Share-Based Payments - Schedule of Allocation of Share Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 256	$ 379	$ 523	$ 855
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	209	272	299	487
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	31	73	122	160
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	2	5	9	17
Cost of oncology revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 14	$ 29	$ 93	$ 191