<PAGE>   1
                                                                Exhibit 4.11 (b)

NEITHER THIS WARRANT NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT
HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. NO SALE OR
DISPOSITION MAY BE EFFECTED EXCEPT IN COMPLIANCE WITH RULE 144 UNDER SAID ACT OR
WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN OPINION OR
COUNSEL FOR THE HOLDER, SATISFACTORY TO THE COMPANY. THAT SUCH REGISTRATION IS
NOT REQUIRED UNDER THE ACT OR RECEIPT OF A NO-ACTION LETTER FROM THE SECURITIES
AND EXCHANGE COMMISSION.

                 WARRANT TO PURCHASE 2419 SHARES OF COMMON STOCK

                                                                 October 4, 2001

         THIS CERTIFIES THAT, for value received, CAPITAL FINANCE GROUP LLC,
("Holder") is entitled to subscribe for and purchase Two Thousand Four Hundred
Nineteen (2419) shares of the fully paid and nonassessable Common Stock ("the
Shares") of Alliance Medical Corporation, a Delaware corporation (the
"Company"), at the Warrant Price (as hereinafter defined), subject to the
provisions and upon the terms and conditions hereinafter set forth. As used
herein, the term "Common Stock" shall mean the Company's presently authorized
Common Stock, and any stock into which such Common Stock may hereafter be
exchanged.

         1. WARRANT PRICE. The Warrant Price shall initially be One and 75/100
dollars ($1.75) per share, subject to adjustment as provided in Section 7 below.

         2. CONDITIONS TO EXERCISE. The purchase right represented by this
Warrant may be exercised at any time, or from time to time, in whole or in part
during the term commencing on the date hereof and ending on the earlier of:

            (a) 5:00 P.M. Pacific time on the seventh annual anniversary of this
Warrant; or

            (b) the closing of the initial public offering of the Company's
Common Stock pursuant to a registration statement under the Securities Act of
1933, as amended (the "Initial Public Offering"). The Company shall provide
notice of the Initial Public Offering to the Holder at least 30 days prior to
the closing thereof; or

            (c) the effective date of the merger of the Company with or into,
the consolidation of the Company with, or the sale by the Company of all or
substantially all of its assets or all or substantially all of its shares to
another corporation or other entity (other than such a transaction wherein the
shareholders of the Company retain or obtain a majority of the voting capital
stock of the surviving, resulting, or purchasing corporation); provided that the
Company shall notify the registered Holder of this Warrant of the proposed
effective date of the merger, consolidation, or sale at least 30 days prior to
the effectiveness thereof.

         In the event that, although the Company shall have given notice of a
         transaction pursuant to subparagraph (b) or subparagraph (c) hereof,
         the transaction does not close within 60 days of the day specified by
         the Company, unless otherwise elected by the Holder any exercise of the
         Warrant subsequent to the giving of such notice shall be rescinded and
         the

<PAGE>   2
         Warrant shall again be exercisable until terminated in accordance with
         this Paragraph 2.

3.       METHOD OF EXERCISE: PAYMENT ISSUANCE OF SHARES; ISSUANCE OF NEW
         WARRANT.

         (a) Cash Exercise. Subject to Section 2 hereof, the purchase right
represented by this Warrant may be exercised by the Holder hereof, in whole or
in part, by the surrender of this Warrant (with a duly executed Notice of
Exercise in the form attached hereto) at the principal office of the Company (as
set forth in Section 18 below) and by payment to the Company, by check, of an
amount equal to the then applicable Warrant Price per share multiplied by the
number of shares then being purchased. In the event of any exercise of the
rights represented by this Warrant, certificates for the shares of stock so
purchased shall be in the name of, and delivered to, the Holder hereof, or as
such Holder may direct (subject to the terms of transfer contained herein and
upon payment by such Holder hereof of any applicable transfer taxes). Such
delivery shall be made within 30 days after exercise of the Warrant and at the
Company's expense and, unless this Warrant has been fully exercised or expired,
a new Warrant having terms and conditions substantially identical to this
Warrant and representing the portion of the Shares, if any, with respect to
which this Warrant shall not have been exercised, shall also be issued to the
Holder hereof within 30 days after exercise of the Warrant.

         (b) Net Issue Exercise. In lieu of exercising this Warrant pursuant to
Section 3(a), Holder may elect to receive shares equal to the value of this
Warrant (or of any portion thereof remaining unexercised) by surrender of this
Warrant at the principal office of the Company together with notice of such
election, in which event the Company shall issue to Holder the number of shares
of the Company's Common Stock computed using the following formula:

                                   X = Y(A-B)
                                   ----------
                                        A

         Where X = the number of shares of Common Stock to be issued to Holder.

         Y = the number of shares of Common Stock purchasable under this
             Warrant (at the date of such calculation).

         A = the Fair Market Value of one share of the Company's Common Stock
             (at the date of such calculation).

         B = Warrant Price (as adjusted to the date of such calculation).

         (c) Fair Market Value. For purposes of this Section 3, Fair Market
Value of one share of the Company's Common Stock shall mean:

             (i) In the event of an exercise in connection with an Initial
Public Offering, the per share Fair Market Value for the Common Stock shall be
the Offering Price at which the underwriters initially sell Common Stock to the
public; or

             (ii) The average of the closing bid and asked prices of the Common
Stock quoted in the Over-The-Counter Market Summary, or the average of the last
reported sale price of the Common Stock or the closing price quoted on the
Nasdaq National Market System

<PAGE>   3
("NMS") or on any exchange on which the Common Stock is listed, whichever is
applicable, as published in the Western Edition of the Wall Street Journal over
the ten (10) trading days prior to the date of determination of fair market
value; or

             (iii) In the event of an exercise in connection with a merger,
acquisition or other consolidation in which the Company is not the surviving
entity, as described in Section 2(c), the per share Fair Market Value for the
Common Stock shall be the value to be received per share of Common Stock by all
holders of the Common Stock in such transaction as determined by the Board of
Directors; or

             (iv) If the Common Stock is not publicly traded, the per share fair
market value of the Common Stock shall be as determined in good faith by the
Company's Board of Directors.

         In the event of 3(c)(iii) or 3(c)(iv), above, the Company's Board of
         Directors shall prepare a certificate, to be signed by an authorized
         Officer of the Company, setting forth in reasonable detail the basis
         for and method of determination of the per share Fair Market Value of
         the Common Stock. The Board will also certify to the Holder that this
         per share Fair Market Value will be applicable to all holders of the
         Company's Common Stock. Such certification must be made to Holder at
         least thirty (30) business days prior to the proposed effective date of
         the merger, consolidation, sale, or other triggering event as defined
         in 3(c)(iii) and 3(c)(iv).

         (d) Automatic Exercise. To the extent this Warrant is not previously
exercised, it shall be automatically exercised in accordance with Sections 3(b)
and 3(c) hereof (even if not surrendered) immediately before; (i) its
expiration, or (ii) the consummation of any consolidation or merger of the
Company, or any sale or transfer of a majority of the Company's assets or stock
pursuant to Section 2(b).

         4. REPRESENTATIONS AND WARRANTIES OF HOLDER AND RESTRICTIONS ON
TRANSFER IMPOSED BY THE SECURITIES ACT OF 1933.

            (a) Representations and Warranties by Holder. The Holder represents
and warrants to the Company with respect to this purchase as follows:

                 (i) The Holder has substantial experience in evaluating and
investing in private placement transactions of securities of companies similar
to the Company so that the Holder is capable of evaluating the merits and risks
of its investment in the Company and has the capacity to protect its interests.

                 (ii) The Holder is acquiring the Warrant and the Shares of
Common Stock issuable upon exercise of the Warrant (collectively the
"Securities") for investment for its own account and not with a view to, or for
resale in connection with, any distribution thereof. The Holder understands that
the Securities have not been registered under the Securities Act of 1933. as
amended (the "Act") by reason of a specific exemption from the registration
provisions of the Act which depends upon, among other things, the bona fide
nature of the investment intent as expressed herein. In this connection, the
Holder understands that, in the view of the Securities and Exchange Commission
(the "SEC"), the statutory basis for such exemption may be

<PAGE>   4
unavailable if this representation was predicated solely upon a present
intention to hold the Securities for the minimum capital gains period specified
under tax statutes, for a deferred sale, for or until an increase or decrease in
the market price of the Securities or for a period of one year or any other
fixed period in the future.

         (iii) The Holder acknowledges that the Securities must be held
indefinitely unless subsequently registered under the Act or an exemption from
such registration is available. The Holder is aware of the provisions of Rule
144 promulgated under the Act ("Rule 144") which permits limited resale of
securities purchased in a private placement subject to the satisfaction of
certain conditions, including, in case the securities have been held for less
than two years, the existence of a public market for the shares, the
availability of certain public information about the Company, the resale
occurring not less than one year after a party has purchased and paid for the
security to be sold, the sale being through a "broker's transaction" or in a
transaction directly with a "market maker" (as provided by Rule 144(f)) and the
number of shares or other securities being sold during any three-month period
not exceeding specified limitations.

                 (iv) The Holder further understands that at the time the Holder
wishes to sell the Securities there may be no public market upon which such a
sale may be effected, and that even if such a public market exists, the Company
may not be satisfying the current public information requirements of Rule 144,
and that in such event, the Holder may be precluded from selling the Securities
under Rule 144 unless a) a one-year minimum holding period has been satisfied
and b) the Holder was not at the time of the sale nor at any time during the
three-month period prior to such sale an affiliate of the Company.

                 (v) The Holder has had an opportunity to discuss the Company's
business, management and financial affairs with its management and an
opportunity to review the Company's facilities. The Holder understands that such
discussions, as well as the written information issued by the Company, were
intended to describe the aspects of the Company's business and prospects which
it believes to be material but were not necessarily a thorough or exhaustive
description.

         (b) Legends. Each certificate representing the Securities shall be
endorsed with the following legend:

             THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
             OF 1933 AND MAY NOT BE TRANSFERRED UNLESS COVERED BY AN EFFECTIVE
             REGISTRATION STATEMENT UNDER SAID ACT, A "NO ACTION" LETTER FROM
             THE SECURITIES AND EXCHANGE COMMISSION WITH RESPECT TO SUCH
             TRANSFER, A TRANSFER MEETING THE REQUIREMENTS OF RULE 144 OF THE
             SECURITIES AND EXCHANGE COMMISSION, OR (IF REASONABLY REQUIRED BY
             THE COMPANY) AN OPINION OF COUNSEL SATISFACTORY TO THE ISSUER TO
             THE EFFECT THAT ANY SUCH TRANSFER IS EXEMPT FROM SUCH REGISTRATION.
<PAGE>   5

The Company need not enter into its stock record a transfer of Securities unless
the conditions specified in the foregoing legend are satisfied. The Company may
also instruct its transfer agent not to allow the transfer of any of the Shares
unless the conditions specified in the foregoing legend are satisfied.

         (c) Removal of Legend and Transfer Restrictions. The legend relating to
the Act endorsed on a certificate pursuant to paragraph 4(b) of this Warrant and
the stop transfer instructions with respect to the Securities represented by
such certificate shall be removed and the Company shall issue a certificate
without such legend to the Holder of the Securities if (i) the Securities are
registered under the Act and a prospectus meeting the requirements of Section 10
of the Act is available or (ii) the Holder provides to the Company an opinion of
counsel for the Holder reasonably satisfactory to the Company, or a no-action
letter or interpretive opinion of the staff of the SEC reasonably satisfactory
to the Company, to the effect that public sale, transfer or assignment of the
Securities may be made without registration and without compliance with any
restriction such as Rule 144.

      5. CONDITION OF TRANSFER OR EXERCISE OF WARRANT. It shall be a condition
to any transfer or exercise of this Warrant that at the time of such transfer or
exercise, the Holder shall provide the Company with a representation in writing
that the Holder or transferee is acquiring this Warrant and the shares of Common
Stock to be issued upon exercise for investment purposes only and not with a
view to any sale or distribution, or will provide the Company with a statement
of pertinent facts covering any proposed distribution. As a further condition to
any transfer of this Warrant or any or all of the shares of Common Stock
issuable upon exercise of this Warrant, other than a transfer registered under
the Act, the Company must have received a legal opinion, in form and substance
satisfactory to the Company and its counsel, reciting the pertinent
circumstances surrounding the proposed transfer and stating that such transfer
is exempt from the registration and prospectus delivery requirements of the Act.
Each certificate evidencing the shares issued upon exercise of the Warrant or
upon any transfer of the shares (other than a transfer registered under the Act
or any subsequent transfer of shares so registered) shall, at the Company's
option, contain a legend in form and substance satisfactory to the Company and
its counsel, restricting the transfer of the shares to sales or other
dispositions exempt from the requirements of the Act.

         As further condition to each transfer, the Holder shall surrender this
Warrant to the Company and the transferee shall receive and accept a Warrant, of
like tenor and date, executed by the Company.

      6. STOCK FULLY PAID: RESERVATION OF SHARES. All Shares which may be issued
upon the exercise of the rights represented by this Warrant will, upon issuance,
be fully paid and nonassessable, and free from all taxes, liens, and charges
with respect to the issue, thereof. During the period within which the rights
represented by this Warrant may be exercised, the Company will at all times have
authorized, and reserved for issuance upon exercise of the purchase rights
evidenced by this Warrant, a sufficient number of shares of its Common Stock to
provide for the exercise of the rights represented by this Warrant.

      7. ADJUSTMENT FOR CERTAIN EVENTS. In the event of changes in the
outstanding Common Stock by reason of stock dividends, split-ups,
recapitalizations, reclassifications, mergers,
<PAGE>   6
consolidations, combinations or exchanges of shares, separations,
reorganizations, liquidations, or the like, the number and class of shares
available under the Warrant in the aggregate and the Warrant Price shall be
correspondingly adjusted, as appropriate, by the Board of Directors of the
Company. The adjustment shall be such as will give the Holder of this Warrant
upon exercise for the same aggregate Warrant Price the total number, class and
kind of shares as he would have owned had the Warrant been exercised prior to
the event and had he continued to hold such shares until after the event
requiring adjustment.

      8. NOTICE OF ADJUSTMENTS. Whenever any Warrant Price shall be adjusted
pursuant to Section 7 hereof, the Company shall prepare a certificate signed by
an officer of the Company setting forth, in reasonable detail, the event
requiring the adjustment, the amount of the adjustment, the method by which such
adjustment was calculated, and the Warrant Price and number of shares issuable
upon exercise of the Warrant after giving effect to such adjustment, and shall
cause copies of such certificate to be mailed (by certified or registered mail,
return receipt required, postage prepaid) within thirty (30) days of such
adjustment to the Holder of this Warrant as set forth in Section 18 hereof.

      9. "MARKET STAND-OFF" AGREEMENT. Holder hereby agrees that for a period of
up to 180 days following the effective date of the first registration statement
of the Company covering common stock (or other securities) to be sold on behalf
of the Company in an underwritten public offering, it will not, to the extent
requested by the Company and any underwriter, sell or otherwise transfer or
dispose of (other than to donees or transferees who agree to be similarly bound)
any of the Shares at any time during such period except common stock included in
such registration; provided, however, that all officers and directors of the
Company who hold securities of the Company or options to acquire securities of
the Company and all other persons with registration rights enter into similar
agreements.

      10. TRANSFERABILITY OF WARRANT. This Warrant is transferable on the books
of the Company at its principal office by the registered Holder hereof upon
surrender of this Warrant properly endorsed, subject to compliance with Section
5 and applicable federal and state securities laws. The Company shall issue and
deliver to the transferee a new Warrant representing the Warrant so transferred.
Upon any partial transfer, the Company will issue and deliver to Holder a new
Warrant with respect to the Warrant not so transferred. Holder shall not have
any right to transfer any portion of this Warrant to any direct competitor of
the Company.

      11. NO FRACTIONAL SHARES. No fractional share of Common Stock will be
issued in connection with any exercise hereunder, but in lieu of such fractional
share the Company shall make a cash payment therefor upon the basis of the
Warrant Price then in effect.

      12. CHARGES, TAXES AND EXPENSES. Issuance of certificates for shares of
Common Stock upon the exercise of this Warrant shall be made without charge to
the Holder for any United States or state of the United States documentary stamp
tax or other incidental expense with respect to the issuance of such
certificate, all of which taxes and expenses shall be paid by the Company, and
such certificates shall be issued in the name of the Holder.

      13. NO SHAREHOLDER RIGHTS UNTIL EXERCISE. This Warrant does not entitle
the Holder hereof to any voting rights or other rights as a shareholder of the
Company prior to the exercise hereof.

<PAGE>   7
      14. REGISTRY OF WARRANT. The Company shall maintain a registry showing the
name and address of the registered Holder of this Warrant. This Warrant may be
surrendered for exchange or exercise, in accordance with its terms, at such
office or agency of the Company, and the Company and Holder shall be entitled to
rely in all respects, prior to written notice to the contrary, upon such
registry.

      15. LOSS, THEFT, DESTRUCTION OR MUTILATION OF WARRANT. Upon receipt by the
Company of evidence reasonably satisfactory to it of the loss, theft,
destruction or mutilation of this Warrant, and, in the case of loss, theft, or
destruction, of indemnity reasonably satisfactory to it, and, if mutilated, upon
surrender and cancellation of this Warrant, the Company will execute and deliver
a new Warrant, having terms and conditions substantially identical to this
Warrant, in lieu hereof.

      16. MISCELLANEOUS.

          (a) Issue Date. The provisions of this Warrant shall be construed and
      shall be given effect in all respect as if it had been issued and
      delivered by the Company on the date hereof.

          (b) Successors. This Warrant shall be binding upon any successors or
      assigns of the Company.

          (c) Governing Law. This Warrant shall be governed by and construed in
      accordance with the laws of the State of California.

          (d) Headings. The headings used in this Warrant are used for
      convenience only and are not to be considered in construing or
      interpreting this Warrant.

          (e) Saturdays, Sundays, Holidays. If the last or appointed day for the
      taking of any action or the expiration of any right required or granted
      herein shall be a Saturday or a Sunday or shall be a legal holiday in the
      State of California, then such action may be taken or such right may be
      exercised on the next succeeding day not a legal holiday.

          17. NO IMPAIRMENT. The Company will not, by amendment of its
Certificate of Incorporation or any other voluntary action, avoid or seek to
avoid the observance or performance of any of the terms of this Warrant, but
will at all times in good faith assist in the carrying out of all such terms and
in the taking of all such action as may be necessary or appropriate in order to
protect the rights of the Holder hereof against impairment.

          18. ADDRESSES. Any notice required or permitted hereunder shall be in
writing and shall be mailed by overnight courier, registered or certified mail,
return receipt required, and postage pre-paid, or otherwise delivered by hand or
by messenger, addressed as set forth below, or at such other address as the
Company or the Holder hereof shall have furnished to the other party.

                  If to the Company:        ALLIANCE MEDICAL CORPORATION

                                            10232 South 51st Street
                                            Phoenix, AZ 80544
                                            Attn:  Tim Einwechter

                                       2
<PAGE>   8

                  If to the Holder:         CAPITAL FINANCE GROUP LLC

                                            6777 Moore Drive
                                            Oakland, CA 94611
                                            Attn:  Robert Kingsbook, CEO

         IN WITNESS WHEREOF, Alliance Medical Corporation has caused this
Warrant to be executed by its officers thereunto duly authorized.

         Dated as of October 4, 2001.

                                         ALLIANCE MEDICAL CORPORATION

                                         By: /s/ Tim Einwechter
                                             ----------------------------------
                                         Name:   Tim Einwechter
                                             ----------------------------------
                                         Title: CFO
                                               -----