REGISTRATION RIGHTS AGREEMENT DATED AS OF DECEMBER 29, 2004 BY AND BETWEEN ALLIANCE IMAGING, INC. AND DEUTSCHE BANK SECURITIES INC. CITIGROUP GLOBAL MARKETS INC. LEHMAN BROTHERS INC. MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED

EXHIBIT 4.2

REGISTRATION RIGHTS AGREEMENT

DATED AS OF DECEMBER 29, 2004
BY AND BETWEEN

ALLIANCE IMAGING, INC.

AND

DEUTSCHE BANK SECURITIES INC.
CITIGROUP GLOBAL MARKETS INC.
LEHMAN BROTHERS INC.
MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED

        This Registration Rights Agreement (this " Agreement ") is made and entered into as of December 29, 2004, by and among Alliance Imaging, Inc., a Delaware corporation (the " Company ") and Deutsche Bank Securities Inc., Citigroup Global Markets Inc., Lehman Brothers Inc. and Merrill Lynch, Pierce, Fenner & Smith Incorporated (the " Initial Purchasers "), who have agreed to purchase the Company's 7 ¹ / 4 % Senior Subordinated Notes due 2012 (the " Notes ") pursuant to the Purchase Agreement (as defined below).

        This Agreement is made pursuant to the Purchase Agreement, dated December 9, 2004 (the " Purchase Agreement "), by and among the Company and the Initial Purchasers. In order to induce the Initial Purchasers to purchase the Notes, the Company has agreed to provide the registration rights set forth in this Agreement. The execution and delivery of this Agreement is a condition to the obligations of the Initial Purchasers to purchase the Notes as set forth in the Purchase Agreement. Capitalized terms used herein and not otherwise defined shall have the meaning assigned to them in the Indenture (the " Indenture "), dated December 29, 2004, between the Company and The Bank of New York, as Trustee, relating to the Notes and the Series B Notes (as defined below).

        The parties hereby agree as follows:

1.     Definitions

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

•         Act:     The Securities Act of 1933, as amended.

          Affiliate:     As defined in Rule 144 of the Act.

          Broker-Dealer:     Any broker or dealer registered under the Exchange Act.

          Certificated Securities:     The definitive Notes referred to in the second paragraph of Section 201 of the Indenture.

          Closing Date:     The date hereof.

          Commission:     The Securities and Exchange Commission.

          Consummate:     An Exchange Offer shall be deemed "Consummated" for purposes of this Agreement upon the occurrence of (a) the filing and effectiveness under the Act of the Exchange Offer Registration Statement relating to the Series B Notes to be issued in the Exchange Offer, (b) the maintenance of such Exchange Offer Registration Statement continuously effective and the keeping of the Exchange Offer open for a period not less than the period required pursuant to Section 3(b) hereof and (c) the delivery by the Company to the Registrar under the Indenture of Series B Notes in the same aggregate principal amount as the aggregate principal amount of Notes tendered by Holders thereof pursuant to the Exchange Offer.

          Consummation Deadline:     As defined in Section 3(b) hereof.

          Effectiveness Deadline:     As defined in Section 3(a) and 4(a) hereof.

          Exchange Act:     The Securities Exchange Act of 1934, as amended.

          Exchange Offer:     The issuance and exchange by the Company of a principal amount of Series B Notes (which shall be registered pursuant to the Exchange Offer Registration Statement) equal to the outstanding principal amount of Notes that are tendered by such Holders in connection with such exchange and issuance.

          Exchange Offer Registration Statement:     The Registration Statement relating to the Exchange Offer, including the related Prospectus.

• 
  

          Exempt Resales:     The transactions in which the Initial Purchasers propose to sell the Notes to certain "qualified institutional buyers," as such term is defined in Rule 144A under the Act and pursuant to Regulation S under the Act.

          Filing Deadline:     As defined in Sections 3(a) and 4(a) hereof.

          Holders:     As defined in Section 2 hereof.

          Prospectus:     The prospectus included in a Registration Statement at the time such Registration Statement is declared effective, as amended or supplemented by any prospectus supplement and by all other amendments thereto, including post-effective amendments, and all material incorporated by reference into such Prospectus.

          Recommencement Date:     As defined in Section 6(d) hereof.

          Registration Default:     As defined in Section 5 hereof.

          Registration Statement:     Any registration statement of the Company relating to (a) an offering of Series B Notes pursuant to an Exchange Offer or (b) the registration for resale of Transfer Restricted Securities pursuant to the Shelf Registration Statement, in each case, (i) that is filed pursuant to the provisions of this Agreement and (ii) including the Prospectus included therein, all amendments and supplements thereto (including post-effective amendments) and all exhibits and material incorporated by reference therein.

          Regulation S:     Regulation S promulgated under the Act.

          Rule 144:     Rule 144 promulgated under the Act.

          Series B Notes:     The Company's 7 ¹ / 4 % Series B Senior Subordinated Notes due 2012 to be issued pursuant to the Indenture: (i) in the Exchange Offer or (ii) as contemplated by Section 4 hereof.

          Shelf Registration Statement:     As defined in Section 4 hereof.

          Suspension Notice:     As defined in Section 6(d) hereof.

          TIA:     The Trust Indenture Act of 1939 (15 U.S.C. Section 77aaa-77bbbb) as in effect on the date of the Indenture.

          Transfer Restricted Securities:     Each Note, until the earliest to occur of (a) the date on which such Note is exchanged in the Exchange Offer and entitled to be resold to the public by the Holder thereof without complying with the prospectus delivery requirements of the Act, (b) the date on which such Note has been disposed of in accordance with a Shelf Registration Statement, (c) the date on which such Note is distributed to the public pursuant to Rule 144 under the Act, or (d) the date on which such Note is disposed of by a Broker-Dealer pursuant to the "Plan of Distribution" contemplated by the Exchange Offer Registration Statement (including the delivery of the Prospectus contained therein).

2.     Holders

        A Person is deemed to be a holder of Transfer Restricted Securities (each, a " Holder ") whenever such Person owns Transfer Restricted Securities.

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3.     Registered Exchange Offer

        (a)   Unless the Exchange Offer shall not be permitted by applicable law or applicable interpretation of the Staff of the Commission, the Company shall (i) cause the Exchange Offer Registration Statement to be filed with the Commission on or prior to 120 days after the Closing Date (such 120th day being the " Filing Deadline "), (ii) use its commercially reasonable efforts to cause such Exchange Offer Registration Statement to become effective at the earliest possible time, but in no event later than 200 days after the Closing Date (such day being the " Effectiveness Deadline "), (iii) in connection with the foregoing, (A) file all pre-effective amendments to such Exchange Offer Registration Statement as may be necessary in order to cause it to become effective, (B) file, if applicable, a post-effective amendment to such Exchange Offer Registration Statement pursuant to Rule 430A under the Act and (C) cause all necessary filings, if any, in connection with the registration and qualification of the Series B Notes to be made under the Blue Sky laws of such jurisdictions as are necessary to permit Consummation of the Exchange Offer, and (iv) upon the effectiveness of such Exchange Offer Registration Statement, commence and Consummate the Exchange Offer. The Exchange Offer shall be on the appropriate form permitting (i) registration of the Series B Notes to be offered in exchange for the Notes that are Transfer Restricted Securities and (ii) resales of Series B Notes by Broker-Dealers that tendered into the Exchange Offer Notes that such Broker-Dealer acquired for its own account as a result of market-making activities or other trading activities (other than Notes acquired directly from the Company or any of its Affiliates) as contemplated by Section 3(c) below.

        (b)   The Company shall use its commercially reasonable efforts to cause the Exchange Offer Registration Statement to be effective continuously, and shall keep the Exchange Offer open for a period of not less than the minimum period required under applicable federal and state securities laws to Consummate the Exchange Offer; provided , however , that in no event shall such period be less than twenty (20) Business Days. The Company shall cause the Exchange Offer to comply with all applicable federal and state securities laws. No securities other than the Series B Notes shall be included in the Exchange Offer Registration Statement. The Company shall use its commercially reasonable efforts to cause the Exchange Offer to be Consummated on the earliest practicable date after the Exchange Offer Registration Statement has become effective, but in no event later than 230 days after the Closing Date (such day being the " Consummation Deadline ").

        (c)   The Company shall include a "Plan of Distribution" Section in the Prospectus contained in the Exchange Offer Registration Statement and indicate therein that any Broker-Dealer who holds Transfer Restricted Securities that were acquired for the account of such Broker-Dealer as a result of market-making activities or other trading activities (other than Notes acquired directly from the Company or any Affiliate of the Company), may exchange such Transfer Restricted Securities pursuant to the Exchange Offer. Such "Plan of Distribution" Section shall also contain all other information with respect to such sales by such Broker-Dealers that the Commission may require in order to permit such sales pursuant thereto, but such "Plan of Distribution" shall not name any such Broker-Dealer or disclose the amount of Transfer Restricted Securities held by any such Broker-Dealer, except to the extent required by the Commission as a result of a change in policy, rules or regulations after the date of this Agreement.

        Because such Broker-Dealer may be deemed to be an "underwriter" within the meaning of the Act and must, therefore, deliver a prospectus meeting the requirements of the Act in connection with its initial sale of any Series B Notes received by such Broker-Dealer in the Exchange Offer, the Company shall permit the use of the Prospectus contained in the Exchange Offer Registration Statement by such Broker-Dealer to satisfy such prospectus delivery requirement. To the extent necessary to ensure that the prospectus contained in the Exchange Offer Registration Statement is available for sales of Series B Notes by Broker-Dealers, the Company agrees to use its commercially reasonable efforts to keep the Exchange Offer Registration Statement continuously effective, supplemented, amended and current as

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required by and subject to the provisions of Section 6(a) and (c) hereof and in conformity with the requirements of this Agreement, the Act and the policies, rules and regulations of the Commission as announced from time to time, for a period the earlier of (a) 180 days from the Consummation of the Exchange Offer and (b) such shorter period as will terminate when all Transfer Restricted Securities covered by such Registration Statement have been sold pursuant thereto. The Company shall provide sufficient copies of the latest version of such Prospectus to such Broker-Dealers, promptly upon request, and in no event later than one day after such request, at any time during such period.

4.     Shelf Registration

        (a)     Shelf Registration .    If (i) the Exchange Offer is not permitted by applicable law or applicable interpretation of the Staff of the Commission or (ii) if any Holder of Transfer Restricted Securities shall notify the Company within twenty (20) Business Days following the Consummation Deadline that (A) such Holder was prohibited by law or Commission policy from participating in the Exchange Offer or (B) such Holder may not resell the Series B Notes acquired by it in the Exchange Offer to the public without delivering a prospectus and the Prospectus contained in the Exchange Offer Registration Statement is not available for such resales by such Holder or (C) such Holder is a Broker-Dealer and holds Notes acquired directly from the Company or any of its Affiliates, then the Company shall:

• • (x)

    cause to be filed, on or prior to 30 days after the earlier of (i) the date on which the Company determines that the Exchange Offer Registration Statement cannot be filed as a result of clause (a)(i) above and (ii) the date on which the Company receives the notice specified in clause (a)(ii) above, (such earlier date, the " Filing Deadline "), a shelf registration statement pursuant to Rule 415 under the Act (which may be an amendment to the Exchange Offer Registration Statement (the " Shelf Registration Statement ")), relating to all Transfer Restricted Securities, and
    
    

    (y)

    shall use its commercially reasonable efforts to cause such Shelf Registration Statement to become effective on or prior to 75 days after the Filing Deadline for the Shelf Registration Statement (such 75th day the " Effectiveness Deadline ").

        If, after the Company has filed an Exchange Offer Registration Statement that satisfies the requirements of Section 3(a) above, the Company is required to file and make effective a Shelf Registration Statement solely because the Exchange Offer is not permitted under applicable federal law (i.e., clause (a)(i) above), then the filing of the Exchange Offer Registration Statement shall be deemed to satisfy the requirements of clause (x) above; provided that, in such event, the Company shall remain obligated to meet the Effectiveness Deadline set forth in clause (y).

        To the extent necessary to ensure that the Shelf Registration Statement is available for sales of Transfer Restricted Securities by the Holders thereof entitled to the benefit of this Section 4(a) and the other securities required to be registered therein pursuant to Section 6(b)(ii) hereof, the Company shall use its commercially reasonable efforts to keep any Shelf Registration Statement required by this Section 4(a) continuously effective, supplemented, amended and current as required by and subject to the provisions of Sections 6(b) and (c) hereof and in conformity with the requirements of this Agreement, the Act and the policies, rules and regulations of the Commission as announced from time to time, for a period of at least two years (as extended pursuant to Section 6(c)(i)) following the Closing Date, or such shorter period as will terminate when all Transfer Restricted Securities covered by such Shelf Registration Statement have been sold pursuant thereto.

        (b)     Provision By Holders of Certain Information In Connection With The Shelf Registration Statement .    No Holder of Transfer Restricted Securities may include any of its Transfer Restricted Securities in any Shelf Registration Statement pursuant to this Agreement unless and until such Holder furnishes to the Company in writing, within 20 days after receipt of a request therefor, the information specified in Item 507 or 508 of Regulation S-K, as applicable, of the Act for use in connection with any

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Shelf Registration Statement or Prospectus or preliminary Prospectus included therein. No Holder of Transfer Restricted Securities shall be entitled to liquidated damages pursuant to Section 5 hereof unless and until such Holder shall have provided all such information. Each selling Holder agrees to promptly furnish additional information required to be disclosed in order to make the information previously furnished to the Company by such Holder not materially misleading.

5.     Liquidated Damages

        If (i) any Registration Statement required by this Agreement is not filed with the Commission on or prior to the applicable Filing Deadline, (ii) any such Registration Statement has not been declared effective by the Commission on or prior to the applicable Effectiveness Deadline, (iii) the Exchange Offer has not been Consummated on or prior to the Consummation Deadline or (iv) any Registration Statement required by this Agreement is filed and declared effective but shall thereafter cease to be effective or fail to be usable for its intended purpose without being succeeded within two (2) Business Days by a post-effective amendment to such Registration Statement that cures such failure and that is itself declared effective within two (2) Business Days of filing such post-effective amendment to such Registration Statement (each such event referred to in clauses (i) through (iv), a " Registration Default "), then the Company hereby agrees to pay to each Holder of Transfer Restricted Securities affected thereby Liquidated Damages. Liquidated Damages shall accrue at an annual rate of 0.25% of the aggregate principal amount of Transfer Restricted Securities on the date of such Registration Default, payable in cash semi-annually in arrears on each Interest Payment Date. Notwithstanding anything to the contrary set forth herein, (1) upon filing of the Exchange Offer Registration Statement (and/or, if applicable, the Shelf Registration Statement), in the case of (i) above, (2) upon the effectiveness of the Exchange Offer Registration Statement (and/or, if applicable, the Shelf Registration Statement), in the case of (ii) above, (3) upon Consummation of the Exchange Offer, in the case of (iii) above, or (4) upon the filing of a post-effective amendment to the Registration Statement or an additional Registration Statement that causes the Exchange Offer Registration Statement (and/or, if applicable, the Shelf Registration Statement) to again be declared effective or made usable in the case of (iv) above, the liquidated damages payable with respect to the Transfer Restricted Securities as a result of such clause (i), (ii), (iii) or (iv), as applicable, shall cease.

        All accrued liquidated damages shall be paid to the Holders entitled thereto, in the manner provided for the payment of interest in the Indenture, on each Interest Payment Date, as more fully set forth in the Indenture and the Notes. Notwithstanding the fact that any securities for which liquidated damages are due cease to be Transfer Restricted Securities, all obligations of the Company to pay liquidated damages with respect to securities shall survive until such time as such obligations with respect to such securities shall have been satisfied in full.

6.     Registration Procedures

        (a)     Exchange Offer Registration Statement .    In connection with the Exchange Offer, the Company shall (x) comply with all applicable provisions of Section 6(c) below, (y) use its commercially reasonable efforts to effect such exchange and to permit the resale of Series B Notes by Broker-Dealers that tendered in the Exchange Offer Notes that such Broker-Dealer acquired for its own account as a result of its market-making activities or other trading activities (other than Notes acquired directly from the Company or any of its Affiliates) being sold in accordance with the intended method or methods of distribution thereof, and (z) comply with all of the following provisions:

•         (i)    As a condition to its participation in the Exchange Offer, each Holder of Transfer Restricted Securities (including, without limitation, any Holder who is a Broker-Dealer) shall furnish, upon the request of the Company, prior to the Consummation of the Exchange Offer, a written representation to the Company (which may be contained in the letter of transmittal contemplated by the Exchange Offer Registration Statement) to the effect that (A) it is not an

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• Affiliate of the Company, (B) it is not engaged in, and does not intend to engage in, and has no arrangement or understanding with any person to participate in, a distribution of the Series B Notes to be issued in the Exchange Offer and (C) it is acquiring the Series B Notes in its ordinary course of business. As a condition to its participation in the Exchange Offer each Holder using the Exchange Offer to participate in a distribution of the Series B Notes shall acknowledge and agree that, if the resales are of Series B Notes obtained by such Holder in exchange for Notes acquired directly from the Company or an Affiliate thereof, it (1) could not, under Commission policy as in effect on the date of this Agreement, rely on the position of the Commission enunciated in Morgan Stanley and Co., Inc . (available June 5, 1991) and Exxon Capital Holdings Corporation (available May 13, 1988), as interpreted in the Commission's letter to Shearman & Sterling dated July 2, 1993, and similar no-action letters and (2) must comply with the registration and prospectus delivery requirements of the Act in connection with a secondary resale transaction and that such a secondary resale transaction must be covered by an effective registration statement containing the selling security holder information required by Item 507 or 508, as applicable, of Regulation S-K.

          (ii)   Prior to effectiveness of the Exchange Offer Registration Statement, if the Commission so requests, the Company shall provide a supplemental letter to the Commission (A) stating that the Company is registering the Exchange Offer in reliance on the position of the Commission enunciated in Exxon Capital Holdings Corporation (available May 13, 1988), Morgan Stanley and Co., Inc . (available June 5, 1991) as interpreted in the Commission's letter to Shearman & Sterling dated July 2, 1993 and (B) including a representation that the Company has not entered into any arrangement or understanding with any Person to distribute the Series B Notes to be received in the Exchange Offer and that, to the best of the Company's information and belief, each Holder participating in the Exchange Offer is acquiring the Series B Notes in its ordinary course of business and has no arrangement or understanding with any Person to participate in the distribution of the Series B Notes received in the Exchange Offer.

        (b)     Shelf Registration Statement .    

•         (i)    In connection with the Shelf Registration Statement, the Company shall comply with all applicable provisions of Section 6(c) below and use its commercially reasonable efforts to effect such registration to permit the sale of the Transfer Restricted Securities being sold in accordance with the intended method or methods of distribution thereof (as indicated in the information furnished to the Company pursuant to Section 4(b) hereof), and pursuant thereto the Company will prepare and file with the Commission a Registration Statement relating to the registration on any appropriate form under the Act, which form shall be available for the sale of the Transfer Restricted Securities in accordance with the intended method or methods of distribution thereof within the time periods and otherwise in accordance with the provisions hereof, and

          (ii)   issue, upon the request of any Holder or purchaser of Notes covered by any Shelf Registration Statement contemplated by this Agreement, Series B Notes having an aggregate principal amount equal to the aggregate principal amount of Notes sold pursuant to the Shelf Registration Statement and surrendered to the Company for cancellation; the Company shall register Series B Notes on the Shelf Registration Statement for this purpose and issue the Series B Notes to the purchaser(s) of securities subject to the Shelf Registration Statement in the names such purchaser(s) shall designate.

        (c)     General Provisions .    In connection with any Registration Statement and any related Prospectus required by this Agreement, the Company shall:

•         (i)    use its commercially reasonable efforts to keep such Registration Statement continuously effective and provide all requisite financial statements for the per