Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Jan. 31, 2013		Jan. 31, 2012		Jan. 31, 2013		Jan. 31, 2012
Net revenue	$ 2,917		$ 2,396		$ 6,481		$ 5,768
Sales and marketing costs	(658)		(623)		(2,047)		(1,885)
Stock- based compensation expense	(570)		(743)		(1,934)		(2,612)
Personalized Oncology Solutions [Member]
Net revenue	473		649		1,850		1,837
Direct cost of services	(661)		(528)		(2,030)		(1,463)
Sales and marketing costs	(361)		(242)		(495)		(718)
Other operating expenses	0		0		0		0
Stock- based compensation expense	0	[1]	0	[1]	0	[1]	0	[1]
Segment profit (loss)	(549)		(121)		(675)		(344)
Translational Oncology Solutions [Member]
Net revenue	2,444		1,747		4,631		3,931
Direct cost of services	(561)		(801)		(1,740)		(1,904)
Sales and marketing costs	(220)		(175)		(636)		(626)
Other operating expenses	(627)		(851)		(1,463)		(2,419)
Stock- based compensation expense	0	[1]	0	[1]	0	[1]	0	[1]
Segment profit (loss)	1,036		(80)		792		(1,018)
Unallocated Corporate Overhead [Member]
Net revenue	0		0		0		0
Direct cost of services	0		0		0		0
Sales and marketing costs	0		0		0		0
Other operating expenses	(637)		(829)		(2,418)		(2,489)
Stock- based compensation expense	(570)	[1]	(743)	[1]	(1,934)	[1]	(2,612)	[1]
Segment profit (loss)	(1,207)		(1,572)		(4,352)		(5,101)
Consolidated [Member]
Net revenue	2,917		2,396		6,481		5,768
Direct cost of services	(1,222)		(1,329)		(3,770)		(3,367)
Sales and marketing costs	(581)		(417)		(1,131)		(1,344)
Other operating expenses	(1,264)		(1,680)		(3,881)		(4,908)
Stock- based compensation expense	(570)	[1]	(743)	[1]	(1,934)	[1]	(2,612)	[1]
Segment profit (loss)	$ (720)		$ (1,773)		$ (4,235)		$ (6,463)

[1] Stock compensation expense is shown separately and is excluded from direct costs of services, sales and marketing costs, and other operating expenses, as it is managed on a consolidated basis and is not used by management to evaluate the performance of its segments.