any other expenses reasonably incurred,  as such
expenses are incurred, in connection with investigating,  preparing or defending
any such claim, loss, damage, liability or action;  provided,  however, that the
Company will not be liable (i) for amounts paid in  settlement of any such loss,
claim,  damage,  liability or action if such settlement is effected  without the
consent of the Company  (which consent shall not be  unreasonably  withheld) and
(ii) in any such case to the extent that any such claim, loss, damage, liability
or expense  arises out of or is based on any untrue  statement  or  omission  or
alleged  untrue  statement or omission,  made in reliance upon and in conformity
with written information furnished to the Company by an instrument duly executed
by the Investor, controlling person or underwriter and stated to be specifically
for use therein.

                  (ii)  The  Investor  will,  if Shares held by the Investor are
included  in the  securities  as to which such  registration,  qualification  or
compliance is being effected,  indemnify the Company,  each of its directors and
officers, each underwriter,  if any, of the Company's securities covered by such
a  registration  statement,  each  person  who  controls  the  Company  or  such
underwriter  within the meaning of Section 15 of the  Securities Act against all
claims,  losses, damages and liabilities (or actions in respect thereof) arising
out of or based on any untrue  statement  (or  alleged  untrue  statement)  of a
material fact contained in any such registration statement, prospectus, offering
circular or other  document,  or any  omission  (or alleged  omission)  to state
therein a material fact  required to be stated  therein or necessary to make the
statements  therein  not  misleading,  and  will  reimburse  the  Company,  such
directors,  officers, persons,  underwriters or control persons for any legal or
any other  expenses  reasonably  incurred in connection  with  investigating  or
defending any such claim, loss, damage, liability or action, in each case to the
extent,  but only to the extent,  that such untrue  statement (or alleged untrue
statement)  or  omission  (or  alleged  omission)  is made in such  registration
statement,  prospectus, offering circular or other document in reliance upon and
in conformity with written


                                      -5-
<PAGE>

information  furnished  to the  Company by an  instrument  duly  executed by the
Investor  and stated to be  specifically  for use therein.  Notwithstanding  the
foregoing,  the liability of the Investor under this subsection  shall not apply
to amounts paid in  settlement  of any such loss,  claim,  damage,  liability or
action if such settlement is effected without the consent of the Investor (which
consent  shall not be  unreasonably  withheld),  and (ii) shall be limited in an
amount equal to the  aggregate  net proceeds of the shares sold by the Investor,
except  to the  extent  such  liability  arises  out of or is based  on  willful
misconduct by the Investor.

                  (iii) Each  party  entitled  to  indemnification   under  this
Section 5(d) (the  "Indemnified  Party") shall give notice to the party required
to  provide  indemnification  (the  "Indemnifying  Party")  promptly  after such
Indemnified Party has actual knowledge of any claim as to which indemnity may be
sought,  and shall  permit the  Indemnifying  Party to assume the defense of any
such claim or any litigation resulting therefrom,  provided that counsel for the
Indemnifying  Party,  who shall conduct the defense of such claim or litigation,
shall  be  approved  by  the   Indemnified   Party  (whose  approval  shall  not
unreasonably  be withheld),  and the  Indemnified  Party may participate in such
defense at such party's  expense,  and provided  further that the failure of any
Indemnified  Party to give  notice as  provided  herein  shall not  relieve  the
Indemnifying  Party of its obligations under this Agreement except to the extent
that  the  failure  to  give  such  notice  is  materially   prejudicial  to  an
Indemnifying  Party's ability to defend such action and provided  further,  that
the  Indemnifying  Party  shall not assume the  defense  for matters as to which
there is a conflict of interest or separate and  different  defenses,  but shall
pay the fees and expenses of one separate  counsel  retained by the  Indemnified
Party in the event of such conflict of interest.  No Indemnifying  Party, in the
defense of any such claim or litigation,  shall, except with the consent of each
Indemnified Party, consent to entry of any judgment or enter into any settlement
which  does not  include  as an  unconditional  term  thereof  the giving by the
claimant or plaintiff to such Indemnified  Party of a release from all liability
in respect to such claim or litigation.

                  (iv)  If the indemnification provided for in this Section 5(d)
is held by a court of competent jurisdiction to be unavailable to an indemnified
party with respect to any loss, liability, claim, damage, or expense referred to
therein,  then the Indemnifying  Party, in lieu of indemnifying such Indemnified
Party  hereunder,  shall  contribute  to the  amount  paid  or  payable  by such
Indemnified Party as a result of such loss, liability, claim, damage, or expense
in such  proportion  as is  appropriate  to reflect  the  relative  fault of the
Indemnifying  Party on the one hand and of the Indemnified Party on the other in
connection  with  the  statements  or  omissions  that  resulted  in such  loss,
liability,  claim,  damage,  or expense as well as any other relevant  equitable
considerations.  The  relative  fault  of  the  Indemnifying  Party  and  of the
Indemnified  Party shall be  determined  by reference  to,  among other  things,
whether  the  untrue or  alleged  untrue  statement  of a  material  fact or the
omission  to state a  material  fact  relates  to  information  supplied  by the
indemnifying party or by the indemnified party and the parties' relative intent,
knowledge,  access to  information,  and  opportunity to correct or prevent such
statement or omission.

                  (v)   The  obligations  of the Company and the Investor  under
this Section 5(d) shall  survive the  completion  of any offering of Shares in a
registration statement under this Section 5 and otherwise.


                                      -6-
<PAGE>


                  (vi)  INFORMATION BY INVESTOR. The Investor of Shares included
in any  registration  shall  furnish to the Company such  information  regarding
Investor,  the Shares held by it and the distribution  proposed by such Investor
as the Company  may  reasonably  request in writing  and as shall be  reasonably
required  in  connection  with any  registration,  qualification  or  compliance
referred to in this Agreement.

                  (vii) TRANSFER OF REGISTRATION RIGHTS. The rights to cause the
Company to register  securities  granted Holders under Section 5 may be assigned
to a transferee  or assignee in  connection  with any transfer or  assignment of
Shares by a Holder provided that: (i) such transfer may otherwise be effected in
accordance with applicable  securities laws and (ii) such assignee or transferee
becomes a party to this  Agreement  and  assumes all of the  obligations  of the
transferring Holder under Section 5.

      6.    GOVERNING LAW. This Agreement  shall be governed by and construed in
accordance with the laws of the State of Texas.

      7.    COUNTERPARTS.  This  Agreement  may be  executed  in any  number  of
counterparts,  each of which  shall be an  original,  but all of which  together
shall constitute one instrument.

      IN WITNESS  WHEREOF,  the  undersigned  purchasers of  securities  and the
Company have executed this Agreement as of the day and year first above written.


                                            POSITRON CORPORATION


                                            By: /s/ Gary H. Brooks
                                            ------------------------------------
                                                       Its: President


                                            INVESTOR

                                            /s/ S. Lewis Meyer
                                            ------------------------------------
                                                      S. Lewis Meyer

                                      -7-




                                  EXHIBIT 4.12

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (i) IN A  REGISTRATION  UNDER SAID ACT OR
(ii) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.


                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                  TO PURCHASE 1,500,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                       This Warrant Expires June 15, 2009


Warrant No. 99-2                                                1,500,000 Shares


      THIS CERTIFIES that,  subject to the terms and conditions herein set forth
in this  warrant,  S. LEWIS MEYER (the  "Holder")  is entitled to purchase  from
Positron Corporation, a Texas corporation ("Company"),  at any time or from time
to time during the Exercise  Period (defined in Section 12 below) and subject to
the provisions  regarding  Exercise of Warrant (as set forth in Section 6 below)
the  number of fully  paid and  non-assessable  shares  of  common  stock of the
Company (the "Shares") as provided  herein upon surrender of this Warrant at the
principal  office of the  Company,  and, at the  election  of the  Holder,  upon
payment of the purchase price at said office in cash or by cashier's check or by
the wire transfer of funds in a dollar amount equal to the purchase price of the
Shares for which the consideration is being given.

      This Warrant shall be  exercisable  for that number of Shares as set forth
above,  in minimum  units of  100,000  shares.

      1.    PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share of  Common  Stock  (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall Thirty Cents ($0.30).


                                      -1-
<PAGE>


      2.    ADJUSTMENT  OF WARRANT  PRICE AND  NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:

            (a)   ADJUSTMENT FOR DIVIDENDS IN STOCK.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other  securities at the time  receivable  upon the exercise of this
Warrant)  shall have  received,  or, on or after the  record  date fixed for the
determination of eligible  stockholders,  shall have become entitled to receive,
without  payment  therefor,  other or additional  stock of the Company by way of
dividend  (other than as provided for in Section  2(b) below),  then and in each
such case,  upon the exercise of this  Warrant,  the Holder shall be entitled to
receive,  in addition to the number of shares of Common  Stock  receivable,  and
without  payment of any additional  consideration  therefor,  the amount of such
other or  additional  stock of the Company which the Holder would receive on the
date of such  exercise  had it been the holder of record of such Common Stock on
the date  hereof and had  thereafter,  during the period from the date hereof to
and including the date of such  exercise,  retained such shares and/or all other
additional  stock  receivable  by it as  aforesaid  during such period and given
effect to all adjustments called for during such period by this Section 2.

            (b)   ADJUSTMENT  FOR  CHANGES  IN  COMMON  STOCK.  In the  event of
changes in the  outstanding  Common Stock of the Company by reason of split-ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.

      3.    NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

      4.    NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a stockholder of the Company prior to its exercise.

      5.    RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.


                                      -2-
<PAGE>


      6.    EXERCISE  OF  WARRANT;  REPURCHASE  RIGHT.  Subject to the terms and
conditions  hereof,  this  Warrant may be  exercised  by the holder  hereof then
registered  on the books of the  Company  any time on or after  granting  of the
Warrant,  subject  however to the Company's  right to repurchase  any portion of
this  Warrant,  and/or any  portion of any stock  issued  upon  exercise  of the
Warrant ("Repurchase Right"), as of a date 90 days following termination for any
reason or for no reason of the employment by the Company of the initial  holder.
The Company's Repurchase Right shall lapse as follows: immediately upon issuance
as to 375,000 shares;  as to an additional  93,750 shares on September 15, 1999;
and as to an additional  93,750 shares quarterly  thereafter until the Company's
Repurchase  Right shall have lapsed as to all shares.  Subject to the foregoing,
this Warrant may be exercised by the Holder or its registered  assigns, in whole
or in part and in minimum  units of 100,000  shares,  by the  surrender  of this
Warrant at the principal office of the Company,  together with the attached form
of subscription  duly executed,  accompanied by payment in full of the amount of
the Warrant Price in the form described in this Warrant.  Upon partial  exercise
of this  Warrant,  a new  warrant  or  warrants  containing  the  same  date and
provisions  as this  Warrant  shall be issued by the  Company to the  registered
holder  for the  number of shares of Common  Stock  with  respect  to which this
Warrant  shall not have been  exercised.  A Warrant shall be deemed to have been
exercised  immediately  prior  to the  close  of  business  on the  date  of its
surrender for exercise as provided above, and the person entitled to receive the
shares of Common  Stock  issuable  upon such  exercise  shall be treated for all
purposes  as the holder of such  shares of record as of the close of business on
such date. As promptly as  practicable  on or after such date, the Company shall
issue and deliver to the person or persons  entitled  to receive  the shares,  a
certificate  or  certificates  for the  number of full  shares  of Common  Stock
issuable  upon such  exercise,  together  with cash in lieu of any fraction of a
share as provided above.

      7.    CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

      8.    COMPLIANCE WITH  SECURITIES  ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm  in  writing  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

      9.    SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants  of like  tenor and date  representing  in the  aggregate  the right to
purchase  such number of shares of such Common Stock as shall be  designated  by
such holder at the time of such surrender; provided, however, that the Company's
obligations to subdivide  securities  under this Section shall be


                                      -3-
<PAGE>


subject to and  conditioned  upon the  compliance of any such  subdivision  with
applicable state securities laws and with the Securities Act.

      10.   LOSS, THEFT, DESTRUCTION,  OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this Warrant,  and in the case of loss, theft, or
destruction,  of  indemnity  or  security  reasonably  satisfactory  to  it  and
reimbursement to the Company of all reasonable  expenses  incidental thereto, in
the case of mutilation,  and upon surrender and cancellation of this Warrant the
Company  will make and  deliver a new Warrant of like tenor and dates as of such
cancellation, in lieu of this Warrant.

      11.   MISCELLANEOUS.  This  Warrant  shall be  governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference  only,  and shall not be deemed to  constitute a part of this Warrant.
Neither this Warrant nor any term included may be changed,  waived,  discharged,
or terminated  orally but only by an instrument in writing signed by the Company
and the Holder.  All notices  and other  communications  from the Company to the
Holder  shall  be by  telecopy  or  expedited  courier  service  to the  address
furnished to the Company in writing by the last holder of this Warrant who shall
have  furnished  an address to the  Company in  writing.  This  Warrant has been
issued pursuant to a Warrant  Purchase  Agreement dated as of June 15, 1999, the
terms of which, including certain repurchase provisions, are incorporated herein
by reference.  A copy of such Warrant Purchase Agreement may be inspected at the
office of the Company during normal business hours.

      12.   EXERCISE   PERIOD.   The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on June 15, 2009.

      ISSUED this 15th day of June, 1999.

                                                POSITRON CORPORATION

                                                By: /s/ Gary H. Brooks
                                                   -----------------------------
                                                Its: President

ATTEST:


                                                --------------------------------

                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION


         FOR VALUE  RECEIVED the  undersigned  registered  owner of this warrant
hereby sells,  assigns,  and transfers  unto the Assignee named below all of the
rights of the undersigned  under the within Warrant,  with respect to the number
of shares of Common Stock set forth below.


               Name of Assignee

               ---------------------------


               Address

               ---------------------------

               ---------------------------


               Number of Shares

               ---------------------------




and does hereby irrevocably constitute and appoint  ____________________________
Attorney to make such transfer on the books of POSITRON  CORPORATION  maintained
for the purpose, with full power of substitution in the premises.

Dated:
      ------------------------

                                            ------------------------------------
                                            Name of Warrant Holder


                                            ------------------------------------
                                            Signature

Witness:

- ------------------------------

<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)


      The undersigned  registered  owner of this Warrant  irrevocably  exercises
this  Warrant  for and  purchases  ________________  of the  number of shares of
Common Stock of POSITRON CORPORATION purchasable with this Warrant, and herewith
makes  payment  therefor,  all at the  price  and on the  terms  and  conditions
specified in this Warrant.


Dated:
      ---------------------

                                         ---------------------------------------
                                         Signature of Registered Owner

                                         ---------------------------------------
                                         Street Address

                                         ---------------------------------------
                                         City                State     Zip Code



                                  EXHIBIT 4.13

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (I) IN A  REGISTRATION  UNDER SAID ACT OR
(II) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.

                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                   TO PURCHASE 100,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                     This Warrant Expires September 20, 2001

Warrant No. 99-11                                                 100,000 Shares
(Replacement for Warrant No. 95-___)

      THIS CERTIFIES that,  subject to the terms and conditions herein set forth
in this  warrant,  URO-TECH,  Ltd.  (the  "Holder") is entitled to purchase from
Positron Corporation, a Texas corporation ("Company"),  at any time or from time
to time during the Exercise  Period (defined in Section 12 below) and subject to
the provisions  regarding  Exercise of Warrant (as set forth in Section 6 below)
the  number of fully  paid and  non-assessable  shares  of  common  stock of the
Company (the "Shares") as provided  herein upon surrender of this Warrant at the
principal  office of the  Company,  and, at the  election  of the  Holder,  upon
payment of the purchase price at said office in cash or by cashier's check or by
the wire transfer of funds in a dollar amount equal to the purchase price of the
Shares for which the consideration is being given.

      This  Warrant  shall  replace  Warrant  No.  95-_____.   which  is  hereby
cancelled,  and is exercisable  for that number of Shares as set forth above, in
minimum units of 10,000 shares.

      1.    PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share,  of Common  Stock (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall One Dollar ($1.00).

      2.    ADJUSTMENT  OF WARRANT  PRICE AND  NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:

<PAGE>


            a.    ADJUSTMENT FOR DIVIDENDS IN STOCK.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other  securities at the time  receivable  upon the exercise of this
Warrant)  shall have  received,  or, on or after the  record  date fixed for the
determination of eligible  stockholders,  shall have become entitled to receive,
without  payment  therefor,  other or additional  stock of the Company by way of
dividend  (other than as provided for in Section  2(b) below),  then and in each
such case,  upon the exercise of this  Warrant,  the Holder shall be entitled to
receive,  in addition to the number of shares of Common  Stock  receivable,  and
without  payment of any additional  consideration  therefor,  the amount of such
other or  additional  stock of the Company which the Holder would receive on the
date of such  exercise  had it been the holder of record of such Common Stock on
the date  hereof and had  thereafter,  during the period from the date hereof to
and including the date of such  exercise,  retained such shares and/or all other
additional  stock  receivable  by it as  aforesaid  during such period and given
effect to all adjustments called for during such period by this Section 2.

            b.    ADJUSTMENT  FOR  CHANGES  IN  COMMON  STOCK.  In the  event of
changes in the  outstanding  Common Stock of the Company by reason of split-ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.

      3.    NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

      4.    NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a stockholder of the Company prior to its exercise.

      5.    RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.

      6.    EXERCISE OF  WARRANT.  Subject to the terms and  conditions  hereof,
this Warrant may be exercised by the holder hereof then  registered on the books
of the Company at any time during the Exercise Period as set forth in Section 12
herein, and may be exercised by the Holder or its registered  assigns,  in whole
or in part and in  minimum  units of 10,000  shares,  by the  surrender  of this
Warrant at the principal office of the Company,  together with the attached form


                                      -2-
<PAGE>

of subscription  duly executed,  accompanied by payment in full of the amount of
the Warrant Price in the form described in this Warrant.  Upon partial  exercise
of this  Warrant,  a new  warrant  or  warrants  containing  the  same  date and
provisions  as this  Warrant  shall be issued by the  Company to the  registered
holder  for the  number of shares of Common  Stock  with  respect  to which this
Warrant  shall not have been  exercised.  A Warrant shall be deemed to have been
exercised  immediately  prior  to the  close  of  business  on the  date  of its
surrender for exercise as provided above, and the person entitled to receive the
shares of Common  Stock  issuable  upon such  exercise  shall be treated for all
purposes  as the holder of such  shares of record as of the close of business on
such date. As promptly as  practicable  on or after such date, the Company shall
issue and deliver to the person or persons  entitled  to receive  the shares,  a
certificate  or  certificates  for the  number of full  shares  of Common  Stock
issuable  upon such  exercise,  together  with cash in lieu of any fraction of a
share as provided above.

      7.    CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

      8.    COMPLIANCE WITH  SECURITIES  ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm in  writing,  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

      9.    SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants  of like nature and date  representing  in the  aggregate  the right to
purchase  such number of shares of such Common Stock as shall be  designated  by
such holder at the time of such surrender; provided, however, that the Company's
obligations to subdivide  securities  under this Section shall be subject to and
conditioned  upon the compliance of any such  subdivision  with applicable state
securities laws and with the Securities Act.

      10.   LOSS THEFT,  DESTRUCTION,  OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this Warrant,  and in the case of loss, theft, or
destruction,  of  indemnity  or  security  reasonably  satisfactory  to  it  and
reimbursement to the Company of all reasonable  expenses  incidental thereto, in
the case of mutilation,  and upon surrender an~ cancellation of this Warrant the
Company  will make and  deliver a new Warrant of like tenor and dates as of such
cancellation, in lieu of this Warrant.

                                      -3-

<PAGE>

      11.   MISCELLANEOUS.  This  Warrant  shall be  governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference  only,  and shall not be deemed to  constitute a part of this Warrant.
Neither this Warrant nor any term included may be changed,  waived,  discharged,
or terminated  orally but only by an instrument in writing signed by the Company
and the Holder.  All notices  and other  communications  from the Company to the
Holder  shall be by  telecopy  or  expedited.  courier  service  to the  address
furnished to the Company in writing by the last holder of this Warrant who shall
have  furnished  an address to the  Company in  writing.  This  Warrant has been
issued pursuant to a Warrant  Purchase  Agreement dated as of June 15, 1999, the
terms of which, including certain repurchase provisions, are incorporated herein
by reference.  A copy of such Warrant Purchase Agreement may be inspected at the
office of the Company during normal business hours.

      12.   EXERCISE   PERIOD.   The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on September 20, 2001.

      ISSUED this 20th day of September, 1999.

                                               POSITRON CORPORATION


                                               By: /s/ Gary H. Brooks
                                                  ------------------------------
                                               Gary H. Brooks, President

ATTEST:


- ----------------------------


                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION

      FOR VALUE RECEIVED the undersigned registered owner of this Warrant hereby
sells, assigns, and transfers unto the Assignee named below all of the rights of
the undersigned  under the within Warrant,  with respect to the number of shares
of Common Stock set forth below:

NAME OF ASSIGNEE           ADDRESS                              NUMBER OF SHARES



The undersigned does hereby irrevocably constitute and appoint _________________
Attorney to make such transfer on the books of POSITRON  CORPORATION  maintained
for the purpose, with full power of substitution in the premises.

Dated:
      -------------------------

                                              ----------------------------------
                                              Name of Warrant Holder

                                              Signature:
                                                        ------------------------

Witness:
        -----------------------


                                      -1-
<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)

      The undersigned  registered  owner of this Warrant  irrevocably  exercises
this Warrant for and purchases  _____ of the number of shares of Common Stock of
POSITRON  CORPORATION  purchasable with this Warrant, and herewith makes payment
therefor,  all at the price and on the terms and  conditions  specified  in this
Warrant.

Dated:
      ---------------------

                                         ---------------------------------------
                                         (Signature of Registered Owner)

                                         ---------------------------------------
                                         (Street Address)

                                         ---------------------------------------
                                         (City)             (State)   (Zip Code)

                                      -1-




            [Letterhead of Allen Matkins Leck Gamble & Mallory LLP]







February 10, 2000                                                    Exhibit 5.1


Positron Corporation
1304 Langham Creek Blvd, Suite 300
Houston, Texas 77084

Gentlemen:

      You have requested our opinion with respect to certain matters in
connection with the filing by Positron Corporation (the "Company") of a
Registration Statement on Form SB-2 (the "Registration Statement") with the
Securities and Exchange Commission on behalf of certain Selling Stockholders
covering the offering of up to 78,732,990 shares of the Company's Common Stock
(the "Shares"), of which total 51,172,990 Shares are currently issued and
outstanding and a total of 27,560,000 Shares are issuable upon exercise of
issued and outstanding Warrants to purchase the Company's Common Stock.

      In connection with this opinion, we have examined and relied upon the
Registration Statement and related Prospectus, the Company's Certificate of
Incorporation and Bylaws, as amended, and such other records, documents,
certificates, memoranda and other instruments as in our judgment are necessary
or appropriate to enable us to render the opinion expressed below. We have
assumed the genuineness and authenticity of all documents submitted to us as
originals, the conformity to originals of all documents submitted to us as
copies thereof, and the due execution and delivery of all documents where due
execution and delivery are a prerequisite to the effectiveness thereof.

      We are admitted to practice law in the State of California. Our opinion is
rendered solely with respect to California law and federal law. On the basis of
the foregoing, and in reliance thereon, we are of the opinion that:

      The Shares, when sold and issued in accordance with the Registration
Statement and related Prospectus, will be validly issued, fully paid, and
nonassessable.

      This opinion is intended solely for your benefit and is not to be made
available to or be relied upon by any other person, firm or entity without our
prior written consent. We consent to the filing of this opinion as an Exhibit to
the Registration Statement.

                                     Very truly yours,


                                     /s/ Allen Matkins Leck Gamble & Mallory LLP




                                  EXHIBIT 10.61

                         EXECUTIVE EMPLOYMENT AGREEMENT

       THIS EXECUTIVE  EMPLOYMENT AGREEMENT (the "Agreement") dated as of August
1, 1999, is made by and between  Positron  Corporation a Texas  Corporation (the
"Company"), and Mr. Gary H. Brooks (the "Executive").

       The Company now wishes to employ the Executive  and the Executive  wishes
to accept such employment, subject to the terms and conditions hereof.

       Accordingly, the parties agree as follows:

       1.     TERM OF EMPLOYMENT. The initial term of the Executive's employment
under this Agreement (the initial "Term") commenced on January 22, 1999 and will
end on June 15, 2000,  unless sooner  terminated as herein provided.  As of June
15, 2000,  the  Executive  shall be employed for rolling (6) six month  periods,
whereby  the  Executive's  term  of  employment  shall  be (6) six  months  on a
continuing basis.

              2.     EMPLOYMENT, DUTIES AND ACCEPTANCE.

              2.1.   EMPLOYMENT BY THE COMPANY.  The Company, for itself and its
affiliates,  employs the Executive to render  services in such capacities as the
Board of  Directors  of the Company  ("Board")  may assign  and,  in  connection
therewith,  to  perform  such  duties  as are  consistent  with the  Executive's
appointment  and as the  Board of  Directors  of the  Company  shall  reasonably
direct.  The parties agree and  acknowledge  that  Executive's  services will be
rendered on a full time basis on and after June 15, 1999. The Executive shall be
initially  appointed to the  position of President of the Company.  In addition,
the company will nominate  Executive to serve as a member of the Board.  Subject
to Section 5.1.1 hereof,  the Executive's  expenditure of reasonable  amounts of
time for personal  business,  charitable or professional  activities will not be
deemed as a breach of his undertaking to provide full-time  services  hereunder,
provided that such  activities do not interfere  materially with the Executive's
ability to render such services.

              2.2.   ACCEPTANCE OF EMPLOYMENT  BY THE  EXECUTIVE.  The Executive
accepts  such  employment  and shall render the services  described  above.  The
Executive  shall also serve during all or any part of the Term as an officer and
director  of the  Company and of any of its  affiliates  without any  additional
compensation therefor other than that specified in this Agreement.

              2.3.   PLACE OF EMPLOYMENT. Executive shall relocate his principal
residence at the Company's expense as provided in Section 2.4 hereof to a within
reasonable   commuting  distance  of  the  Company's   corporate   headquarters.
Notwithstanding  the foregoing,  the Executive  acknowledges and agrees that the
nature of his duties to be performed here under are such that he may be required
to travel  extensively  both throughout the United States and abroad and in some
cases  spend   certain   limited   periods  of  time  away  from  the  corporate
headquarters,  and the Executive agrees to do so as is necessary or desirable to
perform his duties here under in a fully professional  manner to the best of his
ability.

<PAGE>


              2.4.   RELOCATION.  In the event that the Executive  relocated his
principal  residence as provided by Section 2.3 hereof, the Company will provide
an   amount   not  to   exceed   $20,000.00   as   reimbursement   of  costs  of
moving/storing/packing  the  Executive's  household  goods,  as well as  interim
travel expenses,  temporary  living  expenses,  etc. The Executive shall provide
receipts to the company to support the reimbursement requested.

       3.     COMPENSATION.

              3.1.   SALARY,  BONUSES,  LIFE INSURANCE.  As compensation for all
services to be rendered  pursuant to this  Agreement,  the Company shall pay the
Executive  as follows:  For the period of January 22, 1999 to June 15,  1999,  a
base salary in the gross amount of $1,000.00 per month;  for the period June 15,
1999 through August 30, 1999, a base salary in the gross amount of $3,416.67 per
month;  on and  after  September  1,  1999,  a base  salary  of  $185,000  on an
annualized  basis.  All base  salary is subject to  withholding  and  authorized
deductions and payable in accordance with the payroll policies of the Company as
from time to time in effect.  In addition to the Annual  Salary,  the  Executive
shall be awarded (no less frequently than annually) to such bonuses,  if any, as
the Board of  Directors  of the  Company  may,  from  time to time,  in its sole
discretion award.

              3.2.   ANNUAL  REVIEW.  Commencing  June  15,  2000  and  annually
thereafter during the Term, the Annual Salary shall be reviewed by the Board and
may be adjusted  (but in no event to an amount less than the Annual  Salary then
in effect)  for the then  upcoming  year,  if the Board in its sole  discretion,
determine that such adjustment is warranted.

              3.3.   PARTICIPATION  IN EMPLOYEE  BENEFIT  PLANS.  The  Executive
shall be entitled during the Term, if and to the extent eligible, to participate
in the Company's  group benefit plans including  life,  hospitalization  or long
term disability insurance plans, health program, pension plan or similar benefit
plans of the Company,  which may be available to other senior  executives of the
Company on generally the same terms as such other executives.

              3.4.   EXPENSES. Subject to such policies as may from time to time
be established by the Company,  the Company shall pay or reimburse the Executive
for all reasonable  business expenses actually incurred or paid by the Executive
during  the Term in the  performance  of the  Executive's  services  under  this
Agreement,  upon  presentation  of expense  statements or vouchers or such other
supporting information as the Company may reasonably require.

              3.5.   AUTOMOBILE.  The  Company  shall  pay to the  Executive  an
automobile  allowance  in the  amount of $500 per month  during  the term of the
Executive's employment.

              3.6.   EQUITY  PARTICIPATION/STOCK  OPTIONS. Pursuant to action of
the Board of Directors at its meeting held on June 15, 1999, the Executive shall
be provided with an opportunity to purchase a common stock purchase  warrant for
3,000,000  shares of the Company's  common stock  exercisable at $0.30 per share
for the sum of $20,000.  The common stock purchase warrant shall be subject to a
right of  repurchase  by the Company at the purchase  price,  or, if  previously
exercised, the common stock shall be subject to repurchase by the Company at the
exercise price which repurchase rights shall lapse as follows:


                                      -2-
<PAGE>


           o  June 15, 1999   Repurchase  right with  respect to 750,000  shares
                              shall lapse immediately.

           o  June 15, 2000   Repurchase  right with  respect  to an  additional
                              750,000  shares  shall  lapse  (1,500,000  in  the
                              aggregate).

           o  June 15, 2001   Repurchase  right with  respect  to an  additional
                              750,000  shares  shall  lapse  (2,250,000  in  the
                              aggregate).

           o  June 15, 2002   Right to repurchase  with respect to the remaining
                              750,000  shares  shall  lapse  (3,000,000  in  the
                              aggregate).

In addition,  during the time periods  between the  anniversary  dates above the
Company's right to repurchase the warrant or the common stock resulting from the
exercise of the warrants above shall lapse in equal quarterly intervals.

              3.7.   VACATION. The Executive shall be entitled to four (4) weeks
paid vacation per year during the Term, with a maximum accrual of six (6) weeks,
to be taken at a time or times  which  do not  unreasonably  interfere  with his
duties here under.

       4.     TERMINATION.

              4.1.   TERMINATION  UPON DEATH.  If the Executive  dies during the
Term, this Agreement shall terminate as of the date of his death.

              4.2.   TERMINATION  UPON  DISABILITY.  If,  during  the Term,  the
Executive becomes physically or mentally disabled, whether totally or partially,
so that the Executive is unable  substantially to perform his services hereunder
for (i) a period  of three  consecutive  months,  or (ii)  for  shorter  periods
aggregating three months during any twelve-month  period, the Company may at any
time after the last day of the three consecutive months of disability or the day
on which the shorter  periods of disability  equal an aggregate of three months,
by 30  days  written  notice  to  the  Executive,  terminate  the  Term  of  the
Executive's employment hereunder. Nothing in this Section 4.2 shall be deemed to
extend  the  Term.  If the  Term of the  Executive's  employment  is  terminated
pursuant  to this  Section  4.2,  the  Executive  shall be  entitled  to receive
benefits as defined by the terms of the Company long-term  disability  insurance
policy for key executives as in effect in the time of termination.

              4.3.   TERMINATION FOR CAUSE. The Board may terminate  Executive's
employment  for "cause" which for purposes of this  Agreement is defined as: (i)
gross  misconduct in connection with performance of his duties  hereunder;  (ii)
material breach of any undertaking hereunder; or (iii) conviction of, or plea of
nolo contendere to, a felony or any other serious crime or offense.  Termination
is effective on written notice to the Executive.

              4.4.   TERMINATION IN THE DISCRETION OF THE COMPANY. The Board may
terminate  Executive's  employment  without  cause in the sound  exercise of its
discretion. In such event, the Board may: (i) terminate the Executive's right to
enter the premises of the Company by giving notice of such termination, and such
notice shall be effective on the date given pursuant to


                                      -3-
<PAGE>


Section  6.1  hereof;  and  (ii)  by 30 days  written  notice  to the  Executive
thereafter  shall  have only such  right to  receive  monetary  compensation  or
benefits  hereunder  in respect of any period after the  effective  date of such
termination as are provided in Section 4.5.1 hereof.

              4.5.   COMPENSATION ON TERMINATION.

                     4.5.1  If the Term of the Executive's  employment hereunder
is terminated pursuant to Section 4.4 hereof, the Executive shall be entitled to
receive all compensation  accrued and unpaid up to the date of such termination,
plus additional compensation as follows:

           o  Termination prior to June 15, 2000: continued monthly compensation
              for the period from the date of termination  through June 15, 2000
              or six months at the annual  salary rate then in effect  whichever
              total cumulative salary is greater.  Any payments made pursuant to
              this Section  4.5.1 shall be reduced by required  withholdings  or
              authorized deductions.

           o  Termination after June 15, 2000: Six (6) months of compensation at
              the annual salary rate then in effect.  Any payments made pursuant
              to this Section 4.5.1 shall be reduced by required withholdings or
              authorized deductions.

                     4.5.2  If Executive's  employment is terminated pursuant to
Section  4.4 or upon a change of control,  the  Executive  shall be  immediately
entitled to exercise any equity participation  rights (stock options,  warrants,
etc.)  as   provided  in  the   agreement(s)   pursuant  to  which  such  equity
participation  rights  were or are  granted.  For  purposes  of this  Agreement,
"Change of Control" means:  (i) a liquidation or dissolution of the Company,  or
(ii) a merger or consolidation in which the Company is not the surviving entity,
or (iii) a sale of all or substantially  all of the Company" assets,  or (iv) an
acquisition  (other than directly from the Company) by an individual,  entity or
group (excluding the Company or one of its benefit plans or an entity controlled
by the Company's shareholders) of more than 50% of the Company's common stock or
voting securities.

       5.     CERTAIN COVENANTS OF THE EXECUTIVE.

              5.1.   COVENANTS AGAINST COMPETITION.  The Executive  acknowledges
that as of the date  hereof (i) the  principal  business  of the Company and its
affiliates  is the  development  and marketing of Positron  Emission  Tomography
(PET)  Scanners and the related  equipment and computer  programs and "software"
and various  distribution  methods and investment  structures  including imaging
clinics (the  "Company  Business");  (ii) the Company  Business is national (and
international)  in scope; and (iii) his work for the Company has brought him and
will  continue to bring into close  contact with many  confidential  affairs not
readily  available  to the  public,  including  without  limitation,  corporate,
business and financial plans, marketing strategy, product research,  development
and  improvement,  plans for future  development and other matters.  In order to
induce the Company to enter into this  Agreement,  the  Executive  covenants and
agrees:

NON-COMPETE.  During his employment and any period of payment  thereafter,  (the
"Restricted  Period"),  the Executive  shall not in the United States of America
(or in any foreign country),  directly or indirectly,  (i) engage in the Company
Business for his own  account;  (ii) enter the


                                      -4-
<PAGE>


employ of, or render any services to, any person engaged in such activities; and
(iii) become interested in any person engaged in the Company Business,  directly
or  indirectly,  as an  individual,  partner,  shareholder,  officer,  director,
principal,  agent, employee, trustee, consultant or in any other relationship or
capacity; provided, however, that the Executive may own, directly or indirectly,
solely as an  investment,  securities  of any  person  which  are  traded on any
national  securities  exchange if the Executive (a) is not a controlling  person
of, or a member of a group which controls,  such person or (b) does not directly
or indirectly own 5% or more of any class of securities of such person.

                     5.1.1  CONFIDENTIAL  INFORMATION.  The Executive shall keep
secret  and  retain in  strictest  confidence,  and shall not use except for the
benefit  of the  Company  and the  business  and  affairs  of the  Company,  all
confidential  matters  of the  Company  and its  affiliates,  including  without
limitation,  trade "know-how," secrets,  consultant  contracts,  customer lists,
investor  lists,  pricing  policies,  operational  methods,  marketing  plans or
strategies,  product  development or improvement  techniques or plans,  business
acquisition  plans,  new personnel  acquisition  plans,  methods of manufacture,
methods of  manufacture,  technical  processes,  designs  and  design  projects,
inventions and research  projects and other business  affairs of the Company and
its affiliates learned by the Executive or coming into his possession heretofore
or hereafter,  and shall not disclose them to anyone  outside of the company and
its affiliates,  either during or after  employment by the Company or any of its
affiliates,  expect as required in the course of performing  duties hereunder or
with the Company's express prior written consent.

                     5.1.2  PROPERTY  OF  THE   COMPANY.   All   correspondence,
memoranda,  notes,  lists,  records,  computer tapes, discs and design and other
document and data storage and retrieval materials (and all copies,  compilations
and summaries thereof), and all other personal property, made or compiled by the
Executive,  in whole or in part and alone or with  others,  or in any way coming
into his  possession  concerning the business or other affairs of the Company or
any of its affiliates, shall be the Company's property and shall be delivered to
the Company promptly upon the termination of the Executive's employment with the
Company or any of its affiliates for any reason or at any other time on request,
and no copies thereof shall be retained by the Executive.

                     5.1.3  DISCLOSURE AND ASSIGNMENT OF RIGHTS.

                            (A)    The  Executive  agrees that he will  promptly
disclose and assign to the Company and its affiliates or its nominee(s)  (except
as expressly  provided in paragraphs  5.1.4 (C) and (D) below) all right,  title
and  interest  of  the  Executive  in  and to any  and  all  ideas,  inventions,
discoveries,  secret processes and methods, and improvements,  together with any
and all  patents  that may be issued  thereon  in the  United  States and in all
foreign countries,  which the Executive may invent, develop or improve, or cause
to  be  invented,  developed  or  improved,  during  the  Term,  or  during  the
twelve-month  period  commencing  on the  date  the  Executive's  employment  is
terminated pursuant to Section 4.3 hereof, which are (i) conceived and developed
during normal working hours, or

(ii) which are related to the scope of the Company's  Business or are related to
any work carried on by the Company or are related to any  problems  specifically
assigned to the  Executive.  The word "invent" as used herein  includes  "make,"
"discover," "develop,"  "manufacture," or "produce," or any of them; "invention"
includes  the  phrase  "any new or useful  original  art,  machine,  methods  of
manufacture,  process,  composition of matter,  design,  or configuration of any
kind" and the words "improvement,"


                                      -5-
<PAGE>


"discovery"  or  "production,"  or any of them; and "patent"  includes  "Letters
Patent"  and "all the  extensions,  renewals,  modifications,  improvements  and
reissues of such patents."

                            (B)    The Executive agrees to disclose  immediately
to  duly  authorized  representatives  of the  Company  any  ideas,  inventions,
discoveries,  secret  processes  and methods,  and  improvements  covered by the
provisions  of  paragraph  5.1.4(A),  and to execute  all  documents  reasonably
required in connection with the application for an issuance of Letters Patent in
the United States and in all foreign  countries,  and the assignment  thereof to
the Company and its affiliates or its nominee(s).

                            (C)    Set  forth in  Exhibit  A  hereto  is a brief
description of all inventions,  patented and un-patented which the Executive has
made or conceived  prior to his  employment  by the Company  which are expressly
excluded from the provisions of this Agreement.

                            (D)    This   Agreement   does   not   require   the
assignment of any invention which Executive may not be obligated to assign under
Section 2870 of the California Labor Code.

              5.2.   RIGHT AND REMEDIES UPON BREACH. If the Executive  breaches,
or  threatens to commit a breach of, any of the  provisions  of Section 5.1 (the
"Restrictive  Covenants"),  the  Company  shall  have the  following  rights and
remedies,  each of which rights and remedies  shall be  independent of the other
and  severally  enforceable,  and all of which rights and  remedies  shall be in
addition to, and not in lieu of, any other rights and remedies  available to the
Company under law or in equity:

           o  Specific Performance. The right and remedy to have the Restrictive
              Covenant   specifically   enforced  by  any  court  having  equity
              jurisdiction,  including  without  limitation,  the  granting of a
              preliminary injunction which may be granted without the posting of
              a bond or other security,  it being  acknowledged  and agreed that
              any such breach or threatened breach will cause irreparable injury
              to the Company and that money damages will not provide an adequate
              remedy to the Company.

              5.3.   SEVERABILITY OF COVENANTS. If any court determines that any
of the Restrictive Covenants,  or any part thereof, is invalid or unenforceable,
the  remainder of the  Restrictive  Covenants  shall not thereby be affected and
shall be given full effect, without regard to the invalid portions.

              5.4.   BLUE   PENCILING.   If  any  court  construes  any  of  the
Restrictive  Covenants,  or any part thereof, to be unenforceable because of the
duration of such  provision or the area covered  thereby,  such court shall have
the  power to  reduce  the  duration  of the  area of or  otherwise  alter  such
provision and, in its reduced form, such provision shall then be enforceable and
shall then be enforced.

              5.5.   ENFORCEABILITY  IN JURISDICTION.  The parties intend to and
hereby confer jurisdiction to enforce the Restrictive  Covenants upon the courts
of any  jurisdiction  within the  geographical  scope of such Covenants.  If the
courts of any one or more of such jurisdictions


                                      -6-
<PAGE>


hold the Restrictive  Covenants wholly  unenforceable by reason of the breath or
scope or otherwise,  it is the intention of the parties that such  determination
not bar or in any way effect the Company's right to the relief provided above in
the  courts of any other  jurisdiction  within  the  geographical  scope of such
Covenants  as  to  breaches  of  such   Covenants   in  such  other   respective
jurisdictions,  such Covenants as they relate to each  jurisdiction  being,  for
this purpose, severable into diverse and independent covenants.

       6.     MISCELLANEOUS.

              6.1.   NOTICES.  Any  notice or other  communication  required  or
which  may be  given  hereunder  shall be in  writing  and  shall  be  delivered
personally,   telegraphed,   telexed,  or  telecopies,  or  sent  by  certified,
registered or express mail,  postage prepaid,  and shall be deemed given when so
delivered personally, telegraphed, telexed or telecopied, or if mailed, two days
after the date of mailing, as follows:

           o  If to the Company, addressed to it at:

              Positron Corporation
              1304 Langham Creek, #300
              Houston, Texas  77084

           o  If to the Executive,  addressed to him at such address as he shall
              have  filed  with the  Company  for such  purpose or at such other
              address as a party may from time to time specify by giving  notice
              as provided herein.

              6.2.   ENTIRE  AGREEMENT.  Subject to  Section  3.6  hereof,  this
Agreement  contains the entire agreement between the parties with respect to the
subject matter hereof and supersedes all prior agreements, written or oral, with
respect thereto.

              6.3.   WAIVERS  AND  AMENDMENTS.  This  Agreement  may be amended,
modified,  superseded,   canceled,  renewed  or  extended,  and  the  terms  and
conditions  hereof may be waived,  only by a written  instrument  signed by both
parties or, in the case of a waiver, by the party waiving  compliance.  No delay
on the part of any party in exercising any right,  power or privilege  hereunder
shall operate as a waiver thereof, nor shall any waiver on the part of any party
of any right, power or privilege  hereunder,  nor any single or partial exercise
of any  right,  power or  privilege  hereunder  preclude  any  other or  further
exercise  thereof  or the  exercise  of any  other  right,  power  or  privilege
hereunder.

              6.4.   ASSIGNMENT.  This  Agreement is personal to the  Executive,
and the Executive's rights and obligations  hereunder may not be assigned by the
Executive.  The Company may assign this Agreement and its rights,  together with
its  obligations  hereunder  in  connection  with any  sale,  transfer  or other
disposition of all or substantially  all of its assets or business(es),  whether
by merger, consolidation or otherwise.

              6.5.   COUNTERPARTS. This Agreement may be executed in two or more
counterparts,  each of  which  shall  be  deemed  an  original  but all of which
together shall constitute one and the same instrument.


                                      -7-
<PAGE>


              6.6.   HEADINGS.  The section  headings in this  Agreement are for
reference  purposes  only  and  shall  not in any  way  affect  the  meaning  or
interpretation of this Agreement.

       IN WITNESS WHEREOF,  the parties have executed this Executive  Employment
Agreements as of the date first above written.


/s/ Gary H. Brooks                       /s/ S. Lewis Meyer
- --------------------------------------   ---------------------------------------
EXECUTIVE                                POSITRON CORPORATION

Date: Sept. 1, 1999                      Date: Sept 1, 1999
     ---------------------------------        ----------------------------------


                                      -8-




                                  EXHIBIT 10.62

                              AGREEMENT AND RELEASE


       THIS AGREEMENT AND RELEASE ("Agreement") is entered into this 29th day of
November,  1999  by  and  between  Positron  Corporation,  a  Texas  corporation
("Positron") and K. Lance Gould, M. D. ("Gould").


                                R E C I T A L S :
                                 - - - - - - - -

       1.     Positron  and  Gould  previously  have  entered  into a series  of
agreements, including:

              a.     Amended and Restated License Agreement dated as of June 30,
1987  by  and  among  Positron,  Gould,  the  Clayton  Foundation  for  Research
("Clayton")   and  Nizar  A.  Mullani   ("Mullani")   regarding  the  ownership,
manufacturing and marketing of certain proprietary  property relating to medical
imaging,  design and  construction  of positron  imaging  cameras and associated
equipment for medical and diagnostic applications ("License Agreement");

              b.     Royalty Exchange Agreement dated as of June 30, 1987 by and
between Positron and Gould;

              c.     Royalty  Assignment  dated as of  December  22, 1988 by and
between Positron and Gould pursuant to which Gould sold to Positron one-third of
his  royalty  interest  under  the  License  Agreement  for good and  sufficient
consideration ("Gould Royalty Assignment");

              d.     Clarification  Agreement  dated as of December  22, 1988 by
and among  Positron,  Gould,  Clayton and Mullani  clarifying  certain terms and
conditions  set  forth in the  Gould  Royalty  Assignment  and  related  Royalty
Assignments ("Clarification Agreement");

              e.     Master  Agreement  dated  as of  January  15,  1993  by and
between Positron and Gould ("Master Agreement");

              f.     Consulting  Agreement  dated as of January  15, 1993 by and
between  Positron and Gould  pursuant to which Gould  agreed to provide  certain
consulting services to Positron under certain terms and conditions  ("Consulting
Agreement");

              g.     Letter Agreement dated May 19, 1993 by and between Positron
and Gould  amending the Master  Agreement  and  Consulting  Agreement in certain
respects and confirming certain  obligations  existing between the parties as of
that date (" 1993 Letter Agreement");

<PAGE>


              h.     Two  convertible  promissory  notes dated as of October 31,
1993  indicating  Gould as Borrower  and  Positron as Holder,  in the  principal
amounts of $138,593.63 and $281,250.00 respectively,  plus interest ("Promissory
Note(s)");

              i.     Agreement  by and  between  Positron  and Gould dated as of
November  15,  1993  amending  certain  provisions  of the  Promissory  Notes to
automatically  convert the principal amounts of the Promissory Notes to Positron
common stock  pursuant to an agreed  formula and further,  clarifying the rights
and  obligations  of the  parties in the event of certain  defined  defaults  by
Positron, and certain other agreements ("Conversion Agreement"); and

              j.     Letter Agreement by and between Positron and Gould dated as
of December 16, 1998  regarding  modifications  to some or all of the agreements
listed above ("1998 Letter Agreement").

       2.     Positron  and Gould now wish to  resolve  any and all  differences
between  them arising out of the above listed  agreements  or any other  matter,
without  dispute,  and to agree  on terms  and  conditions  of their  continuing
relationship, all pursuant to the terms and conditions set forth below.

       NOW THEREFORE, for good and sufficient  consideration,  the parties agree
as follows:

                                    AGREEMENT

       1.     ROYALTIES,  DIRECTOR FEES,  CONSULTING  FEES AND ANY OTHER SERVICE
FEES.  Positron owes to Gould certain sums in past due royalties pursuant to the
agreements listed above in Recital 1, which amounts have not been paid. Further,
Positron owes to Gould certain sums in fees for serving as a member of the board
of directors, as a consultant and/or for other services,  which amounts have not
been paid. On the other hand,  Gould owes to Positron  certain sums of principal
and interest  under the Promissory  Notes,  which amounts have not been paid and
which  Promissory  Notes are  secured  by  Positron  common  stock.  In full and
complete  settlement of all  royalties  payable by Positron to Gould through the
date of this Settlement  Agreement,  and further in full and complete settlement
of any and all sums  which  may be  payable  by  Positron  to Gould for fees for
serving  as a  member  of the  board  of  directors  or as a  consultant  or for
providing any other services through the date of this Agreement,  and further in
full and complete  settlement of all sums of principal and interest  which Gould
may owe to Positron under the Promissory Notes, the parties agree as follows:

              (a)    Positron  will pay to Gould the sum of $38,872 as  promptly
as  possible,  but in no  event  later  than  fifteen  business  days  following
execution of this Agreement.

              (b)    Positron  grants to Gould,  and will  instruct its transfer
agent to issue to Gould,  168,000 shares of Positron  unregistered common stock,
to be issued as promptly as practicable following execution of this Agreement.

              (c)    On and  after  the  date  of  this  Agreement,  any and all
royalties  payable by Positron to Gould pursuant to the License  Agreement,  the
Royalty Assignment,  or pursuant to any other agreements listed above in Recital
1, shall be calculated at the rate of one percent (1%) of gross revenues derived
from the  initial  sale,  use,  lease,  licensing  or rental of the  Proprietary


                                      -2-
<PAGE>


Property as set forth in the License Agreement. In addition to any other waivers
and releases set forth in this Agreement, Gould waives any and all demand rights
he may have,  pursuant  to the  Conversion  Agreement  or any  other  agreement,
regarding  increasing  the  royalty  payments  otherwise  due and  payable  from
Positron to Gould from 1% to 1.5%.

              (d)    The parties further agree that Gross  Revenues,  as used in
the License Agreement and in this Agreement, serves as the basis for calculating
royalties payable to Gould, and shall be defined as revenues actually  collected
by  Positron,  less:  (i) cash or trade  discounts;  (ii)  credits for return of
defective  or  trade-in  products;  (iii)  sales  and  use  taxes;  and/or  (iv)
transportation charges. The foregoing notwithstanding, the parties further agree
that Gross  Revenues  does not  include,  and is not  intended to  include:  (v)
maintenance   charges;   (vi)  service  revenue;   (vii)  revenue  derived  from
pass-through  sales of other  components and third party  vendors'  software and
operating systems;  and/or (viii) resale of refurbished products previously sold
and thereafter returned to the Company and on which royalties were paid based on
the prior sale.

       2.     FUTURE SERVICES. Positron seeks to encourage Gould to continue his
work in  developing  clinical  software and to provide  additional  know-how and
proprietary property to the Company as it relates to the clinical application of
PET  technology  in  cardiology.   Further,  Positron  seeks  to  encourage  the
University of Texas PET Imaging Center to support  Gould's  efforts to do so. In
order to provide this  encouragement to their mutual benefit,  the parties agree
as follows:

              (a)    Positron will provide to Gould original source code for all
the software and cardiology algorithms  ("Software") currently developed for and
in use with the PET system currently utilized by Gould in the PET Imaging Center
at the  University of Texas  ("University  PET System").  A list of the Software
components  intended  to be covered  by this  limited  non-exclusive  license is
attached  hereto as  Attachment  A. Such Software is provided for the purpose of
supporting  the  research  activities  engaged in directly  and/or  specifically
directed by Gould at the  University's  PET Imaging Center.  The original source
code for such  Software is  provided on  condition  that  neither  Gould nor the
University  will use the Software,  or any derivative  thereof,  for any purpose
other than the research and development  purposes set forth herein  ("Acceptable
Purposes")  and further on  condition  that Gould will  provide to Positron  the
source code for any and all enhancements  made to the Software  pursuant to this
license . Acceptable Purposes  specifically  exclude any commercial use, sale or
distribution whatsoever of the Software or any derivative,  or other transfer of
the Software or any  derivative  to any third person for other than research and
development  purposes,  or use by Gould and/or the University of the software or
any  derivative  for other  than an  Acceptable  Purpose  as it  relates  to the
clinical   application   of  PET   technology  in   cardiology.   The  foregoing
notwithstanding,  the parties agree that Acceptable Purposes" includes utilizing
the Software at other  Positron  centers using Positron PET machines and related
equipment.

              (b)    Gould will  provide  and  deliver to  Positron  any and all
software    developments,     derivatives,    and/or    protocol    developments
("Enhancements") he prepares or develops with or from the Software.  Positron is
authorized to and will use such Enhancements in or as part of its business,  and
will include such Enhancements in the Proprietary  Property to which the License
Agreement and this Agreement apply.


                                      -3-
<PAGE>


              (c)    Gould agrees to serve on Positron's Medical Advisory Board,
at no  additional  charge or fee, for a minimum of three (3) years from the date
of this Agreement  ("Service  Period").  During the Service Period,  Gould shall
devote  such time and effort as is mutually  agreed by Gould and  Positron to be
appropriate  and  necessary  to achieve  the  purposes  of such  service,  which
purposes  are  deemed  to be the  enhancement  of  clinical  utilization  of PET
technology in cardiology.

              (d)    To encourage the  University to allow Gould to continue his
research and development activities as contemplated by this Agreement,  Positron
agrees to provide to the  University  PET  Imaging  Center,  and the  University
accepts pursuant to the conditions set forth herein,  for a period of five years
from the effective date of this Agreement  ("Maintenance  Period"),  maintenance
services  regarding the POSICAM (TM) PET System at no charge for labor. Costs of
hardware  components will be charged at Positron's cost. At Positron's  request,
the  University  will  advance  or  otherwise  pay the costs to obtain  hardware
components  necessary to provide the maintenance  services  contemplated herein.
Further,  Positron will continue during the Maintenance Period to provide to the
University any software  upgrades and other software  enhancements to the system
as it  typically  provides  to other  third  party  maintenance  customers,  and
University  agrees  to and will  execute  Positron's  standard  maintenance  and
service  agreement  consistent  with the terms herein.  University  specifically
waives any rights to any and all rights to any software, derivatives,  know-how,
or  proprietary  property  developed  either by Positron or by Gould  during the
Maintenance Period.

       The foregoing  notwithstanding,  the provisions of this  subsection  3(d)
shall have no force and effect  unless and until the  University of Texas and/or
the University of Texas Health Science  Center at Houston  agrees,  acknowledges
and approves this Agreement.

       3.     ISSUANCE AND REGISTRATION OF COMMON STOCK.

              (a)    Gould  represents  and warrants  that he is  acquiring  the
common stock pursuant to this Agreement for his own account for investment  only
and not with a view towards,  or for resale in connection  with, the public sale
or distribution  thereof,  except pursuant to sales registered or exempted under
the 1933  Securities  Act.  Gould further  represents and warrants that he is an
"accredited  investor" as that term is defined in Rule 501(a)(3) of Regulation D
as promulgated by the SEC.

              (b)    Positron  agrees to include the common  stock  delivered in
connection  with this  Agreement,  as well as any other  Positron  common  stock
currently held by Gould in his name, in the next registration statement Positron
files  with the  Securities  and  Exchange  Commission  ("SEC")  relating  to an
offering for its own account or the account of others under the 1933  Securities
Act (other  than on Form S-4 or Form S-8 or their then  equivalents  relating to
securities to be issued solely in connection  with any acquisition of any entity
or business or equity  securities  issuable in  connection  with stock option or
other employee benefit plans).  If the registration  referred to herein is to be
an  underwritten  public  offering  for the account of Positron and the managing
underwriter(s)  determine,  in  their  reasonable  good  faith  opinion,  that a
limitation  on the number of shares of common stock which may be included in the
registration  statement is necessary to facilitate and not adversely  affect the
proposed offering,  then Positron will include the common stock held by Gould in
the next  registration  statement  Positron


                                      -4-
<PAGE>


thereafter files with the SEC. The foregoing notwithstanding, Positron agrees to
include the common stock delivered in connection with this Agreement, as well as
any other Positron common stock currently held by Gould in his name, in the next
registration  statement  relating to an offering for the account of others under
the 1933 Securities Act.

       4.     RELEASE OF CLAIMS.

              (a)    Positron  (on  behalf  of  and  including  its   respective
officers,   directors,   shareholders,    employees,   agents,   administrators,
representatives,  successors  and assigns,  in the aggregate  "Positron  Related
Parties")  on the one hand,  and Gould (on behalf of and  including  his marital
community, agents,  administrators,  representatives,  executors and assigns, in
the  aggregate  "Gould  Related  Parties")  on the other hand,  hereby  mutually
release and discharge each other and their  respective  Related Parties from all
liability,  claims,  demands,  actions,  or  causes  of  action  of any  kind or
character,  whether fixed or contingent (collectively "Claims") arising from the
beginning  of time to the date of this  Agreement,  and from  whatever  sources,
including but not limited to claims relating to any of the agreements  listed in
Recital I to this  Agreement,  except for any provisions  that by their specific
terms are  intended to survive  termination  of the  respective  agreement,  and
except for the provisions of this Agreement.

              (b)    Positron  and Gould  understand  and  acknowledge  that the
provisions of this Section 6 and of Section 1 above are intended to and do apply
to and  include  all known and unknown or  unsuspected  consequences  or results
arising from or relating to the  transactions,  occurrences or agreements listed
in Recital 1. Positron and Gould,  on behalf of themselves and their  respective
Related  Parties  represent  and warrant that the  releases of claims  contained
herein are intended to be full and general  releases,  and they hereby expressly
waive any and all rights and  benefits  under any  statute or  principal  of law
reserving any rights to any claims which Positron  and/or Gould or either one of
them does not know or suspect to exist in its/his favor at the time of executing
the release,  and which, if known by it/him,  must have materially affected this
settlement and release.

              (c)    Positron and Gould each hereby  acknowledges that it/he has
read  this  Agreement,  that  it/he  fully  understands  the  contents  of  this
Agreement,  and that this is a GENERAL  RELEASE giving up rights with respect to
the agreements,  transactions or occurrences  that are being released under this
Agreement.

       5.     RESOLUTION OF DISPUTES.

              (a)    The  parties  shall  submit all  disputes  relating to this
Agreement, or any agreement listed on Recital 1 (whether contract, tort or both)
to binding arbitration in accordance with the rules of the American  Arbitration
Association  ("AAA")  relating to resolution  of  commercial  disputes in Harris
County,  Texas or otherwise as mutually agreed. The parties understand and agree
that they are waiving their rights to a jury trial.

              (b)    The  party  demanding  arbitration  shall  submit a written
claim to the other party,  setting out the basis of the claim and  proposing the
name of an arbitrator. The responding party shall have twenty (20) business days
in which to respond to the demand in a written  answer.  If the  response is not
timely  made,  or if the  responding  party  agrees with the person


                                      -5-
<PAGE>


proposed as  arbitrator  by the  demanding  party,  then the person named by the
demanding  party shall serve as arbitrator.  If the  responding  party submits a
written answer rejecting the proposed  arbitrator then, unless the parties agree
on an arbitrator,  an arbitrator  will be selected  pursuant to the rules of the
AAA.  Within  fifteen  (15)  days  after  completion  of  the  arbitration,  the
arbitrator will submit a decision in writing. Before arbitration commences, each
party shall pay the arbitrator half of the expected cost of the arbitration.  At
the conclusion of the arbitration, the arbitrator may award the prevailing party
some or all of the  arbitration  costs, as well as some or all of the prevailing
party's other expenses,  including reasonable attorney fees and witness fees, in
such proportion as the arbitrator deems appropriate. Unless otherwise determined
by the arbitrator,  each side shall bear its own expenses other than the cost of
arbitration, which shall be split.

       6.     MISCELLANEOUS.

              (a)    All notices,  requests,  demands,  or other  communications
under this Agreement shall be in writing. Notice shall be sufficiently given for
all purposes if delivered personally (upon receipt),  by first class mail (three
mail delivery days after  deposit),  by certified mail (upon  receipt,  delivery
confirmed by return  receipt),  overnight  delivery  (upon  receipt,  by Federal
Express or comparable  carrier,  charges prepaid or charged to sender's account,
delivery confirmed by carrier),  or by facsimile  transmission (upon receipt, if
delivery confirmed by notice), to the following:

       If to Positron:

              1304 Langham Creek Drive, Suite 300
              Houston, Texas   77084
              Attn:  President
              Phone: 281-492-7100 x 208 (Main)
              1-281-492-2961 (Fax)


       If to Gould:

              2330 Albans
              Houston, Texas 77005
              Phone: 713-500-6611
              Fax:   713-500-6615

              (b)    This  Agreement  may be modified or amended  only by mutual
agreement and in writing, signed by the party to be charged.

              (c)    This  Agreement,   including   exhibits  and   attachments,
constitutes  the final,  complete  and  exclusive  statement of the terms of the
agreement  between the parties  pertaining  to the subject  matter  herein,  and
supercedes  all prior and  contemporaneous  understandings  or agreements of the
parties.  No party has been induced to enter into this  Agreement by, nor is any
party relying on, any  representation  or warranty  outside those  expressly set
forth in this Agreement.


                                      -6-
<PAGE>


              (d)    The parties  hereto  agree that each of them will use their
best  reasonable  efforts to obtain the approval of the Health Science Center of
the provisions of this  Agreement.  The parties further agree that if the Health
Science  Center does not  formally  approve the  provisions  of this  Agreement,
Positron's  maintenance  obligations  as set forth in ss. 3(d) herein  shall not
take effect,  but the  provisions of this  Agreement as they relate to Gould and
Positron  shall be binding  and inure to the  benefit  those  parties  and their
respective heirs, executors, administrators, assigns and successors in interest.

              (e)    This Agreement may be executed in several  counterparts and
by facsimile transmission,  each of which shall be deemed an original but all of
which shall constitute one instrument binding on all parties.


       AGREED to this 29th day of November, 1999.


                                        POSITRON CORPORATION


                                        By: [ORIGINAL SIGNED: Gary H. Brooks
                                        Its: President

                                        [ORIGINAL SIGNED]
                                        K. LANCE GOULD, M.D.



       AGREED, ACKNOWLEDGED AND APPROVED this 16th day of December, 1999.



                                        UNIVERSITY OF TEXAS HEALTH SCIENCE
                                        CENTER AT HOUSTON


                                        By: [ORIGINAL SIGNED]

                                        Its: Executive Vice President
                                            ------------------------------------

                                      -7-


                                  EXHIBIT 10.63

                              POSITRON CORPORATION
                             1999 STOCK OPTION PLAN



                                          Date of Board Approval:  June 15, 1999
                                 Date of Shareholder Approval: December 17, 1999

       1. PURPOSE AND SCOPE.  The purposes of this Plan are to induce persons of
outstanding  ability and potential to join and remain with Positron  Corporation
(the  "Company"),  to provide an  incentive  for such  employees  as well as for
non-employee consultants to expand and improve the profits and prosperity of the
Company  by  enabling  such  persons  to acquire  proprietary  interests  in the
Company, and to attract and retain key personnel through the grant of Options to
purchase shares of the Company's common stock. As used herein, the term "Option"
includes both Incentive Stock Options and Non-Qualified Stock Options. This 1999
Stock  Option Plan is intended to amend and restate any other stock  option plan
of the Company currently in effect.

       2.  DEFINITIONS.  Each  term set forth in this  Section 2 shall  have the
meaning  set forth  opposite  such term for  purposes  of this Plan  unless  the
context  otherwise  requires,  and for the  purposes  of such  definitions,  the
singular shall include the plural and the plural shall include the singular:

           (a)  "Affiliate"  shall mean any  parent  corporation  or  subsidiary
corporation of the Company as those terms are defined in Sections 424(e) and (f)
respectively of the Internal Revenue Code of 1986, as amended.

           (b) "Board" shall mean the Board of Directors of the Company.

           (c) "Committee" shall have the meaning set forth in Section 3 hereof.

           (d) "Company" shall mean Positron Corporation, a Texas corporation.

           (e) "Code" shall mean the Internal Revenue Code of 1986, as amended.

           (f) "Fair Market Value" for a share of Stock means the price that the
Board or the Committee acting in good faith  determines,  through any reasonable
valuation  method  (including but not limited to reference to prices existing in
any established market in which the Stock is traded), to be the price at which a
share of Stock might change hands between a willing buyer and a willing  seller,
neither being under any compulsion to buy or to sell and both having  reasonable
knowledge of the relevant facts.

<PAGE>

           (g) "Option" shall mean a right to purchase Stock granted pursuant to
the Plan.

           (h) "Exercise Price" shall mean the purchase price for Stock under an
Option,  as  determined  in  Sections 7 -  "Incentive  Stock  Options" - and 8 -
"Non-Incentive  Stock Options" - below. (i) "Participant" shall mean an employee
or non-employee consultant to the Company to whom an Option is granted under the
Plan.

           (j) "Plan"  shall mean this  Positron  Corporation  1999 Stock Option
Plan.

           (k)  "Stock"  shall  mean the  $0.01 par  value  common  stock of the
Company.

           (l) "1934 Act" means the Securities Exchange Act of 1934, as amended.

       3.  ADMINISTRATION.  The Plan shall be  administered  (i) with respect to
individuals  who receive options under the Plan and who are or become subject to
the reporting requirements and short-swing liability provisions of Section 16 of
the  Securities  Exchange Act of 1934,  as amended (the "1934 Act")  ("Reporting
Persons")  by a  committee  consisting  of at least two  members of the Board of
Directors of the Company (the "Board"),  each of whom is a non-employee director
(as such term is  defined  under  Rule  16b-3 of the 1934  Act) (the  "Reporting
Persons Committee") and (ii) with respect to all individuals who receive Options
under  the Plan and are who are not  Reporting  Persons,  by a  committee  which
consists of at least two members of the Board (the  "Stock  Option  Committee").
For  purposes  of this  Plan,  references  to the  "Committee"  shall  mean  the
Reporting Persons Committee, the Stock Option Committee, or both, as the context
may require.

       The Committee shall have full authority in its discretion, subject to and
not inconsistent with the express  provisions of the Plan, to grant Options,  to
determine the Exercise Price and term of each Option,  and to select the persons
to whom, and the time or times at which, Options shall be granted and the number
of shares of Stock to be covered  by each  Option;  to  interpret  the Plan;  to
prescribe,  amend,  and rescind rules and  regulations  relating to the Plan; to
determine the terms and provisions of the option  agreements  (which need not be
identical)  entered into in connection with the grant of Options under the Plan;
and to make all other  determinations  deemed  necessary  or  advisable  for the
administration  of the  Plan.  The Board  may  delegate  to one or more of their
members,  or to one or more agents,  such  administrative  duties as it may deem
advisable,  and the  Board or any  person  to whom it has  delegated  duties  as
aforesaid  may employ one or more  persons to render  advice with respect to any
responsibility  the Board or such person may have under the Plan.  The Board may
employ  attorneys,  consultants,  accountants,  or other persons,  and the Board
shall be entitled  to rely upon the  advice,  opinions,  or  valuations  of such
persons.  All actions taken and all  interpretations  and determinations made by
the Board in good faith shall be final and binding  upon all  Participants,  the
Company,  and all other  interested  persons.  No  member of the Board  shall be
personally liable for any action, determination,  or interpretation made in good
faith with  respect  to the Plan;  and all  members of the Board  shall be fully
protected  by the  Company  in  respect of any such  action,  determination,  or
interpretation.



                                      -2-
<PAGE>

       4. SHARES SUBJECT TO THE PLAN. Subject to adjustment under the provisions
of Section 14 - "Effect of Change in Stock  Subject to Plan" - of the Plan,  the
maximum number of shares of Stock that may be optioned or sold under the Plan is
Four Million  (4,000,000).  Such shares may be authorized but unissued shares of
Stock of the Company,  or issued shares of Stock  reacquired by the Company,  or
shares purchased in the open market expressly for use under the Plan. If for any
reason any shares of Stock as to which an Option  has been  granted  cease to be
subject  to  purchase  thereunder,   then  (unless  the  Plan  shall  have  been
terminated) such shares shall become available for subsequent  awards under this
Plan in the discretion of the Board.  The Company shall,  at all times while the
Plan is in force,  reserve such number of common shares as will be sufficient to
satisfy the requirements of all outstanding Options granted under the Plan.

       5.  ELIGIBILITY; FACTORS TO BE CONSIDERED IN GRANTING OPTIONS.

           (a) Options may be granted  to: (i) any  regular  full-time  employee
(including officers and directors) of either the Company or any affiliate of the
Company; and (ii) any non-employee consultant of the Company.

           (b) In determining to whom options shall be granted and the number of
shares of Stock to be covered by each Option,  the Board shall take into account
the nature the participants'  duties, their present and potential  contributions
to the success of the Company,  and such other factors as it shall deem relevant
in connection with  accomplishing the purposes of the Plan. The Board shall also
determine  the time(s) of grant,  the type and term of Option  granted,  and the
time(s) of  exercise,  in whole or part. A  Participant  who has been granted an
Option  under the Plan may be granted new  Options,  which may be in addition to
prior Options granted under the Plan or may be in exchange for the surrender and
cancellation  of prior  Options  having a higher  or lower  Exercise  Price  and
containing such other terms as the Board may deem appropriate.

       6.  TERMS AND CONDITIONS OF OPTIONS.

           (a) General. Options granted pursuant to the Plan shall be authorized
by the Board and shall be evidenced by agreements ("Option  Agreements") in such
form as the Board from time to time shall approve.  Such Option Agreements shall
comply with and be subject to the following  general terms and  conditions,  and
shall also comply with and be subject to the provisions of Section 7 relating to
Incentive Stock Options or Section 8 relating to Non-Qualified Stock Options, as
applicable, as well as such other terms and conditions as set forth in this Plan
and as the  Board  may deem  desirable,  not  inconsistent  with the  Plan.

           (b)  Employment  Agreement.  The  Committee  may, in its  discretion,
include in any Option  granted under the Plan a condition  that the  Participant
shall  agree to remain in the  employ  of,  and/or to render  services  to,  the
Company for a period of time (specified in the Option  Agreement)  following the
date the Option is  granted.  No such  Option  Agreement  shall  impose upon the
Company any obligation to employ and/or retain the Participant for any period of
time.

           (c) Manner of  Exercise.  A  Participant  may  exercise  an Option by
giving written  notice of such exercise to the Company at its principal  office,
attention to the Secretary,


                                      -3-
<PAGE>

and  paying  the  Exercise  Price  either  (i) in cash  in  full at the  time of
exercise, or (ii) in the discretion of the Board:

           (d) by delivery of other previously  outstanding  common stock of the
Company,

              (i) by an approved deferred payment schedule or other arrangement,
which  arrangement  shall be  contained in writing in the Option  Agreement,  in
which event an interest rate will be stated which is not less than the rate then
specified which will prevent any imputation of higher interest under Section 483
of the Code,

              (ii) by  retention by the Company of some of the Stock as to which
the  Option is then being  exercised,  in which  case the  Optionee's  notice of
exercise  shall  include a statement (1) directing the Company to retain so many
shares that would  otherwise have been delivered by the Company upon exercise of
this Option as equals the number of shares that would have been  surrendered  to
the  Company if the  purchase  price had been paid with  previously  outstanding
stock of the Company,  and (2) confirming  the aggregate  number of shares as to
which this Option is being thus exercised and therefore surrendered, or

              (iii) in any other form of legal  consideration  acceptable to the
Committee at the time of grant or exercise.

           (e) Time of  Exercise.  Promptly  after the exercise of an Option and
the payment of the  Exercise  Price,  either in full or pursuant to the approved
payment  schedule,  the Participant shall be entitled to the issuance of a stock
certificate evidencing ownership of the appropriate number of shares of Stock. A
Participant  shall have none of the  rights of a  shareholder  until  shares are
issued to him/her,  and no adjustment will be made for dividends or other rights
for which the record date has occurred prior to the date such stock  certificate
is issued.

           (f) Number of Shares.  Each Option  shall  state the total  number of
shares of Stock to which it pertains.

           (g) Option Period and Limitations on Exercise.  The Board may, in its
discretion, provide that an Option may not be exercised in whole or part for any
period(s) of time  specified in the Option  Agreement,  except that the right to
exercise  must be at the rate of at least 20% per year over five  years from the
date the Option is granted,  subject to the further  conditions  of the Plan and
the Option Agreement such as continued  employment.  However,  in the case of an
Option  granted to  officers,  directors,  or  non-employee  consultants  of the
Company or any of its  affiliates,  the Option  may  become  fully  exercisable,
subject to the further  conditions of the Plan and the Option Agreement,  at any
time or during any period  established  by the  Company or its  affiliates.  The
exercise  period  shall be  stated in the  Option  Agreement.  No Option  may be
exercised  after the  expiration of ten years from the Grant Date. No Option may
be  exercised as to less than one hundred  (100) shares at any one time,  or the
remaining shares covered by the Option if less than one hundred (100).


                                      -4-
<PAGE>

       7. INCENTIVE  STOCK OPTIONS.  The Board may grant Incentive Stock Options
("ISOs") which meet the requirements of Section 422 of the Code, as amended from
time to time.

           (a) ISOs may be  granted  only to  employees  of the  Company  or its
affiliates.

           (b) Each ISO granted  under the Plan must be granted  within 10 years
from the date the Plan is  adopted or is  approved  by the  shareholders  of the
Company, whichever is earlier.

           (c) The  purchase  price shall not be less than the Fair Market Value
of the common shares at the time of grant,  except that the purchase price shall
be 110% of the  Fair  Market  Value  in the case of any  person  who owns  stock
possessing  more than 10% of the total  combined  voting power of all classes of
stock of the Company or its affiliates at the time of grant.

           (d) No ISO granted under the Plan shall be  exercisable  more than 10
years  from the date of grant,  except  that in the case of any  person who owns
stock possessing more than 10% of the total combined voting power of all classes
of stock of the Company or its affiliates at the time of grant,  no ISO shall be
exercisable more than five years from the date of grant.

           (e) To the  extent  that the  aggregate  Fair  Market  Value of stock
(determined at the time of grant) with respect to which ISOs are exercisable for
the first time by any individual during any calendar year under all plans of the
Company and its subsidiaries exceeds $100,000,  such options shall be treated as
Non-Qualified stock options, but only to the extent of such excess. Should it be
determined  that an entire  option or any portion  thereof  does not qualify for
treatment  as an ISO by  reason  of  exceeding  such  maximum,  or for any other
reason, such option or portion shall be considered a Non-Qualified stock option.

       8. NON-QUALIFIED  STOCK OPTIONS.  The Board may grant Non-Qualified Stock
Options  ("NSOs")  under the Plan in addition to or in lieu of  Incentive  Stock
Options.  NSOs are not intended to meet the  requirements  of Section 422 of the
Code, and shall be subject to the following terms and conditions:

           (a) NSOs may be granted to any eligible Participant.

           (b) The purchase price of the shares shall be determined by the Board
in its absolute  discretion,  but in no event shall such purchase  price be less
than 85% of the Fair  Market  Value of the  shares at the time of grant.  In the
case of any person who owns stock possessing more than 10% of the total combined
voting  power of all  classes of stock of the Company or its  affiliates  at the
time of grant, the price shall be 110% of the Fair Market Value.

           (c) NSOs shall not be  exercisable  more than ten years from the date
of grant.

       9.  TRANSFERABILITY.  Options  granted  under  this  Plan  shall  not  be
transferable other than by will or by the laws of descent and distribution,  and
during a  Participant's  life  shall be  exercisable  only by such  Participant.
Options granted under this Plan shall not be subject to execution, attachment or
other process.

                                      -5-
<PAGE>

       10.  TERMINATION  OF  EMPLOYMENT.  Options held by  employees,  including
directors, shall terminate three months after termination of employment with the
Company or affiliate, unless:

           (a) If employment is  terminated  for cause,  as such term is defined
pursuant to the  optionee's  contract of employment  or the Option  Agreement or
otherwise by Texas law, the Option shall immediately terminate.

           (b) If  termination  is due to the  employee's  permanent  and  total
disability within the meaning of Section 22(e)(3) of the Code, the Option may be
exercised at any time within one year following termination.

           (c) The  Option  Agreement  by its terms  specifies  whether it shall
terminate  later than three (3) months after  termination of employment.  If the
Option may be  exercised  later than three  months  following  termination,  any
portion  exercised  beyond three months shall be a  non-qualified  stock option.
This  paragraph  shall not be  construed to extend the term of any Option nor to
permit anyone to exercise the Option after expiration of its term.

           (d)  Options  granted  under this Plan shall not be  affected  by any
change of duties or position of the Participant so long as Participant continues
to be a regular, full-time employee of the Company. Any Option, or any rules and
regulations relating to the Plan, may contain such provisions as the Board shall
approve with reference to the  determination of the date employment  terminates.
Nothing in the Plan or in any Option  granted  pursuant to the Plan shall confer
upon any Participant any right to continue in the employ of the Company or shall
interfere in any way with the right of the Company to terminate such  employment
at its will at any time.

       11. RIGHTS IN THE EVENT OF DEATH.  If an employee dies during the term of
this Option,  his/her legal representative or representatives,  or the person or
persons  entitled to do so under the employee's last will and testament or under
applicable  intestate  laws,  shall have the right to exercise this Option,  but
only for the number of shares as to which the  employee was entitled to exercise
this  Option on the date of his  death,  and such  right  shall  expire and this
Option shall  terminate  six (6) months after the date of Grantee's  death or on
the  expiration  date of this  Option,  whichever  date is sooner.  In all other
respects, this option shall terminate upon such death.

       12. LEAVES OF ABSENCE.  For purposes of the Plan, an employee on approved
leave of absence from the Company shall be considered as currently  employed for
90 days  following  beginning  the  leave  or for so long as  his/her  right  to
reemployment is guaranteed by statute or contract, whichever is longer.

       13. EFFECT OF CHANGE IN STOCK SUBJECT TO PLAN.

           (a) In the event that outstanding common shares are hereafter changed
by   reason  of   reorganization,   merger,   consolidation,   recapitalization,
reclassification,  stock split,  combination of shares,  stock dividends and the
like, the Board shall make adjustments as it deems  appropriate in the aggregate
number of shares  advisable  under the Plan and the number and price  subject to
outstanding  option. Any adjustment shall apply  proportionately and only to the
unexercised  portion of options granted.



                                      -6-
<PAGE>

           (b) In the event the  Company  dissolves  or  liquidates  or  another
entity succeeds to its assets,  or in the event of a merger or  consolidation in
which the  Company  is not the  surviving  entity,  or in the event of a reverse
merger in which the Company survives but its common stock immediately  preceding
the merger is converted  into other  property by virtue of the merger,  then the
surviving  entity shall assume the  outstanding  Options or  substitute  similar
Options for those outstanding.

       14. AGREEMENT AND REPRESENTATION OF EMPLOYEES.

           (a) Acquiring  stock for investment  purposes.  As a condition to the
exercise of any Option,  the  Company  may  require the person  exercising  such
Option to represent  and warrant at the time of such exercise that any shares of
Stock  acquired at exercise are being  acquired only for  investment and without
any present  intention to sell or  distribute  such shares if, in the opinion of
Company's  counsel,  such  representation  is  required or  desirable  under the
Securities Act of 1933 or any other applicable law,  regulation,  or rule of any
governmental agency.

           (b)  Withholding.  With respect to the exercise of any Option granted
under this Plan, each Participant shall fully and completely consent to whatever
the Board directs to satisfy the federal and state tax withholding requirements,
if any, which the Board in its discretion deems applicable to such exercise.

           (c)  Delivery.  The  Company is not  obligated  to deliver any common
shares until there has been qualification  under or compliance with all state or
federal laws,  rules and  regulations  deemed  appropriate  by the Company.  The
Company  will use all  reasonable  efforts  to  obtain  such  qualification  and
compliance.

       15.  AMENDMENT AND  TERMINATION  OF PLAN. The Board,  by resolution,  may
terminate,  amend,  or revise  the Plan with  respect  to any shares as to which
Options have not been granted;  provided however, that any amendment that would:
(a) increase the  aggregate  number of shares of common stock that may be issued
under the Plan, (b) materially  increase the benefits  accruing to Participants,
or (c) materially modify the requirements as to eligibility for participation in
the Plan,  shall be subject to shareholder  approval  within 12 months before or
after adoption.  It is expressly  contemplated that the Board may amend the Plan
in any  respect  necessary  to  provide  employees  with  the  maximum  benefits
available  under and/or to satisfy the  requirements of or amendments to Section
422 of the Code.

           No  termination,  modification  or amendment of the Plan may however,
alter or impair the rights conferred by an Option previously granted without the
consent of the individual to whom the Option was previously granted.

           Unless  sooner  terminated,  the Plan  shall  remain in effect  for a
period  of ten  years  from  the  date  of the  Plan's  adoption  by the  Board.
Termination of the Plan shall not affect any Option previously granted.

           16. USE OF PROCEEDS. The proceeds from the sale of shares pursuant to
Options granted under the Plan shall constitute general funds of the Company.



                                      -7-
<PAGE>

           17.  EFFECTIVE  DATE OF PLAN. The Effective Date of this Plan is June
15,  1999,  the  effective  date  it was  adopted  by the  Board,  provided  the
shareholders  of the Company  approve this Plan within  twelve (12) months after
such effective  date.  Any Options  granted under this Plan prior to the date of
shareholder  approval  shall be deemed to be granted  subject to such  approval.
Should  shareholder  approval not be obtained  within  twelve (12)  months,  any
Options granted pursuant to the Plan shall be null and void.

           18. INDEMNIFICATION OF COMMITTEE. In addition to such other rights of
indemnification  as they may have and subject to limitations of applicable  law,
the members of the Committee  shall be  indemnified  by the Company  against all
costs and expenses  reasonably  incurred by them in connection  with any action,
suit or  proceeding to which they or any of them may be a party by reason of any
action  taken or  failure  to act  under or in  connection  with the Plan or any
rights  granted  thereunder  and against all amounts paid by them in  settlement
thereof or paid by them in satisfaction  of a judgment of any such action,  suit
or proceeding, the Board or Committee member or members shall notify the Company
in writing, giving the Company an opportunity at its own cost to defend the same
before such  Committee  member or members  undertake to defend the same on their
own behalf.

           19.  INFORMATION   REQUIREMENTS.   The  Company  shall  provide  each
participant with annual financial statements.

           20.  GOVERNING  LAW. The Plan shall be governed by, and all questions
arising  hereunder,  shall be determined in accordance with the laws of State of
Texas as such laws are applied to  agreements  between Texas  residents  entered
into and to be performed entirely within Texas.


                                      -8-

                                  Exhibit 10.64

                              POSITRON CORPORATION
                 1999 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN


                                        Date of Board Approval:  October 6, 1999
                                 Date of Shareholder Approval: December 17, 1999

       1. PURPOSE AND SCOPE. This 1999 Non-Employee Directors' Stock Option Plan
(the  "Plan")  is  adopted  for  the  benefit  of  the   directors  of  Positron
Corporation,  a Texas  corporation  (the  "Company")  who,  at the time of their
service,  are not  employees  of the  Company  or any of its  subsidiaries  (the
"Non-Employee  Directors").  It is  intended  to advance  the  interests  of the
Company by providing the  Non-Employee  Directors with  additional  incentive to
serve the Company by increasing their proprietary interest in the success of the
Company.

       2. ADMINISTRATION.

           (a) The Plan shall be  administered  by the Board of Directors of the
Company (the "Board").  The Board may delegate  administration  of the Plan to a
committee ("Committee") comprised of not less than two (2) members of the Board.
If  administration  is delegated to a Committee,  the  Committee  shall have, in
connection  with the  administration  of the Plan,  the powers  possessed by the
Board, subject to such resolutions,  not inconsistent with the provisions of the
Plan,  as may be adopted  from time to time by the Board.  The Board may abolish
the  committee  at any time and  revest in the Board the  administration  of the
Plan.

           (b) The Board  shall have the  authority  to adopt,  alter and repeal
such  administrative  rules,  guidelines and practices  governing the Plan as it
shall, from time to time, deem advisable;  to interpret the terms and provisions
of the Plan and any Option granted under the Plan (and any  agreements  relating
thereto);  and to otherwise  supervise the  administration  of the plan,  and to
exercise  such powers and  perform  such acts as the Board  deems  necessary  or
expedient to promote the best  interests  of the Company.  The Board may correct
any defect, supply any omission or reconcile any inconsistency in the Plan or in
any Option in the manner and to the extent it shall deem  necessary to carry the
Plan into effect.

           (c) All actions taken and all interpretations and determinations made
by the Board in good  faith  shall be final and  binding  upon all  Non-Employee
Directors, the Company, and all other interested persons.

           (d) No member of the Board shall be personally liable for any action,
determination,  or  interpretation  made in good faith with respect to the Plan;
and all members of the Board shall be fully  protected by the Company in respect
of any such action, determination, or interpretation.

<PAGE>

       3. STOCK SUBJECT TO AND RESERVED FOR THE PLAN.

           (a) The total number of shares of the Company's  Common Stock, no par
value (the "Common  Stock"),  with respect to which Options may be granted under
the Plan, shall not exceed the aggregate of 500,000 shares;  provided,  however,
that the  class and  aggregate  number of  shares  which may be  subject  to the
Options granted  hereunder shall be subject to adjustment in accordance with the
provisions  of Section  14 of this Plan.  Such  shares may be  treasury  shares,
reacquired shares or authorized but unissued shares.

           (b) The Company shall reserve for issuance pursuant to this Plan such
number of shares of Common  Stock as may from time to time be subject to Options
granted hereunder. If any Option expires or is canceled prior to its exercise in
full, the shares theretofore subject to such Option may again be made subject to
an Option under the Plan.

           (c) All Options granted under the Plan will constitute  non-qualified
options (the "Option").

       4. ELIGIBILITY.  Options shall be granted only to Non-Employee  Directors
of the Company.

       5. NON-DISCRETIONARY GRANT OF OPTIONS.

           (a)  NON-EMPLOYEE  DIRECTORS  ELECTED AFTER THE EFFECTIVE DATE OF THE
PLAN.  Initial  Grant.  For so long as this Plan is in  effect  and  shares  are
available  for the grant of Options  hereunder,  each person who is elected as a
Non-Employee Director of the Company for the first time after the effective date
of the Plan,  and who is not and has not been an  employee of the Company or any
of the  Company's  subsidiaries  (as defined in Section  424(f) of the  Internal
Revenue  Code of 1986,  as  amended  (the  "Code") (a "New  Director")  shall be
granted a one-time Option ("Initial Option") to purchase 25,000 shares of Common
Stock at a per  share  exercise  price  equal to 85% of the  Fair  Market  Value
(defined  below)  of a share  of  Common  Stock  on such  date  (subject  to the
adjustments  provided in Section 14 hereof).  This Section 5(a) shall only apply
to New  Director  the first time he or she is elected a director  of the Company
after the effective date of this Plan.

           (b) ANNUAL OPTIONS GRANT TO NON-EMPLOYEE DIRECTORS. ANNUAL OPTION. In
addition,  for so long as (i) this Plan is in effect,  and (ii) there are shares
available for the grant of Options hereunder,  each person serving as an elected
Non-Employee  Director  as of the  effective  date of this  Plan  and  each  New
Director  (together  "Eligible  Director")  shall be granted  automatically,  on
January 1st of each year (or the next day on which the Company's common stock is
traded should the Company's  common stock not trade on such date,  commencing as
of  January  1, 2000 and  subject  to the  adjustments  provided  in  Section 14
hereof),  an Option to  purchase  25,000  shares of Common  Stock at a per share
exercise price equal to 85% of the Fair Market Value (defined  below) of a share
of Common Stock. The foregoing notwithstanding, such Eligible Director must have
served as a  Non-Employee  Director  continuously  for at least thirty (30) days
immediately preceding the first day of January of any given year, in order to be
eligible  for grant of an Annual  Option as of January  1st of that  year.  Both
Initial Options and Annual Options shall be Non-Statutory Options.

                                      -2-
<PAGE>

           (c)  OPTION  PRICE.  For the  purposes  of this  Section 5, the "Fair
Market Value" as of any  particular  date shall mean (i) the closing sales price
on the immediately preceding business day of a share of Common Stock as reported
on the  principal  securities  exchange on which shares of Common Stock are then
listed or  admitted  to trading or (ii) if not so  reported,  the average of the
closing  bid and asked  prices  for a share of Common  Stock on the  immediately
preceding  business  day as quoted on the  National  Association  of  Securities
Dealers Automated  Quotation System ("NASDAQ") or (iii) if not quoted on NASDAQ,
the average of the closing bid and asked  prices for a share of Common  Stock as
quoted  by the  National  Quotation  Bureau's  "Pink  Sheets"  or  the  National
Association of Securities  Dealers' OTC Bulletin Board System. If the price of a
share of Common Stock shall not be so reported, the Fair Market Value of a share
of Common Stock shall be determined by the Board in its absolute discretion.

       6.  OPTION  AGREEMENT.  Each  Option  granted  under  the  Plan  shall be
evidenced  by an  agreement,  in a form  approved  by the Board,  which shall be
subject to the terms and  conditions of the Plan. Any agreement may contain such
other terms,  provisions  and  conditions  as may be determined by the Board and
that are not inconsistent with the Plan.

       7.  VESTING AND TERM OF OPTIONS.

           (a) Each Option  granted  under this Plan shall be subject to vesting
pursuant to one of two schedules:  (i) vesting in full on the date of grant;  or
(ii) vesting in four (4) equal installments  commencing on the first anniversary
of the date of grant;  provided,  however, that each such Option,  regardless of
the manner of vesting,  shall be subject to termination as provided in Section 9
hereof.  The schedule of vesting,  whether  vesting in full or in  installments,
shall  be  determined  by the  Board  as part of and at the  time of the  grant;
provided however, that any Option granted under this Plan which vests in full on
the date of grant as set forth in subsection (i) above,  shall be subject,  as a
condition of such Option grant, to the Company's right to repurchase as provided
in Section 16 hereof.

           (b) Each Option  agreement  shall also  provide that the Option shall
expire ten years from the date of grant,  unless sooner  terminated  pursuant to
Section 9 hereof.

       8. EXERCISE OF OPTIONS.  Options shall be  exercisable  at any time after
their appropriate  vesting date, subject to termination as provided in Section 9
hereof  and to the  Company's  right to  repurchase  as  provided  in Section 16
hereof.  Options  shall be  exercised by written  notice to the Company  setting
forth the number of shares with  respect to which the Option is being  exercised
and specifying the address to which the  certificates  representing  such shares
are to be mailed.  Such notice shall be accompanied by cash or certified  check,
bank  draft,  or postal  or  express  money  order  payable  to the order of the
Company, for an amount equal to the product obtained by multiplying the exercise
price of the  Option by the  number of shares of Common  Stock  with  respect to
which the Option is then being  exercised.  As  promptly  as  practicable  after
receipt of such written  notification and payment,  the Company shall deliver to
the Eligible  Director a certificate or certificates  representing the number of
shares of Common Stock with respect to which such Option has been so  exercised,
issued in the Eligible Director's name,  provided,  however,  that such delivery
shall be deemed  effected for all purposes  when the  Company's  transfer  agent
shall have deposited such  certificates in the United States mail,  addressed to
the Eligible Director, at the address specified pursuant to this Section 8.

                                      -3-
<PAGE>

       9. TERMINATION OF OPTIONS.  Except as may be otherwise expressly provided
in this Plan or otherwise determined by the Board, each Option, to the extent it
shall not have been exercised previously, shall terminate on the earliest of the
following:  (i) on the last day of the three-month period commencing on the date
on which the Eligible Director ceases to be a member of the Board for any reason
other than the death or total disability (within the meaning of Section 22(e)(3)
of the Internal Revenue Code) of the Eligible Director, in which case the option
may be exercised at any time within eighteen (18) months  following  termination
of such directorship or service, during which period the Eligible Director shall
be entitled to exercise all Options held by the Eligible Director on the date on
which the Eligible  Director  ceased to be a member of the Board that could have
been  exercised on such date;  or (ii) ten years after the date of grant of such
Option.

       10. TRANSFERABILITY OF OPTIONS.  During the term of an Option, the Option
shall not be assignable or otherwise  transferable except by will or by the laws
of descent and distribution.  Each Option shall be exercised during the Eligible
Director's lifetime only by the Eligible Director.

       11. NO RIGHTS AS STOCKHOLDER.  No Eligible Director shall have any rights
as a stockholder  with respect to shares  covered by an Option until the date of
issuance of a stock certificate or certificates representing such shares. Except
as provided in Section 14 hereof, no adjustment for dividends or otherwise shall
be made if the  record  date  therefore  is  prior to the  date of  issuance  of
certificates  representing shares of Common Stock purchased pursuant to exercise
of this Option.

       12.  INVESTMENT  REPRESENTATIONS.  Whether or not the  Options and shares
covered by the Plan have been  registered  under the  Securities Act of 1933, as
amended,  each person exercising an option under the Plan may be required by the
Company to give a  representation  in writing that such person is acquiring such
shares for  investment  and not with a view to, or for sale in connection  with,
the  distribution  of any part  thereof.  The Company will endorse any necessary
legend   referring  to  the  foregoing   restriction  upon  the  certificate  or
certificates  representing  any shares  issued or  transferred  to the  Eligible
Director upon the exercise of any Option granted under the Plan.

       13.  AMENDMENT OR  TERMINATION.  The Board may amend,  modify,  revise or
terminate this Plan at any time and from time to time. All Options granted under
this Plan  shall be  subject  to the terms and  provisions  of this Plan and any
amendment,  modification  or  revision  of this  Plan  shall be deemed to amend,
modify or revise  all  Options  outstanding  under this Plan at the time of such
amendment, modification or revision. If this Plan is terminated by action of the
Board, all outstanding Options may be terminated.

       14.  CHANGES  IN  THE  COMPANY'S  CAPITAL  STRUCTURE.  The  existence  of
outstanding  Options  shall  not  affect  in any way the  right  or power of the
Company or its  stockholders to make or authorize the dissolution or liquidation
of the Company,  any sale or transfer of all or any part of the Company's assets
or business, any reorganization or other corporate act or proceeding, whether of
a similar  character or otherwise,  any or all  adjustments,  recapitalizations,
reorganizations  or other  changes in the  Company's  capital  structure  or its
business,  any merger or consolidation of the Company, or any issuance of bonds,
debentures, preferred or prior


                                      -4-
<PAGE>

preference  stock senior to or affecting the Common Stock or the rights thereof;
provided,  however,  that if (i) the  outstanding  shares of Common Stock of the
Company  shall  be  subdivided  into a  greater  number  of  shares  or (ii) the
outstanding  shares of Common Stock shall be combined  into a smaller  number of
shares thereof,  then (a) the number of shares of Common Stock available for the
grant of Options  under the Plan shall be  proportionally  adjusted to equal the
product  obtained by multiplying  such number of available shares remaining by a
fraction,  the numerator of which is the number of outstanding  shares of Common
Stock after giving effect to such combination or subdivision and the denominator
of which is that  number of  outstanding  shares of Common  Stock  prior to such
combination  or  subdivision,   (b)  the  exercise  price  of  any  Option  then
outstanding  under  the Plan  shall be  proportionately  adjusted  to equal  the
product obtained by multiplying such exercise price by a fraction, the numerator
of which is the  number of  outstanding  shares of  Common  Stock  prior to such
combination  or  subdivision  and the  denominator  of which is that  number  of
outstanding  shares of Common Stock after giving effect to such  combination  or
subdivision,  and (c) the  number  of shares of  Common  Stock  issuable  on the
exercise of any Option then  outstanding  under the Plan or  thereafter  granted
under the Plan shall be  proportionately  adjusted to equal the product obtained
by  multiplying  such  number  of  shares of  Common  Stock by a  fraction,  the
numerator  of which is the number of  outstanding  shares of Common  Stock after
giving effect to such combination or subdivision and the denominator of which is
that number of outstanding  shares of Common Stock prior to such  combination or
subdivision.

       15. COMPLIANCE WITH OTHER LAWS AND REGULATIONS.

           (a) The Plan, the grant and exercise of Options  thereunder,  and the
obligation of the Company to sell and deliver  shares  acquirable on exercise of
such Options,  shall be subject to all applicable  federal and state laws, rules
and regulations and to such approvals by any  governmental or regulatory  agency
or national  securities  exchange as may be required.  The Company  shall not be
required to sell or issue any shares on  exercise of any Option if the  issuance
of such shares shall constitute a violation by the Non-Employee  Director or the
Company  of  any  provisions  of  any  law or  regulation  of  any  governmental
authority.

           (b) Each  Option  granted  under  this Plan  shall be  subject to the
requirement that, if at any time the Board shall determine that (i) the listing,
registration  or  qualification  of the shares subject thereto on any securities
exchange or under any state or federal law of the United  States or of any other
country or governmental subdivision thereof, (ii) the consent or approval of any
governmental  regulatory  body,  or (iii)  the  making  of  investment  or other
representations,  are  necessary or desirable  in  connection  with the issue or
purchase of shares subject thereto,  no such Option may be exercised in whole or
in part unless such listing, registration,  qualification,  consent, approval or
representation shall have been effected or obtained,  free of any conditions not
acceptable to the Board.

           (c) These  provisions do not obligate the Company to register  either
the Plan,  any option  granted  under the Plan,  or any stock issued or issuable
pursuant to any such Option, under any state or federal law of the United States
or of any other country or governmental subdivision thereof.

           (d) Any  determination  by the  Board in  connection  with any of the
above determinations shall be final, binding and conclusive.

                                      -5-
<PAGE>

       16. REPURCHASE RIGHT OF THE COMPANY.

           (a) GENERAL.  Shares of stock issued or issuable  upon exercise of an
option  grant  with  immediate  vesting,  as set forth in Section  7(a)(i),  are
subject  to  a  right  of  repurchase  by  the  Company.  If  the  service  of a
Non-Employee  Director  to  the  Company  or a  subsidiary  of  the  Company  is
terminated  for any reason  other than by death or total  disability,  except as
otherwise described in Section 16(d), the Company (or any subsidiary  designated
by it) shall have the option for 90 days after the termination of service by the
Non-Employee  Director  to  repurchase  all or any part of his  stock  issued or
issuable upon exercise of the option, as provided in this Section 16.


           (b) NOTICE.  Within 30 days of receiving  notice from a  Non-Employee
Director or his  representative of the termination of the director's  service to
the Company or a subsidiary of the Company,  the Company must give notice to the
director of the  Company's  decision  whether or not to exercise its  repurchase
right.

           (c) REPURCHASE  PRICE. The repurchase price per share  repurchased in
accordance  with this Section 16 shall be the original per share  purchase price
set  forth in the  accompanying  Notice of Stock  Option  Grant.  The  Company's
repurchase right at this price lapses at the rate of 25% per year, starting with
the first  anniversary of the Option Grant, and continues over 4 years,  without
reference to the date the Option was exercised or became exercisable.

           (d) SHARES ACQUIRED THROUGH  EXERCISE OF OPTION AFTER  TERMINATION OF
SERVICES.  If the Non-Employee Director exercises in whole or in part his option
after termination of his services to the Company for any reason other than death
or total disability, the Company shall have, for 90 days after the exercise, the
right  to  repurchase  the  shares  so  acquired  upon  written  notice  to  the
Non-Employee  Director. The purchase price and terms of payment will be governed
by Sections 16(c) and (e) of this Plan.

           (e) PAYMENT OF THE PURCHASE PRICE.  The Company's right to repurchase
must be exercised for cash or  cancellation of purchase money  indebtedness  for
the shares within 90 days of termination of service by the Non-Employee Director
(or in the case of securities  issued upon exercise of Options after the date of
termination, within 90 days after the date of exercise).

           (f) DEATH OR TOTAL DISABILITY.  There shall be no right of repurchase
by the Company upon the Non-Employee's death or total disability.  The foregoing
notwithstanding, the provisions of this Section 16(g) do not extend or otherwise
affect the  termination  of any Option which shall not have been  exercised,  as
otherwise set forth in Section 9 herein.

           (g) REPURCHASE RIGHT AS TO OTHER Shares.  The repurchase right of the
Company  shall  apply  as well to all  shares  or  other  securities  issued  in
connection  with  any  stock  split,   reverse  stock  split,   stock  dividend,
recapitalization,  reclassification,  spin-off, split-off, merger, consolidation
or reorganization ("Other Shares") but such right shall expire on the occurrence
of any event or transaction upon which the Option terminates.

       17.  INDEMNIFICATION  OF BOARD OF DIRECTORS.  The Company  shall,  to the
fullest extent permitted by law, indemnify,  defend and hold harmless any person
who at any time is a party or

                                      -6-
<PAGE>

is threatened to be made a party to any threatened, pending or completed action,
suit or proceeding (whether civil, criminal, administrative or investigative) in
any way relating to or arising out of this Plan or any Options granted hereunder
by reason of the fact that such  person is or was at any time a director  of the
Company against judgments, fines, penalties, settlements and reasonable expenses
(including  attorneys' fees) actually incurred by such person in connection with
such action,  suit or proceeding.  This right of indemnification  shall inure to
the benefit of the heirs,  executors and  administrators of each such person and
is in  addition  to all other  rights to which such  person may be  entitled  by
virtue  of the  bylaws  of the  Company  or as a  matter  of  law,  contract  or
otherwise.

       18. ADDITIONAL PROVISIONS.  (a) Nothing in the Plan, or in any instrument
executed  pursuant thereto,  shall confer upon any Non-Employee  Director either
the  right  or  the  obligation  to  continue  acting  as a  director  of (or to
employment by) the Company,  nor shall any Plan provision or instrument executed
pursuant  thereto  affect  any  right  of the  Company,  its  Board  and/or  its
shareholders to terminate the  directorship  (or employment) of any Non-Employee
Director  with or without  cause.  (b) In  connection  with each option  granted
pursuant  to the  Plan,  each  Non-Employee  Director  shall  make  arrangements
satisfactory  to the  Company to insure  that the amount of any federal or other
withholding tax required to be withheld with respect to such sale or transfer is
made available to the Company for timely payment of such tax.

       19. EFFECTIVE DATE OF THE PLAN. This Plan shall become effective, subject
to stockholder approval, on October 6, 1999. No Option shall be granted pursuant
to this Plan on or after December 31, 2009.

       20.  GOVERNING  LAW.  The Plan shall be  governed  by, and all  questions
arising hereunder,  shall be determined in accordance with the laws of the State
of Texas as such laws are applied to agreements  between Texas residents entered
into and to be performed entirely within Texas.

                                      -7-

                                  Exhibit 10.65

                              POSITRON CORPORATION
                         1999 STOCK BONUS INCENTIVE PLAN


                                        Date of Board Approval:  October 6, 1999
                                 Date of Shareholder Approval: December 17, 1999


       1.  PURPOSE  AND SCOPE.  Positron  Corporation  ("Company")  adopted  the
Positron  Stock  Bonus  Incentive  Plan (the  "Plan") on October 6, 1999.  It is
effective as of November 1, 1999 for the 1999 Plan year. The purpose of the Plan
is to provide selected employees and outside consultants with stock bonus awards
("Bonus  Shares")  to reward them for past  services  and to  encourage  them to
remain in the Company's service as well as providing the Company with a valuable
tool to recruit  and retain  managers,  employees  and  outside  consultants  of
outstanding ability.

       2.  DEFINITIONS.

           (a) "Bonus  Shares"  means the shares of the  Company's  Common Stock
issuable or issued under the Plan.

           (b)  "Committee"  means the Stock Option  Committee  appointed by the
Company's Board of Directors.

           (c) "Company" means Positron Corporation, a Texas Corporation.

           (d)  "Disability"  means that the  Participant is unable to engage in
any  substantial  gainful  activity  by  reason  of any  medically  determinable
physical or mental  impairment which can be expected to result in death or which
has lasted, or can be expected to last, for a continuous period of not less than
12 months.

           (e)  "Participant"  means  an  employee  who has  been  selected  for
participation in the Plan pursuant to Article 4.

           (f)  "Retirement"  means that the  Participant  has  retired  under a
qualified plan, if any, of the Company or is otherwise deemed to have retired by
the Committee.


<PAGE>

       3.  ADMINISTRATION.  The Plan shall be  administered  by the Stock Option
Committee of the Board of Directors (the "Committee"), which has been authorized
to act on behalf of the Company.  The Committee  shall determine the meaning and
application of the provisions of the Plan. Subject to the terms of the Plan, the
Committee shall have the exclusive authority to act on the following matters:

           (a)  Select  the  employees,  including  officers,  who are to become
Participants;

           (b) Determine each Participant's stock bonus award;

           (c) Waive or change the Plan's condition as it deems appropriate;

           (d) Adopt,  amend or rescind rules,  guidelines and forms relating to
the Plan;

and

           (e) Take any other actions the Committee deems necessary or advisable
for the administration of the Plan.

       All decisions,  interpretations  and other actions of the Committee shall
be final and binding on all  Participants  and all persons deriving their rights
from a Participant. No member of the Committee shall be liable for any action he
or she has taken,  or has failed to take, in good faith with respect to the Plan
or any bonus award.  The Committee may delegate such  ministerial  actions as it
deems necessary or proper.

       4. ELIGIBILITY.  The Participants  shall be selected from time to time by
the Committee from those employees  (including  officers or directors) and those
outside  consultants who, in the opinion of the Committee,  are in a position to
contribute  materially to the attainment of the Company's  financial  objectives
and managerial goals.  Participation may be based on the  recommendations of the
Company's officers,  subject to the Committee's  approval.  Such recommendations
shall include a  recommendation  as to the number of Bonus Shares that should be
awarded to each such  individual.  In  selecting  eligible  participants  and in
determining  the number of Bonus Shares it wishes to award,  the Committee shall
consider the position and responsibility of the eligible participants, the value
of their service to the Company and its subsidiary and such other factors as the
Committee deems pertinent.

       5. BONUS AWARDS.

           (a)  GENERAL.  After  an  employee  or  outside  consultant  has been
selected as a Participant,  the Committee will notify the  Participant of his or
her selection by letter (the "Award  Letter").  The Award Letter will advise the
Participant  of the  number  of Bonus  Shares  awarded.  A  Participant  will be
entitled to receive a maximum bonus  representing  40% of his or her salary,  in
the case of an employee.  The intention of the Plan is to reward the Participant
for helping the Company meet its annual business plan goals through a high level
of  goal  oriented   performance  that  substantially   exceeds  the  day-to-day
responsibilities  expected of the  Participant  and for which (s)he is regularly
paid a salary or consulting fee.

           (b) PAYMENT.  The Committee shall determine the Participant's  actual
stock  bonus  award (if any) and such bonus  shall be awarded  from time to time
within the Committee's


                                      -2-
<PAGE>

discretion. To minimize the market impact of the issuance of bonus stock, shares
to be  issued to a  Participant  which are  valued at less than  $3,000  will be
issued as soon as practicable  following the award, and shares to be issued to a
Participant  which are  valued  at $3,000 or more will be issued  within 60 days
thereafter.  Distributions  of Bonus  Shares  may be made  from  authorized  but
unissued shares. All authorized and unissued shares issued as Bonus Shares shall
be fully paid and  nonassessable  shares and free from  preemptive  rights.

           (c) TERMINATION OF SERVICES.  No Participant is eligible to receive a
bonus award  unless  such  Participant  is  employed  by or  actively  providing
services to the Company at the time the Bonus Award is granted.

           (d) DEATH, DISABILITY OR RETIREMENT.  In the event that a Participant
ceases to be an employee or service  provider by reason of death,  disability or
retirement the Committee,  in its sole discretion,  may award a partial bonus to
the  Participant  who  otherwise  would be  eligible  (or,  in the  event of the
Participant's  death, to his or her  Beneficiary).  Payment shall be made to the
Participant  (or his or her Beneficiary as the case may be) according to Article
4(2).

           (e) WITHHOLDING TAXES. Participants shall be obligated to satisfy all
federal and state tax  withholding  obligations  arising from the award of Bonus
Shares.

           (f)  NONTRANSFERABILITY OF RIGHTS. Any right to a stock bonus payment
under  the  Plan  shall  be  nontransferable,  except  that  such  right  may be
transferred to a Beneficiary upon a Participant's  death, as provided in Section
4.4. Any attempted alienation,  assignment,  pledge, hypothecation,  attachment,
execution or similar process, whether voluntary or involuntary,  with respect to
any such right shall be void and, at the  Committee's  option,  shall cause such
right to be forfeited.

       6. STOCK SUBJECT TO THE PLAN. The total number of shares of the
Company's Common Stock ("Common Stock") which may be issued under the Plan shall
not exceed 1,000,000 shares. Provided in no event may the Company make more than
200,000 shares per year  available for issuance  pursuant to bonus awards in any
single  fiscal year of the Company.  The Company  shall,  at all times while the
Plan is in force,  reserve such number of Common shares as will be sufficient to
satisfy the  requirements  of the number of shares  available for issuance under
the Plan.

       In the event the  outstanding  shares of Common  Stock are  increased  or
decreased as a result of any stock split,  stock dividend,  recapitalization  or
other  similar  change in corporate  structure  effected  without the receipt of
consideration,  or if the  Common  Stock  is  converted  into  other  shares  or
securities  of the  Company  or any other  corporation  as a result of a merger,
reorganization, or other similar transaction, then appropriate adjustments shall
be made by the  Committee  to the  class  and/or  number  of  shares  which  are
available  for issuance  under the Plan in order that there shall be no dilution
or  enlargement  of  benefits  hereunder.

       7. Beneficiary  Designations.  Upon commencement of  participation,  each
Participant  will name  beneficiaries  under the plan. If no  beneficiaries  are
named  specifically  for this purpose,  the Company will deem any  beneficiaries
named for Life Insurance  purposes  under the Company's Life Insurance  Plan, if
any, to be beneficiaries named under this Plan. If the



                                      -3-
<PAGE>

participant has not named a beneficiary or if none of the named beneficiaries is
living  when any  payment  is to be made,  then (a) the  spouse of the  deceased
Participant  shall be the  beneficiary,  or (b) if the Participant has no spouse
living at the time of such  payment,  the then living  children of the  deceased
Participant  shall  be  the  beneficiaries  in  equal  shares,  or  (c)  if  the
Participant  has neither spouse nor children living at the time of such payment,
the estate of the  Participant  shall be the  beneficiary.  The  Participant may
change the  designation  of a beneficiary  from time to time in accordance  with
procedures established by the Committee. Any designation of a beneficiary (or an
amendment or revocation thereof) will be effective only if it is made in writing
on the prescribed  form and is received by the Company or the Committee prior to
the Participant's death.

       8.  SHAREHOLDER  RIGHTS.  No  Participant  shall  have  any  rights  as a
shareholder  until  such time as any Bonus  Shares are  actually  issued to such
Participant.

       9. NO  EMPLOYMENT  RIGHTS.  No  provision  of the  Plan,  nor  any  bonus
opportunity established under the Plan, will be construed to give any person any
right to remain in the  Company's  service.  The Company  reserves  the right to
terminate any person's service at any time, with or without cause.

       10.  Amendments  Or  Terminations.  The  Company  may  amend,  suspend or
terminate  the Plan at any time and for any reason.  Neither an amendment of the
Plan nor the  termination  thereof  shall  affect  any Bonus  Shares  previously
issued.

       11.  Choice of Law. The Plan shall be construed  in  accordance  with and
governed by the laws of the State of Texas.


                                      -4-

                                  EXHIBIT 10.66

                              POSITRON CORPORATION
                        1999 EMPLOYEE STOCK PURCHASE PLAN



                                         Date of Board Approval: October 6, 1999
                                 Date of Shareholder Approval: December 17, 1999


         1. PURPOSE AND SCOPE. This Employee Stock Purchase Plan (the "Plan") is
established to provide  Eligible  Employees with an opportunity  through regular
payroll  deductions  to  purchase  Common  Stock of  Positron  Corporation  (the
"Company") so that they may increase their proprietary  interest in the Company.
The Plan is  intended  to qualify as an  "employee  stock  purchase  plan" under
Section 423 of the Internal Revenue Code.

         2. DEFINITIONS. As used herein, the following definitions shall apply:

            (a)  "Board  of  Directors"  means  the  Committee  if one has  been
appointed,  or the Board of Directors  of the Company if no  Committee  has been
appointed.

            (b) "Code" means the Internal Revenue Code of 1986.

            (c)  "Committee"  means  the  committee  appointed  by the  Board of
Directors  to  administer  the  Plan  in  accordance  with  Section  3  below  -
"Administration" - if one is appointed.

            (d) "Company" means Positron  Corporation and such present or future
Subsidiaries, as defined in Section 425 of the Code, of the Company as the Board
of Directors shall from time to time designate.

            (e)  "Compensation"   means  the  annual  base  rate  of  pay  of  a
Participant as of the first day of an Offering Period,  determined in accordance
with  nondiscriminatory  rules  adopted  by the  Board of  Directors,  including
commissions,  but excluding  income with respect to stock options or other stock
purchases or moving expense reimbursements.

            (f) "Eligible  Employee"  means any regular  employee of the Company
whose  date of hire was at least  six  months  prior to the  commencement  of an
Offering Period or an Interim  Offering  Period and who is customarily  employed
for at least  twenty  (20)  hours per week and more than five (5)  months in any
calendar year.

            (g) "Exchange Act" means the Securities and Exchange Act of 1934.

            (h) "Fair Market Value" of share of Stock means if the shares listed
on any national or regional  securities  exchange,  then the last  reported sale
price on the composite tape of



<PAGE>

that exchange on the last Business day before the applicable date. If the shares
of Stock of the same class are not listed on any national or regional securities
exchange  and if the sales  prices  for shares of stock of the same class in the
over-the-counter  market are reported by the National  Association of Securities
Dealers,  IncAutomatic Quotations,  Inc. (NASDAQ) National Market (or such other
system in use) at the date of  determining  Fair Market Value,  then Fair Market
Value means the last  reported  sales price so reported  or, if not so reported,
then the average of the high bid and low asked  prices on the last  Business Day
before the date in question.

            (i) "Interim  Offering Period" means each three-month  period during
and within an Offering Period.

            (j) "Option"  means the rights of a  Participant  to purchase  Stock
during the applicable Offering Period.

            (k) "Offering Date" means the first day of each offering Period.

            (l)  "Offering   Period"  means,   in  the  absence  of  a  specific
determination  to the  contrary  by the Board of Director  or the  Committee,  a
27-month  period during which  contributions  may be made toward the purchase of
Stock under the Plan. The Board of Directors or the Committee may establish from
time to time Option Periods which may be up to twenty-seven (27) months.

            (m)   "Participant"   means  an  Eligible  Employee  who  elects  to
participate in the Plan.

            (n)  "Plan   Account"  means  the  account   established   for  each
Participant pursuant to the Plan.

            (o)  "Purchase  Price"  means  the price at which  Participants  may
purchase Stock as determined pursuant to the Plan.

            (p) "Stock" means the Common Stock of the Company.

            (q)  "Subsidiary"  means a  corporation  a majority of whose  voting
shares are owned by the Company.

         3.  ADMINISTRATION.  The Plan  shall be  administered  by the  Board of
Directors  and/or by a duly  appointed  Committee.  Whether or not the Board has
delegated administration,  the Board shall have the final power to determine all
questions of policy and expediency that may arise in the  administration  of the
Plan.  The Board of Directors may from time to time remove  members from, or add
members to, the Committee.  Vacancies on the Committee,  howsoever caused, shall
be filled by the Board of  Directors.  The  Committee  shall  select  one of its
members as Chairman,  and shall hold meetings at such times and places as it may
determine.  The interpretation and construction by the Board of Directors or the
Committee of any  provision of the Plan or of any right to purchase  Stock shall
be conclusive and binding on all persons.

            (a) DELEGATION TO COMMITTEE.  The Board may delegate  administration
of the Plan to the  Committee  composed of not fewer than two (2) members of the
Board. All of the



                                      -2-
<PAGE>

members  of such  Committee  shall be  disinterested  persons  as defined by the
provisions of subparagraph  3(b) - "Disinterested  Person." If administration is
delegated to the  Committee,  the Committee  shall have, in connection  with the
administration  of the Plan,  the  powers  theretofore  possessed  by the Board,
subject,  however, to such resolutions,  not inconsistent with the provisions of
the Plan;  as may be  adopted  from time to time by the Board.  The Board  shall
otherwise  comply  with the  requirements  of Rule 16b-3  promulgated  under the
Exchange  Act,  as from  time to time in  effect,  The  Board  may  abolish  the
Committee  at any time and revest in the Board the  administration  of the Plan.
Two members of the Committee  shall  constitute a quorum for the  transaction of
business.

            (b) DISINTERESTED  PERSON. The term "Disinterested  Person," as used
in this Plan, shall mean an  administrator of the Plan,  whether a member of the
Board or of any Committee to which responsibility for administration of the Plan
has been delegated pursuant to subparagraph 3 (a), - "Delegation to Committee" -
who is not during the one year prior to service as an administrator of the plan,
or during such service,  granted or awarded  equity  securities  pursuant to the
plan or any other plan of the Company or any of its affiliates, except that: (A)
participation  in a formula plan meeting the conditions of Rule  16b-3(c)(2)(ii)
pursuant to the  Securities  Exchange Act shall not  disqualify a director  from
being  a  disinterested  person;  (B)  participation  in an  ongoing  securities
acquisition  plan  meeting  the  conditions  in Rule  16b-3(d)(2)(i)  shall  not
disqualify  a director  from being a  disinterested  person;  (C) an election to
receive  an  annual  retainer  fee in  either  cash or an  equivalent  amount of
securities,  or partly in cash and partly in securities,  shall not disqualify a
director from being a  disinterested  person;  and (D)  participation  in a plan
shall not  disqualify  a  director  from  being a  disinterested  person for the
purpose of  administering  another  plan that does not permit  participation  by
directors.  Any such person shall otherwise comply with the requirements of Rule
16b-3 promulgated under the Exchange Act, as from time to time in effect.

            (c) Number Of Shares To Be Offered.  The maximum aggregate number of
shares  which  shall be offered  under the Plan shall be Five  Hundred  Thousand
(500,000)  shares of Stock,  subject to  adjustment  as provided in Section 8 --
"Recapitalization,  Etc." -hereof In the event that any Option granted under the
Plan  expires or is  terminated  for any reason,  such shares  allocable  to the
unexercised portion of such Option shall again be subject to an Option under the
Plan. The stock subject to the Plan may be unissued shares or reacquired shares,
bought on the market or otherwise.

         4. ELIGIBILITY AND PARTICIPATION.

            (a) INITIAL  PARTICIPATION.  An  Eligible  Employee  shall  become a
Participant on an Offering Date after satisfying the eligibility requirements by
delivering  to the  Company's  payroll  office an  enrollment  form  authorizing
payroll  deductions  not less than ten (10) business days prior to such Offering
Date. An Eligible  Employee who did not enroll in the Plan prior to the Offering
Date, or a person who becomes an Eligible  Employee  after an Offering Date, may
enroll in the Plan for the remainder of the Offering  Period as of the beginning
of the next Interim  Offering Period by completing and filing an enrollment form
prior to the commencement date of such Interim Offering Period.

                                      -3-
<PAGE>

            (b)  CONTINUED  PARTICIPATION.  A  Participant  shall  automatically
participate in each  successive  Offering  Period  (including  Interim  Offering
Periods)  until  such time as such  Participant  withdraws  from the Plan as set
forth below.  A Participant  is not required to file any  additional  enrollment
forms for subsequent  Offering  Periods or Interim  Offering Periods in order to
continue participation in the Plan.

            (c) PAYROLL  DEDUCTION RATE. The Participant  shall designate on the
enrollment  form the  percentage  of  Compensation  which  s/he  elects  to have
withheld  for the  purchase of Stock,  which may be 2%, 4%, 6%, 8% or 10% of the
Participant's Compensation. A Participant may reduce (but not increase) the rate
of payroll withholding during an Offering Period by filing an amended enrollment
form with the  payroll  office at any time prior to the first day of any Interim
Offering  Period (for which such change is to be  effective),  but not more than
three (3) changes may be made in any  Offering  Period (or such other  number of
changes as may be approved by the Board or the  Committee).  A  Participant  may
increase or decrease the rate of payroll  deduction for any subsequent  Offering
Period by filing with the Company a new enrollment  form for payroll  deductions
not less  than ten (10)  days  prior to the  Offering  Date for such  subsequent
Offering Period.

            (d) MAXIMUM ELECTION.  By enrolling in the Plan, a Participant shall
be deemed to have  elected to  purchase  the maximum  number of whole  shares of
Stock which can be purchased with the amount of the  Participant's  Compensation
which is  withheld  during  the  Offering  Period;  provided,  however,  that no
Participant may purchase shares of Stock in excess of the amount permitted under
Section 9 - "Limitation on Stock Ownership."

            (e) OFFERING PERIOD.  Any Options granted pursuant to the Plan shall
be subject to the Company obtaining all necessary  governmental approvals and/or
qualifications of the sale and/or issuance of Options and/or Stock.

            (f) PURCHASE PRICE. The Purchase Price for each share of Stock to be
purchased  under the Plan shall be eighty-five  percent (85)% of the Fair Market
Value of such  share on either (i) the  Offering  Date (or the date of entry for
new or  re-enrolling  employees)  or (ii) the last day of each Interim  Offering
Period, whichever is less.

            (g)  CONTRIBUTIONS.  The  Purchase  Price  of  the  Stock  shall  be
accumulated by payroll deductions throughout the Offering Period, which shall be
applied  automatically  to purchase  Stock at the end of each  Interim  Offering
Period. In the absence of a contrary  determination prior to the commencement of
an Offering  Period,  each  Interim  Offering  Period  shall have a  three-month
duration. At the end of each Interim Offering Period, accrued payroll deductions
will be  automatically  applied to the purchase of Stock at the Purchase  Price.
Payroll  deductions  shall  commence on the first payday  following the Offering
Date (or, in the case of a new or  re-enrolling  employee,  on the first  payday
following the commencement of the applicable  Interim Offering Period) and shall
continue unless altered or terminated as provided in the Plan.

            (h) EFFECT OF LEAVE OF ABSENCE.  During a leave of absence  approved
by the Company,  a Participant  may, for such period as the Committee shall deem
reasonable,  continue  contributions  to the Plan by making cash payments to the
Company  on his or her  normal  paydays  in an  amount  equal to the  difference
between the amount of his or her regular payroll deductions

                                      -4-
<PAGE>

taken while such employee was participating under the Plan and the amount of his
payroll  deductions  taken  while on such leave of  absence.  Failure to pay any
installment  within  ten (10) days  after the payday on which it is due shall be
treated as a withdrawal from the Plan.

            (i) PURCHASE OF STOCK.  The Company will  maintain a Plan Account on
its books in the name of each  Participant,  On each payday the amount  deducted
from the Participant's  Compensation will be credited to the Participant's  Plan
Account.  No interest shall accrue on any such payroll deductions As of the last
day of each Interim  Offering Period the amount then in the  Participant's  Plan
Account  will  be  divided  by  the  Purchase   Price  and  the  amount  in  the
Participant's  Plan Account shall be used to purchase the number of whole shares
of Stock which result.  Share certificates  representing the number of shares of
Stock so purchased  shall be issued and delivered to the  Participant as soon as
reasonably  practicable  after the close of each Interim  Offering  Period.  Any
balance  remaining  in a  Participant's  Plan  Account  at the end of an Interim
Offering  Period after deducting the amount of the Purchase Price for the number
of whole shares issued to the Participant  shall become the beginning balance in
the  Participant's  Plan Account for the next following Interim Offering Period.
Any  balance  remaining  in the  Participant's  Plan  Account  at the  end of an
Offering  Period after deducting the amount of the Purchase Price for the number
of whole shares issued to the Participant  shall become the beginning balance in
the Participant's Plan Account for the next following Offering Period unless the
Participant elects to withdraw from participation.  If the Participant withdraws
from  participation,  the  balance in the  Participant's  Plan  Account  will be
refunded to the Participant, without interest.

            (j)   WITHDRAWAL.   A   Participant   may  elect  to  withdraw  from
participation in the Plan at any time before the last day of an Interim Offering
Period by filing the  prescribed  form with the payroll  office.  At the time of
withdrawal  the  amount  credited  to the  Participant's  Plan  Account  will be
refunded in cash,  without  interest.  Upon withdrawal from the Plan accumulated
payroll deductions,  if any, shall be returned to the withdrawn  Participant and
the withdrawn Participant's interest in the Plan shall terminate. In the event a
Participant  voluntarily  elects to withdraw from the Plan, such Participant may
not resume  participation in the Plan until after the expiration of one complete
Interim Offering Period;  re-enrollment  shall be made in the same manner as set
forth above for initial participation in the Plan.

         5. PRO RATA  ALLOCATION.  In the  event  that the  aggregate  number of
shares  which all  Participants  elect to  purchase  during an Interim  Offering
Period shall exceed the number of shares remaining  available for issuance under
the Plan, the number of shares to which each  Participant  shall become entitled
shall be determined by multiplying  the number of shares  available for issuance
by a  fraction,  the  numerator  of which is the sum of the number of shares the
Participant  has elected to purchase and the  denominator of which is the sum of
the number of shares which all Participants have elected to purchase.

         6. EFFECT OF TERMINATION OF EMPLOYMENT.  Termination of a Participant's
employment for any reason,  including  retirement or death,  or the failure of a
Participant  to remain an  Eligible  Employee  shall be treated as a  withdrawal
under  the Plan.  In the event of the  Participant's  death,  the  refund of the
Participant's   Plan  Account   shall  be  paid,   without   interest,   to  the
representative of the Participant's estate. A transfer by a Participant from the
Company to a


                                      -5-
<PAGE>

Subsidiary,  from one Subsidiary to another, or from a Subsidiary to the Company
shall not be treated as a termination of employment.

         7. RIGHTS NOT TRANSFERABLE.  The rights or interests of any Participant
in the Plan, in any Option  granted under the Plan, or in any Stock or moneys to
which he or she may be entitled under the Plan,  shall not be,  transferable  by
voluntary  or  involuntary  assignment  or by  operation of law, or by any other
manner   otherwise  than  by  will  or  the  applicable   laws  of  descent  and
distribution. If the Participant shall in any manner attempt to transfer, assign
or otherwise  encumber his or her rights or interests under the Plan, other than
by will, such act shall be treated as a withdrawal from the Plan.

         8.  RECAPITALIZATION,  ETC.  Subject  to  any  required  action  by the
shareholders  of the  Company,  the  number of shares of Stock  covered  by each
Option under the Plan which has not yet been  exercised and the number of shares
of Stock which have been authorized for issuance under the Plan but have not yet
been placed under an Option (collectively the "Reserves"),  as well as the price
per share of Stock  covered by each Option under the Plan which has not yet been
exercised, shall be proportionately adjusted for any increase or decrease in the
number of issued  shares of Stock  resulting  from a stock split,  reverse stock
split, stock dividend,  combination or  reclassification  of Stock, or any other
increase or decrease in the number of shares of Stock effected  without  receipt
of  consideration  by the Company;  provided,  however,  that  conversion of any
convertible securities of the Company shall not be deemed to have been "effected
without receipt of  consideration."  Such adjustment shall be made by the Board,
whose  determination  in that respect  shall be final,  binding and  conclusive.
Except as expressly  provided  herein,  no issue by the Company of the shares of
Stock of any class shall affect,  and no  adjustment by reason  thereof shall be
made with  respect  to,  the  number or price of shares of Stock  subject  to an
Option.

         In the event of the proposed dissolution or liquidation of the Company,
the Offering Period will terminate immediately prior to the consummation of such
proposed  action,  unless  otherwise  provided  by the Board.  In the event of a
proposed sale of all or substantially  all of the assets of the Company,  of the
merger of the Company  with or into another  corporation,  each option under the
Plan shall be assumed  or an  equivalent  option  shall be  substituted  by such
successor corporation,  unless the Board determines, in the exercise of its sole
discretion and in lieu of such assumption or substitution,  that the Participant
shall  have the right to  exercise  the  Option as to all of the  opined  Stock,
including  shares as to which the Option would not otherwise be exercisable.  If
the  Board  makes  an  Option  fully   exercisable  in  lieu  of  assumption  or
substitution in the event of a merger or sale of assets,  the Board shall notify
the  Participant  that the  Option  shall be fully  exercisable  for a period of
thirty (30) days from the date of such  notice,  and the Option  will  terminate
upon the expiration of such period.

         The Board may also,  if it so  determines  in the  exercise of its sole
discretion,  make provision for adjusting the Reserves, as well as the price per
share of Stock covered by each outstanding Option, in the event that the Company
effects one or more  reorganizations,  recapitalizations,  rights  offerings  or
other  increases or reductions of shares of its  outstanding  Stock,  and in the
event  of  the  Company  being  consolidated  with  or  merged  into  any  other
corporation.


                                      -6-
<PAGE>

         9. LIMITATION ON STOCK OWNERSHIP.  Notwithstanding any provision herein
to the  contrary,  no  Participant  shall be granted a right to  purchase  Stock
pursuant  to  Section  4  -  "Eligibility  and  Participation"  -  if  (i)  such
Participant,  immediately after electing to purchase such Stock, would own Stock
possessing  five (5) percent or more of the total combined voting power or value
of all  classes  of stock of the  Company  or any  parent or  Subsidiary  of the
Company,  or (ii)  under the terms of the Plan the  rights  of the  employee  to
purchase Stock under this and all other qualified  employee stock purchase plans
of the Company or its  Subsidiaries  would accrue at a rate that exceeds $20,000
of fair market value of such Stock  (determined  on the Offering  Date) for each
calendar year for which such right is  outstanding  at any time. For purposes of
this Section 9, ownership of Stock shall be determined by the attribution  rules
of Section  424(d) of the Code and  Participants  shall be considered to own any
Stock  which  they have a right or option to  purchase  under  this or any other
stock purchase plan.

         10. LIMITATIONS ON OFFICERS AND DIRECTORS.  Participants subject to the
provisions  of Section 16 of the Exchange Act (Company  officers and  directors)
must  comply  with the  following  requirements:

            (a) Shares of Stock purchased  pursuant to the Plan must be held and
may not be transferred for a period of six (6) months from the date of purchase,
provided,  however,  that  distributions  in connection with death,  retirement,
disability,  termination of employment,  or a qualified domestic relations order
as  defined  by the  Code,  or the  rules  thereunder,  are not  subject  to the
requirement set forth in this subparagraph 10(a).

            (b) Officer and director Participants who cease participation in the
Plan may not participate again for a period of at least six (6) months.

            (c) Shares of Stock purchased  pursuant to the Plan must be held for
at least six (6) months from the date the Purchase Price is fixed.

         11.  RIGHTS AS AN  EMPLOYEE.  Nothing in the Plan shall be construed to
give any  Participant  the  right to remain in the  employ of the  Company  or a
Subsidiary  or to affect the right of the  Company and its  Subsidiaries  or the
Participant to terminate such employment at any time with or without cause.

         12. RIGHTS AS A  SHAREHOLDER.  A Participant  shall have no rights as a
shareholder  with  respect  to any shares of Stock he or she may have a right to
purchase  under the Plan until the date of  issuance of a stock  certificate  to
such Participant for shares issued pursuant to the Plan.

         13. COVENANTS OF THE COMPANY.

            (a)  During  the terms of the  rights  granted  under the Plan,  the
Company shall keep available at all times the number of shares of stock required
to satisfy such rights.

            (b) The Company shall seek to obtain from each regulatory commission
or agency having jurisdiction over the Plan such authority as may be required to
issue and sell  shares of Stock upon  exercise of the rights  granted  under the
Plan. If the Company is unable to obtain from any such regulatory  commission or
agency the  authority  which  counsel for the Company  deems  necessary  for the
lawful issuance and sale of stock under the Plan, the Company



                                      -7-
<PAGE>

shall be relieved  from any  liability  for failure to issue and sell stock upon
exercise of such rights unless and until such authority is obtained.

         14.  USE OF  PROCEEDS  FROM  STOCK.  Proceeds  from  the  sale of stock
pursuant to rights granted under the Plan shall constitute  general funds of the
Company.

         15.  AMENDMENT OR TERMINATION OF THE PLAN. The Board of Directors shall
have the  right to  amend,  modify  or  terminate  the Plan at any time  without
notice,  provided that no Participant's  existing rights are adversely  affected
thereby,  and provided  further that no amendment of the Plan shall be effective
until such amendment is approved by a vote of the holders of at least a majority
of the  outstanding  shares of Common Stock of the Company  within twelve months
before  or after  the date  upon  which  such  action  is taken by the  Board of
Directors,  if such amendment would:

            (a)  Increase the  aggregate  number of shares of Stock to be issued
under the Plan  (except  as  provided  in Section 8  "Recapitalization,  Etc." -
hereof);

            (b)  Materially   modify  the   requirements   for   eligibility  to
participate in the Plan;

            (c)  Increase  the  maximum  number  of  shares  of  Stock  which  a
Participant may purchase in any Offering Period;

            (d) Extend the term of the Plan;

            (e) Alter the Purchase  Price  formula so as to reduce the price for
shares of Stock to be purchased under the Plan;

            (f)  Otherwise   materially   increase  the  benefits   accruing  to
Participants under the Plan; or

            (g) Cause the Plan to fail to meet the  requirements of an "employee
stock purchase plan" under Section 423 of the Code.

         16. TERMINATION OR SUSPENSION OF THE PLAN.

            (a) The Board may suspend or terminate the Plan at any time.  Unless
sooner  terminated,  the Plan shall  terminate  ten (10) years from the date the
Plan is adopted by the Board or approved  by the  stockholders  of the  Company,
whichever is earlier.  No rights may be granted under the Plan while the Plan is
suspended or after it is terminated.

            (b) Rights and  obligations  under any rights granted while the Plan
is in effect shall not be altered or impaired by  suspension or  termination  of
the Plan,  except  with the  consent  of the  person to whom  such  rights  were
granted.

         17.  EFFECTIVE  DATE OF PLAN.  The Plan  shall  become  effective  upon
adoption by the Board or the shareholders,  whichever is earlier. Rights granted
under the Plan shall be subject to revocation unless and until the Plan has been
approved by the shareholders of the Company.


                                      -8-
<PAGE>


                              POSITRON CORPORATION
                1999 EMPLOYEE STOCK PURCHASE PLAN ENROLLMENT FORM



         For the Offering Period beginning: _____________, _____________

         For the Interim (Three Month)
         Offering Period beginning:         _____________, _____________

_______ Application to begin participation
_______ Change in Payroll Deduction Rate


_______ Change of Beneficiary(ies)


         1.  _________________hereby  elects to participate in the 1999 Positron
Corporation  Employee  Stock  Purchase  Plan (the  "Stock  Purchase  Plan")  and
subscribes to purchase  shares of the Company's  Common Stock in accordance with
this Enrollment Form and the Employee Stock Purchase Plan.

         2. I hereby  authorize  payroll  deductions  from each  paycheck in the
amount of 2%, 4%, 6%, 8% or 10% (please  circle one) of my  Compensation  during
the Offering Period in accordance with the Stock Purchase Plan.

         3. I  understand  that said  deductions  shall be  accumulated  for the
purchase of shares of Common Stock at the applicable  Purchase Price  determined
in  accordance  with the Stock  Purchase  Plan.  I  understand  that if I do not
withdraw from an Offering  Period,  any accumulated  payroll  deductions will be
used to  automatically  purchase  shares.  I understand  that no interest  shall
accrue on any funds deducted under the terms of the Plan.

         4. I have received a copy of the complete  "1999  Positron  Corporation
Employee Stock Purchase Plan." I understand that my  participation  in the Stock
Purchase Plan is in all respects  subject to the terms of the Plan. I understand
that  participation  in the Stock  Purchase Plan under this  Enrollment  Form is
subject to obtaining shareholder approval of the Stock Purchase Plan.

         5.  Shares  purchased  for me under the Stock  Purchase  Plan should be
issued in the name(s) of (employee and/or spouse only):

         6. I understand that if I dispose of any shares received by me pursuant
to the Plan within 2 years after the applicable  Offering Date (the first day of
the Offering Period during which I purchased such shares) or within I year after
the final day of the applicable  Interim  Offering  Period (the date I purchased
such  shares),  I will be treated  for  federal  income tax  purposes  as having
received ordinary income at the time of such disposition in an amount equal

<PAGE>

to the excess of the fair  market  value of the  shares at the time such  shares
were delivered to me over the price which I paid for the shares.  I HEREBY AGREE
TO  NOTIFY  THE  COMPANY  IN  WRITING  WITHIN  30  DAYS  AFTER  THE  DATE OF ANY
DISPOSITION OF MY SHARES AND I WILL MAKE ADEQUATE  PROVISION FOR FEDERAL,  STATE
OR OTHER TAX WITHHOLDING  OBLIGATIONS,  IF ANY, WHICH ARISE UPON THE DISPOSITION
OF THE COMMON  STOCK.  The Company may, but will not be obligated  to,  withhold
from my  compensation  the amount  necessary to meet any applicable  withholding
obligation including any withholding  necessary to make available to the Company
any tax  deductions or benefits  attributable  to sale or early  disposition  of
Common Stock by me. If I dispose of such shares at any time after the expiration
of the holding period  described  above, I understand that I will be treated for
federal income tax purposes as having  received  income only at the time of such
disposition,  and that such income will be taxed as ordinary  income only to the
extent of an amount  equal to the  lesser of (1) the  excess of the fair  market
value of the  shares at the time of such  disposition  over the  purchase  price
which I paid for the shares or (2) 15% of the fair market value of the shares on
the first day of the applicable  Offering Period.  The remainder of the gain, if
any, recognized. on such disposition will be taxed as capital gain.

         7. I hereby agree to be bound by the terms of the Stock  Purchase Plan.
The  effectiveness  of this  Enrollment Form is dependent upon my eligibility to
participate in the Employee Stock Purchase Plan.

         8. In the event of my death,  I hereby  designate  the  following as my
beneficiary(ies)  to  receive  all  payments  and  shares due me under the Stock
Purchase Plan:



NAME: (Please print)
                           ----------------------------------------------------
                                (First)          (Middle)           (Last)
Relationship
                           ----------------------------------------------------
                           Relationship

                           ----------------------------------------------------
                           (Address)

NAME: (Please print)
                           ----------------------------------------------------
                                (First)          (Middle)           (Last)
Relationship
                           ----------------------------------------------------
                           Relationship

                           ----------------------------------------------------
                           (Address)


<PAGE>



                              POSITRON CORPORATION
                        1999 EMPLOYEE STOCK PURCHASE PLAN

                              NOTICE OF WITHDRAWAL



         The undersigned participant in the Offering Period of the 1999 Positron
Corporation  Employee Stock Purchase Plan which began on 19 (PLEASE INSERT DATE)
hereby  notifies the Company that he or she hereby  withdraws  from the Offering
Period. S/He hereby directs the Company to pay to the undersigned as promptly as
practicable  all the payroll  deductions  credited  to his or her  account  with
respect to such Offering Period. The undersigned understands and agrees that his
or her option for such Offering  Period will be  automatically  terminated.  The
undersigned  understands further that no further payroll deductions will be made
for the purchase of shares in the current  Offering  Period and the  undersigned
shall  be  eligible  to  participate  in  succeeding  Offering  Periods  only by
delivering to the Company a new  Enrollment  Form. The  undersigned  understands
that upon withdrawal from a particular  Offering Period,  he or she is precluded
from subsequent participation for a period of time specified in the Plan.



                                         Name and Address of Participant

                                         -------------------------------

                                         -------------------------------

                                         -------------------------------


                                         Signature


                                         -------------------------------

                                         Dated:
                                                ------------------------





                                  EXHIBIT 10.67

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (i) IN A  REGISTRATION  UNDER SAID ACT OR
(ii) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.

                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                   TO PURCHASE 160,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                     This Warrant Expires September 1, 2004

WARRANT NO. 99-12                                                 160,000 SHARES

         THIS CERTIFIES  that,  subject to the terms and  conditions  herein set
forth in this warrant,  OKAMURA  ASSOCIATES,  INC. (the "Holder") is entitled to
purchase from Positron Corporation, a Texas corporation ("Company"), at any time
or from time to time during the  Exercise  Period  (defined in Section 12 below)
and  subject to the  provisions  regarding  Exercise of Warrant (as set forth in
Section 6 below) the number of fully  paid and  non-assessable  shares of common
stock of the Company (the  "Shares") as provided  herein upon  surrender of this
Warrant at the  principal  office of the  Company,  and, at the  election of the
Holder,  upon  payment  of the  purchase  price  at  said  office  in cash or by
cashier's check or by the wire transfer of funds in a dollar amount equal to the
purchase price of the Shares for which the consideration is being given.

         This  Warrant  shall be  exercisable  for that  number of Shares as set
forth above, in minimum units of 10,000 shares.

         1. PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share of  Common  Stock  (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall be Thirty Cents ($0.30).

         2.  ADJUSTMENT  OF WARRANT  PRICE AND NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:

             a.  Adjustment  for Dividends in Stock.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other

<PAGE>

securities at the time  receivable upon the exercise of this Warrant) shall have
received,  or, on or after  the  record  date  fixed  for the  determination  of
eligible  stockholders,  shall have become entitled to receive,  without payment
therefor,  other or  additional  stock of the Company by way of dividend  (other
than as provided for in Section 2(b)  below),  then and in each such case,  upon
the  exercise of this  Warrant,  the Holder  shall be  entitled  to receive,  in
addition to the number of shares of Common Stock receivable, and without payment
of any additional consideration therefor, the amount of such other or additional
stock of the Company which the Holder would receive on the date of such exercise
had it been the holder of record of such Common Stock on the date hereof and had
thereafter,  during the period from the date hereof to and including the date of
such exercise, retained such shares and/or all other additional stock receivable
by it as aforesaid during such period and given effect to all adjustments called
for during such period by this  Section 2.

             b.  Adjustment for Changes in Common Stock. In the event of changes
in the  outstanding  Common  Stock  of the  Company  by  reason  of  split--ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.


         3. NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

         4. NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a stockholder of the Company prior to its exercise.

         5. RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.

         6.  EXERCISE OF WARRANT.  Subject to the terms and  conditions  hereof,
this Warrant may be exercised by the holder hereof then  registered on the books
of the Company at any time during the exercise Period as set forth in Section 12
hereof. Subject to the foregoing, this Warrant may be exercised by the Holder or
its  registered  assigns,  in whole or in part and in  minimum  units of  10,000
shares, by the surrender of this Warrant at the principal office of the Company,
together with the attached form of  subscription  duly executed,  accompanied by
payment in full of the amount of the Warrant Price in the form described in this
Warrant. Upon



                                      -2-
<PAGE>

partial exercise of this Warrant, a new warrant or warrants  containing the same
date and  provisions  as this  Warrant  shall be  issued by the  Company  to the
registered holder for the number of shares of Common Stock with respect to which
this Warrant  shall not have been  exercised.  A Warrant shall be deemed to have
been  exercised  immediately  prior to the close of  business on the date of its
surrender for exercise as provided above, and the person entitled to receive the
shares of Common  Stock  issuable  upon such  exercise  shall be treated for all
purposes  as the holder of such  shares of record as of the close of business on
such date. As promptly as  practicable  on or after such date, the Company shall
issue and deliver to the person or persons  entitled  to receive  the shares,  a
certificate  or  certificates  for the  number of full  shares  of Common  Stock
issuable  upon such  exercise,  together  with cash in lieu of any fraction of a
share as provided  above.

         7. CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

         8. COMPLIANCE  WITH  SECURITIES ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm  in  writing  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

         9. SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants  of like nature and date  representing  in the  aggregate  the right to
purchase  such number of shares of such Common Stock as shall be  designated  by
such holder at the time of such surrender; provided, however, that the Company's
obligations to subdivide  securities  under this Section shall be subject to and
conditioned  upon the compliance of any such  subdivision  with applicable state
securities laws and with the Securities Act.

         10. LOSS, THEFT, DESTRUCTION, OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this Warrant,  and in the case of loss, theft, or
destruction,  of  indemnity  or  security  reasonably  satisfactory  to  it  and
reimbursement to the Company of all reasonable  expenses  incidental thereto, in
the case of mutilation,  and upon surrender and cancellation of this Warrant the
Company  will make and  deliver a new Warrant of like tenor and dates as of such
cancellation, in lieu of this Warrant.

         11.  MISCELLANEOUS.  This Warrant  shall be governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference only, and shall not


                                      -3-
<PAGE>

be deemed to  constitute  a part of this  Warrant.  Neither this Warrant nor any
term included may be changed, waived,  discharged, or terminated orally but only
by an  instrument in writing  signed by the Company and the Holder.  All notices
and other  communications from the Company to the Holder shall be by telecopy or
expedited  courier service to the address furnished to the Company in writing by
the last  holder of this  Warrant  who shall  have  furnished  an address to the
Company in writing.  This Warrant has been issued pursuant to a Warrant Purchase
Agreement  dated as of June 15,  1999,  the  terms of which,  including  certain
repurchase  provisions,  are  incorporated  herein by reference.  A copy of such
Warrant Purchase  Agreement may be inspected at the office of the Company during
normal business hours.

         12.  EXERCISE  PERIOD.  The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on August 31, 2004.

         ISSUED this first day of September, 1999.

                                             POSITRON CORPORATION


                                             By:  /s/ Gary H. Brooks
                                                -----------------------------
                                                  Gary H. Brooks, President

ATTEST:


- -----------------------------

                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION

         FOR VALUE  RECEIVED the  undersigned  registered  owner of this Warrant
hereby sells,  assigns,  and transfers  unto the Assignee named below all of the
rights of the undersigned  under the within Warrant,  with respect to the number
of shares of Common Stock set forth below:

<TABLE>
<CAPTION>
Name of Assignee                                        Address                           Number of Shares
<S>                                                     <C>                               <C>


</TABLE>



The undersigned does hereby irrevocably  constitute and appoint  _______________
_______________________  Attorney to make such transfer on the books of POSITRON
CORPORATION  maintained for the purpose,  with full power of substitution in the
premises.


Dated:______________________


                                                Name of Warrant Holder

                                                Signature:
                                                          ---------------------
Witness:____________________



<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)

         The undersigned  registered owner of this Warrant irrevocably exercises
this  Warrant  for and  purchases  ________________  of the  number of shares of
Common Stock of POSITRON CORPORATION purchasable with this Warrant, and herewith
makes  payment  therefor,  all at the  price  and on the  terms  and  conditions
specified in this Warrant.

Dated:_____________________


                  -------------------------------------------------------------
                  (Signature of Registered Owner)


                  -------------------------------------------------------------
                  (Street Address)


                  -------------------------------------------------------------
                  (City)                       (State)                (Zip Code)





                                  EXHIBIT 10.68

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (i) IN A  REGISTRATION  UNDER SAID ACT OR
(ii) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.

                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                  TO PURCHASE 3,000,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                      This Warrant Expires August 18, 2004

WARRANT NO. 99-14                                               3,000,000 SHARES

      THIS CERTIFIES that,  subject to the terms and conditions herein set forth
in this warrant,  MORRIS HOLDINGS LIMITED (the "Holder") is entitled to purchase
from Positron Corporation, a Texas corporation ("Company"),  at any time or from
time to time  during  the  Exercise  Period  (defined  in  Section 12 below) and
subject to the provisions regarding Exercise of Warrant (as set forth in Section
6 below) the number of fully paid and  non-assessable  shares of common stock of
the Company (the "Shares") as provided  herein upon surrender of this Warrant at
the principal  office of the Company,  and, at the election of the Holder,  upon
payment of the purchase price at said office in cash or by cashier's check or by
the wire transfer of funds in a dollar amount equal to the purchase price of the
Shares for which the consideration is being given.

      This Warrant shall be  exercisable  for that number of Shares as set forth
above,  in minimum  units of  100,000  shares.

      1.    PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share of  Common  Stock  (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall be Five Cents ($0.30).

      2.    ADJUSTMENT  OF WARRANT  PRICE AND  NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:

<PAGE>


            a.    ADJUSTMENT FOR DIVIDENDS IN STOCK.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other  securities at the time  receivable  upon the exercise of this
Warrant)  shall have  received,  or, on or after the  record  date fixed for the
determination of eligible  stockholders,  shall have become entitled to receive,
without  payment  therefor,  other or additional  stock of the Company by way of
dividend  (other than as provided for in Section  2(b) below),  then and in each
such case,  upon the exercise of this  Warrant,  the Holder shall be entitled to
receive,  in addition to the number of shares of Common  Stock  receivable,  and
without  payment of any additional  consideration  therefor,  the amount of such
other or  additional  stock of the Company which the Holder would receive on the
date of such  exercise  had it been the holder of record of such Common Stock on
the date  hereof and had  thereafter,  during the period from the date hereof to
and including the date of such  exercise,  retained such shares and/or all other
additional  stock  receivable  by it as  aforesaid  during such period and given
effect to all adjustments called for during such period by this Section 2.

            b.    Adjustment  for  Changes  in  Common  Stock.  In the  event of
changes in the outstanding  Common Stock of the Company by reason of split--ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.

      3.    NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

      4.    NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a stockholder of the Company prior to its exercise.

      5.    RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.


                                      -2-
<PAGE>

      6.    EXERCISE OF  WARRANT.  Subject to the terms and  conditions  hereof,
this Warrant may be exercised by the holder hereof then  registered on the books
of the Company at any time during the exercise Period as set forth in Section 12
hereof. Subject to the foregoing, this Warrant may be exercised by the Holder or
its  registered  assigns,  in whole or in part and in  minimum  units of 100,000
shares, by the surrender of this Warrant at the principal office of the Company,
together with the attached form of  subscription  duly executed,  accompanied by
payment in full of the amount of the Warrant Price in the form described in this
Warrant.  Upon  partial  exercise  of this  Warrant,  a new  warrant or warrants
containing  the same date and  provisions as this Warrant shall be issued by the
Company to the  registered  holder for the number of shares of Common Stock with
respect to which this Warrant shall not have been exercised.  A Warrant shall be
deemed to have been exercised  immediately prior to the close of business on the
date of its surrender for exercise as provided above, and the person entitled to
receive the shares of Common Stock  issuable upon such exercise shall be treated
for all  purposes  as the  holder  of such  shares  of record as of the close of
business on such date.  As promptly as  practicable  on or after such date,  the
Company shall issue and deliver to the person or persons entitled to receive the
shares,  a certificate or  certificates  for the number of full shares of Common
Stock issuable upon such exercise, together with cash in lieu of any fraction of
a share as provided  above.

      7.    CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

      8.    COMPLIANCE WITH  SECURITIES  ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm  in  writing  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

      9.    SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants of like nature and date


                                      -3-
<PAGE>


representing  in the  aggregate  the right to purchase  such number of shares of
such  Common  Stock as shall be  designated  by such  holder at the time of such
surrender;  provided,  however,  that the  Company's  obligations  to  subdivide
securities  under this  Section  shall be subject  to and  conditioned  upon the
compliance of any such  subdivision  with applicable  state  securities laws and
with the Securities Act.

      10.   LOSS, THEFT, DESTRUCTION,  OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this Warrant,  and in the case of loss, theft, or
destruction,  of  indemnity  or  security  reasonably  satisfactory  to  it  and
reimbursement to the Company of all reasonable  expenses  incidental thereto, in
the case of mutilation,  and upon surrender and cancellation of this Warrant the
Company  will make and  deliver a new Warrant of like tenor and dates as of such
cancellation, in lieu of this Warrant.

      11.   MISCELLANEOUS.  This  Warrant  shall be  governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference  only,  and shall not be deemed to  constitute a part of this Warrant.
Neither this Warrant nor any term included may be changed,  waived,  discharged,
or terminated  orally but only by an instrument in writing signed by the Company
and the Holder.  All notices  and other  communications  from the Company to the
Holder  shall  be by  telecopy  or  expedited  courier  service  to the  address
furnished to the Company in writing by the last holder of this Warrant who shall
have  furnished  an address to the  Company in  writing.  This  Warrant has been
issued pursuant to a Warrant  Purchase  Agreement dated as of June 15, 1999, the
terms of which, including certain repurchase provisions, are incorporated herein
by reference.  A copy of such Warrant Purchase Agreement may be inspected at the
office of the Company during normal business hours.

      12.   EXERCISE   PERIOD.   The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on August 18, 2004.

      ISSUED this 18, day of August, 1999.

                                              POSITRON CORPORATION


                                              By: /s/ Gary H. Brooks
                                                 -------------------------------
                                                    Gary H. Brooks, President

         ATTEST:

         ---------------------------


                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION

      FOR VALUE RECEIVED the undersigned registered owner of this Warrant hereby
sells, assigns, and transfers unto the Assignee named below all of the rights of
the undersigned  under the within Warrant,  with respect to the number of shares
of Common Stock set forth below:

NAME OF ASSIGNEE                    ADDRESS                 NUMBER OF SHARES
- ----------------                    -------                 ----------------


The undersigned does hereby irrevocably  constitute and appoint  _______________
_______________________  Attorney to make such transfer on the books of POSITRON
CORPORATION  maintained for the purpose,  with full power of substitution in the
premises.

Dated:
      ----------------------

                                   ---------------------------------------------
                                   Name of Warrant Holder

                                   Signature:
                                             -----------------------------------

Witness:
        -----------------------

<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)

      The undersigned  registered  owner of this Warrant  irrevocably  exercises
this  Warrant  for and  purchases  ________________  of the  number of shares of
Common Stock of POSITRON CORPORATION purchasable with this Warrant, and herewith
makes  payment  therefor,  all at the  price  and on the  terms  and  conditions
specified in this Warrant.

Dated:
      ---------------------

                                      ------------------------------------------
                                      (Signature of Registered Owner)


                                      ------------------------------------------
                                      (Street Address)


                                      ------------------------------------------
                                      (City)             (State)      (Zip Code)




                                  EXHIBIT 10.69

THIS WARRANT AND THE SHARES OF STOCK OF POSITRON  CORPORATION  TO BE ISSUED UPON
ANY EXERCISE OF THIS WARRANT HAVE NOT BEEN AND WILL NOT BE  REGISTERED  WITH THE
SECURITIES AND EXCHANGE COMMISSION UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNDER  ANY  STATE  SECURITIES  LAW AND ANY  SALE,  TRANSFER,  PLEDGE OR OTHER
DISPOSITION  THEREOF  MAY BE MADE ONLY (i) IN A  REGISTRATION  UNDER SAID ACT OR
(ii) IF AN  EXEMPTION  FROM  REGISTRATION  UNDER SAID ACT AND  APPLICABLE  STATE
SECURITIES  LAWS IS AVAILABLE AND THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL
TO THAT EFFECT REASONABLY SATISFACTORY TO IT.

                              POSITRON CORPORATION

                          COMMON STOCK PURCHASE WARRANT
                  TO PURCHASE 3,000,000 SHARES OF COMMON STOCK
                             OF POSITRON CORPORATION

                      This Warrant Expires August 18, 2004

WARRANT NO. 99-15                                               3,000,000 SHARES

      THIS CERTIFIES that,  subject to the terms and conditions herein set forth
in this warrant,  VISTULA FINANCE LIMITED (the "Holder") is entitled to purchase
from Positron Corporation, a Texas corporation ("Company"),  at any time or from
time to time  during  the  Exercise  Period  (defined  in  Section 12 below) and
subject to the provisions regarding Exercise of Warrant (as set forth in Section
6 below) the number of fully paid and  non-assessable  shares of common stock of
the Company (the "Shares") as provided  herein upon surrender of this Warrant at
the principal  office of the Company,  and, at the election of the Holder,  upon
payment of the purchase price at said office in cash or by cashier's check or by
the wire transfer of funds in a dollar amount equal to the purchase price of the
Shares for which the consideration is being given.

      This Warrant shall be  exercisable  for that number of Shares as set forth
above, in minimum units of 100,000 shares.

      1.    PURCHASE PRICE. Subject to adjustment as hereinafter  provided,  the
purchase  price of one  share of  Common  Stock  (or such  securities  as may be
substituted for one share of Common Stock pursuant to the provisions hereinafter
set forth) (the "Warrant Price") shall be Five Cents ($0.30).

      2.    ADJUSTMENT  OF WARRANT  PRICE AND  NUMBER OF SHARES.  The number and
kind of  securities  issuable upon the exercise of this Warrant shall be subject
to adjustment from time to time upon the happening of certain events as follows:

<PAGE>


            a.    ADJUSTMENT FOR DIVIDENDS IN STOCK.  If at any time on or after
the date  hereof,  the holders of the Common Stock of the Company (or any shares
of stock or other  securities at the time  receivable  upon the exercise of this
Warrant)  shall have  received,  or, on or after the  record  date fixed for the
determination of eligible  stockholders,  shall have become entitled to receive,
without  payment  therefor,  other or additional  stock of the Company by way of
dividend  (other than as provided for in Section  2(b) below),  then and in each
such case,  upon the exercise of this  Warrant,  the Holder shall be entitled to
receive,  in addition to the number of shares of Common  Stock  receivable,  and
without  payment of any additional  consideration  therefor,  the amount of such
other or  additional  stock of the Company which the Holder would receive on the
date of such  exercise  had it been the holder of record of such Common Stock on
the date  hereof and had  thereafter,  during the period from the date hereof to
and including the date of such  exercise,  retained such shares and/or all other
additional  stock  receivable  by it as  aforesaid  during such period and given
effect to all adjustments called for during such period by this Section 2.

            b.    Adjustment  for  Changes  in  Common  Stock.  In the  event of
changes in the outstanding  Common Stock of the Company by reason of split--ups,
recapitalizations,  reclassifications,  mergers, consolidations, combinations or
exchanges of shares, separations,  reorganizations,  liquidations,  or the like,
the number and class of shares  available under the Warrant in the aggregate and
the Warrant Price shall be correspondingly adjusted by the Board of Directors of
the Company.  The  adjustment  shall be such as will give the Holder on exercise
for the same aggregate Warrant Price the total number, class, and kind of shares
as the Holder would have owned had the Warrant been exercised prior to the event
and had the Holder continued to hold such shares until after the event requiring
adjustment.

      3.    NO FRACTIONAL  SHARES.  No fractional shares of Common Stock will be
issued in connection with any  subscription  under this Warrant.  In lieu of any
fractional shares which would otherwise be issuable,  the Company shall pay cash
equal to the product of such fraction multiplied by the fair market value of one
share of Common Stock on the date of exercise as determined in good faith by the
Company's Board of Directors.

      4.    NO STOCKHOLDER  RIGHTS. This Warrant shall not entitle its holder to
any of the rights of a  stockholder  of the Company  prior to its  exercise.

      5.    RESERVATION OF STOCK.  The Company  covenants that during the period
this Warrant is  exercisable,  the Company will reserve from its  authorized and
unissued Common Stock a sufficient  number of shares to provide for the issuance
of Common Stock upon the exercise of this Warrant.  The Company  agrees that its
issuance of this Warrant shall constitute full authority to its officers who are
charged with the duty of executing  stock  certificates to execute and issue the
necessary  certificates  for shares of Common  Stock upon the  exercise  of this
Warrant.


                                      -2-
<PAGE>


      6.    EXERCISE OF  WARRANT.  Subject to the terms and  conditions  hereof,
this Warrant may be exercised by the holder hereof then  registered on the books
of the Company at any time during the exercise Period as set forth in Section 12
hereof. Subject to the foregoing, this Warrant may be exercised by the Holder or
its  registered  assigns,  in whole or in part and in  minimum  units of 100,000
shares, by the surrender of this Warrant at the principal office of the Company,
together with the attached form of  subscription  duly executed,  accompanied by
payment in full of the amount of the Warrant Price in the form described in this
Warrant.  Upon  partial  exercise  of this  Warrant,  a new  warrant or warrants
containing  the same date and  provisions as this Warrant shall be issued by the
Company to the  registered  holder for the number of shares of Common Stock with
respect to which this Warrant shall not have been exercised.  A Warrant shall be
deemed to have been exercised  immediately prior to the close of business on the
date of its surrender for exercise as provided above, and the person entitled to
receive the shares of Common Stock  issuable upon such exercise shall be treated
for all  purposes  as the  holder  of such  shares  of record as of the close of
business on such date.  As promptly as  practicable  on or after such date,  the
Company shall issue and deliver to the person or persons entitled to receive the
shares,  a certificate or  certificates  for the number of full shares of Common
Stock issuable upon such exercise, together with cash in lieu of any fraction of
a share as provided above.

      7.    CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price is adjusted as
provided in Section 2, the Company shall  promptly  deliver to the record holder
of this Warrant a  certificate  of an officer of the Company  setting  forth the
relevant  Warrant  Price or number of shares after such  adjustment  and setting
forth a brief statement of the facts requiring such adjustment.

      8.    COMPLIANCE WITH  SECURITIES  ACT. The Holder,  by acceptance of this
Warrant,  agrees that this  Warrant and the shares of Common  Stock to be issued
upon its exercise (or shares of any security into which such Common Stock may be
converted)  (the "Shares") are being acquired for investment and that the Holder
will not offer,  sell,  or  otherwise  dispose of this Warrant and any shares of
Common  Stock to be issued upon its  exercise  (or shares of any  security  into
which such Common Stock may be converted) except under  circumstances which will
not  result in a  violation  of the  Securities  Act of 1933,  as  amended  (the
"Securities  Act").  Upon exercise of this Warrant,  the holder hereof shall, if
requested  by the  Company,  confirm  in  writing  its  investment  purpose  and
acceptance of the restrictions on transfer of the Shares.

      9.    SUBDIVISION OF WARRANT. At the request of the holder of this Warrant
in  connection  with a transfer or exercise of a portion of the Warrant and upon
surrender of this  Warrant for such  purpose to the Company,  the Company at its
expense  (except for any transfer tax payable)  will issue in exchange  therefor
warrants of like nature and date


                                      -3-
<PAGE>


representing  in the  aggregate  the right to purchase  such number of shares of
such  Common  Stock as shall be  designated  by such  holder at the time of such
surrender;  provided,  however,  that the  Company's  obligations  to  subdivide
securities  under this  Section  shall be subject  to and  conditioned  upon the
compliance of any such  subdivision  with applicable  state  securities laws and
with the Securities Act.

      10.   LOSS, THEFT, DESTRUCTION,  OR MUTILATION OF WARRANT. Upon receipt by
the  Company  of  evidence  reasonably  satisfactory  to it of the loss,  theft,
destruction,  or mutilation of this Warrant,  and in the case of loss, theft, or
destruction,  of  indemnity  or  security  reasonably  satisfactory  to  it  and
reimbursement to the Company of all reasonable  expenses  incidental thereto, in
the case of mutilation,  and upon surrender and cancellation of this Warrant the
Company  will make and  deliver a new Warrant of like tenor and dates as of such
cancellation, in lieu of this Warrant.

      11.   MISCELLANEOUS.  This  Warrant  shall be  governed by the laws of the
State of Texas. The headings in this Warrant are for purposes of convenience and
reference  only,  and shall not be deemed to  constitute a part of this Warrant.
Neither this Warrant nor any term included may be changed,  waived,  discharged,
or terminated  orally but only by an instrument in writing signed by the Company
and the Holder.  All notices  and other  communications  from the Company to the
Holder  shall  be by  telecopy  or  expedited  courier  service  to the  address
furnished to the Company in writing by the last holder of this Warrant who shall
have  furnished  an address to the  Company in  writing.  This  Warrant has been
issued pursuant to a Warrant  Purchase  Agreement dated as of June 15, 1999, the
terms of which, including certain repurchase provisions, are incorporated herein
by reference.  A copy of such Warrant Purchase Agreement may be inspected at the
office of the Company during normal business hours.

      12.   EXERCISE   PERIOD.   The  Exercise  Period  shall  mean  the  period
commencing on the date hereof and ending on August 18, 2004.

      ISSUED this 20th day of January, 2000.

                                              POSITRON CORPORATION


                                              By: /s/ Gary H. Brooks
                                                  ------------------------------
                                                    Gary H. Brooks, President

         ATTEST:

         --------------------------


                                      -4-
<PAGE>


                               FORM OF ASSIGNMENT
                              POSITRON CORPORATION

      FOR VALUE RECEIVED the undersigned registered owner of this Warrant hereby
sells, assigns, and transfers unto the Assignee named below all of the rights of
the undersigned  under the within Warrant,  with respect to the number of shares
of Common Stock set forth below:

NAME OF ASSIGNEE                    ADDRESS                     NUMBER OF SHARES
- ----------------                    -------                     ----------------


The undersigned does hereby irrevocably  constitute and appoint  _______________
_______________________  Attorney to make such transfer on the books of POSITRON
CORPORATION  maintained for the purpose,  with full power of substitution in the
premises.

Dated:
      ----------------------

                                   ---------------------------------------------
                                   Name of Warrant Holder

                                   Signature:
                                             -----------------------------------

Witness:
        ------------------------


<PAGE>


                                SUBSCRIPTION FORM
                              POSITRON CORPORATION

                 (To be executed only upon exercise of Warrant)

      The undersigned  registered  owner of this Warrant  irrevocably  exercises
this  Warrant  for and  purchases  ________________  of the  number of shares of
Common Stock of POSITRON CORPORATION purchasable with this Warrant, and herewith
makes  payment  therefor,  all at the  price  and on the  terms  and  conditions
specified in this Warrant.

Dated:
      ---------------------

                                     -------------------------------------------
                                     (Signature of Registered Owner)


                                     -------------------------------------------
                                     (Street Address)


                                     -------------------------------------------
                                     (City)              (State)      (Zip Code)


            CONSENT OF HAM, LANGSTON& BREZINA, INDEPENDENT AUDITORS

      We consent to the reference of our firm under the caption "Experts" and to
the use of our report dated March 26, 1999 in the  Registration  Statement  Form
SB-2 dated February 14, 2000 and the related prospectus of Positron  Corporation
for the registration of 78,732,990 shares of its common stock.

                                             /s/ Ham, Langston & Brezina LLP


                                             -------------------------------


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