UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2023	Jan. 31, 2022
Income Statement [Abstract]
Oncology services revenue	$ 12,773	$ 13,193	$ 40,799	$ 36,232
Costs and operating expenses:
Cost of oncology services	7,699	6,406	22,194	17,411
Research and development	3,202	2,181	8,693	6,783
Sales and marketing	1,761	1,549	5,153	4,764
General and administrative	2,569	2,227	7,494	6,356
Total costs and operating expenses	15,231	12,363	43,534	35,314
Income (loss) from operations	(2,458)	830	(2,735)	918
Other income (loss)	36	(32)	9	11
Income (loss) before provision for income taxes	(2,422)	798	(2,726)	929
Provision for income taxes	17	11	48	37
Net income (loss)	$ (2,439)	$ 787	$ (2,774)	$ 892
Net income (loss) per common share outstanding
Net (income) loss per common share outstanding, basic (in dollars per share)	$ (0.18)	$ 0.06	$ (0.20)	$ 0.07
Net (income) loss per common share outstanding, diluted (in dollars per share)	$ (0.18)	$ 0.05	$ (0.20)	$ 0.06
Weighted average common shares outstanding
Weighted average common shares outstanding, basic (in shares)	13,558,642	13,500,444	13,532,990	13,170,880
Weighted average common shares outstanding, diluted (in shares)	13,558,642	14,387,009	13,532,990	14,178,082
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]	Service [Member]
Cost, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]	Service [Member]