EXHIBIT 10.4


                               SUBLEASE AGREEMENT

     Toshiba America MRI, Inc. ("TAMI"), located at 280 Utah Ave, South San
Francisco, CA, and AccuImage Diagnostics Corporation ("TENANT"), located at 400
Oyster Point Blvd., Suite 114, South San Francisco, CA hereby agree as follows:

1.   SUBLEASE. TAMI hereby subleases to TENANT approximately 7,430 square feet
     (the "Premises") of the space leased by TAMI at 400 Grandview Drive, South
     San Francisco, CA, under the Lease Agreement ("Lease Agreement") entered
     into between TAMI and Bedford property Investors, Inc. ("Landlord"). The
     Lease Agreement is attached hereto and by this reference is deemed
     incorporated into this Sublease Agreement. The Premises is identified on
     the attached "Exhibit A".

2.   NO WARRANTIES. TAMI subleases the Premises to TENANT AS IS, without any
     warranties whatsoever concerning the condition of the Premises or the
     suitability of the same for TENANT's purposes.

3.   TERM. The term of this Sublease Agreement will begin on June 20, 2001 and
     end on December 31, 2003. However, TAMI may terminate this Sublease
     Agreement immediately at any time during its term should TENANT breach any
     of the terms and conditions specified in the Sublease Agreement. TAMI may
     also avail itself of any other remedies provided under the law.

4.   RENTAL. The monthly rental to be paid by TENANT will be as follows:

          June 20, 2001 through June 30, 2001              $2279.00
          July 1, 2001 through December 31. 2001           $6836.00
          January 1, 2002 through December 31, 2002        $7133.00
          January 1, 2003 through December 31, 2003        $7579.00

     The first installment of rent ($2,279.00) shall be paid upon execution of
     this Sublease Agreement. Future installments will be paid in advance no
     later than the first day of each month throughout the term of this Sublease
     Agreement at the following address (or any other to be designated by TAMI):

     TOSHIBA AMERICA MRI, INC.
     2441 Michelle Drive
     Tustin, California 92680
     Attention:  Keith Wilford

     All rentals paid after due date will be assessed a late payment charge of
     the lesser of 1 1/2% per month or the maximum rate permitted by law. TAMI
     may require TENANT to pay the rent quarterly, in advance, if TENANT tenders
     late rent payments on three (3) or more occasions during the sublease term.
     Should TAMI take such action, it does not constitute a waiver of any other
     rights or remedies TAMI may have regarding late or nonpayment of rent by
     TENANT.

<PAGE>


5.   OPERATING EXPENSES AND TAXES. In addition to the rentals specified above,
     TENANT is to pay all Operating Expenses, utility and maintenance costs, as
     the same is defined in the Lease Agreement or as may otherwise be required
     to properly maintain the facility, and real property taxes and assessments,
     as required under the Lease Agreement. TENANT shall be responsible for
     payment of all its personal property taxes without regard to any base year.

6.   UTILITIES. TENANT shall pay for all utilities separately metered for the
     Premises.

7.   PARKING. TENANT may use all parking and shall pay for the same to the
     extent specified in the Lease Agreement.

8.   SECURITY DEPOSIT. Upon execution of this Sublease Agreement, TENANT is to
     pay TAMI the sum of $6,836.00 (six thousand, eight hundred thirty six
     dollars), to be used as security deposit for the performance of TENANT's
     obligations under this Sublease Agreement including, without limitation,
     the surrender of possession of the Premises to TAMI upon expiration of the
     term of this Sublease Agreement. It is expressly understood and agreed that
     such deposit is not an advance rental deposit or a measure of TAMI's
     damages in case of TENANT's default. If TAMI applies any part of the
     security deposit to cure any default of TENANT, TENANT will, upon demand,
     deposit with TAMI the amount so applied so that TAMI will have the full
     deposit on hand at all times during the term of this Sublease Agreement. No
     interest will be due on the security deposit and TAMI will not be obligated
     to apply the security deposit to rents or other charges in arrears or to
     damages for TENANT's failure to perform under this Sublease Agreement.
     However, TAMI may so apply the security deposit at TAMI's option, and
     TAMI's right to possession of the Premises for nonpayment of rent or for
     any other reason will not in any way be affected by reason of the fact that
     TAMI holds such security deposit.

     Based on the obligations set forth in Section 4 and this Section 8,
     Tenant's payment obligation upon execution of this sublease shall be
     $9,115.00 (nine thousand one hundred fifteen dollars).

9.   TENANT IMPROVEMENTS. TAMI will pay for the actual cost of improvements to
     the Premises, up to a maximum amount not to exceed twenty-five thousand
     dollars ($25,000). The cost of any improvements in excess of $25,000 will
     he borne by Tenant. All such improvements must be good quality and
     workmanship, and must be made under the terms specified in the Master
     Lease. Tenant is responsible for securing any permits or other approvals
     required for such improvement. Tenant must repay to TAMI a prorated share
     of the amounts for these improvements based on the actual number of months
     the Tenant occupies the space if this lease terminates prior to December
     31, 2003 due to a default by Tenant.

10.  FINANCIAL INFORMATION. TENANT will provide TAMI with all financial
     information reasonably requested by TAMI from time to time to determine
     TENANT's ability to comply with its obligations under this Sublease
     Agreement.

                                      -2-
<PAGE>


11.  ASSUMPTION. OF OBLIGATIONS. TENANT agrees to fully perform all of the
     obligations of TAMI (except TAMI's obligation to pay rent, and except as
     otherwise specified in this Sublease Agreement) under the terms of the
     Lease Agreement with respect to the Premises and to accord TAMI all of the
     rights, privileges, and indemnities with respect to and from TAMI to
     Landlord under the Lease Agreement and agrees that all of the terms and
     conditions of the Lease Agreement are hereby incorporated in this Sublease
     Agreement, including, without limitation, the obligation to maintain and
     repair the Premises.

12.  INDEMNIFICATION. TENANT will defend, indemnify, and hold TAMI harmless from
     all claims, damages, liabilities, and costs (including attorney's fees)
     arising out of TENANTS failure to comply with its obligations under this
     Sublease Agreement or otherwise arising out of TENANT'S occupancy of the
     Premises, including, without limitation, any claim made by the Landlord.

13.  ATTORNEY'S FEES. In the event of any legal proceeding involving any party
     to this Sublease Agreement against the other relating to the subject matter
     of this Sublease Agreement, the prevailing party in such proceeding will be
     entitled to recover attorney's fees, expert fees, and court costs against
     the non-prevailing party.

14.  ENTIRE AGREEMENT; MODIFICATION. This Agreement and its attachments contain
     the entire agreement and understanding between the parties relating to its
     subject matter. It supersedes all prior agreements and understandings,
     whether oral or written, relating to such subject matter. It also
     supersedes all standard terms and conditions on any form to be exchanged
     between the parties, including, invoice, purchase order, order
     acknowledgment quotation and delivery documents. This Agreement may not be
     amended or modified in any manner except by means of a writing executed by
     all parties.

TOSHIBA AMERICA MRI, INC.                      ACCUIMAGE DIAGNOSTICS CORPORATION


By:    /s/ FREDRIC J. FRIEDBERG                By:    /s/ LEON KAUFMAN
       ------------------------                       ------------------------
       Fredric J. Friedberg                           Leon Kaufman
       Senior Vice President                          CEO

Dated: 5/25/01                                 Dated: 5/24/01
       ------------------------                       ------------------------

                                      -3-