Exhibit 4.15



                              PROMISSORY NOTE


US$ 650,000                                            October 18, 2002
                                                 Peabody, Massachusetts

         FOR VALUE RECEIVED, the undersigned Cedara Software Corp., an
Ontario corporation whose address is 6509 Airport Road, Mississauga,
Ontario, Canada, (hereinafter referred to as the "Maker"), promises to pay
to the order of Analogic Corporation, a Massachusetts corporation
(hereinafter referred to as "Payee", Payee and any and all other holders of
this Note being hereinafter collectively referred to as "Holder"), at
Payee's principal place of business at Eight Centennial Drive, Peabody,
Massachusetts 01960 or such other place as Holder hereof may designate in
writing, the principal sum of SIX HUNDRED AND FIFTY THOUSAND AND 00/100
($650,000) UNITED STATES DOLLARS, on or before thirty (30) days of the date
first set forth above. Said principal sum shall bear interest from the date
hereof to the date on which the said principal sum hereof is paid in full.
The rate of interest hereon shall be equal to the prime rate announced from
time to time by said Sovereign Bank (the "Prime Rate"), each adjustment to
be effective as of the opening of business on the date of announcement of a
change in the Prime Rate.

         If any payment due under this Note is not paid when due (whether
at stated maturity, acceleration or otherwise) or if any other default or
breach shall occur which, by the terms of this Note, would entitle Holder
to declare this Note to be immediately due and payable (whether or not
Holder exercises its option to so declare this Note to be immediately due
and payable), then the entire unpaid principal balance of this Note shall
bear interest, from the date on which such overdue payment became due and
payable until payment in full is made (whether before or after judgment) at
a rate of four percent (4%) per annum in excess of the Prime Rate.

         Maker may, on any business day, without premium or penalty, prepay
the outstanding principal amount of this Note, in whole at any time, or
ratably in part from time to time, with accrued interest to the date of
such payment on the principal amount prepaid.

         From time to time, without affecting the obligations of Maker or
any sureties, guarantors, endorsers, accommodation parties or other persons
liable or to become liable on this Note to pay the outstanding principal
balance of this Note and observe the covenants of Maker contained herein,
without giving notice to or obtaining the consent of Maker or any such
sureties, guarantors, endorsers, accommodation parties or other persons,
and without liability on the part of Holder, Holder may, at the option of
Holder, extend the time for payment of said outstanding principal balance,
interest or any part thereof, reduce the payments thereon, release anyone
liable for any of said outstanding principal balance, accept a renewal of
this Note, modify the terms and time of payment of said outstanding
principal balance or join in any extension or subordination agreement,
and/or agree in writing with Maker to modify the rate of interest. No one
or more of such actions shall constitute a novation.

         Presentment, notice of dishonor, protest and notice of protest are
hereby waived by Maker and all sureties, guarantors, endorsers and
accommodation parties hereof and all other persons liable or to become
liable on this Note. Maker further waives any and all exemption rights
under the laws and constitutions of the United States of America, the
Commonwealth of Massachusetts and any other domestic or foreign state,
including without limitation the federal laws of Canada and the provincial
laws of Ontario. This Note shall be the joint and several obligation of
Maker and all sureties, guarantors, endorsers, accommodation parties and
all other persons liable or to become liable on this Note, and shall be
binding upon them and their heirs, legal representatives, successors and
assigns.

         This Note and Maker's Obligations (as defined below) are secured by a
duly executed indemnity and security agreement dated December 14, 2001 (as
from time to time amended and in effect, the "Indemnity and Security
Agreement") between the Maker and the Payee. "Obligations" shall have the
meaning ascribed thereto in the Indemnity and Security Agreement. This Note
shall be governed and construed in accordance with the laws of the
Commonwealth of Massachusetts, without regard to its conflict of laws
provisions.

         This Note may not be amended, modified, or changed, nor shall any
waiver of any provision hereof be effective, except only by an instrument in
writing signed by the party against whom enforcement of any waiver, amendment,
change, modification or discharge is sought.

         Whenever used herein, the words "Maker" and "Holder" shall be deemed
to include their respective heirs, legal representatives, successors and
assigns.

         IN WITNESS WHEREOF, Maker has executed this Note under seal as of the
date first above written.

                                       Cedara Software Corp.,
                                       an Ontario corporation



                                       By:       /s/ FRASER SINCLAIR
                                           -----------------------------------
                                                     , its duly authorized CFO
                                            and Corporate Secretary