Exhibit 10.2


STOCK PLEDGE
AGREEMENT
   STOCK PLEDGE AGREEMENT, dated
April 10, 2008, by and between POSITRON CORPORATION,a
publicly-owned Texas corporation (the “Pledgor”) and IMAGIN MOLECULAR CORPORATION,a publicly-owned Delaware corporation (the “Secured Party”).
  WI T N E S S E T H
  WHEREAS, simultaneously with
the execution of this Agreement, Pledgor and Secured Party have entered into a
Promissory Note in the principal amount of $1,346,000 to formalize previous
advances made by the Secured Party to the Pledgor (the “Note”);
  WHEREAS, to induce the Secured
Party to make the Note to Pledgor, Pledgor has agreed to pledge, the in favor of
Secured Party, the security set forth herein, pursuant to the terms and
conditions of this Agreement; and
  NOW, THEREFORE, in
consideration of the premises and for other good and valuable consideration, the
receipt of which is hereby acknowledged, the Pledgor hereby agrees as
follows:
  1.           Defined
Terms.  As used herein, the following terms shall have the
following meanings:
  “Agreement” shall mean
this Stock Pledge Agreement, as the same may from time to time be amended or
supplemented.
  “Pledged Securities”
shall mean the 100,000,000 shares of the Pledgor’s common stock, par value $0.01
per share, together with the certificates therefor, and any additional shares,
certificates or other property received pursuant to Section 3 of this
Agreement.
  “Security Interest”
shall have the meaning provided in Section 2(a) of this Agreement.
  “UCC” shall have the
meaning provided in Section 5(c) of this Agreement.
  2.           Pledge.
  (a)         As
security for the full payment and performance of the obligations under the Note,
the Pledgor does hereby pledge, assign, hypothecate, mortgage, transfer and
deliver to the Secured Party all of their rights and interest in and to the
Pledged Securities (together with appropriate undated, medallion guaranteed
stock powers duly executed in blank) and hereby grants to the Secured Party, as
collateral security for the payment and performance when due of all the
obligations under the Note, a continuing first priority security interest in the
Pledged Securities, together with all additions thereto, substitutions and
replacements thereof (the “Security Interest”).
  
  (b)         The
Pledgor herewith deposits with the Secured Party, and the Secured Party
acknowledges receipt of, certificates representing the Pledged
Securities.  The Secured Party hereby accepts delivery of the Pledged
Securities and shall hold the Pledged Securities pursuant to this
Agreement.  The certificates representing the Pledged Securities shall
be accompanied by undated stock powers endorsed in blank for
transfer.
  3.           Stock Dividends,
Distributions, etc.  Subject to Section 5 of this Agreement,
if, while this Agreement is in effect, the Pledgor shall become entitled to
receive any shares of stock (including, without limitation, a distribution in
connection with any reclassification, increase or reduction of capital or in
connection with any reorganization), or any option or right to acquire shares of
stock, in substitution of, or in exchange for, any shares of Pledged Securities,
or shall receive any stock dividend with respect to any shares of Pledged
Securities, the Pledgor agrees to pledge the same as additional collateral
security for the obligations under the Note, such shares shall become part of
the Pledged Securities, the Pledgor shall deposit with the Secured Party the
certificates representing such shares (together with appropriate undated stock
powers duly executed in blank), and the Secured Party shall hold such additional
shares of Pledged Securities pursuant to this Agreement.  Any sums
paid upon or in respect of the Pledged Securities upon the recapitalization,
reorganization, liquidation or dissolution of the issuer thereof shall be paid
over to the Secured Party, as additional collateral security for the payment of
the obligations under the Note.
  4.           Representations and
Warranties.  The Pledgor hereby represents and warrants
that:
  (a)         Except
for the security interest granted to the Secured Party pursuant to this
Agreement, the Pledgor is the sole owner of the Pledged Securities, having good
and valid title thereto, free and clear of any and all liens, claims,
encumbrances, security interests, attachments, charges, rights or equitable
rights of any other persons.
  (b)         All
books, records and documents relating to the Security Interest are genuine, true
and correct and in all respects what they purport to be.
  (c)         The
security interest granted to the Secured Party pursuant to this Agreement
constitutes and creates a valid and continuing and first, prior and perfected
lien on and first security interest in the Security Interest in favor of the
Secured Party.
  (d)         The
Pledged Securities delivered to the Secured Party pursuant to this Agreement are
fully paid and is non-assessable as of the date of issuance. There are no
options, warrants, convertible securities or other securities exchangeable,
convertible or issuable into any of the Pledged Securities or that give the
holder thereof any rights, directly or indirectly, to any of the Pledged
Securities.
  5.           Covenants and
Agreements.  The Pledgor hereby agrees that, so long as the
Note has not been terminated, the Pledgor shall:
  (a)         Defend
the Security Interest against all claims and demands of all Persons (other than
the Secured Party) at any time claiming the same or any interest
therein.
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 (b)         Furnish
to the Secured Party such information concerning the Security Interest as the
Secured Party may from time to time reasonably request, and will allow the
Secured Party to inspect and copy, or will furnish the Secured Party with copies
of, all records reasonably requested by the Secured Party.
  (c)         At
any time and from time to time, upon the request of the Secured Party and at the
expense of the Pledgor promptly execute and deliver any and all such further
instruments and  documents and will cause such opinions of counsel to
be delivered and will take such further action as may be deemed necessary or
desirable in the reasonable discretion of the Secured Party to obtain, maintain
and perfect the security interest granted hereby, including, without limitation,
the provision of all instruments and documents reasonably necessary to perfect
the security interest granted hereby under Article 8 of Uniform Commercial Code
as in effect in the State of Texas (the “UCC”), and execute and deliver one or
more proxies, powers of attorney, orders, notices, statements, agreements or
other writings.
  (d)         Not
sell, assign, transfer, exchange, or otherwise dispose of, or grant any option
with respect to, the Pledged Securities, or create, incur or permit to exist any
adverse claim or Lien with respect to any of the Pledged Securities, or any
interest therein, or any proceeds thereof, except for the security interest
provided for by this Agreement.
  (e)         Require
the Secured Party to present, send or file any claim or notices, perform any
services, exercise any rights of collection, enforcement, conversion or
exchange, vote, pay for any insurance, pay any taxes or other charges, make any
demand, make any inquiry as to the nature or sufficiency of any payment received
by them or take any action of any kind in connection with the management
thereof, and the Secured Party's only duty with respect thereto shall be to use
reasonable care in the custody and preservation of the Security Interest while
the Security Interest is in its actual possession, which shall not include any
steps necessary to preserve rights against prior or  third
parties.
  (f)          File,
record, make, execute and deliver all such acts, deeds, things, notices and
instruments as may be reasonably necessary or desirable to vest in and assure to
the Secured Party a continuing first priority security interest in and to the
collateral and the enforcement of, and giving effect to, the rights, remedies
and powers hereunder.
  (g)         In
the event that all or any part of the securities constituting the Security
Interest are lost, destroyed or wrongfully taken while such securities are in
the possession of the Secured Party, cause the issuance of new securities in
place of the lost, destroyed or wrongfully taken securities upon request
therefor by the Secured Party without the necessity of the provision by the
Secured Party of any indemnity bond or other security, other than the Secured
Party's agreement of indemnity therefor.
  (h)         Not
redeem, or permit the redemption, of any part of the Security Interest, or sell
or permit the sale or other transfer of any of the Pledged
Securities.
  (i)          Not
declare, or permit the declaration of, any dividends on or make any distribution
in respect of the Pledged Securities, or purchase, redeem or acquire for value
any shares of the Pledged Securities.
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  (j)           Not
take any action which the Secured Party may reasonably request in order for the
Secured Party to obtain and enjoy the full rights and benefits granted to it by
this Agreement and the Note.
  6.           Voting
Rights.  The Pledgor has classified the Pledged Securities as
“issued but not outstanding”.  However, unless and until an Event of
Default shall have occurred and be continuing, the Pledgor shall retain the
right to vote the Pledged Securities and to give consents, waivers and
ratifications in respect of the Pledged Securities to the extent same
exist.  Once an Event of Default shall have occurred and so long as it
is continuing, the Secured Party shall have the right to vote the Pledged
Securities and to give consents, waivers and ratification in respect of the
Pledged Securities.
  7.           Events of
Default.  The occurrence of an Event of Default under the Note
shall constitute an Event of Default hereunder.
  8.           Rights and Remedies Upon an
Event of Default.  If an Event of Default shall have occurred
and be continuing, subject to the receipt of all required regulatory
approvals:
  (a)         The
Secured Party shall, after giving written notice to the Pledgor specifying the
action to be taken, register any or all shares of the Pledged Securities held by
the Secured Party in the name of the Secured Party.
  (b)        
The Secured Party may demand, sue for, collect or make any compromise or
settlement the Secured Party deems suitable in respect of the Pledged Securities
held by it hereunder.
  (c)         The
Secured Party shall have all of the rights and remedies with respect to the
Pledged Securities of a secured party under the UCC.
  (d)         The
Secured Party may, upon fifteen (15) days prior written notice to the Pledgor of
the time and place, with respect to the Pledged Securities, sell, lease, assign
or otherwise dispose of all or any of such Pledged Securities, at such place or
places as the Secured Party deems best, and for cash or on credit for future
delivery (without thereby assuming any credit risk), at public or private sale,
without demand of performance or notice of intention to erect any such
disposition or of time or place thereof (except such notice as is required
hereunder or by applicable statute and cannot be waived) and the Secured Party
or anyone else may be the purchaser, lessee, assignee or recipient of any or all
of the Pledged Securities so disposed of at public sale (or, to the extent
permitted by law, at any private sale), and thereafter hold the same absolutely,
free from any claim or right of whatsoever kind, including any equity of
redemption, of the Pledgor, any such demand, notice or right and equity being
hereby expressly waived and released.  The net proceeds of any sale of
Pledged Securities pursuant to this Section 8 shall be applied first to the
repayment of the outstanding principal and accrued interest under the Note and
any reasonable costs and expenses of Secured Party (including attorney's fees,
costs and disbursements) incurred by Secured Party in enforcing its rights under
this Agreement and only after so applying such net proceeds and after such
payment need the Secured Party account for the surplus, if any, to the Pledgor,
or to whomsoever may be lawfully entitled to receive the same, or as a court of
competent jurisdiction my direct.
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  9.           Private Sale and Compliance with
Law.
  (a)         The
Secured Party shall incur no liability as a result of the sale of the Pledged
Securities, or any part thereof, at any private sale conducted in a commercially
reasonable manner.  The Pledgor hereby waives any claim against the
Secured Party arising by reason of the fact that the price at which the Pledged
Securities may have been sold at such a private sale conducted in a commercially
reasonable manner was less than the price which might have been obtained at a
public sale or was less than the aggregate amount due under the Note, even if
the Secured Party accepts the first offer received and does not offer the
Pledged Securities to more than one offeree.
  (b)         The
Pledgor agrees that in any sale of any of the Pledged Securities whenever an
Event of Default shall have occurred and be continuing, the Secured Party is
hereby authorized to comply with any limitation or restriction in connection
with such sale as it may be advised by counsel is necessary in order to avoid
any violation of applicable law (including, without limitation, compliance with
such procedures as may restrict the number of prospective bidders and purchasers
or require that such prospective bidders and purchasers be persons who will
represent and agree that they are purchasing for their own account for
investment and not with a view to the distribution or resale of such Pledged
Securities), or in order to obtain any required approval of the sale or of the
purchaser by any governmental regulatory authority or official, and the Pledgor
further agrees that such compliance shall not result in such sale being
considered or deemed not to have been made in a commercially reasonable manner,
nor shall the Secured Party be liable or accountable to the Pledgor for any
discount allowed by the reason of the fact that such Pledged Securities is sold
in compliance with any such limitation or restriction.
  10.         Retention of
Collateral.  Notwithstanding any provision of this Agreement to
the contrary, the Secured Party may in its discretion retain all or a portion of
the Security Interest in satisfaction of any or all due and payable obligations
under the Note.  The portion of the Security Interest that may in its
discretion be retained by the Secured Party in satisfaction of such obligations
shall be that portion having a fair market value or cash value, as applicable,
equal to the amount of such obligations at the time such public or private sale
would have been held.  Such fair market value or cash value, as
applicable, shall be determined jointly by the Pledgor and the Secured Party,
and the parties hereby agree to cooperate in such determination.  In
the event that the parties are unable to agree on such fair market value or cash
value, as applicable, it shall be determined by a recognized actuarial or
accounting firm jointly selected by the Pledgor and the Secured
Party.  All expenses of such determination, including without
limitation the fees and expenses of such actuarial or accounting firm, shall he
borne by the Pledgor.
  11.         Further
Assurances.  The Pledgor agrees that at any time and from time
to time upon the written request of the Secured Party, it will execute and
deliver such further documents and do such further acts and things as the
Secured Party may reasonably request in order to affect the purposes of this
Agreement.
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  12.         No Waiver; Cumulative
Remedies.  The Secured Party shall not by any act, delay,
omission or otherwise be deemed to have waived any of its rights or remedies
hereunder and no waiver shall be valid unless in writing, and then only to the
extent therein set forth.  A waiver by the Secured Party of any right
or remedy hereunder on any one occasion shall not be construed as a bar to any
right or remedy which the Secured Party would otherwise have on any future
occasion.  No failure to exercise nor any delay in exercising on the
part of the Secured Party of any right, power or privilege hereunder, shall
operate as a waiver thereof by the Secured Party; nor shall 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.
  13.         Notices.  All
communications, notices, instructions or demands given under this Agreement
shall be in writing and shall be deemed to have been duly given when delivered
to, or on the third business day after the same is mailed by prepaid registered
or certified mail addressed to, or when sent by facsimile to, the party for whom
intended, as follows, or to such other address as may be furnished by such party
by notice in the manner provided herein:
  To
      the Pledgor:
              Positron
      Corporation
 1304
Langham Creek Drive, #300
 Houston,
Texas 77084
 Fax:
(282) 492-2961
 
 To
      the Secured Party:
              Imagin
      Molecular Corporation
 104 W.
Chestnut Street, #215
 Hinsdale,
Illinois 60521
 Fax:
(630) 371-5584
 
 With
      a Copy to:
              Peter
      Campitiello, Esq.
 Tarter,
Krinsky & Drogin, LLP
 New York,
New York 10018
 Fax:  (212)
216-8001
 
 14.         Waivers,
Amendments.  None of the terms or provisions of this Agreement
may be waived, altered, modified or amended except by an instrument in writing,
duly executed by the Pledgor and the Secured Party.
  15.         Indemnification.  Without
limitation of any of the provisions of the Note, Pledgor hereby covenants and
agrees to pay, indemnify, and hold the Secured Party harmless from and against
any and all other out-of-pocket liabilities, costs, expenses or disbursements of
any kind or nature whatsoever arising in connection with any claim or litigation
by any Person resulting from the execution, delivery, enforcement, performance
and administration of this Agreement, provided, however, that the
Pledgor shall have no obligation hereunder with respect to indemnified
liabilities directly or primarily arising from, the willful misconduct or gross
negligence of the Secured Party. The provisions in this Section 15 shall survive
repayment of the loan facility under the Note and termination of this
Agreement.
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  16.         Successors and
Assigns.  This Agreement shall be binding upon and inure to the
benefit of the heirs, executors, administrators, successors and assigns of the
Pledgor and the Secured Party.  The benefits of this Agreement may not
be assigned or transferred by the Secured Party without the prior written
consent of the Pledgor.  The rights and obligations of the Pledgor may
not be assigned or transferred by the Pledgor without the prior written consent
of the Secured Party.
  17.         Governing Law; Severability;
Submission to Jurisdiction.
  (a)         THIS
AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE
GOVERNED BY AND INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK
APPLICABLE TO AGREEMENTS MADE AND FULLY TO BE PERFORMED THEREIN BY RESIDENTS
THEREOF.  The provisions of this Agreement are severable and if any
clause or provisions shall be held invalid or unenforceable in whole or in part
in any jurisdiction, then such invalidity or unenforceability shall affect only
such clause or provision, or part thereof, in such jurisdiction and shall not in
any manner affect such clause or provision in any other jurisdiction, or any
other clause or provision in this Agreement in any jurisdiction.
  (b)         THE
PLEDGOR HEREBY IRREVOCABLY SUBMITS TO THE NON-EXCLUSIVE JURISDICTION OF ANY
TEXAS STATE COURT LOCATED IN NEW YORK, NEW YORK OR ANY FEDERAL COURT LOCATED IN
NEW YORK, NEW YORK FOR THE ADJUDICATION OF ANY MATTER ARISING OUT OF OR RELATING
TO THIS AGREEMENT AND CONSENTS TO THE SERVICE OF PROCESS BY REGISTERED OR
CERTIFIED MAIL TO ITS ADDRESS SET FORTH IN SECTION 13 HEREOF OUT OF ANY SUCH
COURT.  NOTHING CONTAINED IN THE FOREGOING SHALL AFFECT THE RIGHT OF
THE SECURED PARTY TO SERVE LEGAL PROCESS IN ANY OTHER MANNER OR TO BRING ANY
PROCEEDING HEREUNDER OR UNDER THE NOTE IN ANY JURISDICTION WHERE THE BORROWER
MAY BE AMENABLE TO SUIT.  THE BORROWER HEREBY WAIVES ANY CLAIM THAT
ANY NEW YORK STATE COURT LOCATED IN NEW YORK, NEW YORK OR ANY FEDERAL COURT
LOCATED IN NEW YORK, NEW YORK IS AN INCONVENIENT FORUM.
  18.         Termination.
  (a)         This
Agreement shall terminate upon the payment in full of the obligations under the
Note.
  (b)         Upon
termination of this Agreement, the Secured Party shall deliver the Pledged
Securities to the Pledgor and all instruments evidencing the Pledged Securities
and necessary to transfer such Pledged Securities, and the Secured Party will
execute and deliver to the Pledgor all such further agreements and instruments
as the Pledgor shall reasonably request in order to terminate the security
interest in the Pledged Securities and this Agreement.
  [Remainder
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  IN
WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly
executed and delivered on the day and year first above written.
  
 
 IMAGING
      MOLECULAR CORPORATIONBy:COREY
      S. CONN,CHIEF
      FINANCIAL OFFICERPOSITRON
      CORPORATIONBy:PATRICK
      G. ROONEY,CHAIRMAN




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