EXHIBIT 10.21
                            TREX MEDICAL CORPORATION

                          STOCK HOLDING ASSISTANCE PLAN

                          (As adopted on July 19, 1996)

        SECTION 1.   Purpose.

             The  purpose  of  this  Plan  is  to  benefit  Trex  Medical
        Corporation  (the "Company") and its stockholders by  encouraging
        Key Employees  to acquire  and maintain  share ownership  in  the
        Company, by increasing  such employees'  proprietary interest  in
        promoting the  growth  and performance  of  the Company  and  its
        subsidiaries and by providing for the implementation of the Stock
        Holding Policy.  

        SECTION 2.     Definitions.

             The following terms, when used  in the Plan, shall have  the
        meanings set forth below:

             Committee: The Human  Resources Committee of the Board  of
        Directors of the Company as appointed from time to time.

             Common Stock: The common  stock of  the Company  and any
        successor thereto.

             Company: Trex Medical Corporation, a Delaware corporation.

             Stock Holding  Policy:  The  Stock Holding  Policy of  the
        Company, as adopted by the Committee  and as in effect from  time
        to time.

             Key Employee: Any  employee of the Company  or any of its
        subsidiaries, including any  officer or  member of  the Board  of
        Directors  who  is  also  an  employee,  as  designated  by   the
        Committee, and who, in the judgment of the Committee, will be  in
        a position to contribute significantly  to the attainment of  the
        Company's strategic goals and long-term growth and prosperity.

             Loans: Loans  extended to  Key Employees  by the  Company
        pursuant to this Plan.

             Plan: The   Trex  Medical  Corporation  Stock   Holding
        Assistance Plan, as amended from time to time.

        SECTION 3.     Administration.

             The Plan and the Stock Holding Policy shall be  administered
        by the Committee,  which shall  have authority  to interpret  the
        Plan  and  the  Stock  Holding  Policy  and,  subject  to   their
        provisions,  to  prescribe,  amend  and  rescind  any  rules  and
        regulations and  to make  all other  determinations necessary  or
        desirable  for  the  administration  thereof.    The  Committee's
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        interpretations and decisions  with regard  to the  Plan and  the
        Stock Holding Policy  and such  rules and regulations  as may  be
        established thereunder  shall  be  final  and  conclusive.    The
        Committee may  correct  any  defect or  supply  any  omission  or
        reconcile any  inconsistency in  the Plan  or the  Stock  Holding
        Policy, or  in any  Loan in  the  manner and  to the  extent  the
        Committee deems desirable to carry it into effect.  No member  of
        the Committee  shall be  liable  for any  action or  omission  in
        connection with the Plan or the Stock Holding Policy that is made
        in good faith.

        SECTION 4.     Loans and Loan Limits.

             The Committee  has determined  that the  provision of  Loans
        from time to time  to Key Employees in  such amounts as to  cause
        such Key Employees to comply with the Stock Holding Policy is, in
        the judgment of the Committee, reasonably expected to benefit the
        Company and authorizes the Company  to extend Loans from time  to
        time to Key Employees in such amounts as may be requested by such
        Key Employees in order to  comply with the Stock Holding  Policy.
        Such Loans may be used solely for the purpose of acquiring Common
        Stock (other than  upon the  exercise of stock  options or  under
        employee stock  purchase plans)  in open  market transactions  or
        from the Company.

             Each  Loan  shall  be  full  recourse  and  evidenced  by  a
        non-interest bearing promissory  note substantially  in the  form
        attached hereto  as  Exhibit A       (the  "Note")  and  maturing
        accordance  with  the  provisions   of  Section  6  hereof,   and
        containing  such  other  terms  and  conditions,  which  are  not
        inconsistent with  the  provisions  of the  Plan  and  the  Stock
        Holding Policy, as the Committee shall determine in its sole  and
        absolute discretion.

        SECTION 5.     Federal Income Tax Treatment of Loans.

             For federal income tax purposes, interest on Loans shall  be
        imputed on any interest free Loan extended under the Plan.  A Key
        Employee shall be deemed to have paid the imputed interest to the
        Company and the Company shall be deemed to have paid said imputed
        interest back  to the  Key Employee  as additional  compensation.
        The deemed interest payment  shall be taxable  to the Company  as
        income, and may be deductible to  the Key Employee to the  extent
        allowable under the rules relating  to investment interest.   The
        deemed compensation payment to the Key Employee shall be  taxable
        to the employee and deductible to the Company, but shall also  be
        subject to employment taxes such as FICA and FUTA.

        SECTION 6.     Maturity of Loans.

             Each Loan  to a  Key  Employee hereunder  shall be  due  and
        payable on demand  by the Company.   If no  such demand is  made,
        then each  Loan  shall mature  and  the principal  thereof  shall
        become due and payable in five equal annual installments from the

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        payment of  annual cash  incentive compensation  (referred to  as
        bonus) to the  Key Employee  by the Company,  beginning with  the
        first such bonus  payment to  occur after  the date  of the  Note
        evidencing the Loan, and on each  of the next four bonus  payment
        dates.  Each Loan shall  also become immediately due and  payable
        in full,  without demand,  upon   the occurrence  of any  of  the
        events set forth in the Note; provided that the Committee may, in
        its sole and absolute discretion,  authorize an extension of  the
        time for repayment of  a Loan upon such  terms and conditions  as
        the Committee may determine.

        SECTION 7.     Amendment and Termination of the Plan.

             The Committee may from time to time alter or amend the  Plan
        or the Stock Holding Policy in any respect, or terminate the Plan
        or the Stock Holding  Policy at any time.   No such amendment  or
        termination, however, shall alter  or otherwise affect the  terms
        and conditions  of  any Loan  then  outstanding to  Key  Employee
        without such Key Employee's written consent, except as  otherwise
        provided herein or in the promissory note evidencing such Loan.

        SECTION 8.     Miscellaneous Provisions.

             (a)  No employee or  other person  shall have  any claim  or
        right to receive  a Loan under  the Plan, and  no employee  shall
        have any right to be retained in the employ of the Company due to
        his or her participation in the Plan.

             (b)  No Loan shall be made hereunder unless counsel for  the
        Company shall be satisfied that  such Loan will be in  compliance
        with applicable federal, state and local laws.

             (c)  The expenses of the Plan shall be borne by the Company.

             (d)  The Plan shall be unfunded,  and the Company shall  not
        be required to establish any special or separate fund or to  make
        any other segregation of assets to assure the making of any  Loan
        under the Plan.

             (e)  Except as otherwise  provided in Section  7 hereof,  by
        accepting any Loan  under the  Plan, each Key  Employee shall  be
        conclusively  deemed  to  have   indicated  his  acceptance   and
        ratification of, and consent to, any action taken under the  Plan
        or the  Stock  Holding  Policy  by  the  Company,  the  Board  of
        Directors of the Company or the Committee.

             (f)  The appropriate officers of the Company shall cause  to
        be filed  any reports,  returns  or other  information  regarding
        Loans hereunder, as  may be required  by any applicable  statute,
        rule or regulation.

        SECTION 9.     Effective Date.

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             The Plan and the Stock Holding Policy shall become effective
        upon approval and adoption by the Committee.


































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                     EXHIBIT A TO STOCK HOLDING ASSISTANCE PLAN


                            TREX MEDICAL CORPORATION

                                 Promissory Note



        $_________                                                       
                                                Dated:____________


             For value  received, ________________,  an individual  whose
        residence is located at _______________________ (the "Employee"),
        hereby  promises  to  pay   to  Trex  Medical  Corporation   (the
        "Company"), or assigns, ON DEMAND, but  in any case on or  before
        [insert date which is the fifth anniversary of date of  issuance]
        (the "Maturity  Date"),  the principal  sum  of [loan  amount  in
        words] ($_______), or such part  thereof as then remains  unpaid,
        without interest.  Principal shall be payable in lawful money  of
        the United States of America, in immediately available funds,  at
        the principal office of the Company or at such other place as the
        Company may  designate  from  time  to time  in  writing  to  the
        Employee. 

              Unless the Company has already made a demand for payment in
        full of this Note, the Employee  agrees to repay the Company   an
        amount equal to 20% of the  initial principal amount of the  Note
        from the payment of annual cash incentive compensation  (referred
        to as bonus) to the Employee  by the Company, beginning with  the
        first such bonus payment  to occur after the  date of this  Note,
        and on each  of the next  four bonus payment  dates.  Any  amount
        remaining unpaid under this Note, if  no demand has been made  by
        the Company, shall be due and payable on the Maturity Date.

             This Note may be prepaid at  any time or from time to  time,
        in whole  or  in part,  without  any  premium or  penalty.    The
        Employee acknowledges and agrees that the Company has advanced to
        the Employee the principal  amount of this  Note pursuant to  the
        Company's Stock Holding Assistance Plan,  and that all terms  and
        conditions of such Plan are incorporated herein by reference.  

             The unpaid principal amount of this Note shall be and become
        immediately due  and payable  without notice  or demand,  at  the
        option of  the  Company,  upon  the  occurrence  of  any  of  the
        following events:

                  (a)  the termination of the Employee's employment  with
             the Company, with or without cause, for any reason or for no
             reason;

                  (b)  the death or disability of the Employee;
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                  (c)  the failure  of the  Employee to  pay his  or  her
             debts as they  become due, the  insolvency of the  Employee,
             the filing by or against the Employee of any petition  under
             the United  States Bankruptcy  Code (or  the filing  of  any
             similar  petition   under   the  insolvency   law   of   any
             jurisdiction),  or  the  making   by  the  Employee  of   an
             assignment or trust mortgage for the benefit of creditors or
             the appointment of  a receiver, custodian  or similar  agent
             with respect  to,  or  the  taking by  any  such  person  of
             possession of, any property of the Employee; or

                  (d)  the issuance of any writ of attachment, by trustee
             process or otherwise, or any restraining order or injunction
             not removed, repealed or  dismissed within thirty (30)  days
             of issuance, against or affecting the person or property  of
             the Employee or any liability or obligation of the  Employee
             to the Company.

             In case any payment  herein provided for  shall not be  paid
        when due,  the Employee  further  promises to  pay all  costs  of
        collection, including all reasonable attorneys' fees.

             No  delay  or  omission  on  the  part  of  the  Company  in
        exercising any right hereunder shall operate as a waiver of  such
        right or of any other right of the Company, nor shall any  delay,
        omission or waiver  on any  one occasion be  deemed a  bar to  or
        waiver of the  same or any  other right on  any future  occasion.
        The  Employee  hereby  waives  presentment,  demand,  notice   of
        prepayment,  protest  and  all  other  demands  and  notices   in
        connection with the delivery, acceptance, performance, default or
        enforcement of this Note.  The undersigned hereby assents to  any
        indulgence  and  any  extension  of  time  for  payment  of   any
        indebtedness  evidenced  hereby  granted  or  permitted  by   the
        Company.  

             This Note  has been  made pursuant  to the  Company's  Stock
        Holding Assistance Plan and shall be governed by and construed in
        accordance with, such Plan and the laws of the State of  Delaware
        and shall have the effect of a sealed instrument.


                                      _______________________________

                                      Employee Name: _________________


        ________________________
        Witness

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