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 quarterly period ended June 30, 2008, as filed with the Securities
and Exchange Commission on August 11, 2008 (the "Report"), I, Howard G. Berger,
M.D., Chairman of the Board of Directors 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, President and Chief Executive
                                         Officer (Principal Executive Officer)
                                         August 11, 2008

A signed original of this written statemn 906 has been provided to the Company
and will be furnished to the srz or its staff upon request.