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                                                                     EXHIBIT 4.1

                                 PROMISSORY NOTE

$2,000,000.00

Bio-imaging Technologies, Inc.
826 Newtown-Yardley Road
Newtown, Pennsylvania 18940
(Individually and collectively "Borrower")

Wachovia Bank, National Association
123 South Broad Street
Philadelphia, Pennsylvania 19109
(Hereinafter referred to as "Bank")

Borrower promises to pay to the order of Bank, in lawful money of the United
States of America, at its office indicated above or wherever else Bank may
specify, the sum of Two Million and No/100 Dollars ($2,000,000.00) or such sum
as may be advanced and outstanding from time to time, with interest on the
unpaid principal balance at the rate and on the terms provided in this
Promissory Note (including all renewals, extensions or modifications hereof,
this "Note").

RENEWAL/MODIFICATION/INCREASE. This Promissory Note renews, extends, increases
and/or modifies that certain Promissory Note dated April 30, 2002 (the "Original
Promissory Note"), evidencing an original principal amount of $1,000,000.00.
This Promissory Note is not a novation to the extent of the principal balance
currently outstanding under the Original Promissory Note.

LOAN AGREEMENT. This Note is subject to the provisions of that certain Loan
Agreement between Bank and Borrower dated 09 May 2003 as modified from time to
time.

LINE OF CREDIT ADVANCES. Borrower may borrow, repay and reborrow, and, upon the
request of Borrower, Bank shall advance and readvance under this Note from time
to time until the maturity hereof (each an "Advance" and together the
"Advances"), so long as the total principal balance outstanding under this Note
at anyone time does not exceed the principal amount stated on the face of this
Note, subject to the limitations described in any loan agreement to which this
Note is subject. Bank's obligation to make Advances under this Note shall
terminate if Borrower is in Default. As of the date of each proposed Advance,
Borrower shall be deemed to represent that each representation made in the Loan
Documents is true as of such date.

If Borrower subscribes to Bank's cash management services and such services are
applicable to this line of credit, the terms of such service shall control the
manner in which funds are transferred between the applicable demand deposit
account and the line of credit for credit or debit to the line of credit.

USE OF PROCEEDS. Borrower shall use the proceeds of the loan(s) evidenced by
this Note for the commercia! purposes of Borrower, as follows: for working
capital.

SECURITY. Borrower has granted Bank a security interest in the collateral
described in the Loan Documents, including, but not limited to, personal
property collateral described in that certain Security Agreement dated April
30,2002.

INTEREST RATE. Interest shall accrue on the unpaid principal balance of this
Note from the date hereof at the Bank's Prime Rate, as that rate may change from
time to time in accordance with changes in the Bank's Prime Rate ("Interest
Rate"). "Bank's Prime Rate" means that rate announced by Bank from time to time
as its prime rate and is one of several interest rate bases used by Bank. Bank
lends at rates both

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above and below Bank's Prime Rate, and Borrower acknowledges that Bank's Prime
Rate is not represented or intended to be the lowest or most favorable rate of
interest offered by Bank.

DEFAULT RATE. In addition to all other rights contained in this Note, if a
Default (as defined herein) occurs and as long as a Default continues, all
outstanding Obligations shall bear interest at the Interest Rate plus 3%
("Default Rate"). The Default Rate shall also apply from acceleration until the
Obligations or any judgment thereon is paid in full.

INTEREST AND FEE(S) COMPUTATION (ACTUAL/360). Interest and fees, if any, shall
be computed on the basis of a 360-day year for the actual number of days in the
applicable period ("Actual/360 Computation"). The Actual/360 Computation
determines the annual effective interest yield by taking the stated (nominal)
rate for a year's period and then dividing said rate by 360 to determine the
daily periodic rate to be applied for each day in the applicable period.
Application of the Actual/360 Computation produces an annualized effective rate
exceeding the nominal rate.

REPAYMENT TERMS. This Note shall be due and payable in consecutive monthly
payments of accrued interest only, commencing on June 1, 2003, and continuing on
the same day of each month thereafter until fully paid. In any event, all
principal and accrued interest shall be due and payable on June 30, 2004.

AUTOMATIC DEBIT OF CHECKING ACCOUNT FOR LOAN PAYMENT. Borrower authorizes Bank
to debit demand deposit account number 2000011294955 or any other account with
Bank (routing number 031000503) designated in writing by Borrower, beginning
June 1, 2003 for any payments due under this Note. Borrower further certifies
that Borrower holds legitimate ownership of this account and preauthorizes this
periodic debit as part of its right under said ownership.

AVAILABILITY FEE. Borrower shall pay to Bank monthly an availability fee equal
to 0.15% per annum on the difference between (i) the face amount of this Note
and (ii) the outstanding principal balance of this Note, for each day during the
preceding calendar month or portion thereof, commencing on June 1, 2003 and
continuing on the same day of each month thereafter, with a final payment due
and payable on the date that all principal and accrued interest is paid in full.

APPLICATION OF PAYMENTS. Monies received by Bank from any source for application
toward payment of the Obligations shall be applied to accrued interest and then
to principal. If a Default occurs, monies may be applied to the Obligations in
any manner or order deemed appropriate by Bank.

If any payment received by Bank under this Note or other Loan Documents is
rescinded, avoided or for any reason returned by Bank because of any adverse
claim or threatened action, the returned payment shall remain payable as an
obligation of all persons liable under this Note or other Loan Documents as
though such payment had not been made.

DEFINITIONS. Loan Documents. The term "Loan Documents", as used in this Note and
the other Loan Documents, refers to all documents executed in connection with or
related to the loan evidenced by this Note and any prior notes which evidence
all or any portion of the loan evidenced by this Note, and any letters of credit
issued pursuant to any loan agreement to which this Note is subject, any
applications for such letters -ot-credit and any other documents executed in
connection therewith or related thereto, and may include, without limitation, a
commitment letter that survives closing, a loan agreement, this Note, guaranty
agreements, security agreements, security instruments, financing statements,
mortgage instruments, any renewals or modifications, whenever any of the
foregoing are executed, but does not include swap agreements (as defined in 11
U.S.C. Section 101). Obligations. The term "Obligations", as used in this Note
and the other Loan Documents, refers to any and all indebtedness and other
obligations under this Note, all other obligations under any other Loan
Document(s), and all obligations under any swap agreements (as defined in 11
U.S.C. Section 101) between Borrower and Bank whenever executed. Certain Other
Terms. All terms that are used but not otherwise defined in any of the Loan
Documents shall have the definitions provided in the Uniform Commercial Code.

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LATE CHARGE. If any payments are not timely made, Borrower shall also pay to
Bank a late charge equal to 5% of each payment past due for 10 or more days.

Acceptance by Bank of any late payment without an accompanying late charge shall
not be deemed a waiver of Bank's right to collect such late charge or to collect
a late charge for any subsequent late payment received.

ATTORNEYS' FEES AND OTHER COLLECTION COSTS. Borrower shall pay all of Bank's
reasonable expenses incurred to enforce or collect any of the Obligations
including, without limitation, reasonable arbitration, paralegals', attorneys'
and experts' fees and expenses, whether incurred without the commencement of a
suit, in any trial, arbitration, or administrative proceeding, or in any
appellate or bankruptcy proceeding.

USURY. If at any time the effective interest rate under this Note would, but for
this paragraph, exceed the maximum lawful rate, the effective interest rate
under this Note shall be the maximum lawful rate, and any amount received by
Bank in excess of such rate shall be applied to principal and then to fees and
expenses, or, if no such amounts are owing, returned to Borrower.

DEFAULT. If any of the following occurs, a default ("Default") under this Note
shall exist: Nonpayment; Nonperformance. The failure of timely payment or
performance of the Obligations or Default under this Note or any other Loan
Documents. False Warranty. A warranty or representation made or deemed made in
the Loan Documents or furnished Bank in connection with the loan evidenced by
this Note proves materially false, or if of a continuing nature, becomes
materially false. Cross Default. At Bank's option, any default in payment or
performance of any obligation under any other loans, contracts or agreements of
Borrower, any Subsidiary or Affiliate of Borrower, any general partner of or the
holder(s) of the majority ownership interests of Borrower with Bank or its
affiliates ("Affiliate" shall have the meaning as defined in 11 U.S.C. Section
101, except that the term "Borrower" shall be substituted for the term "Debtor"
therein; "Subsidiary" shall mean any business in which Borrower holds, directly
or indirectly, a controlling interest). Cessation; Bankruptcy. The death of,
appointment of a guardian for, dissolution of, termination of existence of, loss
of good standing status by, appointment of a receiver for, assignment for the
benefit of creditors of, or commencement of any bankruptcy or insolvency
proceeding by or against Borrower, its Subsidiaries or Affiliates, if any, or
any general partner of or the holder(s) of the majority ownership interests of
Borrower, or any party to the Loan Documents. Material Business Alteration.
Without prior written consent of Bank, a material alteration in the kind or type
of Borrower's business. Material Capital Structure or Business Alteration.
Without prior written consent of Bank, (i) a material alteration in the kind or
type of Borrower's business or that of Borrower's Subsidiaries or Affiliates, if
any; (ii) the sale of substantially all of the business or assets of Borrower,
any of Borrower's Subsidiaries or Affiliates or any guarantor, or a material
portion (10% or more) of such business or assets if such a sale is outside the
ordinary course of business of Borrower, or any of Borrower's Subsidiaries or
Affiliates or any guarantor, or more than 50% of the outstanding stock or voting
power of or in any such entity in a single transaction or a series of
transactions; (iii) the acquisition of substantially all of the business or
assets or more than 50% of the outstanding stock or voting power of any other
entity; or (iv) should any Borrower or any of Borrower's Subsidiaries or
Affiliates or any guarantor enter into any merger or consolidation. Material
Adverse Change. Bank determines in good faith, in its sole discretion, that the
prospects for payment or performance of the Obligations are impaired or there
has occurred a material adverse change in the business or prospects of Borrower,
financial or otherwise.

REMEDIES UPON DEFAULT. If a Default occurs under this Note or any Loan
Documents, Bank may at any time thereafter, take the following actions: Bank
Lien. Foreclose its security interest or lien against Borrower's accounts
without notice. Acceleration Upon Default. Accelerate the maturity of this Note
and, at Bank's option, any or all other Obligations, other than Obligations
under any swap agreements (as jefined in 11 U.S.C. Section 101) between Borrower
and Bank, which shall be governed by the default and termination provisions of
said swap agreements; whereupon this Note and the accelerated Obligations shall
be immediately due and payable; provided, however, if the Default is based upon
a bankruptcy or insolvency proceeding commenced by or against Borrower or any
guarantor or endorser of this Note, all Obligations (other than Obligations
under any swap agreement as referenced above) shall automatically

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and immediately be due and payable. Cumulative. Exercise any rights and remedies
as provided under the Note and other Loan Documents, or as provided by law or
equity.

FINANCIAL AND OTHER INFORMATION. Borrower shall deliver to Bank such information
as Bank may reasonably request from time to time, including without limitation,
financial statements and information pertaining to Borrower's financial
condition. Such information shall be true, complete, and accurate.

CONFESSION OF JUDGMENT. THE FOLLOWING PARAGRAPH SETS FORTH A POWER OF AUTHORITY
FOR ANY ATTORNEY TO CONFESS JUDGMENT AGAINST BORROWER. IN GRANTING THIS WARRANT
OF ATTORNEY TO CONFESS JUDGMENT AGAINST BORROWER, THE BORROWER, FOLLOWING
CONSULTATION WITH (OR DECISION NOT TO CONSULT) SEPARATE COUNSEL FOR BORROWER AND
WITH KNOWLEDGE OF THE LEGAL EFFECT HEREOF, HEREBY KNOWINGLY, INTENTIONALLY,
VOLUNTARILY, INTELLIGENTLY AND UNCONDITIONALLY WAIVES ANY AND ALL RIGHTS THE
BORROWER HAS OR MAY HAVE TO PRIOR NOTICE AND AN OPPORTUNITY FOR HEARING UNDER
THE RESPECTIVE CONSTITUTIONS AND LAWS OF THE UNITED STATES OF AMERICA,
COMMONWEALTH OF PENNSYLVANIA, OR ELSEWHERE INCLUDING, WITHOUT LIMITATION, A
HEARING PRIOR TO GARNISHMENT AND ATTACHMENT OF THE BORROWER'S BANK ACCOUNT AND
OTHER ASSETS. BORROWER ACKNOWLEDGES AND UNDERSTANDS THAT BY ENTERING INTO THIS
NOTE CONTAINING A CONFESSION OF JUDGMENT CLAUSE THAT BORROWER IS VOLUNTARILY,
INTELLIGENTLY AND KNOWINGLY GIVING UP ANY AND ALL RIGHTS, INCLUDING
CONSTITUTIONAL RIGHTS, THAT BORROWER HAS OR MAY HAVE TO NOTICE AND A HEARING
BEFORE JUDGMENT CAN BE ENTERED AGAINST BORROWER AND BEFORE THE BORROWER'S
ASSETS, INCLUDING, WITHOUT LIMITATION, ITS BANK ACCOUNTS, MAY BE GARNISHED,
LEVIED, EXECUTED UPON AND/OR ATTACHED. BORROWER UNDERSTANDS THAT ANY SUCH
GARNISHMENT, LEVY, EXECUTION AND/OR ATTACHMENT SHALL RENDER THE PROPERTY
GARNISHED, LEVIED, EXECUTED UPON OR ATTACHED IMMEDIATELY UNAVAILABLE TO
BORROWER. IT IS SPECIFICALLY ACKNOWLEDGED BY BORROWER THAT THE BANK HAS RELIED
ON THIS WARRANT OF ATTORNEY AND THE RIGHTS WAIVED BY BORROWER HEREIN IN
RECEIVING THIS NOTE AND AS AN INDUCEMENT TO GRANT FINANCIAL ACCOMMODATIONS TO
THE BORROWER.

If a Default occurs under this Note or any other Loan Documents, each Borrower
hereby jointly and severally authorizes and empowers any attorney of any court
of record or the prothonotary or clerk of any county in the Commonwealth of
Pennsylvania, or in any jurisdiction where permitted by law or the clerk of any
United States District Court, to appear for Borrower in any and all actions
which may be brought hereunder and enter and confess judgment against the
Borrower or any of them in favor of the Bank for such sums as are due or may
become due hereunder or under any other Loan Documents, together with costs of
suit and actual collection costs including, without limitation, reasonable
attorneys' fees equal to 5% of the Obligations then due and owing but in no
event less than $5,000.00, with or without declaration, without prior notice,
without stay of execution and with release of all procedural errors and the
right to issue executions forthwith. To the extent permitted by law, Borrower
waives the right of inquisition on any real estate levied on, voluntarily
condemns the same, authorizes the prothonotary or clerk to enter upon the writ
of execution this voluntary condemnation and agrees that such real estate may be
sold on a writ of execution; and also waives any relief from any appraisement,
stay or exemption law of any state now in force or hereafter enacted. Borrower
further waives the right to any notice and hearing prior to the execution, levy,
attachment or other type of enforcement of any judgment obtained hereunder,
including, without limitation, the right to be notified and heard prior to the
garnishment, levy, execution upon and attachment of Borrower's bank accounts and
other property. If a copy of this Note verified by affidavit of any officer of
the Bank shall have been filed in such action, it shall not be necessary to file
the original thereof as a warrant of attorney, any practice or usage to the
contrary notwithstanding. The authority herein granted to confess judgment shall
not be exhausted by any single exercise thereof, but shall continue and may be
exercised from time to time as often as the Bank shall find it necessary and
desirable and at all times until full payment of all amounts due hereunder and
under any other Loan Documents. The Bank may confess one or more judgments in
the same or different jurisdictions for all or any part of the Obligations
arising hereunder or under any other Loan Documents to which Borrower is a
party, without regard to whether judgment has theretofore been confessed on more
of payments. All payments received during normal banking hours after

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2:00pm local time at the office of Bank first shown above shall be deemed
received at the opening of the next banking day. Joint and Several Obligation.
Each person who signs this Note as a Borrower (as defined herein) is jointly and
severally obligated. Fees and Taxes. Borrower shall promptly pay all
documentary, intangible recordation and/or similar taxes on this transaction
whether assessed at closing or arising from time to time.

WAIVER OF JURY TRIAL. TO THE EXTENT PERMITTED BY APPLICABLE LAW, BORROWER BY
EXECUTION HEREOF AND BANK BY ACCEPTANCE HEREOF, KNOWINGLY, VOLUNTAILY AND
INTENTIONALLY WAIVE ANY RIGHT THEY MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY
BASED ON, OR ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS NOTE, THE LOAN
DOCUMENTS OR ANY AGREEMENT CONTEMPLATED TO BE EXECUTED IN CONNECTION WITH THIS
NOTE, OR ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR
WRITTEN) OR ACTIONS OF ANY PARTY WITH RESPECT HERETO. THIS PROVISION IS A
MATERIAL INDUCEMENT TO BANK TO ACCEPT THIS NOTE.

BORROWER AD BANK AGREE THAT THEY SHALL NOT HAVE A REMEDY OF PUNITIVE OR
EXEMPLARY DAMAGES AGAINST THE OTHER IN ANY DISPUTE AND HEREBY WAIVE ANY RIGHT OR
CLAIM TO PUNITIVE OR EXEMPLARY DAMAGES THEY HAVE NOW OR WHICH MAY ARISE IN THE
FUTURE IN CONNECTION WITH ANY DISPUTE WHETHER THE DISPUTE IS RESOLVED BY
ARBITRATION OR JUDICALLY.

IN WITNESS WHEREOF, Borrower, on the day and year first above written, has
caused this Note to be executed under seal/

PLACE OF EXECUTION AND DELIVERY. Borrower hereby certified that this Note and
the Loan Documents were executed in the Commonwealth of Pennsylvania and
delivered to Bank in the Commonwealth of Pennsylvania.

Bio-Imaging Technologies, Inc.
By:   /s/ Ted Kaminer
      ---------------
Name: Ted Kaminer         Title: CFO
      ---------------            ---
(SEAL)

Tracking #: 54128PLY
CAT - Deal # 187835 Facility IS 146004

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