<PAGE>

                                                                   EXHIBIT 10.26

                       KOHLBERG KRAVIS ROBERTS & CO., L.P.
                               2800 SAND HILL ROAD
                              MENLO PARK, CA 94025




                                                          As of November 2, 1999


Alliance Imaging, Inc.
1065 North PacifiCenter Drive, Suite 200
Anaheim, CA 92806

Dear Ladies/Gentlemen:


         This letters serves to confirm our retention by Alliance Imaging, Inc.
(the "Company") to provide management, consulting and financial services to the
Company, as follows:

         1.       The Company has retained us, and we hereby agree to accept
such retention, to provide to the Company, when and if called upon, certain
management, business strategy, consulting and financial services of the type
customarily performed by us, including our services on the board of directors of
the Company. The Company agrees to pay us an annual fee of Six Hundred Fifty
Thousand dollars ($650,000), payable in quarterly installments in arrears at the
end of each calendar quarter.

         2.       We may also invoice the Company for additional fees in
connection with acquisition, divestiture or financing transactions or in the
event that we, or any of our affiliates, perform services for the Company above
and beyond those called for by this agreement.

         3.       In addition to any fees that may be payable to us under this
agreement, the Company also agrees to reimburse us and our affiliates, from time
to time upon request, for all reasonable costs and expenses incurred in
connection with (i) this retention, including, without limitation, the
reasonable costs and expenses of our counsel and (ii) the ownership of shares of
common stock, par value $0.01 per share of the Company, by our affiliates.

         4.       The Company agrees to indemnify and hold us, our affiliates
and their and our respective partners, members, executives, officers, directors,
employees, agents and controlling persons (each such person, including us, being
an "Indemnified Party") harmless from and against any and all losses, claims,
damages, and liabilities (including, without limitation, losses, claims, damages
and liabilities arising from or in connection with legal actions brought by or
on behalf of the holders or future holders of the outstanding securities of the
Company or creditors or future creditors of the Company), joint, several or
otherwise, to which such Indemnified Party may become subject under any
applicable federal or state law, or otherwise, related to or arising out of any
activity contemplated by this agreement or our retention pursuant to, and our or
our affiliates' performance of the services contemplated by this

<PAGE>

agreement, including any services on the Company's board of directors, and will
reimburse any Indemnified Party for all expenses (including counsel fees and
disbursements) upon request as they are incurred in connection with the
investigation of, preparation for or defense of any pending or threatened claim
or any action or proceeding arising therefrom, whether or not such Indemnified
Party is a party and whether or not such claim, action or proceeding is
initiated or brought by the Company, PROVIDED, HOWEVER, that you will not be
liable under the foregoing indemnification provision (and amounts previously
paid that are determined not required to be paid by the Company pursuant to the
terms of this Paragraph shall be repaid promptly) to the extent that any loss,
claim, damage, liability or expense is found in a final judgment by a court to
have resulted from our willful misconduct, bad faith or gross negligence. You
also agree that no Indemnified Party shall have any liability (whether direct or
indirect, in contract or tort or otherwise) to the Company related to or arising
out of our retention pursuant to, or our affiliates, performance of the services
contemplated by, this agreement except to the extent that any loss, claim,
damage, liability or expense is found in a final, non-appealable judgment by a
court to have resulted from our willful misconduct, bad faith or gross
negligence.

         You also agree that, without our prior written consent, you will not
settle, compromise or consent to the entry of any judgment in any pending or
threatened claim, action or proceeding to which an Indemnified Party is an
actual or potential party and in respect of which indemnification could be
sought under the indemnification provision in the immediately preceding
paragraph, unless such settlement, compromise or consent includes an
unconditional release of each Indemnified Party from all liability arising out
of such claim, action or proceeding.

         Promptly after receipt by an Indemnified Party of notice of any suit,
action, proceeding or investigation with respect to which an Indemnified Party
may be entitled to indemnification hereunder, such Indemnified Party will notify
the Company in writing of the assertion of such claim or the commencement of
such suit, action, proceeding or investigation, but the failure so to notify the
Company shall not relieve the Company from any liability which it may have
hereunder, except to the extent that such failure has materially prejudiced the
Company. If the Company so elects within a reasonable time after receipt of such
notice, the Company may participate at its own expense in the defense of such
suit, action, proceeding or investigation. Each Indemnified Party may employ
separate counsel to represent it or defend it in any such suit, action,
proceeding or investigation in which it may become involved or is named as a
defendant and, in such event, the reasonable fees and expense of such counsel
shall be borne by the Company; PROVIDED, HOWEVER, that the Company will not be
required in connection with any such suit, action, proceeding or investigation,
or separate but substantially similar actions arising out of the same general
allegations or circumstances, to pay the fees and disbursements of more than one
separate counsel (other than local counsel) for all Indemnified Parties in any
single action or proceeding. Whether or not the Company participates in the
defense of any claim, both the Company and we shall cooperate in the defense
thereof and shall furnish such records, information and testimony, and attend
such conferences, discovery proceedings, hearing, trial and appeals, as may be
reasonably requested therewith.

         If the indemnification provided for hereunder is finally judicially
determined by a court of competent jurisdiction to be unavailable to an
Indemnified Party, or insufficient to hold

                                       2
<PAGE>

any Indemnified Party harmless, in respect of any losses, claims, damages or
liabilities (other than any losses, claims, damages or liabilities found in a
final judgment by a court to have resulted from our willful misconduct, bad
faith or gross negligence), then the Company, on the one hand, in lieu of
indemnifying such Indemnified Party, and we, on the other hand, will contribute
to the amount paid or payable by such Indemnified Party as a result of such
losses, claims, damages or liabilities (i) in such proportion as is appropriate
to reflect the relative benefits received, or sought to be received, by the
Company on the one hand and us, solely in our capacity as an advisor under this
agreement, on the other hand in connection with the transactions to which such
indemnification, contribution or reimbursement is sought, or (ii) if (but only
if) the allocation provided by clause (i) above is not permitted by applicable
law, in such proportion as is appropriate to reflect not only the relative
benefits referred to in clause (i) but also the relative fault of the Company on
the one hand and us on the other, as well as any other relative equitable
considerations; PROVIDED, HOWEVER, that in no event shall our aggregate
contribution hereunder exceed the amount of fees actually received by us in
respect of the transaction at issue pursuant to this agreement. The amount paid
or payable by a party as a result of the losses, claims, damages and liabilities
referred to above will be deemed to include any legal or other fees or expense,
reasonably incurred in defending any action or claim. The Company and we agree
that it would not be just and equitable if contribution pursuant to this
paragraph were determined by pro rata allocation or by any other method which
does not take into account the equitable considerations referred to in this
paragraph. The indemnity, contribution and expenses reimbursement obligations
the Company has under this Paragraph shall be in addition to any liability the
Company may have, and notwithstanding any other provision of this letter, shall
survive the termination of this agreement.

         5.       Any advice or opinions provided by us may not be disclosed or
referred to publicly or to any third party (other than the Company's legal, tax,
financial or other advisors), except in accordance with our prior written
consent.

         6.       We shall act as an independent contractor, with duties solely
to the Company. The provisions hereof shall inure to the benefit of and shall be
binding upon the parties hereto and their respective successors and assigns.
Nothing in this agreement, expressed or implied, is intended to confer on any
person other than the parties hereto or their respective successors and assigns,
and, to the extent expressly set forth herein, the Indemnified Parties, any
rights or remedies under or by reason of this agreement. Without limiting the
generality of the foregoing, the parties acknowledge that nothing in this
agreement, expressed or implied, is intended to confer on any present or future
holders of any securities of the Company or its subsidiaries or affiliates, or
any present or future creditor of the Company or its subsidiaries or affiliates,
any rights or remedies under or by reason of this agreement or any performance
hereunder.

         7.       This agreement shall be governed by and construed in
accordance with the laws of New York without regard to principles of conflicts
of law.

         8.       The terms of this agreement are effective as of November 2,
1999. This agreement shall continue in effect from year to year unless amended
or terminated by the mutual consent of the parties hereto.

                                       3
<PAGE>

         9.       Each party hereto represents and warrants that the execution
and delivery of this agreement by such party has been duly authorized by all
necessary action of such party.

         10.      If any term or provision of this agreement or the application
thereof shall, in any jurisdiction and to any extent, be invalid and
unenforceable, such term or provision shall be ineffective, as to such
jurisdiction, solely to the extent of such invalidity or unenforceability
without rendering invalid or unenforceable any remaining terms or provisions
hereof or affecting the validity or enforceability of such term or provision in
any other jurisdiction. To the extent permitted by applicable law, the parties
hereto waive any provision of law that renders any term or provision of this
agreement invalid or unenforceable in any respect.

         11.      Each of the Company and us waives all right to trial by jury
in any action, proceeding or counterclaim (whether based upon contract, tort or
otherwise) related to or arising out of our retention pursuant to, or our
performance of the services contemplated by this agreement.

         12.      Notwithstanding any provision hereof, none of our obligations
or our affiliates' obligations under this Agreement shall be an obligation of
our or our affiliates' officer, director, member, limited partner or general
partner (or of any officer, director, member, limited partner or general partner
of any member, limited partner or general partner of any of the foregoing
entities). Any such liability or obligation arising out of this Agreement shall
be limited to and satisfied only out of our assets or the assets of our
affiliates, as applicable.

         13.      It is expressly understood that the foregoing paragraphs 4, 5,
10, 11 and 12 in their entirety shall survive any termination of this agreement.








                                       4
<PAGE>


         If the foregoing sets forth the understanding between us, please so
indicate on the enclosed signed copy of this letter in the space provided
therefor and return it to us, whereupon this letter shall constitute a binding
agreement among us.

                                       Very truly yours,


                                       KOHLBERG KRAVIS ROBERTS & CO., L.P.


                                       By:    /s/  MICHAEL W. MICHELSON
                                          --------------------------------------
                                            Name:  Michael W. Michelson
                                            Title: Manager



AGREED TO AND ACCEPTED


ALLIANCE IMAGING, INC.


By:    /s/  KENNETH S. ORD
   --------------------------------------
     Name:  Kenneth S. Ord
     Title: Executive Vice President and CFO