EXECUTIVE AGREEMENT
     EXECUTIVE AGREEMENT dated as of ______________, 1997 among
Diagnostics Holding, Inc., a  Delaware corporation (the "Company"),
and <FIRST> <LAST> ("Executive").
     Pursuant to the Company's 1997 Executive Stock Purchase and Option
Plan (the "1997 Plan"), the Company and Executive desire to enter into
an agreement pursuant to which Executive will purchase, and the Company
will sell, <<L>> shares of Class L Common and <L> [COMMON] shares of 
Common.  In addition, the Company desires to grant to Executive options 
to acquire <TOTALALL> shares of Common, which options shall be divided
into three grants, two grants for <TARGET7> shares of Common which will 
be based on performance targets and will have different exercise  prices
(the "Target Options") and one grant for <TIME> shares of Common which
will be subject to time vesting (the "Time Option").  The Target Options
and the Time Option are hereinafter referred to individually as an
"Option" and collectively as the "Options".  All shares of Common Stock
now or hereafter acquired by Executive pursuant to the 1997 Plan are
referred to herein as the "Executive Stock."
     The parties hereto agree as follows:
                      STOCK AND OPTION PROVISIONS
           1.  Purchase and Sale of Stock.
           (A) Upon execution of this Agreement, Executive will purchase, 
andthe Company will sell, <<L>> shares of Class L Common at a price of 
$44.00 <L> per share and [COMMON] shares of Common at a price of $4.00 
per share (collectively, the "Purchased Stock").  The Company will 
deliver to Executive a copy of, and a receipt for, the certificate 
representing such Class L Common and such Common, and Executive will 
deliver to the Company a certified check or wire transfer of funds 
in the amount of $<TOTALCOST>.  Such shares of Class L Common and Common 
shall be fully vested immediately upon issuance.
            (B)  83(b) Election.   Within  30 days after the date 
hereof, Executive will make an effective election with the Internal 
Revenue Service under Section 83(b) of the Internal Revenue Code and the
regulations promulgated thereunder.
            (C)  (Representations  and  Warranties.  In connection 
with the purchase and sale of the Purchase Stock hereunder, Executive 
represents and warrants to the Company that:
                 (I) The Purchased Stock to be acquired by Executive 
     pursuant to this Agreement will be acquired for Executive's own 
     account and not with  a  view to,  or  intention of,  distribution  
     thereof in violation of  the Securities  Act of  1933, as  amended 
     (the "1933 Act"), or any applicable state  securities laws, and 
     the Purchased Stock will not be disposed of  in contravention of 
     the 1933 Act or any applicable state securities laws.
                 (II) Executive is sophisticated in financial matters 
     and is able to evaluate the  risks and benefits of  the investment 
     in the Purchase Stock.
                 (III) Executive is able to bear the economic risk of 
     his investment in the Purchase Stock for  an indefinite period of 
     time because the Purchased Stock has not been registered under the  
     1933 Act and, therefore, cannot be sold unless subsequently 
     registered under the 1933 Act or an exemption from such 
     registration is available.
                  (IV) Executive has had an opportunity to ask 
     questions and receive answers concerning the terms and conditions 
     of the offering of Purchased Stock and has had full access to such 
     other requested.
<PAGE>
                  (V) This Agreement constitutes the legal, valid and 
     binding obligation of Executive, enforceable in accordance with its  
     terms, and the execution, delivery and performance of this Agreement  
     by Executive does not and will not  conflict with, violate or cause 
     a breach of any agreement, contract or instrument to which Executive
     is a party or any judgment, order or decree to which Executive is
     subject.
          (D)  Acknowledgment.  As an inducement to the Company to sell  
the Purchased Stock to Executive, as a condition thereto, Executive
acknowledges and agrees that neither the issuance of the Purchased Stock
to Executive nor any provision contained herein shall entitle  Executive
to remain in the employment of the Company and its Subsidiaries or
affect the right of the Company to terminate Executive's employment at
any time for any reason.
          (E)  (1997 Plan Acknowledgment.  The Company and Executive
acknowledge and agree that this Agreement has been executed and
delivered, and the Purchased Stock has been issued hereunder, in
connection with and as part of the compensation and incentive
arrangements between the Company and Executive.
     
      2.  Stock Options.
      (A)  Target Option Grants.  The Company hereby grants to Executive,
pursuant to the Plan, the Target Options to purchase (A) <TARGET7>
shares of Common (the "Tranche I Options"), with an exercise price of
$7.00 (the "Tranche I Price"), and (B) <TARGET16> shares of Common (the
"Tranche II Options") with an exercise  price of $16.00 the "Tranche  II
Price").  The shares issued upon exercise of the Tranche I Options  or
the Tranche II Options are referred  to herein as the ("Target  Option
Shares").  The number of Target Option Shares, the Tranche I Price, and
the Tranche II Price will be  equitably adjusted for any stock split,
stock dividend, reclassification or recapitalization of the Company
which occurs  subsequent to the date of this  Agreement.  The Target
Options will expire (the "Expiration Date") on the earlier of the tenth
anniversary of the date hereof or the date of termination of Executive's
employment with the Company or a Subsidiary for any reason (the
"Termination Date"), provided that Executive will have 30 days after the
Expiration Date to exercise the Target Options with respect to the
Target Option Shares which are then exercisable pursuant to the terms of
the 1997 Plan.
     (B)  Time Option Grant.  The Company hereby grants to Executive,
pursuant to the Plan, the Time Option to purchase <TIME> shares of
Common Stock ("Time Option Shares"), at a price per share of $4.00 (the
"Option Price").  The Option Price and the number of Time Option Shares
will be equitably adjusted for any stock split, stock dividend,
reclassification or recapitalization of the Company which occurs
subsequent to the date of this reement.  The Time Option will expire
on the Expiration Date, provided that Executive will have 30 days after
the Expiration Date to exercise the Time Option with respect to the
percentage of Time Option Shares as determined pursuant to the terms of
the 1997 Plan.
<PAGE> 
      (C)  Securities Laws Restrictions.  Executive represents that when
Executive exercises the Options he will be purchasing Executive Stock
for Executive's own account and not on behalf of others.  Executive
understands and acknowledges that federal and state securities laws
govern and restrict Executive's  right to offer, sell or otherwise
dispose of any Executive Stock unless Executive's offer, sale or other
disposition thereof is registered under the 1933 Act and state
securities laws or, in the opinion of the Company's counsel, such offer,
sale or  other  disposition  is  exempt from registration thereunder.
Executive agrees that he  will not offer, sell  or otherwise dispose  of
any Executive Stock in any manner  which would: (i) require the Company
to file any registration statement (or  similar filing under state  law)
with the Securities and  Exchange Commission or  to amend or  supplement
any such filing or (ii) violate or cause the Company to violate the 1933
Act, the rules and regulations promulgated thereunder or any other state
or federal law.  Executive further understands that the certificates for
any Executive Stock Executive purchases will  bear the legend set  forth
in Paragraph 5 her eof or  such  other  legends  as the  Company  deems
necessary or desirable in connection with  the 1933 Act or other  rules,
regulations or laws.
      (D)  Non-Transferability of Option.  The Options are personal to
Executive and are not transferable by Executive.  Only Executive or his
estate or heirs is entitled to exercise the Options.
      3.  Repurchase Option.  In the event that Executive is no longer
employed by the Company or any of its Subsidiaries for any reason (the
date of such termination being referred to herein as the "Termination
Date"), the Executive Stock, whether held  by Executive, or one or  more
Permitted Transferees (as defined in Paragraph 4 below), will be subject
to repurchase by the Company and the Investors (solely at their  option)
pursuant to the  terms and conditions  set forth in  the 1997 Plan  (the
"Repurchase Option").
      4.   Restrictions on Transfer.
      (A)  Transfer of Executive Stock.  Without the express written
consent of the Company to transfers of Executive Stock in accordance
with the terms of this Agreement,  Executive will not sell, pledge or
otherwise transfer any interest in any shares of Executive Stock, except
pursuant to (i) the provisions of Paragraphs 2, 3 and 7 hereof, (ii) the
provisions of Paragraph 4(b) below, (iii) pursuant to the  Registration
Agreement, dated as of December 20, 1994, as amended, among the Company
and its stockholders or (iv) pursuant to the provisions of the 1997
Plan.                                  
      (B)  Certain Permitted Transfers.  The restrictions contained in
this Paragraph 4 will not apply with respect to transfers of Executive
Stock pursuant to applicable laws of descent and distribution, provided
that the restrictions contained in this Paragraph 4 will continue to be
applicable to the Executive Stock after any such transfer and the
transferees of such Executive Stock shall agree in writing to be bound
by the provisions of this Agreement.  Any transferee of Executive Stock
pursuant to a transfer  in accordance with the provisions  of this
Paragraph 4(b) is herein referred to as a "Permitted Transferee."  Upon
the transfer of Executive Stock pursuant to this Paragraph 4(b), the
Permitted Transferee(s) will deliver a written notice (the "Transfer
Notice") to the Company.    The Transfer Notice will disclose in
reasonable detail the identity of the Permitted Transferee(s).
<PAGE>
      5.   Additional Restrictions on Transfer.
      (A)  The certificates representing the Executive Stock will bear
the following legend:

    "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
     REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
     "ACT"), AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF
     AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR AN
     EXEMPTION FROM REGISTRATION THEREUNDER.  THE SECURITIES
     REPRESENTED BY THIS CERTIFICATE ARE ALSO SUBJECT TO ADDITIONAL
     RESTRICTIONS ON TRANSFER, CERTAIN REPURCHASE OPTIONS AND
     CERTAIN OTHER AGREEMENTS SET FORTH IN AN EXECUTIVE AGREEMENT
     BETWEEN THE ISSUER (THE "COMPANY") AND A CERTAIN EMPLOYEE  OF
     THE COMPANY DATED AS OF ________________,  1997, A COPY OF
     WHICH MAY BE OBTAINED BY THE HOLDER HEREOF AT THE COMPANY'S
     PRINCIPAL PLACE OF BUSINESS WITHOUT CHARGE."

     (B)  No holder of Executive Stock may sell, transfer or dispose of
any Executive Stock (except pursuant  to an effective registration
statement under the Securities Act of 1933) without first delivering to
the Company  an opinion of counsel reasonably acceptable in form and
substance to the Company (which  counsel shall be reasonably acceptable
to the Company) that registration under the 1933 Act is not required in
connection with such transfer.
     6.   Definition of  Executive  Stock.   For  all purposes  of  this
Agreement, Executive Stock will  continue to be  Executive Stock in  the
hands of any  holder other than  Executive (except for  the Company  and
purchasers pursuant  to an  offering registered  under the  1933 Act  or
purchasers pursuant  to a  Rule 144  transaction), and  each such  other
holder of Executive  Stock will succeed  to all  rights and  obligations
attributable to  Executive as  a holder  of Executive  Stock  hereunder.
Executive Stock will also include shares of the Company's capital  stock
issued with  respect to  shares of  Executive Stock  by way  of a  stock
split, stock dividend or other recapitalization.
     7.  Sale of the Company.
     (A) If the Board and the holders of a majority of the shares  of
Common Stock then outstanding approve a sale of all or substantially all
of the Company's assets determined on a consolidated basis or a sale  of
all or  substantially all  of the  Company's outstanding  capital  stock
(whether by  merger,  recapitalization,  consolidation,  reorganization,
combination or otherwise)  to any Independent  Third Party  or group  of
Independent Third Parties (collectively an "Approved Sale"), each holder
of Executive Stock  will vote for,  consent to and  raise no  objections
against such Approved Sale.  If the Approved Sale is structured as (i) a
merger or consolidation, each holder of  Executive Stock will waive  any
dissenters rights, appraisal rights or similar rights in connection with
such merger or  consolidation or (ii)  a sale of  stock, each holder  of
Executive Stock will agree to sell all of his shares of Executive  Stock
and rights  to  acquire shares  of  Executive  Stock on  the  terms  and
conditions approved by the  Board and the holders  of a majority of  the
Common Stock then outstanding.  Each holder of Executive Stock will take
all necessary or desirable actions  in connection with the  consummation
of the Approved Sale as requested by the Company.
<PAGE>
(B) The obligations of the holders of Common Stock with respect to
the Approved Sale of the Company are subject to the satisfaction of the
following conditions:  (i) upon the consummation of the Approved Sale,
each holder of Common Stock will receive the same form of consideration
and the same portion of the aggregate consideration that such holders of
Common Stock would have received if such aggregate consideration had
been distributed by the Company in complete liquidation pursuant to the
rights and  preferences  set  forth  in  the  Company's  Certificate  of
Incorporation as in effect immediately prior to such Approved Sale; (ii)
if any holders of a class of Common Stock are given an option as to  the
form and amount  of consideration to  be received, each  holder of  such
class of Common  Stock will  be given the  same option;  and (iii)  each
holder of then currently exercisable rights to acquire shares of a class
of Common Stock  will be given  an opportunity to  exercise such  rights
sale as holders of such class of Common Stock.
     (C)  If the  Company or  the holders  of the  Company's securities
enter into any  negotiation or transaction  for which Rule  506 (or  any
similar rule  then in  effect) promulgated  by the  Securities  Exchange
Commission  may  be  available  with  respect  to  such  negotiation  or
transaction (including a merger, consolidation or other reorganization),
the holders of  Executive Stock  will, at  the request  of the  Company,
appoint a purchaser representative (as such term is defined in Rule 501)
reasonably acceptable to the Company.  If any holder of Executive  Stock
appoints a  purchaser  representative  designated by  the  Company,  the
Company will pay the fees of  such purchaser representative, but if  any
holder  of   Executive  Stock   declines   to  appoint   the   purchaser
representative designated  by  the  Company  such  holder  will  appoint
another purchaser representative,  and such holder  will be  responsible
for the fees of the purchaser representative so appointed.
     (D)  Executive and the other holders of Executive Stock (if any)
will bear their pro-rata share (based upon the number of shares sold) of
the costs of any sale of Executive Stock pursuant to an Approved Sale to
the extent such  costs are incurred  for the benefit  of all holders  of
Common Stock and are not otherwise paid by the Company or the acquiring
party.  Costs incurred by Executive and the other holders of Executive
Stock on their own behalf will not be considered costs of the
transaction hereunder.
      (E)  The provisions of this Paragraph 7 will terminate upon
completion of the initial public offering of the Common Stock.
      8.  Public Offering.  In the event that the Board and the holders
of a majority of the shares of Common Stock then outstanding approve  an
initial public offering and sale of  Common Stock (a "Public  Offering")
pursuant to an effective registration statement under the Securities Act
of 1933,  as amended,  the  holders of  Executive  Stock will  take  all
necessary or desirable  actions in connection  with the consummation  of
the Public  Offering.   In the  event that  such Public  Offering is  an
underwritten offering and the  managing underwriters advise the  Company
in writing  that  in  their opinion  the  Common  Stock  structure  will
adversely affect  the  marketability of  the  offering, each  holder  of
Executive Stock  will  consent  to  and  vote  for  a  recapitalization,
reorganization and/or exchange of the Common Stock into securities  that
the managing underwriters, the  Board and holders of  a majority of  the
shares of Common Stock  then outstanding find  acceptable and will  take
all necessary or desirable actions  in connection with the  consummation
of the recapitalization, reorganization and/or exchange.
<PAGE>
     9.  Termination of Provisions Relating to Executive Stock.  The
provisions of Paragraphs 3 and 4, and the rights of Executive under
Paragraph 7 of the Plan, will terminate  upon the first to occur of (i)
an Approved Sale, or (ii) (A) the Company (or its successor as a result
of merger, consolidation, reorganization  or sale) becoming a reporting
company under the Securities Exchange Act  of 1934 as a result of the
registration of its common equity securities thereunder and (B) the
Investors and their affiliates collectively ceasing to own at least 50%
of the aggregate number of shares of Common Stock that they own on the
date  hereof  (as adjusted for stock splits, stock dividends and
recapitalization and for exchanges in connection with a merger,
consolidation, reorganization or sale).
                        MISCELLANEOUS PROVISIONS
     10.  Notices.  Any notice provided for in this Agreement must be in
writing and must  be personally delivered,  received by certified  mail,
service, to the Investors  at the addresses  indicated in the  Company's
records and to the other recipients at the address indicated below:
     
     To the Company:
          Diagnostics Holding Inc.
          c/o Bain Capital, Inc.
          Two Copley Place
          Boston, Massachusetts 02116
          Attn:   Mark Nunnelly
                  Stephen G. Pagliuca
                  Adam Kirsch
    
     To Executive:
          <FIRST> <LAST>
          <STREET>
          [CITY]

or such other address or to the attention of such other person as the
recipient party shall have specified by prior written  notice to the
sending party.  Any notice under  this Agreement will be deemed to have
been given when so delivered or mailed.
       11.  Severability.  Whenever possible each provision of this
Agreement will be interpreted in such manner as to be effective and
valid under applicable law, but if any provision of this Agreement is
held to be invalid, illegal or unenforceable in any respect under any
applicable law or rule in any jurisdiction, such invalidity, illegality
or unenforceability will not affect any other provision or the
effectiveness or validity of any provision in any other jurisdiction,
and this Agreement will be reformed, construed and enforced in  such
jurisdiction as if such invalid, illegal or unenforceable provision  had
never been contained herein.
       12.  Complete Agreement.  This Agreement embodies the complete
agreement and understanding among the parties and supersedes and
preempts any prior understandings,  agreements or representations by  or
among the  parties, written or  oral, which may  have related to the
subject matter hereof in any way.
       13.  Counterparts.  This Agreement may be executed in separate 
counterparts, each of which will be deemed to be an original and all of
which taken together will constitute one and the same agreement.
<PAGE>       
       14.  Successors and Assigns.  This Agreement is intended to bind 
and inure to the benefit of and be enforceable by Executive, the 
Company, the Investors and their respective successors and assigns, 
provided that
Executive may not  assign any of  his rights or  obligations, except  as
expressly provided by the terms of this Agreement.
       15.  Governing Law.  The corporate law of Delaware will govern all
issues concerning the relative rights of the Company and its
stockholders.  All other issues concerning the enforceability, validity
and binding effect of this Agreement will be governed by and construed
in accordance with  the laws of  the State of  Illinois, without  giving
effect to  any  choice of  law  or conflict  of  law provision  or  rule
(whether of the State of Illinois or any other jurisdiction) that  would
cause the application  of the  law of  any jurisdiction  other than  the
State of Illinois.
       16.  Remedies.  The parties hereto agree and acknowledge that 
money damages may not be an adequate remedy for any breach of the 
provisions of this Agreement and that any party hereto will have the 
right to injunctive relief, in addition to all  of its other rights and
remedies at law or in equity, to enforce the provisions of this 
Agreement.
       17.  Effect of Transfers in Violation of Agreement.  The Company 
will not be required (a) to transfer on its books any shares of Executive
Stock which have been sold or transferred in violation of any of the
provisions set forth in this Agreement or (b) to treat as owner of such
shares, to accord the right to vote as such owner or to pay dividends to
any transferee to whom such shares have been transferred in violation of
this Agreement.
<PAGE>
       18.  Amendments and Waivers.  Any provision of this Agreement may 
be amended or waived only  with the prior written consent of the Company,
Executive and the Investors who hold 70% of the Common Stock held by the
Third Party Beneficiaries.  The parties hereto acknowledge and agree 
that the Investors are third party beneficiaries of this Agreement. 
This  Agreement  will  inure  to  the  benefit  of  and  be enforceable 
by the Investors and their respective successors andassigns.
       19.  Diagnostics Holding, Inc. 1997  Executive Stock Purchase and
Option Plan.  The grant of Options and issuance of Executive Stock
hereunder is pursuant to,  and subject to all the terms and conditions
of, the Company's 1997 Executive Stock Purchase and  Option Plan (the
"1997 Plan"), attached hereto as Exhibit A.  Capitalized terms defined
in the 1997 Plan and otherwise  not defined herein are used herein  as
therein defined.
          *          *          *          *          *
  IN WITNESS WHEREOF, the  parties have executed this  Agreement on the
day and year first above written.
                                
Diagnostics Holding, Inc.


By:_______________________________
Title:


Participant's Signature:

__________________________________
    <<FIRST>>      <<LAST>>