<PAGE>

                                                                    EXHIBIT 4.3


              -----------------------------------------------------

                             ALLIANCE IMAGING, INC.


                          $260,000,000 Principal Amount


              Senior Subordinated Promissory Notes Due May 2, 2001



                             NOTE PURCHASE AGREEMENT




                             Dated November 2, 1999



<PAGE>





                                TABLE OF CONTENTS

<TABLE>
<CAPTION>

                                                                                                               PAGE
                                                                                                               ----

<S>               <C>                                                                                          <C>
SECTION 1.        PURCHASE AND SALE OF NOTE.......................................................................1
         1.1      Issue of Note...................................................................................1
         1.2      Sale and Purchase of the Note; the Closing......................................................1
         1.3      Purchaser's Representations; Source of Funds....................................................2
         1.4      Expenses........................................................................................2
         1.5      Indemnification.................................................................................3
         1.6      Contribution....................................................................................4
         1.7      Registration of Securities; etc.................................................................5
         1.8      Further Action..................................................................................5


SECTION 2.        CLOSING CONDITIONS..............................................................................5
         2.1      Opinion of Counsel..............................................................................5
         2.2      Representations and Warranties True.............................................................6
         2.3      Compliance with this Agreement..................................................................6
         2.4      Your Purchase Permitted by Applicable Laws; Legal Investment....................................6
         2.5      Conditions in Merger Agreement..................................................................6


SECTION 3.        HOLDER'S SPECIAL RIGHTS.........................................................................6
         3.1      Delivery Expenses...............................................................................7
         3.2      Issue Taxes.....................................................................................7
         3.3      Direct Payment..................................................................................7
         3.4      Lost, etc. Note.................................................................................8


SECTION 4.        REPRESENTATIONS AND WARRANTIES..................................................................8
         4.1      Organization, Standing and Qualification........................................................8
         4.2      Authorization of Agreement......................................................................9
         4.3      No Violation....................................................................................9
         4.4      No Default.....................................................................................10
         4.5      Representations and Warranties in Merger Agreement.............................................10
         4.6      Solvency.......................................................................................10
         4.7      Survival of Representations and Warranties.....................................................10


SECTION 5.        DEFINITIONS....................................................................................10


SECTION 6.        MISCELLANEOUS..................................................................................12
         6.1      Notices........................................................................................12
         6.2      Successors and Assigns.........................................................................13
         6.3      Amendment and Waiver...........................................................................13
         6.4      Counterparts...................................................................................13
         6.5      Headings.......................................................................................13
         6.6      Governing Law..................................................................................13
         6.7      Entire Agreement...............................................................................13
         6.8      Severability...................................................................................14

</TABLE>


<PAGE>


SCHEDULE 1.2               Company Bank Account
SCHEDULE 4.1               Organization, Standing and Qualification

ANNEX A                    FORM OF NOTE




                                      ii
<PAGE>


                             ALLIANCE IMAGING, INC.
                      1065 Pacific Center Drive, Suite 200
                            Anaheim, California 92806





                                                                November 2, 1999


To the KKR 1996 Fund L.P.

Ladies and Gentlemen:

         Alliance Imaging, Inc., a Delaware corporation (the "Company") hereby
agrees with you as follows:

1.       PURCHASE AND SALE OF NOTE

1.1      ISSUE OF NOTE

         On or before the Closing (as hereinafter defined), the Company will
have authorized the issuance of its Senior Subordinated Promissory Note due May
2, 2001 (the "Note"), in the aggregate principal amount of $260,000,000 to be
issued in the form attached hereto as Annex A.

         Capitalized terms used herein without definition shall have the
meanings specified in Section 5 hereof.

1.2      SALE AND PURCHASE OF THE NOTE; THE CLOSING

         In reliance upon your representations made in Section 1.3 hereof and
subject to the terms and conditions set forth herein, the Company hereby agrees
to sell to you the Note at an aggregate purchase price of $260,000,000. In
reliance upon the representations and warranties of the Company contained
herein, and subject to the terms and conditions set forth herein, you hereby
agree to purchase the Note from the Company.

         The sale and purchase of the Note shall take place at a closing (the
"Closing") at the offices of Latham & Watkins, 633 West Fifth Street, Los
Angeles, California at 10:00 a.m. on November 2, 1999, or such other business
day on or prior to November 2, 1999, as may be agreed upon by you and the
Company (the "Closing Date"). At the Closing, the Company will deliver to you
the Note to be purchased by you, dated the Closing Date, against payment of the
purchase price therefor by intra-bank or federal funds bank wire transfer of
same day funds to such bank account as the Company shall designate at least two
Business Days prior to the Closing and which is identified on Schedule 1.2
hereto.


                                       1
<PAGE>


1.3      PURCHASER'S REPRESENTATIONS; SOURCE OF FUNDS

         (a) INVESTMENT INTENTION. You represent and warrant that you are
purchasing the Note solely for your own account for the purpose of investment
and not with a view to or for sale in connection with any distribution thereof.
You agree that you will not, directly or indirectly, offer, transfer, sell,
pledge, hypothecate or otherwise dispose of the Note (or solicit any offers to
buy, purchase, or otherwise acquire or take a pledge of the Note), except in
compliance with the Securities Act of 1933, as amended (the "Act"), and the
rules and regulations thereunder.

         (b) LEGENDS. The Note shall bear the following legend:

                  "THIS NOTE HAS BEEN ACQUIRED BY THE HOLDER SOLELY FOR ITS OWN
         ACCOUNT FOR THE PURPOSE OF INVESTMENT AND NOT WITH A VIEW TO OR FOR
         SALE IN CONNECTION WITH ANY DISTRIBUTION THEREOF. THE NOTE HAS NOT BEEN
         REGISTERED UNDER THE SECURITIES ACT OF 1933 ("ACT") OR STATE SECURITIES
         LAWS AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE TRANSFERRED WITHOUT
         REGISTRATION UNDER THE ACT OR AN EXEMPTION THEREFROM."

         (c) FEDERAL SECURITIES LAWS MATTERS. You represent that you are
familiar with Release No. 5226 issued by the SEC under the Act, you have
consulted with your counsel with regard thereto, and you are fully aware of the
position of the SEC limiting the resale to the public of the Note.

         (d) COMPLIANCE WITH RULE 144. If the Note is disposed of in accordance
with Rule 144 under the Act, you shall deliver to the Company, at or prior to
the time of such disposition an executed copy of Form 144 (if required by Rule
144) and such other documentation as the Company may reasonably require in
connection with such sale.

         (e) ABILITY TO BEAR RISK. You represent and warrant that (a) your
financial situation is such that you can afford to bear the economic risk of
holding the unregistered Note for an indefinite period and (b) can afford to
suffer the complete loss of your investment in the Note.

         (f) ACCESS TO INFORMATION; EVALUATION OF RISKS. You represent and
warrant that (a) you understand and have taken cognizance of all the risk
factors related to the purchase of the Note, including those set forth in the
Memorandum, (b) you have received and carefully reviewed the Memorandum and have
been granted the opportunity to ask questions of, and receive answers from,
representatives of the Company concerning the terms and conditions of the
purchase of the Note and to obtain any additional information which you deem
necessary to verify the accuracy of the information contained in the Memorandum
and (c) your knowledge and experience in financial and business matters is such
that you are capable of evaluating the risks of the investment in the Note.

1.4      EXPENSES

         The Company agrees, subject to the Closing, to pay or reimburse all
expenses relating to this Agreement, including but not limited to:



                                       2
<PAGE>

         (a) the cost of preparing and reproducing this Agreement, the Note and
any other documents contemplated hereby or thereby;

         (b) all reasonable out-of-pocket expenses incurred by you in connection
with the transactions contemplated by this Agreement and the other documents
referred to in clause (a) above, including, without limitation, travel and
lodging expenses and all costs incurred in connection with your review of the
Company's business and operations;

         (c) to the extent not specifically included in subparagraph (b)
immediately above, the reasonable fees and other charges of your counsel, Latham
& Watkins, in connection herewith;

         (d) the cost of delivering to your home office or the office of your
designee, insured to your satisfaction, the Note and any other documents
contemplated hereby or thereby;

         (e) all your reasonable out-of-pocket expenses (including the
reasonable fees and expenses of counsel) relating to any amendment,
modification, waiver, consent or preservation or enforcement of rights under
this Agreement and any other documents contemplated hereby or thereby; and

         (f) all other reasonable expenses, including counsel's fees, incurred
by the Company in connection with the transactions contemplated by this
Agreement.

1.5      INDEMNIFICATION

         The Company (the "Indemnifying Party") hereby agrees, without
limitation as to time, to indemnify you and your Agents and Affiliates
(collectively, the "Indemnified Parties") against, and hold you and them
harmless from, all losses, claims, damages, liabilities, costs (including the
costs of preparation and reasonable attorneys' fees and expenses) (collectively,
"Losses") incurred by you or them and arising out of or in connection with this
Agreement or the transactions contemplated hereby or thereby (or any other
document or instrument executed herewith or pursuant hereto or thereto), whether
or not the transactions contemplated by this Agreement are consummated and
whether or not any Indemnified Party is a formal party to any proceeding
(excluding any monetary loss resulting from the resale, or other decline in
value, of any Note; it being understood that such exclusion shall not prevent
you from seeking indemnification or damages from the Company under any other
applicable provision of the Agreement), other than to the extent, and only to
the extent, that any Losses directly result from action on the part of any
Indemnified Party which is finally judicially determined to constitute either
gross negligence or willful misconduct. The Indemnifying Party agrees to
reimburse any Indemnified Party promptly for all such Losses as they are
incurred by such Indemnified Party. The obligations of the Indemnifying Party to
each Indemnified Party hereunder shall be separate obligations and the
Indemnifying Party's liability to any such Indemnified Party hereunder shall not
be extinguished solely because any other Indemnified Party is not entitled to
indemnity hereunder. The obligations of the Indemnifying Party under this
Section 1.5 shall survive the payment or prepayment of the Notes, at maturity,
upon acceleration, redemption or otherwise, any transfer of the Note by you, and
the termination of this Agreement.

         In case any action shall be brought against any Indemnified Party with
respect to which indemnity may be sought against the Indemnifying Party
hereunder, such Indemnified Party shall



                                       3
<PAGE>

promptly notify the Indemnifying Party in writing and they shall, if they so
desire, assume the defense thereof, including the employment of counsel
reasonably satisfactory to such Indemnified Party and payment of all reasonable
fees and expenses. The failure to so notify such Indemnifying Party shall not
affect any obligation it may have to any Indemnified Party under this letter or
otherwise except to the extent it is materially adversely affected by such
failure. Each Indemnified Party shall have the right to employ separate counsel
in such action and participate in the defense thereof, but the fees and expenses
of such counsel shall be at the expense of the Indemnified Party unless: (i) the
Indemnifying Party has agreed in writing to pay such expenses; or (ii) the
Indemnifying Party has failed to assume the defense and employ counsel or (iii)
the named parties to any such action (including any impleaded parties) include
any Indemnified Party and such Indemnifying Party, and such Indemnified Party
shall have been advised by outside counsel that there may be one or more legal
defenses available to it which are inconsistent with or additional to those
available to the Indemnifying Party, PROVIDED that, if such Indemnified Party
notifies the Indemnifying Party in writing that it elects to employ separate
counsel in the circumstances described in clauses (i), (ii) or (iii) above, the
Indemnifying Party shall not have the right to assume the defense of such action
or proceeding; PROVIDED, HOWEVER, that the Indemnifying Party shall not, in
connection with any one such action or proceeding or separate but substantially
similar or related actions or proceedings in the same jurisdiction arising out
of the same general allegations or circumstances, be responsible hereunder for
the fees and expenses of more than one such firm of separate counsel (in
addition to any necessary local counsel), which counsel shall be designated by
such Indemnified Party. The Indemnifying Party shall not be liable for any
settlement of any such action effected without its written consent (which shall
not be unreasonably withheld). The Indemnifying Party agrees that it will not,
without the Indemnified Party's prior consent, which shall not be unreasonably
withheld, settle or compromise any pending or threatened claim, action or suit
in respect of which indemnification or contribution may be sought hereunder
unless the foregoing contains an unconditional release of the Indemnified
Parties from all liability and obligation arising therefrom.

1.6      CONTRIBUTION

         If the indemnification provided for in Section 1.5 is unavailable to
any Indemnified Party in respect of any Losses referred to therein, then the
Indemnifying Party, in lieu of indemnifying such Persons, shall have an
obligation to contribute to the amount paid or payable by such Persons as a
result of such Losses in such proportion as is appropriate to reflect the
relative fault of the Indemnifying Party, its subsidiaries and/or any other
Person or Persons (other than you and the other Indemnified Parties) and you and
the other Indemnified Parties in connection with the actions which resulted in
such Losses as well as any other relevant equitable considerations. The amount
paid or payable by any such Person as a result of the Losses referred to above
shall be deemed to include, subject to the limitations set forth in Section 1.5,
any legal or other fees or expenses reasonably incurred by such Person in
connection with any investigation, lawsuit or legal or administrative action or
proceeding.

         The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 1.6 were determined by pro rata allocation
or by any other method of allocation which does not take account of the
equitable considerations referred to in the immediately preceding paragraph. No
Person guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Securities Act) shall be entitled to contribution from any Person
who was not guilty of such fraudulent misrepresentation.




                                       4
<PAGE>

1.7      REGISTRATION OF SECURITIES; ETC.

         (a) The Company shall maintain a register for the Note in which it
shall provide for the registration and transfer of the Note.

         (b) Upon surrender for registration of transfer of the Note, the
Company, at its expense, shall execute and deliver, in the name of the
designated transferee or transferees, one or more new Notes of the same type,
and of a like aggregate principal amount.

         (c) Notes may be exchanged at the option of any Holder thereof for
Notes of a like aggregate principal amount, but in different denominations.
Whenever any Notes are so surrendered for exchange, the Company, at its expense,
shall execute and deliver the Notes which the holder making the exchange is
entitled to receive.

         (d) All Notes issued upon any registration of transfer or exchange of
such shall be the legal and valid obligations of the Company, evidencing the
same interests, and entitled to the same benefits, as Notes surrendered upon
such registration of transfer or exchange.

         (e) Every Note presented or surrendered for registration of transfer or
exchange shall (if so required by the Company) be duly endorsed or shall be
accompanied by a written instrument of transfer in form satisfactory to the
Company duly executed by the Holder thereof or its attorney duly authorized in
writing.

1.8      FURTHER ACTION

         During the period from the date hereof to the Closing Date, the Company
shall use its best efforts, and shall take all action necessary or appropriate,
to cause its representations and warranties contained in Section 4 hereof to be
true as of the Closing Date, after giving effect to the transactions
contemplated by this Agreement, as if made on and as of such date.

2.       CLOSING CONDITIONS

         Your obligations to purchase and pay for the Note to be delivered to
you at the Closing shall be subject to the satisfaction of the following
conditions on or before the Closing Date:

2.1      OPINION OF COUNSEL

         You shall have received a favorable opinion, dated the Closing Date and
addressed to you, from Russell D. Phillips, Jr., Esq., the Company's General
Counsel, in form and substance satisfactory to you, as to the matters covered in
Sections 4.1(a) and (b), as to the Company only, 4.2 and 4.3(a)-(d), as to the
Company only. In rendering such opinion, such counsel may rely as to factual
matters upon certificates or other documents furnished by officers and directors
of the Company (copies of which shall be delivered to you) and by government
officials, and upon such other documents as such counsel deem appropriate as a
basis for their opinion. Such counsel may specify the jurisdictions in which
they are admitted to practice and that they are not admitted to practice in any
other jurisdiction and are not experts in the law of any other jurisdiction.



                                       5
<PAGE>

2.2      REPRESENTATIONS AND WARRANTIES TRUE

         The representations and warranties of the Company contained in Section
4 hereof shall be true at and as of the Closing Date, after giving effect to the
transactions contemplated by this Agreement, in all material respects, as if
made on and as of such date.

2.3      COMPLIANCE WITH THIS AGREEMENT

         The Company shall have performed and complied with all agreements,
covenants and conditions contained herein and any other document contemplated
hereby or thereby which are required to be performed or complied with by the
Company on or before the Closing Date.

2.4      YOUR PURCHASE PERMITTED BY APPLICABLE LAWS; LEGAL INVESTMENT

         Your purchase of and payment for the Note to be purchased by you (a)
shall not be prohibited by any applicable law or governmental regulation
(including, without limitation, Regulations T, U and X of the Board of Governors
of the Federal Reserve System), (b) shall not subject you to any penalty or, in
your reasonable judgment, other onerous condition under or pursuant to any
applicable law or governmental regulation, and (c) shall be permitted by the
laws and regulations of the jurisdictions to which you are subject.

         The Company shall have delivered to you factual certificates or other
evidence requested by you, in form and substance satisfactory to you, to enable
you to establish compliance with this condition.

2.5      CONDITIONS IN MERGER AGREEMENT

         All conditions precedent contained in Sections 6.1 and 6.2 of the
Agreement and Plan of Merger, between Viewer Acquisition Corp. and the Company,
dated as of September 13, 1999 (the "Merger Agreement"), are hereby incorporated
by reference as if stated herein, and shall have, as amended from time to time,
been satisfied, including the simultaneous receipt of the initial advances of
funds under the Senior Bank Facility.

         Counterparts, conformed as executed, of all other documents delivered
at the Closing, shall be delivered to you.

3.       HOLDER'S SPECIAL RIGHTS

         The provisions of this Section 3 (other than Section 3.3(b), shall
apply, notwithstanding anything to the contrary in this Agreement, with respect
to Transfer Restricted Note only.



                                       6
<PAGE>

3.1      DELIVERY EXPENSES

         If a Holder surrenders the Note to the Company for any reason, the
Company agrees to pay the cost of delivering to or from such Holder's home
office or to or from the office of such Holder's designee from or to the
Company, as the case may be, insured to such Holder's satisfaction, the
surrendered Note.

3.2      ISSUE TAXES

         The Company agrees to pay all taxes (other than taxes in the nature of
income, franchise or gift taxes) in connection with the issuance, sale, delivery
or transfer by the Company to the Purchaser of the Note and the execution and
delivery of any other agreements and instruments contemplated thereby and any
modification of the Note or such other agreements and instruments and will save
you harmless without limitation as to time against any and all liabilities with
respect to all such taxes. The obligations of the Company under this Section 3.2
shall survive the payment or prepayment of the Note and the termination of this
Agreement.

3.3      DIRECT PAYMENT

         (a) The Company will pay or cause to be paid all amounts payable with
respect to the Note (without any presentment of such Note and without any
notation of such payment being made thereon) by crediting (before 11:00 a.m.,
New York time), by federal funds bank wire transfer to each Holder's account in
any bank in the United States as may be designated and specified in writing by
such Holder at least two Business Days prior thereto. Your initial bank account
for this purpose is on Schedule 3.3 hereto.

         (b) Notwithstanding anything to the contrary contained in the Note, if
any principal amount payable with respect to a Note is payable on a Legal
Holiday, then the Company shall pay such amount on the next succeeding Business
Day, and interest shall accrue on such amount until the date on which such
amount is paid and payment of such accrued interest shall be made concurrently
with the payment of such amount, provided that the Company may elect to pay in
full (but not in part) any such amount on the last Business Day prior to the
date such payment otherwise would be due, and no such additional interest shall
accrue on such amount. Notwithstanding anything to the contrary contained in the
Notes, if any interest payable with respect to a Note is payable on a Legal
Holiday, then the Company shall pay such interest on the next succeeding
Business Day, and such extension of time shall be included in the computation of
the interest payment, provided that the Company may elect to pay in full (but
not in part) any such interest on the last Business Day prior to the date such
payment otherwise would be due, and such diminution in time shall be included in
the computation of the interest payment.



                                       7
<PAGE>

3.4      LOST, ETC. NOTE

         Notwithstanding any provision to the contrary, if a Note of which the
Purchaser or any other institutional Holder (or nominee thereof) which is a
transferee is the owner is mutilated, destroyed, lost or stolen, then the
affidavit of the Purchaser's or such Holder's treasurer or assistant treasurer
(or other authorized officer), briefly setting forth the circumstances with
respect to such mutilation, destruction, loss or theft, shall be accepted as
satisfactory evidence thereof, and no indemnity, security or payment of charges
or expenses shall be required as a condition to the execution and delivery by
the Company or the transfer agent with respect to such Note, of new securities
for a like aggregate principal amount or number of shares, as applicable, in
substitution therefor, other than such Purchaser's or such Holder's unsecured
written agreement reasonably satisfactory to indemnify the Company or the
transfer agent, as the case may be.

4.       REPRESENTATIONS AND WARRANTIES

         The Company hereby represents and warrants as follows:

4.1      ORGANIZATION, STANDING AND QUALIFICATION

         (a) Each of the Company and its Subsidiaries is duly organized, validly
existing and in good standing under the laws of its jurisdiction of
organization; has all requisite power and authority to own or lease and operate
its properties and to carry on its business as now conducted and as proposed to
be conducted; and is duly qualified or licensed to do business as a foreign
corporation in good standing in all jurisdictions in which it owns or leases
property or in which the conduct of its business requires it so to qualify or be
licensed, except where the failure to be so qualified or licensed would not have
a Material Adverse Effect.

         (b) The Company has all requisite power and authority to enter into and
perform all of its obligations under this Agreement, to issue and perform all of
its obligations under the Note and to carry out the transactions contemplated
hereby and thereby. Each of the Subsidiaries has all requisite power and
authority to enter into and perform all its obligations under the Guarantee.

         (c) The Company has identified on Schedule 4.1 the name and
jurisdiction of incorporation or organization of each of its Subsidiaries and
(ii) the percentage of the issued and outstanding capital stock and other equity
interest (including rights, warrants and options to acquire, and all Note
convertible into or exchangeable for, such capital stock) of each such
Subsidiary owned directly or indirectly by the Company.



                                       8
<PAGE>

4.2      AUTHORIZATION OF AGREEMENT

         The Company has taken all actions necessary to authorize it to enter
into and perform all of its obligations under this Agreement, to issue and
perform all of its obligations under the Note and to consummate the transactions
contemplated hereby and thereby. This Agreement and the Note are legal, valid
and binding obligations of the Company, enforceable against it in accordance
with their respective terms, except for (a) the effect thereon of bankruptcy,
insolvency, reorganization, moratorium and other similar laws relating to or
affecting the rights of creditors generally and (b) limitations imposed by
federal or state law or equitable principles upon the specific enforceability of
any of the remedies, covenants or other provisions thereof and upon the
availability of injunctive relief or other equitable remedies.

4.3      NO VIOLATION

         Neither the execution or delivery of this Agreement nor the issuance,
sale or delivery of the Note, nor the consummation of the transactions
contemplated hereby and thereby, will:

         (a) violate any provision of the Charter Documents of the Company or
any of its Subsidiaries;

         (b) violate any statute, law, rule or regulation or any judgment,
decree, order, regulation or rule of any court or governmental authority to
which the Company or any of its Subsidiaries or any of their respective
properties may be subject;

         (c) permit or cause the acceleration of the maturity of any debt or
obligation of the Company or any of its Subsidiaries in excess of $1,000,000 or
the acceleration of which would result in a Material Adverse Effect; or

         (d) violate, or be in conflict with, or constitute a default under, or
permit the termination of, or require the consent of any Person under, or result
in the creation of any Lien upon any property of the Company or any of its
Subsidiaries under, any mortgage, indenture, loan agreement, note, debenture or
other agreement for borrowed money or any other material agreement to which the
Company or any of its Subsidiaries is a party or by which the Company or any of
its Subsidiaries (or their respective properties) may be bound, other than such
violations, conflicts, defaults, terminations and Liens, or such failures to
obtain consents, which could not reasonably be expected to result in a Material
Adverse Effect.

         The Company is not in default (without giving effect to any grace or
cure period or notice requirement) under any agreement for borrowed money.



                                       9
<PAGE>

4.4      NO DEFAULT

         No event has occurred or failed to occur which constitutes or would
constitute a default under the Note.

4.5      REPRESENTATIONS AND WARRANTIES IN MERGER AGREEMENT

         All representations and warranties made by the Company in Article III
of the Merger Agreement are incorporated by reference as if made herein, and are
true and accurate in all material respects as of the date hereof.

4.6      SOLVENCY

         The Company is not, and will not be after giving effect to the issuance
of the Note and the execution, delivery and performance of this Agreement and
any instrument governing Indebtedness of the Company or a Subsidiary incurred as
of the Closing Date, (x) insolvent or (y) left with unreasonably small capital
with which to engage in its anticipated business, and the Company does not have,
and will not have after giving effect to the issuance of the Note and the
execution, delivery and performance of this Agreement and any instrument
governing Indebtedness of the Company or a Subsidiary incurred as of the Closing
Date, incurred debts beyond its ability to pay such debts as they mature.

4.7      SURVIVAL OF REPRESENTATIONS AND WARRANTIES

         All statements contained in any certificate or other document delivered
to you by or on behalf of the Company pursuant to or in connection with this
Agreement or the Closing shall be deemed to constitute representations and
warranties under this Agreement with the same force and effect as the
representations and warranties expressly set forth herein. All of the Company's
representations and warranties thereunder and hereunder shall survive the
execution and delivery of the same, any investigation by you and the issuance of
the Note.

5.       DEFINITIONS

         As used in this Agreement, the following terms shall have the following
meanings:

         AFFILIATE: With respect to any specified Person, any other Person
directly or indirectly controlling or controlled by or under direct or indirect
common control with such specified Person. For the purposes of this definition,
"control" (including, with correlative meanings, the terms "controlled by" and
"under common control with"), as used with respect to any person, shall mean the
possession, directly or indirectly, of the power to direct or cause the
direction of the management or policies of such Person, whether in the capacity
of officer or director of such Person, through the ownership of voting Note, by
agreement or otherwise.

         AGENT: Any Person authorized to act and who acts on behalf of the
Purchaser with respect to the transactions contemplated by this Agreement or the
Note.

         BUSINESS DAY: Any day which is not a Legal Holiday.



                                       10

<PAGE>

         CHARTER DOCUMENTS: The Articles of Organization, Articles of
Incorporation or Certificate of Incorporation and Bylaws, as amended or restated
(or both) to date, of the Company or any Subsidiary of the Company, as
applicable.

         CLOSING: See Section 1.2.

         CLOSING DATE: See Section 1.2.

         COMPANY: Alliance Imaging, Inc., a Delaware corporation.

         EXCHANGE ACT: The Securities Exchange Act of 1934, as amended, from
time to time, and any successor statute or law thereto.

         GUARANTY: The Guaranty of the Note by the Subsidiaries of the Company
annexed to the Note.

         HOLDER OR HOLDERS: Each Purchaser (so long as it holds the Note) and
any other holder of the Note.

         LEGAL HOLIDAY: A Saturday, Sunday or day on which banks and trust
companies in the principal place of business of the Company or in New York are
not required to be open. If a payment date is a Legal Holiday, payment may be
made on the next succeeding day that is not a Legal Holiday, and interest shall
accrue for the intervening period.

         LIEN: Any lien, mortgage, pledge, assignment, security interest, charge
or other similar encumbrance of any kind (including any conditional sale or
other title retention agreement, any lease in the nature thereof, and any
agreement to give any security interest) and any other similar preferential
arrangement having the practical effect of any of the foregoing.

         MATERIAL ADVERSE EFFECT: (i) Any material adverse effect whatsoever
upon the validity, or enforceability of the Note, (ii) any material adverse
effect on the business, assets, liabilities, properties, condition (financial or
otherwise) or results of operations of the Company and its Subsidiaries, taken
as a whole, or (iii) any material adverse effect on the ability of the Company
to fulfill its obligations under this Agreement and the Note and any instrument
governing Indebtedness of the Company or a Subsidiary incurred as of the Closing
Date, or any document contemplated hereby or thereby.

         MEMORANDUM: The Confidential Memorandum prepared by Salomon Smith
Barney Inc. and BT Alex. Brown Incorporated, from materials and information
supplied by the Company, dated as of June 1999.

         MERGER AGREEMENT: See Section 2.5.

         NOTE: See Section 1.1.

         PERSON: An individual, partnership, corporation, trust or
unincorporated organization or a government or agency or political subdivision
thereof.


                                       11
<PAGE>

                  PURCHASER:  KKR 1996 Fund, L.P., a Delaware limited
partnership.

                  RULE 144: Rule 144 as promulgated by the Securities Exchange
Commission under the Securities Act, as amended from time to time, and any
successor rule or regulation thereto.

                  SEC:  The Securities and Exchange Commission.

                  SENIOR CREDIT FACILITY:  See Note.

                  SECURITIES ACT: The Securities Act of 1933, as amended from
time to time, and any successor statute or law thereto.

                  SUBSIDIARY: With respect to any Person (the "parent"), any
corporation, association or other business entity of which Note or other
ownership interests representing more than 50% of the ordinary voting power are,
at the time as of which any determination is being made, owned or controlled by
the parent or one or more subsidiaries of the parent or by the parent and one or
more subsidiaries of the parent.

                  TRANSFER RESTRICTED NOTE: Note acquired by the Purchaser
directly from the Company or acquired by the holder thereof other than pursuant
to an effective registration under Section 5 of the Securities Act or pursuant
to Rule 144; PROVIDED that a security that has ceased to be a Transfer
Restricted Security cannot thereafter become a Transfer Restricted Security.

6.       MISCELLANEOUS

6.1      NOTICES

         All notices and other communications provided for or permitted
hereunder shall be made by hand-delivery, first-class mail, telecopier, or
overnight air courier guaranteeing next day delivery:

         (a) if to you at your address set forth on the signature page hereof,
with a copy to Latham & Watkins, 633 W. Fifth Street, Suite 4000, Los Angeles,
California 90071, Attention: Randall C. Bassett, Esq.; and

         (b) if to the Company, at 1065 Pacific Center Drive, Suite 200,
Anaheim, California 92806, Attention: Chief Executive Officer or President, with
copies to O'Sullivan Graev & Karabell, LLP, 30 Rockefeller Plaza, New York, New
York 10112, Attention: John J. Suydam, Esq.

         All such notices and communications shall be deemed to have been duly
given: at the time delivered by hand, if personally delivered; five business
days after being deposited in the mail, postage prepaid, if mailed; when
answered back if telexed; when receipt acknowledged, if telecopied; and the next
business day after timely delivery to the courier, if sent by overnight air
courier guaranteeing next day delivery. The parties may change the addresses to
which notices are to be given by giving five days' prior notice of such change
in accordance herewith.



                                       12
<PAGE>

6.2      SUCCESSORS AND ASSIGNS

         This Agreement shall inure to the benefit of and be binding upon the
successors and assigns of each of the parties, including, without limitation and
without the need for an express assignment, subsequent holders of Transfer
Restricted Note.

6.3      AMENDMENT AND WAIVER

         Prior to the Closing Date, this Agreement may be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may be given, PROVIDED that the same are in writing and signed by you and the
Company. Thereafter, except as heretofore expressly provided otherwise, this
Agreement may be amended, modified or supplemented, and waivers or consents to
departures from the provisions hereof may be given, provided that the same are
in writing and signed by the Company and the Holders of a majority in principal
amount of the Notes then outstanding; PROVIDED, HOWEVER, that any amendment,
modification or supplement that (i) affects or proposes to affect the rate or
time for payment of interest on any Note (including default interest) or the
amount of principal or the principal maturity date of any Note or the redemption
or prepayment provisions with respect thereto, (ii) makes or proposes to make
any Note payable in money or property other than that stated in the Note or
(iii) makes or proposes to make any change in this Section 6.3 shall not be
binding upon any Holder of any outstanding Note that has not consented thereto
in writing.

6.4      COUNTERPARTS

         This Agreement may be executed in any number of counterparts and by the
parties hereto in separate counterparts, each of which when so executed shall be
deemed to be an original and all of which taken together shall constitute one
and the same agreement.

6.5      HEADINGS

         The headings in this Agreement are for convenience of reference only
and shall not limit or otherwise affect the meaning hereof.

6.6      GOVERNING LAW

         This Agreement shall be governed by and construed in accordance with
the internal laws of the State of New York.

6.7      ENTIRE AGREEMENT

         This Agreement, together with the Note, is intended by the parties as a
final expression of their agreement and intended to be a complete and exclusive
statement of the agreement and understanding of the parties hereto in respect of
the subject matter contained herein and therein. There are no restrictions,
promises, warranties or undertakings, other than those set forth or referred to
herein and therein. This Agreement, together with the Note, supersedes all prior
agreements and understandings between the parties with respect to such subject
matter.



                                       13
<PAGE>


6.8      SEVERABILITY

         In the event that any one or more of the provisions contained herein,
or the application thereof in any circumstances, is held invalid, illegal or
unenforceable in any respect for any reason, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions hereof shall not be in any way impaired or affected, it being
intended that all of your rights and privileges shall be enforceable to the
fullest extent permitted by law.

         If this Agreement is satisfactory to you, please so indicate by signing
the acceptance at the foot of a counterpart of this Agreement and deliver such
counterpart to the Company whereupon this Agreement will become binding between
us in accordance with its terms.

                                    Very truly yours,

                                    ALLIANCE IMAGING, INC.



                                    By: /s/ Kenneth S. Ord
                                       ---------------------------------
                                       Name:  Kenneth S. Ord
                                       Title: Chief Financial Officer and
                                       Executive Vice President




                                       14
<PAGE>



KKR 1996 FUND, L.P.

By:      KKR Associates 1996 L.P.,
Its:     General Partner

By:      KKR 1996 GP LLC,
Its:     General Partner


         /s/ Michael W. Michelson
         ------------------------------------
         By:  Michael W. Michelson
         Its:  Member


Address: KKR 1996 Fund, L.P.
         c/o Kohlberg Kravis Roberts & Co.
         9 West 57th Street
         New York, New York 10019

Principal amount of Notes to be purchased:
         $260,000,000




                                       15
<PAGE>



                                  Schedule 1.3

                              COMPANY BANK ACCOUNT


Wire authorization instructions

To:  Bank of America
Routing and Transit No.:  121 000 358
For credit of:  Alliance Imaging, Inc.
Account No.:  1457202783
By order of:  [NAME OF SENDER]



<PAGE>


                                  Schedule 3.3


INITIAL BANK ACCOUNT:

Morgan Guaranty Trust Co.
500 Stanton Christiana Rd.
Newark, DE 19713

ABA #031100238

FOR THE ACCOUNT OF:
KKR 1996 Fund, L.P.
Account No. 40006498