NOTE 15 - SUPPLEMENTAL GUARANTOR INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)	$ 56,559	$ 4,981	$ 2,899	$ (152)	$ 4,496	$ 48	$ 3,606	$ (808)	$ 64,287	$ 7,342	$ (12,685)
Depreciation and amortization									57,740	57,481	53,997
Provision for bad debt									25,904	22,339	21,995
Equity in earnings of joint ventures									(6,476)	(5,224)	(4,952)
Distributions from joint ventures									6,477	4,993	7,639
Deferred rent amortization									3,608	2,282	1,848
Amortization of deferred financing cost									2,474	2,940	2,797
Loss (gain) on sale and disposal of equipment									456	(2,240)	1,136
Gain on bargain purchase									(810)
Gain on de-consolidation of joint venture									(2,777)
Amortization of cash flow hedge									918	1,225	917
Stock-based compensation									2,736	3,110	3,718
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable									(17,350)	(45,014)	(24,822)
Other current assets									3,565	(3,935)	(3,226)
Other assets									(60,975)	43	24
Deferred revenue									197	(492)	207
Accounts payable, accrued expenses									(5,868)	12,542	8,256
Net cash (used in) provided by operating activities									75,269	57,636	66,884
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities									(45,493)	(42,990)	(61,774)
Purchase of property and equipment									(44,448)	(42,720)	(40,293)
Proceeds from sale of equipment									1,549	325	685
Proceeds from insurance claims on damaged equipment										2,740
Proceeds from sale of imaging facilities									2,300
Proceeds from sale of joint venture interests									1,800
Purchase of equity interest in joint ventures									(2,756)	(5,094)
Net cash used in investing activities									(87,048)	(87,739)	(101,382)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable									(22,223)	(18,756)	(21,463)
Proceeds from borrowings upon refinancing									344,485		478,313
Repayment of debt									(277,875)		(412,000)
Deferred financing costs									(3,753)	(944)	(13,566)
Proceeds from, net of payments on, line of credit									(25,000)	58,000
Payments to counterparties of interest rate swaps, net of amounts received									5,823	6,455	6,382
Purchase of non-controlling interests									117
Distributions to noncontrolling interests									(71)	(154)	(131)
Proceeds from issuance of common stock upon exercise of options/warrants										242	271
Net cash provided by (used in) financing activities									9,623	31,933	25,042
EFFECT OF EXCHANGE RATE CHANGES ON CASH									63	(2)	(11)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(2,093)	1,828	(9,467)
Parent
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									64,517	7,231	(12,852)
Equity in earnings of consolidated subsidiaries									(64,517)	(7,231)	12,852
CASH FLOWS FROM FINANCING ACTIVITIES
EFFECT OF EXCHANGE RATE CHANGES ON CASH									63
Subsidiary Issuer [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									64,517	7,231	(12,852)
Depreciation and amortization									12,690	13,986	13,656
Provision for bad debt									5,452	4,485	5,243
Equity in earnings of consolidated subsidiaries									(93,080)	(31,410)	(26,258)
Deferred rent amortization									1,917	1,811	254
Amortization of deferred financing cost									2,474	2,940	2,797
Amortization of discount on notes									1,163	244	164
Loss (gain) on sale and disposal of equipment									600	(2,512)	141
Amortization of cash flow hedge									918	1,225	917
Stock-based compensation									684	778	929
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Other current assets									2,203	(3,366)	(2,552)
Other assets									(542)	41	876
Accounts payable, accrued expenses									(6,524)	(27,252)	(27,504)
Net cash (used in) provided by operating activities									(7,528)	(31,799)	(34,318)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities									(10,494)	(1,999)	(1,401)
Proceeds from insurance claims on damaged equipment										2,422
Purchase of property and equipment									(9,173)	(11,125)	(12,024)
Proceeds from sale of equipment									218		121
Net cash used in investing activities									(19,449)	(10,702)	(13,304)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable									(6,061)	(7,181)	(8,903)
Repayment of debt upon extinguishment									(277,875)		(412,000)
Proceeds from borrowings upon refinancing									344,485		478,313
Deferred financing costs									(3,753)	(944)	(13,566)
Proceeds from, net of payments on, line of credit									(25,000)	58,000
Payments to counterparties of interest rate swaps, net of amounts received									(5,823)	(6,455)	(6,382)
Proceeds from issuance of common stock upon exercise of options/warrants										242	271
Net cash provided by (used in) financing activities									25,973	43,662	37,733
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(1,004)	1,161	(9,889)
CASH AND CASH EQUIVALENTS, beginning of period									1,366	205	10,094
CASH AND CASH EQUIVALENTS, end of period									362	1,366	205
Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									93,080	31,410	26,258
Depreciation and amortization									44,870	43,268	40,150
Provision for bad debt									17,888	15,443	14,293
Equity in earnings of consolidated subsidiaries									(151)	(1,275)	(1,045)
Distributions from consolidated subsidiaries									906	1,597	1,247
Equity in earnings of joint ventures									(6,476)	(5,224)	(4,952)
Distributions from joint ventures									6,477	4,993	7,639
Deferred rent amortization									1,691	471	1,594
Loss (gain) on sale and disposal of equipment									(144)	272	995
Gain on bargain purchase									(810)
Gain on de-consolidation of joint venture									(2,777)
Stock-based compensation									2,052	2,332	2,789
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable									(4,051)	(27,886)	(11,818)
Other current assets									1,085	(183)	(635)
Other assets									(60,433)	2	(852)
Deferred revenue									197	(492)	207
Accounts payable, accrued expenses									(9,589)	23,275	24,615
Net cash (used in) provided by operating activities									83,815	88,003	100,485
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities									(34,999)	(40,991)	(60,387)
Proceeds from insurance claims on damaged equipment										318
Purchase of property and equipment									(35,275)	(30,984)	(28,175)
Proceeds from sale of equipment									1,331	325	564
Proceeds from sale of imaging facilities									2,300
Proceeds from sale of joint venture interests									1,800
Purchase of equity interest in joint ventures									(2,756)	(5,094)
Net cash used in investing activities									(67,599)	(76,426)	(87,998)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable									(16,162)	(11,575)	(12,476)
Purchase of non-controlling interests									(117)
Net cash provided by (used in) financing activities									(16,279)	(11,575)	(12,476)
EFFECT OF EXCHANGE RATE CHANGES ON CASH									63	(2)	(11)
Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									(79)	1,386	1,212
Depreciation and amortization									180	227	191
Provision for bad debt									2,564	2,411	2,459
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable									(13,299)	(17,128)	(13,004)
Other current assets									277	(386)	(39)
Accounts payable, accrued expenses									10,245	16,519	11,145
Net cash (used in) provided by operating activities									(112)	3,029	1,964
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities											14
Purchase of property and equipment										(611)	(94)
Net cash used in investing activities										(611)	(80)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable											(84)
Distributions to noncontrolling interests									(977)	(1,751)	(1,378)
Net cash provided by (used in) financing activities									(977)	(1,751)	(1,462)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(1,089)	667	422
CASH AND CASH EQUIVALENTS, beginning of period									1,089	422
CASH AND CASH EQUIVALENTS, end of period										1,089	422
Eliminations [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									(157,748)	(39,916)	(14,451)
Equity in earnings of consolidated subsidiaries									157,748	39,916	14,451
Distributions from consolidated subsidiaries									(906)	(1,597)	(1,247)
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Net cash (used in) provided by operating activities									(906)	(1,597)	(1,247)
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from insurance claims on damaged equipment										2,740
CASH FLOWS FROM FINANCING ACTIVITIES
Distributions to noncontrolling interests									906	1,597	1,247
Net cash provided by (used in) financing activities									906	1,597	1,247
Consolidated
CASH FLOWS FROM OPERATING ACTIVITIES
NET INCOME (LOSS)									64,287	7,342	(12,685)
Depreciation and amortization									57,740	57,481	53,997
Provision for bad debt									25,904	22,339	21,995
Equity in earnings of consolidated subsidiaries
Distributions from consolidated subsidiaries
Equity in earnings of joint ventures									(6,476)	(5,224)	(4,952)
Distributions from joint ventures									6,477	4,993	7,639
Deferred rent amortization									3,608	2,282	1,848
Amortization of deferred financing cost									2,474	2,940	2,797
Amortization of discount on notes									1,163	244	164
Loss (gain) on sale and disposal of equipment									456	(2,240)	1,136
Gain on bargain purchase									(810)
Gain on de-consolidation of joint venture									(2,777)
Amortization of cash flow hedge									918	1,225	917
Stock-based compensation									2,736	3,110	3,718
Changes in operating assets and liabilities, net of assets acquired and liabilities assumed in purchase transactions:
Accounts receivable									(17,350)	(45,014)	(24,822)
Other current assets									3,565	(3,935)	(3,226)
Other assets									(60,975)	43	24
Deferred revenue									197	(492)	207
Accounts payable, accrued expenses									(5,868)	12,542	8,256
Net cash (used in) provided by operating activities									75,269	57,636	66,884
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of imaging facilities									(45,493)	(42,990)	(61,774)
Purchase of property and equipment									(44,448)	(42,720)	(40,293)
Proceeds from sale of equipment									1,549	325	685
Proceeds from sale of imaging facilities									2,300
Proceeds from sale of joint venture interests									1,800
Purchase of equity interest in joint ventures									(2,756)	(5,094)
Net cash used in investing activities									(87,048)	(87,739)	(101,382)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on notes and leases payable									(22,223)	(18,756)	(21,463)
Repayment of debt upon extinguishment									(277,875)		(412,000)
Proceeds from borrowings upon refinancing									344,485		478,313
Deferred financing costs									(3,753)	(944)	(13,566)
Proceeds from, net of payments on, line of credit									(25,000)	58,000
Payments to counterparties of interest rate swaps, net of amounts received									(5,823)	(6,455)	(6,382)
Purchase of non-controlling interests									(117)
Distributions to noncontrolling interests									(71)	(154)	(131)
Proceeds from issuance of common stock upon exercise of options/warrants										242	271
Net cash provided by (used in) financing activities									9,623	31,933	25,042
EFFECT OF EXCHANGE RATE CHANGES ON CASH									63	(2)	(11)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									(2,093)	1,828	(9,467)
CASH AND CASH EQUIVALENTS, beginning of period										627	10,094
CASH AND CASH EQUIVALENTS, end of period									$ 362	$ 2,455	$ 627