SALES SERVICE REVENUE, NET AND ACCOUNTS RECEIVABLE (Schedule of Receivables) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounts receivable, gross	$ 3,180	$ 3,181
Less allowance for doubtful accounts	(2,026)	(2,484)
Accounts receivable, net	1,154	697
Medicaid [Member]
Accounts receivable, gross	45	45
Medicare [Member]
Accounts receivable, gross	963	727
Self-Pay [Member]
Accounts receivable, gross	229	139
Third-Party Payor [Member]
Accounts receivable, gross	1,596	2,111
Contract Diagnostic Services and Other [Member]
Accounts receivable, gross	$ 347	$ 159