<PAGE>   1
                                                            Exhibit 10.3

                              EMPLOYMENT AGREEMENT

         THIS EMPLOYMENT AGREEMENT is entered into as of the 12th day of July,
2001 by and between Alliance Medical Corporation, a Delaware corporation (the
"Company"), and Ricardo M. Ferreira ("Employee").

         WHEREAS, Employee currently serves as President and Chief Executive
Officer of the Company; and

         WHEREAS, the parties hereto desire that an employment relationship
continue between the Company and Employee subject to and upon the terms and
conditions contained herein.

         NOW THEREFORE, in consideration of the promises, covenants and
conditions herein contained, the parties mutually agree as follows:

         1. ENGAGEMENT: The Company hereby engages Employee to provide, and
Employee agrees to perform, for a term commencing as of July 12, 2001, and
continuing until terminated as provided in Section 7 hereof, those services that
are described in Section 4 hereof.

         2. COMPENSATION: The Company agrees to pay Employee, and Employee
agrees to accept as full compensation for the performance and furnishing of
services herein, the sum of $16,250 per month (or pro rata portion thereof for
any partial month), to be payable bi-weekly in arrears on the same day that the
Company pays its employees. In addition to the above, Employee will receive an
auto reimbursement of $500 per month.

         3. REPRESENTATIONS AND WARRANTIES - EMPLOYEE:

         (a) Employee has not filed a registration statement or been named as an
underwriter in connection with any registration or offering statement which is
the subject of any pending Securities and Exchange Commission ("SEC") proceeding
or examination under Section 8 of, or Rule 261 under, the Securities Act of
1933, as amended, or which is the subject of a currently effective refusal order
entered by the SEC or stop order entered pursuant to a law of any state of the
United States of America or province of Canada within the last five (5) years.

         (b) Employee has not been convicted of a misdemeanor or felony within
the last ten (10) years in connection with the offer, purchase or sale of any
security or commodity, involving the making of a false filing with the SEC, or
arising out of the conduct of the business of an underwriter, broker, dealer,
municipal securities dealer or investment advisor, or involving theft, fraud,
breach of fiduciary duty, deceit or intentional wrong doing, or which is a crime
involving moral turpitude, or, within the last five (5) years, of a misdemeanor
or felony which is a criminal violation of statutes designed to protect
consumers against unlawful practices involving insurance, securities,
commodities or of commodity futures, real estate, franchises, business
opportunities, consumer goods or other goods and services.

         (c) Employee is not currently subject to any administrative order or
judgment entered within the last five (5) years arising out of the conduct of
the business of an underwriter, broker, dealer, municipal securities dealer or
investment advisor, or involving theft, fraud or fraudulent conduct, or breach
of fiduciary duty, or been the subject of, or subject to, any administrative

                                      -1-
<PAGE>   2
order or judgment in which fraud, deceit or intentional wrong doing, including
but not limited to making untrue statements of material facts or omitting to
state material facts, was found and the order or judgment was entered within
five (5) years prior hereto.

         (d) Employee is not currently subject to any administrative order or
judgment which prohibits the use of any exemption from registration in
connection with the purchase or sale of securities, or to an SEC censure or
other order based on a finding of a false filing.

         (e) Employee is not subject to any administrative order, order,
judgment or decree of any court of competent jurisdiction temporarily or
preliminarily restraining or enjoining, and is not subject to any order,
judgment or decree of any court of competent jurisdiction entered within the
last five (5) years permanently restraining or enjoining Employee from engaging
in or continuing any conduct or practice in connection with the purchase or sale
of any security or commodity or involving the making of any false filing with
the SEC or any state of the United States of America or province of Canada or
arising out of the conduct of the business of an underwriter, broker, dealer,
municipal securities dealer or investment advisor, or which restrains or enjoins
Employee from activities subject to federal, Canadian or state or provincial
statutes designed to protect consumers against unlawful or deceptive practices
involving insurance, commodities or commodity futures, real estate, franchises,
business opportunities, consumer goods or other goods and services.

         (f) Employee has never been suspended or expelled from membership in,
or suspended or barred from association with a member of, an exchange registered
as a national securities exchange, an association registered as a national
securities association or a Canadian securities exchange or association.

         (g) Employee will immediately advise the Company of any change in any
of the foregoing representations or warranties.

         4. DUTIES: Employee, subject to the direction and control of the Board
of Directors, shall devote substantially his full time, attention and energies
to the business and affairs, and to promote the welfare and best interests, of
the Company; Employee shall perform, to the best of his abilities as the
President and Chief Executive Officer of the Company and shall perform those
duties normally performed by that position in a company such as the Company,
together with those duties from time to time assigned him by the Board of
Directors of the Company. It is specifically understood and agreed that
Employee, in performing his duties hereunder, shall be required to devote
substantially all of his time and attention to the business and affairs of the
Company, and, in so doing, shall be required to spend all of his time at the
Company's principal offices in Arizona, subject to travel necessitated by his
position.

         5. DEDUCTION AND WITHHOLDING: Reimbursement. There shall be deducted
from all compensation paid to Employee such sums, including, without limitation,
social security, income tax withholding and unemployment insurance, as by law
the Company is obligated to do. Upon furnishing the Company with paper vouchers
and expense accounts setting forth the information required by the United States
Treasury Department for deductible business expenses, Employee shall be promptly
reimbursed for those of his expenses which have been approved in advance by the
Company.

                                      -2-
<PAGE>   3

         6. VACATION: Employee will be entitled to four (4) weeks paid vacation
annually.

         7. TERMINATION: This Agreement shall run for a period of three years
from July 12, 2001, through July 11, 2004, subject to prior termination upon the
first to occur of any of the following events:

         (a) In the event that Employee shall habitually neglect his employment
duties, then the Company shall provide Employee with a notice thereof which
describes its charges with respect thereto. If the Employee fails to remedy the
habitually neglectful behavior charged within thirty (30) calendar days
following the giving of the above described notice, then Employee shall be
notified by the Company of such failure within five (5) calendar days after such
thirty (30) day period, and this Agreement may be terminated five (5) calendar
days after receipt of such notice. If no such notice is given within the said
five (5) day period, any alleged neglect or other problem will be deemed
resolved;

         (b) At the option of the Company, in its sole and absolute discretion,
immediately upon notice to Employee of the occurrence of any one of the
following events;

             (i) The willful breach of duty by the Employee in the course of his
employment, which breach results in material injury to the Company, unless
waived by the Company, provided that the Company shall in the case of any such
termination, include in its notice of termination a description of the breach of
duty involved and of the material injury resulting therefrom;

             (ii) Employee's conviction of a felony.

         (c) Employee's death, disability for more than six (6) consecutive
weeks, or resignation;

         (d) The Company's material breach of its obligations hereunder or its
termination of Employee other than pursuant to paragraphs (a) or (b), above; or

         (e) The mutual agreement of the parties to terminate.

         (f) If the Company terminates the employment of Employee during the
Employment Period other than pursuant to Section 7(a) or 7(b), then the Company
shall pay to Employee any portion of his annual base salary which has been
accrued but not paid as of the termination date ("Accrued Salary"). In addition,
the Company shall pay Employee (i) an amount equal to Employee's base salary for
the six-month period immediately preceding Employee's termination of employment,
and (ii) an amount equal to Employee's monthly base salary then in effect for
each year of Employee's employment by the Company from March 1, 1998, through
the date of termination, including any prorated amounts. Such amounts shall be
paid according to the Company's payroll practices over the 3-month period
immediately following Employee's termination of employment.

         (g) If Employee's employment is terminated pursuant to Section 7(a) or
7(b), the Company shall not be obligated to pay any severance benefits to
Employee; provided, however, that the Company shall pay to Employee his Accrued
Salary and provide Employee with the

                                      -3-
<PAGE>   4
ability to elect to receive COBRA coverage with such COBRA premiums to be paid
by Employee during the applicable "period of coverage" as defined in Section
4980(f)(2)(B) of the Code.

         (h) In the event of Employee's death, the Company shall be obligated
within thirty (30) days thereafter to pay to Employee's estate (i) all Accrued
Salary, (ii) an amount equal to Employee's base salary for the six-month period
immediately preceding Employee's demise, and (iii) an amount equal to Employee's
monthly base salary then in effect for each year of Employee's employment by the
Company from March 1, 1998, through the date of demise, including any prorated
amounts. The Company shall have the right to terminate Employee's employment
upon sixty (60) days prior written notice in the event of Employee's total
disability. In the event of Employee's termination as the result of his total
disability, the Company shall, for a period of six (6) months following
termination pay to Employee in each such month one-sixth (1/6) of his total
compensation for the six (6) month period prior to termination; provided,
however, that the dollar amount of any payment hereunder shall be reduced by any
payments made to or with respect to Employee as salary continuation under the
provisions of any disability or workers compensation program or arrangement to
which the Company contributes or reimburses Employee for premiums. For purposes
hereof, a total disability is a physical or mental disability that results in
Employee's inability to substantially perform his duties for a period of six (6)
consecutive weeks or for a period of 45 days within any period of twelve (12)
consecutive months.

         8. MISCELLANEOUS:

         (a) Successors, Etc. This Agreement shall bind and inure to the benefit
of the assigns, personal representatives, heirs or legatees of the respective
parties.

         (b) Further Agreements. Each party agrees to perform any further acts
and execute and deliver any documents which may be necessary to carry out the
provisions of this Agreement.

         (c) Amendment. This Agreement may be amended or modified at any time
only by the written agreement of the Company and Employee.

         (d) Number and Gender. Throughout this Agreement, whenever the context
so requires, the singular shall include the plural and the masculine gender
shall include the feminine and neuter genders.

         (e) Governing Law Venue: Arbitration. This Agreement and all rights,
obligations and liabilities arising hereunder shall be construed and enforced in
accordance with the laws of the State of Arizona. Suit hereon may be brought
only in a court sitting in the City of Phoenix, Arizona. The Company and
Employee agree to use all reasonable efforts to resolve amicably any controversy
or claim arising out of; or relating to, this Agreement, and in that regard
agree that they shall initially submit any controversy or claim which has gone
unresolved for more than thirty (30) days to a mutually satisfactory Phoenix
area mediation service for one-time mediation. In the event any controversy or
claim cannot be resolved by agreement or such mediation, or in the event that a
mediation service cannot be agreed upon, the parties mutually

                                      -4-
<PAGE>   5
agree to arbitration in Phoenix, Arizona, in accordance with the rules of the
American Arbitration Association in effect as of the date of this Agreement
(which are incorporated by reference herein), and judgment upon the award
rendered by the Arbitrator(s) may be entered in any court having jurisdiction.
The arbitration shall proceed in the absence of any party which, after due
notice, fails to be present or fails to obtain an adjournment. The parties shall
have the right to conduct discovery pursuant to the provisions of the Arizona
Code of Civil Procedure, and the aforesaid arbitration requirement shall not
operate to preclude either party hereto from seeking or obtaining injunctive
relief in a court of competent jurisdiction.

         (f) Attorneys' Fees. In the event of any action, suit or proceeding,
including arbitration, brought under or in connection with this Agreement, the
prevailing party therein shall be entitled to recover, and the non-prevailing
party thereto agrees to pay, the prevailing party's costs and expenses in
connection therewith, including reasonable attorneys' fees.

         (g) Severability. In the event that any provision of this Agreement
shall be held invalid or unenforceable, such provision shall be severable from,
and such invalidity or unenforceability shall not be construed to have any
affect on, the remaining provisions of this Agreement.

         (h) Notices. All notices, requests, demands and other communications
provided for by this Agreement shall be in writing and shall be deemed to have
been given and become effective twenty-four hours after deposit thereof for
mailing at any general or branch office of the United States Post Office
enclosed in a registered or certified post-paid envelope and addressed as
follows:

         TO THE COMPANY:                    Attention:  Chairman of the Board
                                            Alliance Medical Corporation
                                            10232 South 51st Street
                                            Phoenix, AZ 85044

         TO EMPLOYEE:                       PERSONAL & CONFIDENTIAL

                                            Ricardo M. Ferreira
                                            P.O. Box 2871
                                            Carefree, AZ 85377

         The parties hereto may designate a different place at which notice
shall be given, provided however, that any such notice of change of address
shall be effective only upon receipt.

         (i) Entire Agreement. This Agreement constitutes the entire agreement
between the parties hereto pertaining to the subject matter hereof. This
Agreement supersedes all prior agreements, written or oral, and all
contemporaneous oral agreements and understandings of the parties, and there are
no warranties, representations or other agreements between the parties in
connection with the subject matter hereof except as set forth or referred to
herein. No waiver of any of the provisions of this Agreement shall constitute a
waiver of any other provision hereof (whether or not similar), nor shall such
waiver constitute a continuing waiver.

                                      -5-
<PAGE>   6


         IN WITNESS WHEREOF, the parties have executed and delivered this
Agreement as of the day and year first above written.

ALLIANCE MEDICAL CORPORATION

a Delaware corporation


By: /s/ Tim Einwechter
____________________________

Name:   Tim Einwechter
____________________________


Its: Chief Financial Officer
____________________________


EMPLOYEE

/s/RICARDO M. FERREIRA
___________________________
RICARDO M. FERREIRA

                                      -6-