EXHIBIT 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of RadNet, Inc. (the "Company") on Form
10-Q for the three month period ended March 31, 2007, as filed with the
Securities and Exchange Commission on May 21, 2007 (the "Report"), I, Howard G.
Berger, M.D., Chairman and Chief Executive Officer of the Company, certify,
pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of
the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Report fairly presents, in all material
respects, the financial condition and results of operations of the Company as
of, and for the periods presented in the Report.

         /s/    Howard G. Berger, M.D.
         -------------------------------------
         Howard G. Berger, M.D.
         Chairman and Chief Executive Officer
         (Principal Executive Officer)
         May 21, 2007

A signed original of this written statement required by Section 906 has been
provided to the Company and will be furnished to the Securities and Exchange
Commission or its staff upon request.