AMENDMENT NUMBER ONE TO JOINT VENTURE AGREEMENT

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                                                                    Exhibit 3.82

                             AMENDMENT NUMBER ONE TO

                             JOINT VENTURE AGREEMENT

      This Amendment Number One to Joint Venture Agreement (this "Amendment") is

made effective as of June 8, 2004, and is entered into by Comprehensive Medical

Imaging, Inc., a Delaware corporation ("CMI"), and Comprehensive Medical Imaging

Centers, Inc., a Delaware corporation ("CMIC" and together with CMI, the

"Members"), in their capacity as the members or venturers of Jefferson MRI, a

Texas general partnership (the "Company"). This Amendment amends the Company's

Joint Venture Agreement dated as December 29, 1989 (the "Agreement").

Capitalized terms used in the Amendment and not otherwise defined have the

meanings ascribed in the Agre