AMENDMENT
                                       TO
                         AGREEMENT OF PURCHASE AND SALE

     Amendment ("Amendment"), dated as of December 12, 1997, to Agreement of 
Purchase and Sale ("Agreement"), dated as of November 25, 1997, between Image 
Guided Technologies, Inc., a Colorado corporation ("Buyer"), and William G. 
and Matthew Lyons (collectively the "Stockholders").

     NOW, THEREFORE, the parties hereto do hereby agree as follows:

     1.   The Purchase Price (as defined in the Agreement) shall be reduced 
by Two Hundred Fifteen Thousand Dollars ($215,000) to Nine Million Two 
Hundred Eighty Five Thousand Dollars ($9,285,000), the cash portion of the 
Purchase Price set forth in Section 2.3(a) of the Agreement shall be reduced 
to Seven Million Seven Hundred Eighty Five Thousand ($7,785,000), and the 
non-escrow cash portion of the Purchase Price shall be reduced to Seven 
Million Two Hundred Eighty Five Thousand Dollars ($7,285,000).

     2.   All other terms and conditions of the Agreement shall remain the 
same.

                              BUYER:

                              IMAGE GUIDED TECHNOLOGIES, INC.

                              By:  /s/ Paul L. Ray                       
                                   ------------------------------------
                              Its: CEO                    
                                   ------------------------------------

                              STOCKHOLDERS:

                              /s/  William G. Lyons                      
                              -----------------------------------------
                              William G. Lyons


                              /s/ Matthew Lyons                          
                              -----------------------------------------
                              Matthew Lyons