<PAGE>
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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
 
                             WASHINGTON, D.C. 20549
 
                            ------------------------
 
                                   FORM 10-Q
 
              QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                        SECURITIES EXCHANGE ACT OF 1934
 
                       FOR QUARTER ENDED: MARCH 31, 1999
                        COMMISSION FILE NUMBER: 0-16334
 
                            ------------------------
 
                             ALLIANCE IMAGING, INC.
 
             (Exact name of registrant as specified in its charter)
 
                  DELAWARE                             33-0239910
      (State or other jurisdiction of         (IRS Employer Identification
       incorporation or organization)                    Number)
 
                         1065 NORTH PACIFICENTER DRIVE
                                   SUITE 200
                           ANAHEIM, CALIFORNIA 92806
 
                    (Address of principal executive office)
 
                                 (714) 688-7100
               Registrant's telephone number, including area code
 
                            ------------------------
 
    Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934, during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes / /  No /X/
 
    Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of April 30, 1999:
 
                    Common Stock, $.01 par value, 4,105,111
 
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<PAGE>
                             ALLIANCE IMAGING, INC.
 
                                   FORM 10-Q
 
                                 MARCH 31, 1999
 
                                     INDEX
 
<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                                                                                                          <C>
PART I--FINANCIAL INFORMATION
 
Item 1--Condensed Financial Statements:
 
  Condensed Consolidated Balance Sheets
    March 31, 1999 and December 31, 1998...................................................................           3
 
  Condensed Consolidated Statements of Operations
    Three months ended March 31, 1999 and 1998.............................................................           4
 
  Condensed Consolidated Statements of Cash Flows
    Three months ended March 31, 1999 and 1998.............................................................           5
 
  Notes to Condensed Consolidated Financial Statements.....................................................           6
 
Item 2--Management's Discussion and Analysis of Financial Condition and Results of Operations..............           9
 
PART II--OTHER INFORMATION.................................................................................          15
 
SIGNATURES.................................................................................................          18
</TABLE>
 
                                       2
<PAGE>
                             ALLIANCE IMAGING, INC.
 
                     CONDENSED CONSOLIDATED BALANCE SHEETS
 
                             (DOLLARS IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                     DECEMBER 31,
                                                                                                        1998*
                                                                                         MARCH 31,   ------------
                                                                                           1999
                                                                                        -----------
                                                                                        (UNAUDITED)
<S>                                                                                     <C>          <C>
                                                     ASSETS
Current assets:
  Cash and short-term investments.....................................................   $   5,535    $    1,681
  Accounts receivable, net of allowance for doubtful accounts.........................      48,659        41,634
  Deferred income taxes...............................................................       3,679         3,679
  Prepaid expenses....................................................................       2,780         3,134
  Other receivables and other current assets..........................................         515           552
                                                                                        -----------  ------------
Total current assets..................................................................      61,168        50,680
Equipment, at cost....................................................................     297,466       273,074
  Less--Accumulated depreciation......................................................     (87,943)      (78,811)
                                                                                        -----------  ------------
                                                                                           209,523       194,263
Goodwill..............................................................................     108,087       109,667
Other intangibles.....................................................................      74,336        75,528
Deferred financing costs..............................................................      12,322        12,867
Deposits and other assets.............................................................      11,309        13,161
                                                                                        -----------  ------------
Total assets..........................................................................   $ 476,745    $  456,166
                                                                                        -----------  ------------
                                                                                        -----------  ------------
 
                                      LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Accounts payable....................................................................   $   3,246    $    4,688
  Accrued compensation and related expenses...........................................       5,174         6,733
  Other accrued liabilities...........................................................      23,550        21,190
  Current portion of long-term debt...................................................      17,678        18,742
                                                                                        -----------  ------------
Total current liabilities.............................................................      49,648        51,353
Long-term debt, net of current portion................................................     451,618       431,247
Other liabilities.....................................................................         627           713
Deferred income taxes.................................................................      38,390        38,390
Redeemable preferred stock............................................................      17,269        16,673
Common stock..........................................................................          41            41
Additional paid-in deficit............................................................     (59,672)      (59,672)
Accumulated deficit...................................................................     (21,176)      (22,579)
                                                                                        -----------  ------------
Total liabilities and stockholders' equity............................................   $ 476,745    $  456,166
                                                                                        -----------  ------------
                                                                                        -----------  ------------
</TABLE>
 
------------------------
 
 *  Derived from audited financial statements
 
SEE NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
 
                                       3
<PAGE>
                             ALLIANCE IMAGING, INC.
 
                CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
 
                                  (UNAUDITED)
 
                (DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<TABLE>
<CAPTION>
                                                                                               THREE MONTHS ENDED
                                                                                                   MARCH 31,
                                                                                              --------------------
<S>                                                                                           <C>        <C>
                                                                                                1999       1998
                                                                                              ---------  ---------
Revenues....................................................................................  $  64,381  $  31,241
Costs and expenses:
  Operating expenses, excluding depreciation................................................     31,635     15,235
  Depreciation expense......................................................................      9,246      4,971
  Selling, general and administrative expenses..............................................      6,331      3,036
  Transaction related costs.................................................................        419        815
  Amortization expense, primarily goodwill..................................................      2,772        810
  Interest expense, net of interest income..................................................     10,241      6,707
                                                                                              ---------  ---------
Total costs and expenses....................................................................     60,644     31,574
                                                                                              ---------  ---------
Income (loss) before income taxes and extraordinary loss....................................      3,737       (333)
Provision for income taxes..................................................................      1,738         --
                                                                                              ---------  ---------
Income (loss) before extraordinary loss.....................................................      1,999       (333)
Extraordinary loss, net of taxes............................................................         --     (1,312)
                                                                                              ---------  ---------
Net income (loss)...........................................................................      1,999     (1,645)
Less: Preferred stock dividends and financing fee accretion.................................        596        510
                                                                                              ---------  ---------
Income (loss) applicable to common stock....................................................  $   1,403  $  (2,155)
                                                                                              ---------  ---------
                                                                                              ---------  ---------
Earnings per common share:
Income (loss) before extraordinary loss.....................................................  $    0.34  $   (0.21)
Extraordinary loss, net of taxes............................................................         --      (0.32)
                                                                                              ---------  ---------
Net income (loss) per common share..........................................................  $    0.34  $   (0.53)
                                                                                              ---------  ---------
                                                                                              ---------  ---------
Earnings per common share--assuming dilution:
  Income (loss) before extraordinary loss...................................................  $    0.32  $   (0.21)
  Extraordinary loss, net of taxes..........................................................         --      (0.32)
                                                                                              ---------  ---------
  Net income (loss) per common share
  --assuming dilution.......................................................................  $    0.32  $   (0.53)
                                                                                              ---------  ---------
                                                                                              ---------  ---------
</TABLE>
 
SEE NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
 
                                       4
<PAGE>
                             ALLIANCE IMAGING, INC.
 
                CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
 
                                  (UNAUDITED)
 
                             (DOLLARS IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                             THREE MONTHS ENDED
                                                                                                  MARCH 31,
                                                                                           -----------------------
<S>                                                                                        <C>         <C>
                                                                                              1999        1998
                                                                                           ----------  -----------
OPERATING ACTIVITIES:
Net income (loss)........................................................................  $    1,999  $    (1,645)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
  Extraordinary loss.....................................................................          --        1,312
  Depreciation and amortization..........................................................      12,018        5,781
  Amortization of deferred financing costs...............................................         545          216
  Distributions in excess of (undistributed) equity in income of investee................        (173)         (73)
  Gain on sale of equipment..............................................................         (31)          --
Changes in operating assets and liabilities:
  Accounts receivable, net...............................................................      (7,025)        (605)
  Prepaid expenses.......................................................................         354           81
  Other receivables......................................................................          37          107
  Other assets...........................................................................         (53)        (208)
  Accounts payable, accrued compensation and other accrued liabilities...................         (88)      (1,560)
  Other liabilities......................................................................         (86)         (68)
                                                                                           ----------  -----------
Net cash provided by operating activities................................................       7,497        3,338
INVESTING ACTIVITIES:
Equipment purchases......................................................................     (25,118)     (12,454)
(Increase) decrease in deposits on equipment.............................................       2,078       (3,550)
Purchase of common stock of Mobile Technology Inc., net of cash acquired.................          --      (94,147)
Proceeds from sale of equipment..........................................................          90           --
                                                                                           ----------  -----------
Net cash used in investing activities....................................................     (22,950)    (110,151)
FINANCING ACTIVITIES:
Principal payments on long-term debt.....................................................      (4,693)      (3,483)
Proceeds from term loan facility.........................................................          --       90,000
Proceeds from revolving loan facility....................................................      24,000       16,394
Decrease in deferred financing costs.....................................................          --          291
Proceeds from exercise of employee stock options.........................................          --           13
                                                                                           ----------  -----------
Net cash provided by financing activities................................................      19,307      103,215
                                                                                           ----------  -----------
Net (decrease) increase in cash and short-term investments...............................       3,854       (3,598)
Cash and short-term investments, beginning of period.....................................       1,681       10,798
                                                                                           ----------  -----------
Cash and short-term investments, end of period...........................................  $    5,535  $     7,200
                                                                                           ----------  -----------
                                                                                           ----------  -----------
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
  Interest paid..........................................................................  $    5,391  $     1,588
  Income taxes paid......................................................................         600           32
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
  Preferred stock dividend accrued and financing fee accretion...........................  $      596  $       510
</TABLE>
 
SEE NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
 
                                       5
<PAGE>
                             ALLIANCE IMAGING, INC.
 
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
 
                                 MARCH 31, 1999
 
                                  (UNAUDITED)
 
                (DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
1. BASIS OF PREPARATION
 
    The accompanying unaudited condensed consolidated financial statements have
been prepared by Alliance Imaging, Inc. (the "Company") in accordance with
generally accepted accounting principles for interim financial information and
with the instructions to Form 10-Q and Article 10 of Regulation S-X of the
Securities and Exchange Commission. Accordingly, they do not include all of the
information and footnotes required by generally accepted accounting principles
for complete financial statements. In the opinion of the Company, all
adjustments (consisting of normal recurring accruals) considered necessary for a
fair presentation have been included. Operating results for the three month
period ended March 31, 1999, are not necessarily indicative of the results that
may be expected for the year ending December 31, 1999. For further information,
refer to the consolidated financial statements and footnotes thereto included in
the Company's annual report on Form 10-K for the year ended December 31, 1998.
 
    The provision for income taxes for the three month period ended March 31,
1999 is higher than the statutory federal rate primarily as a result of
non-deductible goodwill amortization expense.
 
    The following table sets forth the computation of basic and diluted earnings
per share:
 
<TABLE>
<CAPTION>
                                                                     THREE MONTHS ENDED MARCH
                                                                               31,
                                                                    --------------------------
<S>                                                                 <C>           <C>
                                                                        1999          1998
                                                                    ------------  ------------
Numerator:
Income (loss) before extraordinary loss...........................  $      1,999  $       (333)
Preferred stock dividends and financing fee accretion.............          (596)         (510)
                                                                    ------------  ------------
Numerator for basic and diluted earnings per share
  --income available to common stockholders before extraordinary
  loss............................................................  $      1,403  $       (843)
                                                                    ------------  ------------
                                                                    ------------  ------------
Denominator:
Denominator for basic earnings per share
  --weighted average shares.......................................     4,073,000     4,055,000
Effect of dilutive securities:
Employee stock options............................................       251,000            --
                                                                    ------------  ------------
Denominator for diluted earnings per share
  --adjusted weighted-average shares..............................     4,324,000     4,055,000
                                                                    ------------  ------------
                                                                    ------------  ------------
Basic earnings (loss) per share before extraordinary loss.........  $       0.34  $      (0.21)
                                                                    ------------  ------------
                                                                    ------------  ------------
Diluted earnings (loss) per share before extraordinary loss.......  $       0.32  $      (0.21)
                                                                    ------------  ------------
                                                                    ------------  ------------
</TABLE>
 
2. ACQUISITIONS
 
    On March 12, 1998, the Company acquired Mobile Technology Inc. ("MTI"). The
purchase price consisted of $58,300 for all of the equity interests in MTI, plus
direct acquisition costs of approximately $2,000. In connection with the
acquisition, the Company also refinanced $37,400 of MTI's outstanding
 
                                       6
<PAGE>
                             ALLIANCE IMAGING, INC.
 
        NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                                 MARCH 31, 1999
 
                                  (UNAUDITED)
 
                (DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
2. ACQUISITIONS (CONTINUED)
debt and paid MTI direct transaction costs of $3,500. To finance these
expenditures, the Company increased its existing term loan facility by $20,000
to provide total availability of $70,000, established a new $50,000 term loan
facility and borrowed an aggregate of $90,000 thereunder, for which the Company
incurred debt issuance costs of approximately $2,800. The Company also borrowed
$5,400 under its revolving loan facility and used $8,500 of cash on hand at MTI
to complete the financing requirements. The transaction has been accounted for
as a purchase and, accordingly, the results of operations of MTI have been
included in the Company's consolidated financial statements from the date of
acquisition. The goodwill recorded as a result of this acquisition was
approximately $5,979, which is being amortized on a straight-line basis over 20
years. Additionally, the Company assigned $67,200 of the purchase price to
customer contracts and $2,870 of the purchase price to assembled work force. The
amounts are being amortized on a straight-line basis over 20 and four years
respectively. The allocation of the intangible assets acquired was based on an
independent valuation study.
 
    On May 19, 1998, the Company acquired Medical Diagnostics, Inc. ("MDI"), a
subsidiary of U. S. Diagnostic, Inc. The purchase price consisted of
approximately $31,000 plus the assumption of approximately $7,400 in financing
arrangements. The transaction has been accounted for as a purchase and,
accordingly, the results of operations of MDI have been included in the
Company's consolidated financial statements from the date of acquisition. The
goodwill recorded as a result of this acquisition was $17,212, which is being
amortized on a straight-line basis over 20 years. Additionally, the Company
assigned $8,300 of the purchase price to customer contracts and $350 of the
purchase price to assembled work force. The amounts are being amortized on a
straight-line basis over 20 and four years respectively. The allocation of the
intangible assets acquired was based on an independent valuation study.
 
    On November 13, 1998, two wholly owned subsidiaries of the Company acquired
all of the outstanding common stock of CuraCare, Inc. and all of the partnership
interests in American Shared-CuraCare (collectively, "American Shared"). The
purchase price consisted of approximately $13,377 plus the assumption of
approximately $12,241 in financing arrangements. In connection with the
acquisition, the Company also refinanced $13,130 of American Shared's
outstanding debt. The transaction has been accounted for as a purchase and,
accordingly, the results of operations of American Shared have been included in
the Company's consolidated financial statements from the date of acquisition.
The goodwill recorded as a result of this acquisition was approximately $30,445
which is being amortized on a straight-line basis over 20 years. The allocation
of the American Shared purchase price is tentative pending completion of fair
value determinations for the net assets acquired. The allocation may change with
the completion of these determinations.
 
    On April 14, 1999, the Company announced it had signed a definitive
agreement to acquire all of the outstanding common stock of Three Rivers Holding
Corp., parent corporation of SMT Health Services Inc. ("SMT") in a
stock-for-stock merger. SMT is a regional mobile magnetic resonance imaging
("MRI") provider with 35 MRI systems serving 144 customers in 10 states. As part
of the transaction, the Company intends to assume or refinance $66,465 of SMT's
indebtedness. The transaction is subject to customary conditions, including
obtaining sufficient funds to refinance SMT's indebtedness, and is expected to
close by the middle of May 1999.
 
                                       7
<PAGE>
                             ALLIANCE IMAGING, INC.
 
        NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
                                 MARCH 31, 1999
 
                                  (UNAUDITED)
 
                (DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
2. ACQUISITIONS (CONTINUED)
    SMT is wholly owned by an affiliate of Apollo Management, L.P., which
currently owns approximately 82.6% of the Company's outstanding common stock;
accordingly, the merger is expected to be accounted for as a reorganization of
entities under common control in a manner similar to a pooling of interests.
 
                                       8
<PAGE>
MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF
  OPERATIONS.
 
OVERVIEW
 
    The Company is a leading nationwide provider of diagnostic imaging and
therapeutic services and the largest operator of state-of-the-art mobile
diagnostic imaging systems and related outsourced radiology services in the
United States. The Company's diagnostic imaging services include magnetic
resonance imaging ("MRI"), computed axial tomography ("CT"), nuclear medicine
single photon emission computed tomography ("SPECT") camera and ultrasound
systems. The Company's therapeutic services include lithotripsy, brachytherapy
and microwave thermotherapy systems. The Company primarily provides MRI and CT
systems and services to hospitals and other health care providers on a mobile,
shared user basis. The Company also provides dedicated, full-time MRI systems
and services as well as full-service management of imaging operations for
selected hospitals. The Company's MRI services include the provision of high
technology imaging systems, technologists to operate the imaging systems,
equipment maintenance and upgrades, the management of day-to-day operations,
educational and marketing support, patient scheduling, billing and collection
services, managed care contracting and professional liability coverage. The
Company's services enable small to mid-size hospitals to gain access to advanced
diagnostic imaging technology and related value-added services without making a
substantial investment in equipment and personnel. The Company operates a fleet
of 250 MRI systems and services 1,044 customers in 44 states as of March 31,
1999.
 
    The Company's revenues are principally a function of the number of systems
in service, scan volumes and fees per scan. The Company generates substantially
all of its revenues under exclusive one to eight-year contracts with hospitals
and health care providers. The Company's contracts typically offer tiered
pricing with lower fees per scan on incremental scans, allowing customers to
benefit from increased scan volumes and the Company to benefit from the
operating leverage associated with increased scan volumes. The Company expects
modest continuing downward pressure on pricing levels as a result of cost
containment measures in the health care industry. However, in many cases higher
scan volumes justify lower prices on incremental scans.
 
    The principal components of the Company's operating costs include salaries
paid to technologists and drivers, annual system maintenance costs, insurance
and transportation costs. Because a majority of these expenses are fixed,
increased revenues as a result of higher scan volumes significantly improve the
Company's profitability while lower scan volumes result in lower profitability.
 
    Since the beginning of 1995, the Company has substantially increased
revenues by adding new customers and increasing scan volumes at existing
customer sites. The Company has also substantially increased revenue through
acquisitions. During the same period, the growth rate of the Company's EBITDA
(income before income taxes, plus depreciation, amortization and net interest
expense), excluding expenses associated with the Recapitalization Merger (as
hereinafter defined), has exceeded the growth rate of revenues as a result of
spreading costs (which are primarily fixed) over a larger revenue base and
implementing cost reduction and containment measures.
 
    The Company has historically focused on maximizing cash flow and return on
invested capital nationwide, deploying new and upgraded systems in high volume
markets and redeploying older, less advanced systems with lower carrying values
in lower volume markets. The Company's ongoing equipment trade-in and upgrade
program has substantially improved the marketability and productivity of its MRI
systems. Because the Company owns significantly all of its MRI systems, it
periodically evaluates its older, less marketable MRI systems to determine if it
is more beneficial to continue to use such systems in lower volume markets which
are profitable but produce less revenue, or to trade in such equipment in
connection with new system purchases. The Company currently maintains one of the
most advanced fleets in the industry.
 
                                       9
<PAGE>
    Revenues from CT services, lithotripsy services, SPECT camera services, and
other imaging services accounted for approximately 7% of the Company's revenues
for the three months ended March 31, 1999.
 
    On December 18, 1997, after obtaining the approval of stockholders, the
Company completed a series of transactions contemplated by an Agreement and Plan
of Merger between Newport Investment LLC (the "Investor") and the Company (the
"Recapitalization Merger") whereby the Company: obtained proceeds from debt
financing aggregating $215.0 million; issued 150,000 shares of non-voting
redeemable Series F preferred stock to the Investor for proceeds of $15.0
million; issued 3,632,222 shares of its common stock in exchange for all of the
outstanding stock of Newport Acquisition Corporation, a subsidiary of the
Investor, and received net proceeds of $40.0 million from cash placed into
Newport Acquisition Corporation by the Investor; and converted all shares of its
common stock held by existing stockholders in excess of 411,358 shares that were
retained by electing existing stockholders into the right to receive $11 in
cash.
 
    As a result of these transactions, the Company experienced an approximate
90% ownership change. The Investor, which was formed and is wholly owned by
certain affiliates of Apollo Management, L.P., ("Apollo") obtained ownership of
approximately 83.6% of the Company's outstanding common stock, and the Company
became highly leveraged.
 
    On March 12, 1998, the Company acquired Mobile Technology Inc. ("MTI"),
which management believes was the second largest provider of mobile MRI services
in the United States, in a transaction accounted for as a purchase. The Company
has included the operations of MTI in its consolidated financial statements from
the date of acquisition. This acquisition added 68 MRI systems operating in 31
states, 3 CT systems, 9 lithotripsy systems, and 3 brachytherapy systems to the
Company's equipment fleet. The purchase price consisted of $58.3 million for all
of the equity interests in MTI plus direct acquisition costs of approximately
$2.0 million. In connection with the acquisition, the Company also refinanced
$37.4 million of MTI's outstanding debt and paid MTI direct transaction costs of
$3.5 million. To finance these expenditures, the Company increased its then
existing term loan facility by $20.0 million to provide total availability of
$70.0 million, established a new $50.0 million term loan facility and borrowed
an aggregate of $90.0 million thereunder, for which the Company incurred debt
issuance costs of approximately $2.8 million. The Company also borrowed $5.4
million under its revolving loan facility and used $8.5 million of cash on hand
at MTI to complete the financing requirements. The goodwill recorded as a result
of this acquisition was approximately $6.0 million, which is being amortized on
a straight-line basis over 20 years. Additionally, the Company assigned $67.2
million of the purchase price to customer contracts and $2.9 million of the
purchase price to assembled work force. The amounts are being amortized on a
straight-line basis over 20 and four years, respectively. The allocation of the
intangible assets acquired was based on an independent valuation study.
 
    On May 19, 1998, the Company acquired Medical Diagnostics, Inc. ("MDI"), a
subsidiary of U. S. Diagnostic, Inc. The purchase price consisted of
approximately $31.0 million plus the assumption of approximately $7.4 million in
financing arrangements. The Company borrowed $30.0 million under its revolving
loan facility to finance the transaction. The acquisition has been accounted for
as a purchase and, accordingly, the results of operations of MDI have been
included in the Company's consolidated financial statements from the date of
acquisition. The goodwill recorded as a result of this acquisition was $17.2
million which is being amortized on a straight-line basis over 20 years.
Additionally, the Company assigned $8.3 million of the purchase price to
customer contracts and $0.4 million of the purchase price to assembled work
force. The amounts are being amortized on a straight-line basis over 20 and four
years respectively. The allocation of the intangible assets acquired was based
on an independent valuation study.
 
    On November 13, 1998, two wholly owned subsidiaries of the Company acquired
all of the outstanding common stock of CuraCare, Inc. and all of the partnership
interests in American Shared-CuraCare (collectively, "American Shared"). The
purchase price consisted of approximately $13.4 million in cash plus the
assumption of approximately $12.2 million in financing arrangements. In
connection with the acquisition, the Company also refinanced $13.1 million of
American Shared's outstanding debt. The Company
 
                                       10
<PAGE>
borrowed $30.0 million under a new tranche C term loan facility to finance the
transaction. The transaction has been accounted for as a purchase and,
accordingly, the results of operations of American Shared have been included in
the Company's consolidated financial statements from the date of acquisition.
The goodwill recorded as a result of this acquisition was approximately $30.4
million which is being amortized on a straight-line basis over 20 years. The
allocation of the American Shared purchase price is tentative pending completion
of fair value determinations for the net assets acquired. The allocation may
change with the completion of these determinations.
 
RESULTS OF OPERATIONS
 
    QUARTER ENDED MARCH 31, 1999 COMPARED TO QUARTER ENDED MARCH 31,
1998--Revenues for the first quarter of 1999 were $64.4 million, an increase of
$33.1 million, or 106.1%, over 1998, primarily due to the MTI, MDI, and American
Shared acquisitions. The remaining increase reflects higher scan-based MRI
revenue, MRI revenue under fixed fee contracts and other revenue items
(including revenue for other modalities). Overall, MRI revenue increased $30.3
million, as a result of a 112.7% increase in total scan volume partially offset
by a 0.78% decrease in the average revenue realized per MRI scan. The average
daily scan volume per MRI system increased 13.2% to 8.6 from 7.6 in the first
quarter of 1998. Management attributes the non-acquisition volume increase to
the Company's continuing MRI systems upgrade program, which has enabled the
Company to obtain new, long-term contracts from both existing and new customers,
and to the continuing positive effect of marketing programs implemented in early
1997. Management believes the decrease in average revenue realized per scan is
the result of many customers achieving discount price levels in incremental scan
volume; obtaining contracts with customers that have high scan volumes which
justify lower scan prices; and continuing competitive pressure in the MRI
service industry and cost containment efforts by health care payors. Other
revenue increased $2.8 million, or 64.6% partly related to a $1.2 million
increase in lithotripsy revenue associated with the MTI acquisition, as well as
a $0.5 million increase in SPECT camera revenue. The remainder of the increase
in other revenue was primarily due to an increase in revenue associated with
other modalities.
 
    The Company operated 250 MRI systems at March 31, 1999 compared to 193 MRI
systems at March 31, 1998. The increase was primarily a result of the MTI
acquisition and to a lesser degree the American Shared and MDI acquisitions.
 
    Operating expenses, excluding depreciation, totaled $31.6 million in the
first quarter of 1999, an increase of $16.4 million, or 107.6%, from the first
quarter of 1998. Payroll and related employee expenses increased $6.4 million,
or 106.3%, primarily as a result of an increase in the number of employees
necessary to support new units in operation and increased scans per unit.
Preventative maintenance and cryogen expense increased $2.9 million, or 94.2%,
due to an increase in the number of systems in service and the expiration of
warranties on an increased number of MRI systems. Equipment rental expense
increased $2.0 million, or 119.4%, resulting from a higher number of leased MRI
systems in operation. Tractor and transportation expenses increased $0.9
million, or 191.8%, principally as a result of a higher number of leased
tractors in operation associated with the MTI and American Shared acquisitions.
 
    Depreciation expense during the first quarter of 1999 totaled $9.2 million,
an increase of $4.3 million, or 86.0% from the 1998 level principally due to a
higher amount of depreciable assets associated with equipment additions and
upgrades and equipment acquired through acquisitions. Amortization expense
during the first quarter of 1999 increased $2.0 million, or 242.2%, over the
first quarter of 1998 as a result of the acquisitions made during 1998.
 
    Selling, general and administrative expenses totaled $6.3 million in the
first quarter of 1999, an increase of $3.3 million, or 108.5%, from the same
quarter in 1998. Payroll and related expenses increased $1.5 million, or 78.7%,
primarily as a result of increased employee compensation related to increased
sales commissions and increased staffing levels necessary to support the
Company's increased level of operations. Bad debt expense increased $0.9 million
primarily as a result of the growth in revenues and the
 
                                       11
<PAGE>
application of the Company's more conservative bad debt reserve policy to the
acquired MTI, MDI and American Shared operations.
 
    The transaction related costs for the first quarter of 1999 primarily
represent management fees paid to American Shared Hospital Services principally
for direct patient billing services provided to American Shared. The transaction
related costs for the first quarter of 1998 represent a special non-recurring
bonus paid in connection with the MTI acquisition.
 
    Interest expense of $10.2 million in the first quarter of 1999 was $3.5
million, or 52.7%, higher than the first quarter of 1998, as a result of higher
average outstanding debt balances during 1999 as compared to 1998. This increase
was primarily related to debt incurred in connection with the MTI, MDI, and
American Shared acquisitions.
 
    An income tax provision of $1.7 million was recorded in the first quarter of
1999, resulting in an effective tax of 46.5%. The Company generated a loss
before income taxes for the first quarter of 1998 and no income tax benefit was
recorded.
 
    The Company's net income was $2.0 million in the first quarter of 1999
compared to net loss before extraordinary loss of $0.3 million in the first
quarter of 1998, an increase of $2.3 million, primarily attributable to the
increase in revenues. The Company reported an extraordinary loss of $1.3 million
on early extinguishment of debt in the first quarter of 1998. The earnings per
common share calculations reflect preferred dividend requirements and financing
fee accretion of $0.6 million in the first quarter of 1999 and $0.5 million in
the first quarter of 1998.
 
LIQUIDITY AND CAPITAL RESOURCES
 
    The Company generated $7.5 million and $3.3 million from operating
activities during the first quarter of 1999 and 1998, respectively. Capital
expenditures, consisting primarily of new equipment purchases, totaled $25.1
million and $12.5 million during the three months ended March 31, 1999 and 1998,
respectively. Since January 1, 1999, the Company has purchased 14 MRI systems,
including replacement systems. The Company expects to purchase additional
equipment under binding commitments in 1999 and finance such purchases with the
Company's Revolving Loan Facility.
 
    The Company's primary cash needs consist of capital expenditures and debt
service. The Company incurs capital expenditures for the purposes of (i)
providing routine upgrades of its MRI systems; (ii) replacing or making major
upgrades to older, less advanced systems with new state-of-the-art systems; and
(iii) purchasing new systems. The Company expects capital expenditures to be
approximately $75.0 million in 1999, which primarily reflects the anticipated
purchase of 40 new MRI systems, including replacement systems. The Company's
decision to purchase a new system is typically predicated on obtaining new or
extending existing customer contracts, which serve as the basis of demand for
the new system.
 
    As a result of the Recapitalization Merger, the Company issued $185.0
million of Notes (consisting of $140.0 million Senior Subordinated Notes due
2005, bearing interest at the rate of 9 5/8% per annum; and $45.0 million
Floating Interest Rate Subordinated Term Securities due 2005, bearing interest
at a rate per annum equal to LIBOR plus 4.19%) which are payable semiannually,
and require no principal repayments until maturity. The Company also entered
into a $125.0 million Credit Agreement consisting of a $50.0 million Term Loan
Facility and a $75.0 million Revolving Loan Facility, and carried over
approximately $12.7 million of other obligations. The Term Loan matures on the
sixth anniversary of the initial borrowing and requires annual principal
repayments of one percent per year during the first five years and the
outstanding principal amount in the sixth year. The Revolving Loan Facility
matures on the fifth anniversary of the initial borrowing and has mandatory
commitment reductions of $40.0 million on the fourth and fifth anniversaries of
the initial borrowing. The Credit Agreement contains restrictive covenants,
which, among other things, limit the incurrence of additional indebtedness,
dividends, transactions
 
                                       12
<PAGE>
with affiliates, asset sales, acquisitions, mergers and consolidations, liens
and encumbrances, and prepayments of other indebtedness. In addition, the Credit
Agreement requires loans to be prepaid with 100% of the net proceeds of
non-ordinary-course asset sales or other dispositions of property, issuances of
debt obligations and certain preferred stock and certain insurance proceeds, 75%
of annual excess cash flow and 50% of the net proceeds from common equity and
certain preferred stock issuances, in each case subject to limited exceptions.
Voluntary prepayments are permitted in whole or in part. Subsequent amendments
to the Credit Agreement are described below.
 
    Also as part of the Recapitalization Merger, the Company issued $15.0
million of Series F Preferred Stock. The Series F Preferred Stock pays dividends
at the rate of 13.5% per annum, payable quarterly in arrears, with such
dividends payable in kind for the first five years from the issue date and
thereafter in cash. The Series F Preferred Stock is mandatorily redeemable for
its liquidation preference plus accrued and unpaid dividends on the 10th
anniversary of the issue date. The Series F Preferred Stock is redeemable at the
option of the Company prior to the 10th anniversary at premiums (expressed as a
percentage of the accreted face value) declining over ten years from 13.5% to
0%. The Company does not currently intend to redeem the Series F Preferred Stock
prior to the mandatory redemption date.
 
    On March 12, 1998, the Company acquired MTI, another nationwide provider of
diagnostic imaging services. The Company funded the MTI acquisition with $20.0
million of existing Term Loan availability under tranche A, $5.4 million of
revolver borrowings, a $20.0 million increase to the Term Loan Facility under
tranche A, and a new $50.0 million Term Loan Facility under tranche B. The
Credit Agreement was amended to provide for the increased Term Facilities.
 
    On May 19, 1998, the Company acquired MDI, a subsidiary of U. S. Diagnostic,
Inc. The Company borrowed $30.0 million under its Revolving Loan Facility to
finance the transaction.
 
    On September 24, 1998, the Company completed a $90.0 million expansion of
its Credit Agreement. The transaction added a new $85.0 million Term Loan
Facility under tranche C and increased the Revolving Loan Facility to $80.0
million ($46.4 million of which was funded at March 31, 1999). The increased
Loan Facilities provided funds to complete the American Shared acquisition and
will also provide funds for future acquisitions and capital expenditures.
 
    On November 13, 1998, the Company acquired American Shared. The purchase
price consisted of approximately $13.4 million plus the assumption of
approximately $12.2 million in financing arrangements. In connection with the
acquisition, the Company also refinanced $13.1 million of American Shared's
outstanding debt. The Company borrowed $30.0 million under the tranche C Term
Loan Facility to finance the transaction.
 
    On April 14, 1999, the Company announced it had signed a definitive
agreement to acquire all of the outstanding common stock of Three Rivers Holding
Corp., parent corporation of SMT Health Services Inc. ("SMT") in a
stock-for-stock merger. SMT is a regional MRI provider with 35 MRI systems
serving 144 customers in 10 states. SMT is wholly owned by an affiliate of
Apollo, which currently owns approximately 82.6% of the Company's outstanding
common stock; accordingly, the merger is expected to be accounted for as a
reorganization of entities under common control in a manner similar to a pooling
of interests. As part of the transaction, the Company intends to assume or
refinance $66.5 million of SMT's indebtedness. The transaction is subject to
customary conditions, including obtaining sufficient funds to refinance SMT's
indebtedness, and is expected to close by the middle of May 1999.
 
    The Company believes that, based on current levels of operations and
anticipated growth, its cash from operations, together with other available
sources of liquidity, including borrowings available under the Revolving Loan
Facility, will be sufficient over the next several years to fund anticipated
capital expenditures and make required payments of principal and interest on its
debt, including payments due on the Notes and obligations under the Credit
Agreement.
 
                                       13
<PAGE>
    The Company's expansion and acquisition strategy may require substantial
capital, and no assurance can be given that the Company will be able to raise
any necessary additional funds through bank financing or the issuance of equity
or debt securities on terms acceptable to the Company, if at all.
 
YEAR 2000 COMPLIANCE
 
    The following disclosure is a Year 2000 readiness disclosure statement
pursuant to the Year 2000 Readiness and Disclosure Act. The Company has
implemented a process to address its Year 2000 compliance issues. The process
includes: (i) an inventory and assessment of the compliance of essential systems
and equipment of the Company and of Year 2000 mission critical suppliers,
customers, and other third parties, (ii) the remediation of non-compliant
systems and equipment, and (iii) contingency planning. The Company has completed
its inventory of imaging and therapeutic systems and has completed approximately
80% of its inventory of information systems. The Company has identified its
mission critical suppliers, customers and other third parties and is in the
process of communicating with them about their Year 2000 readiness plans and
progress. During 1998, the Company purchased Year 2000 compliant financial
reporting software which has been successfully implemented. As a result, the
Company does not believe that its financial reporting, wholesale billing, or
accounts receivable functions will be adversely affected by Year 2000 concerns.
The cost of this software was approximately $1.0 million, including
installation.
 
    The Company has also been working closely with the original equipment
manufacturers ("OEM") of its imaging and therapeutic systems to address Year
2000 concerns. Approximately 98% of the Company's MRI and CT systems will be
made compliant on a timely basis by the OEMs pursuant to the Company's existing
maintenance contracts. The Company cannot currently estimate the additional
costs that will be incurred to address Year 2000 concerns. The Company's
analysis of its Year 2000 efforts are ongoing and its overall plan and cost
estimations will continue to evolve, as new information becomes available.
 
    The failure of the Company, its mission critical suppliers, customers or
third parties to be fully Year 2000 compliant for essential systems and
equipment by January 1, 2000 could result in interruptions in normal business
work operations. The Company's potential risks include: (i) the inability to
deliver imaging and therapeutic services, (ii) the delayed receipt of payments
from clients or fiscal intermediaries, (iii) the failure of security systems,
elevators, heating systems and other operational systems in the Company's
offices and (iv) the inability to receive critical equipment from vendors. Each
of these events could have a material adverse effect on the Company's business,
results of operations and financial condition.
 
    Contingency plans for Year 2000 related issues continue to be developed and
include, but are not limited to, identification of alternate suppliers,
alternate equipment and manual systems. However, any contingency plan
implemented by the Company may not succeed or may not be adequate to meet the
Company's needs without materially affecting the Company's business, results of
operations or financial condition.
 
    Certain statements contained in Management's Discussion and Analysis of
Financial Condition and Results of Operations, particularly in the section
entitled "Liquidity and Capital Resources" and elsewhere in this quarterly
report on Form 10-Q, are forward-looking statements. Statements in this
quarterly report on Form 10-Q which address activities, events or developments
that the Company expects or anticipates will or may occur in the future,
including such things as results of operations and financial condition, the
consummation of acquisitions and financing transactions and the effect of such
transactions on the Company's business and the Company's plans and objectives
for future operations and expansion are examples of forward-looking statements.
These forward-looking statements are subject to risks and uncertainties,
including those identified as "Risk Factors" in the Company's Registration
Statements on Forms S-2 (No. 333-33817) and S-4 (No. 333-33787). The foregoing
should not be construed as an exhaustive list of all factors which could cause
actual results to differ materially from those expressed in forward-looking
statements made by the Company. Actual results may materially differ from
anticipated results described in these statements.
 
                                       14
<PAGE>
PART II--OTHER INFORMATION
 
ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K
 
    (a) Exhibits
 
<TABLE>
<CAPTION>
 EXHIBIT NO.      NOTE      DESCRIPTION
-------------     -----     ----------------------------------------------------------------------------------------------
<C>            <C>          <S>
        3.1            (5)  Form of Amended and Restated Certificate of Incorporation of the Company.
 
        3.2            (9)  Certificate of Amendment of Certificate of Incorporation, dated July 30, 1998.
 
        3.3           (10)  Certificate of Designations, Powers, Preferences and Rights of Series F Preferred Stock, dated
                              December 18, 1997.
 
        3.4            (9)  Certificate of Amendment of Certificate Designations, Powers, Preferences and Rights of Series
                              F Preferred Stock, dated July 30, 1998.
 
        3.5            (5)  By Laws of the Company, as amended.
 
        4.1            (5)  Form of Indenture for the 9 5/8% Senior Subordinated Notes due 2005 and the Senior
                              Subordinated Floating Rate Notes due 2005 (including the Forms of Notes as Exhibits A and B
                              thereto) between the Company and IBJ Schroder Bank & Trust Company, as trustee.
 
        4.2           (10)  First Supplemental Indenture between the Company, various subsidiaries of the Company and IBJ
                              Shroder, dated January 30, 1998.
 
        4.3           (10)  Second Supplemental Indenture between the Company, various subsidiaries of the Company and IBJ
                              Shroder, dated March 12, 1998.
 
        4.4           (10)  Third Supplemental Indenture between the Company, various subsidiaries of the Company and IBJ
                              Shroder, dated May 19, 1998.
 
        4.5           (10)  Fourth Supplemental Indenture between the Company, various subsidiaries of the Company and IBJ
                              Shroder, dated November 13, 1998.
 
        4.6            (5)  Form of Guarantee of the Notes.
 
       10.1            (1)  Form of Indemnification Agreement between the Company and its directors and/or officers.
 
       10.2            (4)  Amended and Restated 1991 Stock Option Plan of the Company, including forms of agreement used
                              thereunder.
 
       10.3            (8)  1997 Stock Option Plan of the Company, including form of option agreement used thereunder.
 
       10.4            (5)  Employment Agreement dated as of July 23, 1997 between the Company and Richard N. Zehner.
 
       10.5            (5)  Agreement Not to Compete dated as of July 23, 1997 among Newport Investment, LLC, the Company,
                              Richard N. Zehner and Vincent S. Pino.
 
       10.6            (7)  Amendment to Employment Agreement dated as of July 23, 1997 between the Company and Richard N.
                              Zehner.
 
       10.7           (10)  Amendment to Employment Agreement dated as of December 31, 1997 between the Company and
                              Richard N. Zehner.
 
       10.8           (10)  Second Amendment to Employment Agreement dated as of February 5, 1998 between the Company and
                              Richard N. Zehner.
 
       10.9            (5)  Employment Agreement dated as of July 23, 1997 between the Company and Vincent S. Pino.
</TABLE>
 
                                       15
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT NO.      NOTE      DESCRIPTION
-------------     -----     ----------------------------------------------------------------------------------------------
<C>            <C>          <S>
      10.10            (7)  Amendment to Employment Agreement dated as of July 23, 1997 between the Company and Vincent S.
                              Pino.
 
      10.11           (10)  Amendment to Employment Agreement dated as of December 31, 1997 between the Company and
                              Vincent S. Pino.
 
      10.12           (10)  Second Amendment to Employment Agreement dated as of February 5, 1998 between the Company and
                              Vincent S. Pino.
 
      10.13            (8)  Employment Agreement dated as of January 19, 1998 between the Company and Kenneth S. Ord.
 
      10.14            (8)  Agreement Not to Compete dated as of January 19, 1998 between the Company and Kenneth S. Ord.
 
      10.15            (2)  Employment Agreement dated as of September 9, 1993 between the Company and Terry A. Andrues.
 
      10.16            (2)  Employment Agreement dated as of June 6, 1994 between the Company and Cheryl A. Ford.
 
      10.17            (2)  Employment Agreement dated as of September 9, 1993 between the Company and Jay A. Mericle.
 
      10.18            (2)  Employment Agreement dated as of June 6, 1994 between the Company and Neil M. Cullinan.
 
      10.19           (10)  Agreement Not to Compete dated as of April 29, 1998 between the Company and Raymond M.
                              Almieri.
 
      10.20           (10)  Employment Agreement dated as of April 29, 1998 between the Company and Raymond M. Almieri.
 
      10.21           (10)  Employment Agreement dated as of April 29, 1998 between the Company and Russell D. Phillips,
                              Jr.
 
      10.22           (10)  Agreement Not to Compete dated as of April 29, 1998 between the Company and Russell D.
                              Phillips, Jr.
 
      10.23            (3)  Employment Agreement dated as of July 7, 1995 between the Company and Michael W. Grismer.
 
      10.24            (6)  Agreement and Plan of Merger dated as of January 13, 1998 relating to the acquisition of
                              Mobile Technology Inc.
 
      10.25            (8)  Securities Purchase Agreement dated as of March 12, 1998 relating to the acquisition of
                              American Shared-CuraCare and CuraCare, Inc.
 
      10.26            (8)  Stock Purchase Agreement dated as of March 30, 1998 among the Company, US Diagnostic, Inc. and
                              Medical Diagnostics, Inc.
 
      10.27            (9)  Amended and Restated Credit Agreement dated September 24, 1998.
 
      10.28           (11)  Agreement and Plan of Merger dated as of April 14, 1999 among the Company and Three Rivers
                              Holding Corp.
 
       27.1           (12)  Financial Data Schedule.
</TABLE>
 
------------------------
 
 (1) Incorporated by reference herein to the indicated exhibits filed in
     response to Item 16, "Exhibits" of the Company's Registration Statement on
     Form S-1, No. 33-40805, initially filed on May 24, 1991.
 
 (2) Incorporated by reference herein to the indicated exhibit filed in response
     to Item 6(a), "Exhibits" of the Company's Quarterly Report on Form 10-Q for
     the quarter ended June 30, 1994.
 
                                       16
<PAGE>
 (3) Incorporated by reference herein to Exhibit 10.36 filed in response to Item
     6(a), "Exhibits" of the Company's Quarterly report on Form 10-Q for the
     quarter ended June 30, 1995.
 
 (4) Incorporated by reference herein to Exhibits filed with The Company's
     Registration Statement on Form S-1, No. 33-40805, initially filed on May
     24, 1991 and The Company's definitive Proxy Statement with respect to its
     Annual Meeting of Shareholders held May 16, 1996.
 
 (5) Incorporated by reference to exhibits filed with the Company Registration
     Statement on Form S-2, No. 333-33817.
 
 (6) Incorporated by reference to exhibits filed with the Company's Current
     Report on Form 8-K dated January 13, 1998.
 
 (7) Incorporated by reference herein to the indicated Exhibit in response to
     Item 14(a)(3), "Exhibits" of the Company's Annual report on Form 10-K for
     the year ended December 31, 1997.
 
 (8) Incorporated by reference to exhibits filed in response to Item 6,
     "Exhibits" of the Company's Quarterly Report on Form 10-Q for the quarter
     ended March 31, 1998.
 
 (9) Incorporated by reference to exhibits filed in response to Item 6,
     "Exhibits" of the Company's Quarterly Report on Form 10-Q for the quarter
     ended September 30, 1998.
 
 (10) Incorporated by reference herein to the indicated Exhibit in response to
      Item 14(a)(3), "Exhibits" of the Company's Annual Report on Form 10-K for
      the year ended December 31, 1998.
 
 (11) Incorporated by reference to exhibits filed in response to Item 7,
      "Exhibits" of the Company's Form 8-K Current Report dated April 15, 1999.
 
 (12) Filed herewith.
 
    (b) Reports on Form 8-K in the first quarter of 1999:
 
        None filed for the quarter ended March 31, 1999.
 
                                       17
<PAGE>
                                   SIGNATURES
 
    Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.
 
<TABLE>
<S>                             <C>  <C>
                                ALLIANCE IMAGING, INC.
 
May 13, 1999                    By:            /s/ RICHARD N. ZEHNER
                                     -----------------------------------------
                                                 Richard N. Zehner
                                        CHAIRMAN AND CHIEF EXECUTIVE OFFICER
</TABLE>
 
    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
registrant and in the capacities indicated on May 13, 1999.
 
<TABLE>
<CAPTION>
          SIGNATURE                       TITLE
------------------------------  --------------------------
<C>                             <S>
                                Chairman of the Board of
    /s/ RICHARD N. ZEHNER         Directors, Chief
------------------------------    Executive Officer
      Richard N. Zehner           (Principal Executive
                                  Officer)
 
                                Executive Vice President
      /s/ KENNETH S. ORD          and Chief Financial
------------------------------    Officer (Principal
        Kenneth S. Ord            Financial Officer)
</TABLE>
 
                                       18