**Exhibit4.3**

 

**SUPPLEMENTALINDENTURE**

 

Supplemental Indenture (this “*Supplemental Indenture*”), dated as ofApril 2, 2003, among Valencia MRI, LLC, a California limited liability company(“*Valencia*”), Orange CountyRegional PET Center – Irvine, LLC, a California limited liability company (“*Orange County*”), and San Fernando ValleyRegional PET Center, LLC, a California limited liability company (together withValencia and Orange County, each a “*GuaranteeingSubsidiary*” and collectively, the “*GuaranteeingSubsidiaries*”), InSight Health Services Corp., a Delawarecorporation (the “*Company*”),InSight Health Services Holdings Corp., the Subsidiary Guarantors (as definedin the Indenture referred to herein) and U.S. Bank Trust National Association(formerly known as State Street Bank and Trust Company, N.A.), as trustee underthe Indenture referred to below (the “*Trustee*”).

 

W I T N E S S E T H

 

WHEREAS, the Company has heretofore executed anddelivered to the Trustee an indenture (the “Indenture”), dated as of October 30,2001 providing for the issuance of an aggregate principal amount of$225 million of 9 7/8% Senior Subordinated Notes due 2011 (the “Notes”);

 

WHEREAS, the Indenture provides that under certaincircumstances each Guaranteeing Subsidiary shall execute and deliver to theTrustee a supplemental indenture pursuant to which such Guaranteeing Subsidiaryshall unconditionally guarantee all of the Company’s obligations under theNotes and the Indenture on the terms and conditions set forth herein (the“Guarantee”); and

 

WHEREAS, pursuant to Section 9.01 of theIndenture, the Trustee is authorized to execute and deliver this SupplementalIndenture.

 

NOW THEREFORE, in consideration of the foregoing andfor other good and valuable consideration, the receipt of which is herebyacknowledged, each Guaranteeing Subsidiary and the Trustee mutually covenantand agree for the equal and ratable benefit of the Holders of the Notes asfollows:

 

# 1.                                       CapitalizedTerms.  Capitalized terms usedherein without definition shall have the meanings assigned to them in theIndenture.

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# 2.                                       Agreementto Guarantee.  Each GuaranteeingSubsidiary hereby agrees as follows:

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## (a)                                  Alongwith all other Guarantors, to jointly and severally Guarantee to each Holder ofa Note authenticated and delivered by the Trustee and to the Trustee and itssuccessors and assigns, irrespective of the validity and enforceability of theIndenture, the Notes or the obligations of the Company hereunder or thereunder,that:

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(i)                                     theprincipal of and interest on the Notes will be promptly paid in full when due,whether at maturity, by acceleration, redemption or otherwise, and interest onthe overdue principal of and interest on the Notes, if any, if lawful, and allother obligations of the Company to the Holders or

 

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#### the Trustee hereunder or thereunder will be promptlypaid in full or performed, all in accordance with the terms hereof and thereof;and

 

(ii)                                  incase of any extension of time of payment or renewal of any Notes or any of suchother obligations, the same will be promptly paid in full when due or performedin accordance with the terms of the extension or renewal, whether at statedmaturity, by acceleration or otherwise. Failing payment when due of any amount so guaranteed or any performanceso guaranteed for whatever reason, the Guarantors shall be jointly andseverally obligated to pay the same immediately.

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## (b)                                 Theobligations hereunder shall be unconditional, irrespective of the validity,regularity or enforceability of the Notes or the Indenture, the absence of anyaction to enforce the same, any waiver or consent by any Holder of the Noteswith respect to any provisions hereof or thereof, the recovery of any judgmentagainst the Company, any action to enforce the same or any other circumstancethat might otherwise constitute a legal or equitable discharge or defense of aguarantor.

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## (c)                                  Thefollowing are hereby waived:  diligence,presentment, demand of payment, filing of claims with a court in the event ofinsolvency or bankruptcy of the Company, any right to require a proceedingfirst against the Company, protest, notice and all demands whatsoever.

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## (d)                                 ThisGuarantee shall not be discharged except by complete performance of theobligations contained in the Notes and the Indenture.

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## (e)                                  Ifany Holder or the Trustee is required by any court or otherwise to return tothe Company, the Guarantors, or any Custodian, Trustee, liquidator or othersimilar official acting in relation to either the Company or the Guarantors,any amount paid by either to the Trustee or such Holder, this Guarantee, to theextent theretofore discharged, shall be reinstated in full force and effect.

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## (f)                                    SuchGuaranteeing Subsidiary shall not be entitled to any right of subrogation in relationto the Holders in respect of any obligations guaranteed hereby until payment infull of all obligations guaranteed hereby.

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## (g)                                 Asbetween the Guarantors, on the one hand, and the Holders and the Trustee, onthe other hand, (x) the maturity of the obligations guaranteed hereby maybe accelerated as provided in Article Six of the Indenture for thepurposes of this Guarantee, notwithstanding any stay, injunction or otherprohibition preventing such acceleration in respect of the obligations guaranteedhereby, and (y) in the event of any declaration of acceleration of suchobligations as provided in Article Six of the Indenture, such obligations(whether or not due and payable) shall forthwith become due and payable by theGuarantors for the purpose of this Guarantee.

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## (h)                                 Pursuantto Section 10.02 of the Indenture, after giving effect to any maximumamount and any other contingent and fixed liabilities that are relevant underany applicable Bankruptcy or fraudulent conveyance laws, and after giving effectto any collections from, rights to receive contribution from or payments madeby or on behalf of any other Guarantor in respect of the obligations of suchother Guarantor under Article Ten of the Indenture, the obligations ofsuch

 

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Guarantor under its Guarantee shall not constitute a fraudulenttransfer or conveyance.

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# 3.                                       Subordination.  The Obligations of each GuaranteeingSubsidiary under its Guarantee pursuant to this Supplemental Indenture shall bejunior and subordinated to the Senior Indebtedness of such GuaranteeingSubsidiary on the same basis as the Notes are junior and subordinated to theSenior Indebtedness of the Company.  Forthe purposes of the foregoing sentence, the Trustee and the Holders shall havethe right to receive and/or retain payments by each Guaranteeing Subsidiaryonly at such time as they may receive and/or retain payments in respect of theNotes pursuant to the Indenture, including Article Ten hereof.

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# 4.                                       Executionand Delivery.  Each GuaranteeingSubsidiary agrees that the Guarantees shall remain in full force and effectnotwithstanding any failure to endorse on each Note a notation of suchGuarantee.

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# 5.                                       GuaranteeingSubsidiaries May Consolidate, Etc., on Certain Terms.

 

Except as otherwise provided in Section 11.05 ofthe Indenture, a Subsidiary Guarantor may not consolidate with or merge with orinto any other Person or convey, sell, assign, transfer, lease or otherwisedispose of its properties and assets substantially as an entirety to any otherPerson (other than the Company or another Subsidiary Guarantor) unless:

 

(i)                                     subjectto the provisions of the following paragraph, the Person formed by or survivingsuch consolidation or merger (if other than such Subsidiary Guarantor) or towhich such properties and assets are transferred assumes all of the obligationsof such Subsidiary Guarantor under the Indenture and its Guarantee, pursuant toa supplemental indenture in form and substance satisfactory to the Trustee;

 

(ii)                                  immediatelyafter giving effect to such transaction, no Default or Event of Default hasoccurred and is continuing; and

 

(iii)                               theSubsidiary Guarantor delivers, or causes to be delivered, to the Trustee, inform and substance reasonably satisfactory to the Trustee, an Officers’Certificate and an Opinion of Counsel, each stating that such transactioncomplies with the requirements of the Indenture.

 

For purposes of the foregoing, the transfer (by lease,assignment, sale or otherwise, in a single transaction or series oftransactions) of all or substantially all of the properties or assets of one ormore Restricted Subsidiaries, the Capital Stock of which constitutes all orsubstantially all of the properties and assets of the Company, shall be deemedto be the transfer of all or substantially all of the properties and assets ofthe Company.

 

In case of any such consolidation, merger, sale orconveyance and upon the assumption by the successor Person, by supplementalindenture, executed and delivered to the Trustee and reasonably satisfactory inform to the Trustee, of the Guarantee endorsed upon the Notes and the due andpunctual performance of all of the covenants and conditions of the Indenture tobe performed by a Guarantor, such successor Person shall succeed to and besubstituted for a Guarantor with the same effect as if it had been named hereinas a Guarantor.  Such successor Personthereupon may cause to be signed any or all of the Guarantees to be

 

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endorsed upon all of the Notes issuable hereunder which theretoforeshall not have been signed by the Company and delivered to the Trustee.  All the Guarantees so issued shall in allrespects have the same legal rank and benefit under the Indenture as the Guaranteestheretofore and thereafter issued in accordance with the terms of the Indentureas though all of such Guarantees had been issued at the date of executionhereof.

 

# 6.                                       Releases.

 

### (a)                                  ASubsidiary Guarantor will be deemed automatically and unconditionally releasedand discharged from all of its obligations under its Guarantee without anyfurther action on the part of the Trustee or any Holder of the Notes upon asale or other disposition to a Person not an Affiliate of the Company of all ofthe Capital Stock of, or all or substantially all of the assets of, suchSubsidiary Guarantor, by way of merger, consolidation or otherwise, whichtransaction is carried out in accordance with Section 4.10 of theIndenture; *provided* that any suchtermination shall occur (x) only to the extent that all obligations ofsuch Subsidiary Guarantor under all of its guarantees of, and under all of itspledges of assets or other security interests which secure any Indebtedness ofthe Company shall also terminate upon such sale, disposition or release and(y) only if the Trustee is furnished with written notice of such releasetogether with an Officers’ Certificate from such Subsidiary Guarantor to theeffect that all of the conditions to release in this Section 6 have beensatisfied.

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### (b)                                 AnyGuarantor not released from its obligations under its Guarantee shall remainliable for the full amount of principal of and interest on the Notes and forthe other obligations of any Guarantor under the Indenture as provided inArticle Eleven of the Indenture.

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# 7.                                       NoRecourse Against Others.  Nodirector, officer, employee, incorporator or stockholder of the Parent, theCompany or any Subsidiary Guarantor, as such shall have any liability for anyobligations of the Parent, the Company or the Subsidiary Guarantors under theNotes, the Indenture, the Guarantees or for any claim based on, in respect of,or by reason of, such obligations or their creation.  Each Holder of Notes, by accepting a Note, waives and releasesall such liability.  The waiver andrelease are part of the consideration for issuance of the notes.  The waiver may not be effective to waiveliabilities under the federal securities laws.

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# 8.                                       NEWYORK LAW TO GOVERN.  THE INTERNALLAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE THISSUPPLEMENTAL INDENTURE BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OFCONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHERJURISDICTION WOULD BE REQUIRED THEREBY.

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# 9.                                       Counterparts.  The parties may sign any number of copies ofthis Supplemental Indenture.  Eachsigned copy shall be an original, but all of them together represent the sameagreement.

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# 10.                                 Effectof Headings.  The Section headingsherein are for convenience only and shall not affect the construction hereof.

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# 11.                                 Trustee.  The Trustee shall not be responsible in anymanner whatsoever for or in respect of the

 

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validity or sufficiency of this Supplemental Indenture or for or inrespect of the recitals contained herein, all of which recitals are made solelyby each Guaranteeing Subsidiary and the Company.

 

[Remainder of Page LeftIntentionally Blank]

 

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# IN WITNESSWHEREOF, the parties hereto have caused this Supplemental Indenture to be dulyexecuted and attested, all as of the date first above written.

 

Dated:  April 2, 2003

 

 
|   | VALENCIA MRI, LLC                                                 |
|--------|-------------------------------------------------------------------|
|   | By: InSight Health Corp., its sole member and  manager            |
|   |                                                              |
|   |                                                              |
|   | By:                                                               | /s/ Steven T. Plochocki |   |
|   |                                                              | Name:  Steven  T. Plochocki |
|   |                                                              | Title:   President & CEO |
|   |                                                              |
|   |                                                              |
|   | ORANGE COUNTY REGIONAL PET  CENTER – IRVINE, LLC             |
|   | By: InSight Health Corp., its sole member and  manager            |
|   |                                                              |
|   |                                                              |
|   | By:                                                               | /s/ Steven T. Plochocki |   |
|   |                                                              | Name:  Steven  T. Plochocki |
|   |                                                              | Title:   President & CEO |
|   |                                                              |
|   |                                                              |
|   | SAN FERNANDO VALLEY REGIONAL  PET CENTER, LLC                     |
|   | By:  InSight Health Corp., its sole member  and manager |
|   |                                                              |
|   |                                                              |
|   | By:                                                               | /s/ Steven T. Plochocki |   |
|   |                                                              | Name:  Steven  T. Plochocki |
|   |                                                              | Title:   President & CEO |
|   |                                                              |
|   |                                                              |
|   | INSIGHT HEALTH SERVICES CORP.                                     |
|   |                                                              |
|   |                                                              |
|   | By:                                                               | /s/ Steven T. Plochocki |   |
|   |                                                              | Name:  Steven  T. Plochocki |
|   |                                                              | Title:   President & CEO |

 

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|   | INSIGHT HEALTH SERVICES HOLDINGS CORP. |
|--------|----------------------------------------|
|   |                                   |
|   |                                   |
|   | By:                                    | /s/ Steven T. Plochocki |   |
|   |                                   | Name:  Steven  T. Plochocki |
|   |                                   | Title:   President & CEO |
|   |                                   |
|   |                                   |
|   | INSIGHT HEALTH CORP.                   |
|   |                                   |
|   |                                   |
|   | By:                                    | /s/ Steven T. Plochocki |   |
|   |                                   | Name:  Steven  T. Plochocki |
|   |                                   | Title:   President & CEO |
|   |                                   |
|   |                                   |
|   | SIGNAL MEDICAL SERVICES, INC.          |
|   |                                   |
|   |                                   |
|   | By:                                    | /s/ Steven T. Plochocki |   |
|   |                                   | Name:  Steven  T. Plochocki |
|   |                                   | Title:   President & CEO |
|   |                                   |
|   |                                   |
|   | OPEN MRI, INC.                         |
|   |                                   |
|   |                                   |
|   | By:                                    | /s/ Steven T. Plochocki |   |
|   |                                   | Name:  Steven  T. Plochocki |
|   |                                   | Title:   President & CEO |
|   |                                   |
|   |                                   |
|   | MAXUM HEALTH CORP.                     |
|   |                                   |
|   |                                   |
|   | By:                                    | /s/ Steven T. Plochocki |   |
|   |                                   | Name:  Steven  T. Plochocki |
|   |                                   | Title:   President & CEO |

 

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|   | RADIOSURGERY CENTERS, INC.                           |
|--------|------------------------------------------------------|
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |
|   |                                                 |
|   |                                                 |
|   | MAXUM HEALTH SERVICES CORP.                          |
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |
|   |                                                 |
|   |                                                 |
|   | MRI ASSOCIATES, L.P.                                 |
|   | By:  InSight  Health Corp., its general partner |
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |
|   |                                                 |
|   |                                                 |
|   | MAXUM HEALTH SERVICES OF NORTH TEXAS, INC.           |
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |
|   |                                                 |
|   |                                                 |
|   | MAXUM HEALTH SERVICES OF DALLAS, INC.                |
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |
|   |                                                 |
|   |                                                 |
|   | NDDC, INC.                                           |
|   |                                                 |
|   |                                                 |
|   | By:                                                  | /s/ Steven T. Plochocki |   |
|   |                                                 | Name:  Steven  T. Plochocki |
|   |                                                 | Title:   President & CEO |

 

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|   | DIAGNOSTIC SOLUTIONS CORP.                                                                                                                        |
|--------|---------------------------------------------------------------------------------------------------------------------------------------------------|
|   |                                                                                                                                              |
|   |                                                                                                                                              |
|   | By:                                                                                                                                               | /s/ Steven T. Plochocki |   |
|   |                                                                                                                                              | Name:  Steven  T. Plochocki |
|   |                                                                                                                                              | Title:  President  & CEO |
|   |                                                                                                                                              |
|   |                                                                                                                                              |
|   | WILKES-BARRE IMAGING, LLC                                                                                                                         |
|   | By:                InSight Health  Corp., its sole member  and manager |
|   |                                                                                                                                              |
|   |                                                                                                                                              |
|   | By:                                                                                                                                               | /s/ Steven T. Plochocki |   |
|   |                                                                                                                                              | Name:  Steven  T. Plochocki |
|   |                                                                                                                                              | Title:   President & CEO |
|   |                                                                                                                                              |
|   |                                                                                                                                              |
|   | U.S. BANK TRUST NATIONAL  ASSOCIATION (formerly known as State  Street Bank and Trust Company, N.A.), as  Trustee                                 |
|   |                                                                                                                                              |
|   |                                                                                                                                              |
|   | By:                                                                                                                                               | /s/ Cheryl L. Clarke |   |
|   |                                                                                                                                              | Name: Cheryl Louisa Clarke |
|   |                                                                                                                                              | Title: Trust Officer |
|        |                                                                                                                                                   |  |  |  |

 

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