Exhibit 10.18

January 1, 2003

Mr. Paul S. Viviano
19432 Beckonridge Lane
Huntington Beach, CA 92648

AGREEMENT

Dear Mr. Viviano:

        1.    Reference is made to (i) the Alliance Imaging, Inc. 1999 Equity
Plan (the "Option Plan") and (ii) the Stock Option Agreement (the "Option
Agreement") between Alliance Imaging, Inc. (the "Company") and you, dated as of
January 2, 2003. In consideration of the Company granting you options under the
Option Plan, executing and delivering the Option Agreement and making the
payments described in Paragraph 5 below, you agree that no Competition Event (as
defined below) shall occur prior to one year after the Date of Termination (as
defined in the employment agreement between the Company and you as of the date
hereof (the "Employment Agreement")). Defined terms used but not defined herein
shall have the meaning ascribed thereto in the Employment Agreement.

        2.    For purposes of this letter agreement, a Competition Event shall
occur if you directly or indirectly (i) engage in any imaging business or any
other business that becomes material to the Company's business during your
employment by the Company (the "Company Business") within the United States that
is the same or substantially similar to or competitive with any service provided
by the Company; (ii) compete or participate as agent, employee, consultant,
advisor, representative or otherwise in any enterprise engaged in a business
which has any operations engaged in the Company Business within the United
States that is the same or substantially similar to or competitive with any
service provided by the Company; or (iii) compete or participate as a
stockholder, partner or joint venturer, or have any direct or indirect financial
interest, in any enterprise which has any material operations engaged in the
Company Business within the United States that is the same or substantially
similar to or competitive with any service provided by the Company; provided,
however, that nothing contained herein shall prohibit you from (A) owning,
operating or managing any business, or acting upon any business opportunity,
after obtaining approval of a majority of the Board of Directors of the Company
and a majority of the independent members of the Board of Directors of the
Company (if any); (B) acting in the capacity of a Chief Executive Officer or
Chief Operating Officer of a hospital or health system which may have diagnostic
imaging operations; or (C) owning no more than five percent (5%) of the equity
of any publicly traded entity with respect to which you do not serve as an
officer, director, employee, consultant or in any other capacity other than as
an investor.

        3.    As a means reasonably designed to protect certain confidential
information of the Company which would otherwise inherently be utilized in the
following proscribed activities, and in partial consideration of the Company's
covenant to make the payments described in Paragraph 5, you agree that you will
not, prior to the date you cease to receive payments under Paragraph 5 below,
solicit or make any other contact with, directly or indirectly, any customer of
the Company as of the Date of Termination with respect to the provision by you
of any service to any such customer that is the same or substantially similar to
any service provided to such customer by the Company.

        4.    In partial consideration of the Company's covenant to make the
payments described in Paragraph 5, you agree that you will not, prior to the
date you cease to receive payments under paragraph 5, solicit or make any other
contact with, directly or indirectly, any employee of the Company on the Date of
Termination (or any person who was employed by the Company at any time during
the three-month period prior to the Date of Termination) with respect to any
employment, services or other business relationship.

        5.    In partial consideration of your covenants contained herein, the
Company shall, following the Date of Termination, pay you an amount equal to
(A) the sum of your annual base salary as of the

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Date of Termination and (B) your Average Bonus. All payments under this
Paragraph 5 shall be made in equal installments on a bi-weekly basis over a one
year period. Notwithstanding the foregoing, the Company shall not be obligated
to make any payments under this Paragraph 5 to you if you (x) fail to cure a
breach of this Agreement within fifteen days after receipt of notice of such
breach from the Company, or (y) if your employment with the Company is
terminated by reason of your death or disability or for Cause or by reason of
your resignation other than for Good Reason.

        6.    For purposes of this Letter Agreement, "Average Bonus" means
(A) if a termination of your employment occurs prior to December 31, 2003, the
Target Bonus payable with respect to 2003, and (B) if a termination of your
employment occurs on or after January 1, 2004, the actual cash bonus earned by
you for the calendar year completed immediately prior to the date of
transaction.

        7.    Notwithstanding paragraph 1 through 4 hereof, if the Company shall
fail to make any payment to you that the Company is obligated to make pursuant
to Paragraph 5 and such failure shall continue for more than five days after
receipt of notice from you, all future payments to you under Paragraph 5 shall
become immediately due and payable and you shall be relieved of all obligations
under this Agreement.

        8.    For purposes of paragraph 2 through 4 hereof, the term Company
shall include Alliance Imaging, Inc., its subsidiaries and/or its affiliates.

        9.    You acknowledge that irreparable damage would occur in the event
of a breach of the provisions of this Agreement by you. It is accordingly agreed
that, in addition to any other remedy to which it is entitled at law or in
equity, the Company shall be entitled to an injunction or injunctions to prevent
breaches of this letter agreement and to enforce specifically the terms and
provisions of this letter agreement.

        10.  If, at the time of enforcement, any sentence, paragraph, clause, or
combination of the same of this Agreement is in violation of the law of any
state where applicable, such sentence, paragraph, clause, or combination of the
same shall be void in the jurisdictions where it is unlawful, and the remainder
of this Agreement shall remain binding on the parties. In the event that any
part of any covenant of this Agreement is determined by a court of law to be
overly broad thereby making the covenant unenforceable, the parties agree that
such court shall substitute a judicially enforceable limitation in its place,
and that as so modified, the covenants shall be binding upon the parties as if
originally set forth in this Agreement.

        If you are in agreement with the foregoing, please sign a copy of this
letter where indicated below.

    Very truly yours,
 
 
ALLIANCE IMAGING, INC.
 
 
By:
/s/  RICHARD N. ZEHNER      

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Name: Richard N. Zehner
Title: Chairman & CEO

       

Acknowledged and agreed to
as of the date first above
written:  
By:
 
/s/  PAUL S. VIVIANO      

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Name: Paul S. Viviano
 

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