SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details - Key Financial Data on Joint Ventures) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Data:
Current assets	$ 324,264	$ 270,424
Current liabilities	(374,784)	(398,114)
Total net assets	75,489	61,644
Book value of RadNet joint venture interests	34,930	28,079
Cost in excess of book value of acquired joint venture interests accounted for as equity method goodwill	7,299	6,449
Total value of RadNet joint venture interests	42,229	34,528	$ 34,470
Net revenue	1,315,077	1,071,840	1,154,179
Net income	44,319	(1,749)	23,440
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Balance Sheet Data:
Current assets	37,186	27,085
Noncurrent assets	73,592	68,686
Current liabilities	(12,919)	(12,545)
Noncurrent liabilities	(22,370)	(21,582)
Net revenue	129,023	101,921	108,051
Net income	$ 21,893	$ 16,850	$ 18,624