Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Current assets:
Cash and cash equivalents	$ 2,392	$ 5,326
Accounts receivable, net	2,044	1,154
Inventory	645	530
Prepaid expenses and other current assets	426	305
Total current assets	5,507	7,315
Property and equipment, net	1,735	1,609
Right of use asset, net	1,001
Restricted cash	181	181
Inventory, non-current	137	155
Other assets, net	138	162
Total assets	8,699	9,422
Current liabilities:
Accounts payable and accrued expenses	654	683
Lease liability	236
Accrued protocol expense	35	133
Accrued radioactive waste disposal	94	74
Accrued payroll and related taxes	352	89
Accrued vacation	204	142
Total current liabilities	1,575	1,121
Non-current liabilities:
Lease liability, non-current	769
Accrued payroll and related taxes, non-current	55
Asset retirement obligation	577	621
Total liabilities	2,976	1,742
Commitments and contingencies (Note 14)
Stockholders' equity:
Preferred stock, $.001 par value; 7,000,000 shares authorized: Series B: 5,000,000 shares allocated; 59,065 shares issued and outstanding
Common stock, $.001 par value; 200,000,000 shares authorized; 68,897,779 and 67,388,047 shares issued and outstanding	69	67
Additional paid-in capital	93,592	92,105
Accumulated deficit	(87,938)	(84,492)
Total stockholders' equity	5,723	7,680
Series B Preferred Stock [Member]
Stockholders' equity:
Total liabilities and stockholders' equity	$ 8,699	$ 9,422