FORBEARANCE AGREEMENT

Exhibit 10.73

FORBEARANCE AGREEMENT

(Citicorp Vendor Finance, Inc.)

This Forbearance Agreement (the “Agreement ”), dated as of July 12, 2005 is by and between Citicorp Vendor Finance, Inc. (“ Lessor ”) and Molecular Imaging Corporation f/k/a Mobile PET Systems, Inc. (“ Molecular ”). Reference is made to the Master Lease Agreement No: 200079634 dated January 2003 regarding an ECAT Exact 47 PET Imaging System and Chevrolet Truck, VIN 1GBM7C1CXXJ106794 (with addendums, amendments and schedules thereto collectively, the “ Lease” ). Terms used herein and otherwise not defined herein shall have the meanings ascribed thereto in the Lease.

WHEREAS, Molecular is in default of its respective obligations under the Lease for failure to make certain payments when due (the “ Existing Default ”) and Molecular acknowledges said Existing Default; and

WHEREAS, Molecular has not cured the Existing Default; and

WHEREAS, Lessor has accelerated all amounts due and owing to Lessor under the Lease and has made demand for the return of the Equipment subject to the Lease; and

WHEREAS, Molecular acknowledges all of the foregoing, and that the Existing Default remains outstanding; and

WHEREAS, Lessor is willing to forebear only as expressly provided herein in the exercise and enforcement of such rights, powers and remedies only upon compliance and fulfillment by Molecular of the terms and conditions set forth herein.

NOW, THEREFORE, in consideration of the terms and conditions contained herein and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows:

1. CURRENT ARREARAGE UNDER THE LEASE

1.1 Molecular hereby acknowledges, confirms and agrees that, through and including the date of this Agreement, the amount of $533,332.95 is currently past due and owing to Lessor pursuant to the Lease.

1.2 Molecular hereby acknowledges, confirms and agrees that as of the date hereof, the Lease is in full force and effect and represents the valid, legal and binding obligations of Molecular to Lessor.

2. FORBEARANCE

2.1 Lessor hereby agrees to forbear from exercising and enforcing its rights, powers and remedies under the Lease or now existing at law or in equity or by statute with respect to the Event of Default set forth above, provided that Molecular shall comply with and fulfill each of the following terms and conditions:

2.2 Molecular agrees that any breach or default under this Agreement by Molecular will also constitute an Event of Default under the Lease and that any Event of Default (other than the failure to make the full lease payment under the Lease during the forbearance period) under the Lease shall constitute a default hereunder. Molecular hereby waives all notices and cure periods which may be provided for under the Lease and agrees that Lessor shall be immediately entitled to all relief afforded to Lessor thereunder. Notwithstanding anything to the contrary, Lessor shall give five (5) business days written notice to Molecular at the address provided for under the Lease of any occurrence of a default under this Agreement and an opportunity to cure such default without acceleration during such five (5) day period.

2.3 Lessor’ forbearance is further expressly subject to and conditioned upon Molecular’s strict compliance with each and every term and provision of this Agreement and the Lease as modified under this Agreement.

2.4 Upon the breach by Molecular of any provision of this Agreement or any Event of Default under the Lease (other than the failure to make the full lease payment under the Lease during the forbearance period), Lessor, at its option, may withdraw its forbearance hereunder. Lessor shall promptly advise Molecular of any such withdrawal, and until all of the indebtedness (including any accelerated late charges) to Lessor have been paid in full, Lessor shall have the undisputed and absolute right to ex