THIS PROMISSORY  NOTE HAS NOT BEEN REGISTERED  UNDER THE SECURITIES ACT OF 1933,
AS AMENDED.  NO SALE OR DISPOSITION  MAY BE EFFECTED  EXCEPT IN COMPLIANCE  WITH
RULE 144 UNDER SAID ACT OR AN EFFECTIVE  REGISTRATION  STATEMENT RELATED THERETO
OR AN OPINION OF COUNSEL FOR THE HOLDER  SATISFACTORY  TO THE COMPANY  THAT SUCH
REGISTRATION IS NOT REQUIRED UNDER THE ACT OR RECEIPT OF A NO-ACTION LETTER FROM
THE SECURITIES AND EXCHANGE COMMISSION.

                           CONVERTIBLE PROMISSORY NOTE

$1,000,000                                                      October 25, 2001

     For value received, BIO-IMAGING TECHNOLOGIES,  INC., a Delaware corporation
(the  "COMPANY")  promises  to pay to  Quintiles,  Inc.,  whose  address  is c/o
Quintiles Transnational Corp.,  Riverbirch Building,  Suite 200, 4709 Creekstone
Drive, Durham, North Carolina 27703, or its assigns (the "HOLDER") the principal
sum of  One  Million  Dollars  ($1,000,000)  with  interest  on the  outstanding
principal amount at the per annum rate in effect on the business day immediately
prior to the date on which payments are due hereunder  equal to the  Three-Month
London Interbank Offering Rate as published from time to time in the Wall Street
Journal  (the  "Three  Month  LIBOR  Rate")  plus 300 basis  points,  compounded
annually  based on a 365-day year.  Interest shall commence with the date hereof
and shall continue on the outstanding principal until paid in full.

     1. This note (the  "NOTE") is issued  pursuant to the terms of that certain
Asset Purchase  Agreement dated as of October 25, 2001 (the  "AGREEMENT") by and
between the Company and the Holder. This Note is subordinate in right of payment
to the Factoring  Agreement  currently in effect between the Company and Silicon
Valley Bank.  Capitalized  terms used but not defined herein shall have the same
meanings given them in the Agreement.

     2.  Subject to the earlier  conversion  of this Note  pursuant to Section 3
below, the entire outstanding  principal balance and all unpaid accrued interest
shall  become fully due and payable on November 1, 2004 (the  "MATURITY  DATE").
Beginning  on  February  1, 2002,  and on each May 1,  August 1,  November 1 and
February 1 thereafter  until and including the Maturity  Date, the Company shall
pay 11 quarterly  installments  of principal in the amount of  $41,667.00  and a
twelfth  payment of  principal  of  $41,663.00  with  respect to $500,000 of the
principal  amount,  together with accrued  interest thereon at each such payment
date.  All  payments of interest and  principal  shall be in lawful money of the
United States of America in immediately  available  funds. All payments shall be
applied first to accrued interest, and thereafter to principal.

     3. The entire principal  balance,  or any portion thereof,  and all accrued
and unpaid interest thereon shall be convertible into shares of the common stock
of the Company (the "COMMON STOCK"),  at any time and from time to time prior to
the Maturity Date at the sole election of the Holder (the  "Conversion  Right").
In the event that the Holder  exercises the Conversion  Right under this Section
3, this  Note  shall be  canceled  on the date on which the  Holder  delivers  a
written notice (the "Conversion Notice") to the Company of its intention to so





convert this Note, or any portion  thereof,  and the Holder or its assigns shall
be issued: (i) a stock certificate  representing (or which includes) that number
of  shares  of  Common  Stock  equal to the  number  which is (A) the sum of the
principal  balance as to which the Holder has elected to exercise its Conversion
Right and all accrued and unpaid interest thereon, divided by (B) the greater of
(I) 75% of the average  daily closing price per share of the Common Stock on the
OTC Bulletin Board (or such successor securities exchange or quotation system on
which the Common  Stock is then  traded) for the ten  consecutive  trading  days
immediately preceding the date of the Conversion Notice or (II) $0.906; and (ii)
a debt instrument,  substantially in the form of this Note, representing the sum
of the  principal  balance,  if any, as to which  Holder has not  exercised  its
Conversion  Right  under this  Section 3, and all  accrued  and unpaid  interest
thereon.

     4. If, prior to the Maturity Date, (a) the Company consummates an agreement
for the  acquisition  of fifty  percent (50%) or more of the voting power of the
Company by merger, sale or other form of corporate reorganization or the sale or
other  disposition of all or  substantially  all of its assets,  (b) the Company
fails to pay any amount due  hereunder  within 15 days of the date when due, (c)
the  Company  becomes  unable  to pay its  debts  as they  become  due,  files a
voluntary  petition in  bankruptcy,  is  adjudicated as a bankrupt or insolvent,
files any petition or answer seeking for itself any reorganization, liquidation,
dissolution,  or similar  relief  under any  present or future  statute,  law or
regulation,   files  any  answer   admitting  or  not  contesting  the  material
allegations of a petition filed against the Company in any such  proceeding,  or
if there is the appointment of any custodian, trustee, receiver or liquidator of
the Company or of all or any substantial  part of the properties of the Company,
(d) the Company  commits a breach of the Master  Services  Agreement  that has a
material and adverse effect on any customer  relationship  of the Holder and the
Company  fails to cure such  breach  within 30 days of notice from Holder or (e)
the Company  incurs new  indebtedness  after the date hereof with a party (other
than the  Holder)  outside of the  ordinary  course of  business or in which the
amount of such  indebtedness  exceeds  $150,000 (and the Company fails to obtain
the prior  consent of the Holder,  which shall not be  unreasonably  withheld or
delayed,  to the  incurrence  of such  indebtedness),  then the Holder  may,  in
addition to all other rights and remedies it has under  applicable law,  declare
the entire  outstanding  principal  amount  hereunder and all accrued and unpaid
interest thereon immediately due and payable.  In addition,  upon the occurrence
of any of the events under  subparagraphs  (b) and (c) above,  the Company shall
issue,  or cause to be  issued,  the  maximum  number of shares of Common  Stock
issuable to Holder, if any, as Additional Consideration under the Agreement.

     5. The Company shall not, by amendment of its Certificate of  Incorporation
or Bylaws or through  any  reorganization,  transfer  of assets,  consolidation,
merger, dissolution,  issue or sale of securities or any other voluntary action,
avoid or seek to avoid the observance or performance of any of the terms of this
Note,  but shall at all times in good faith  assist in the  carrying  out of all
such terms and in taking of all such action as may be necessary  or  appropriate
in order to protect the rights of the Holder of this Note.

     6. Nothing contained in this Note shall be construed as conferring upon the
Holder of any other person the right to vote or to consent or to receive  notice
as a shareholder of the Company.





     7. In the  event  of any  default  hereunder,  the  Company  shall  pay all
reasonable  attorneys'  fees and court costs incurred by the Holder in enforcing
and collecting this Note.

     8. Any  principal  repayment or interest  payment on the Note not paid when
due,  whether at stated  maturity,  by  acceleration  or  otherwise,  shall bear
interest at ten percent (10%) per annum.

     9. The Company  hereby  waives  demand,  notice,  presentment,  protest and
notice of dishonor.

     10. The Company may not prepay this Note prior to the Maturity Date without
first  obtaining  the written  consent of Holder,  which may be withheld for any
reason.

     11. The terms of this Note shall be construed in  accordance  with the laws
of the State of Delaware,  without  giving  effect to principles of conflicts of
law.

     12. The terms and  conditions  of this Note shall not be  amended,  waived,
altered, supplemented, modified or terminated in any manner whatsoever except by
a written instrument, duly executed by the Company and the Holders.

     13.  Any notice  required  or  permitted  under this Note shall be given in
writing and shall be deemed  effectively  given upon  personal  delivery or upon
deposit with the United States Post Office, or Federal Express, postage prepaid,
addressed to the Company at the address set forth in the  Agreement,  or at such
other address as the Company may designate by ten days advance written notice to
the Holder.

     14.  In case  any  provision  of this  Note  shall  be held to be  invalid,
illegal, or unenforceable,  it shall, to the extent practicable,  be modified so
as to make  it  valid,  legal  and  enforceable  and to  retain,  as  nearly  as
practicable,  the  intent  of  the  parties,  and  the  validity,  legality  and
enforceability of the remaining  provisions of this Note shall not in any way be
affected or impaired thereby.


                                                  BIO-IMAGING TECHNOLOGIES, INC.


                                                  By:  /s/ Mark L. Weinstein
                                                       -------------------------
                                                       Mark L. Weinstein
                                                       President & CEO