UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
Income Statement [Abstract]
Revenue, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]	Service [Member]
Oncology revenue	$ 17,039	$ 12,019	$ 44,589	$ 36,153
Costs and operating expenses:
Cost, Product and Service [Extensible List]	Service [Member]	Service [Member]	Service [Member]	Service [Member]
Cost of oncology revenue	$ 6,617	$ 7,849	$ 21,118	$ 22,151
Research and development	1,719	2,186	4,862	7,494
Sales and marketing	1,806	1,797	5,236	5,288
General and administrative	2,398	2,764	6,813	8,305
Total costs and operating expenses	12,540	14,596	38,029	43,238
Income (loss) from operations	4,499	(2,577)	6,560	(7,085)
Other income (expense)	19	58	30	(33)
Income (loss) before provision for income taxes	4,518	(2,519)	6,590	(7,118)
Provision for income taxes	23	11	54	49
Net income (loss)	$ 4,495	$ (2,530)	$ 6,536	$ (7,167)
Net income (loss) per common share outstanding
basic (in dollars per share)	$ 0.33	$ (0.19)	$ 0.48	$ (0.53)
and diluted (in dollars per share)	$ 0.31	$ (0.19)	$ 0.46	$ (0.53)
Weighted average common shares outstanding
basic (in shares)	13,700,627	13,593,758	13,620,686	13,538,480
and diluted (in shares)	14,364,904	13,593,758	14,132,712	13,538,480