Ultrasound virtual endoscopy: Polyp detection and reliability of measurement in an in vitro study with pig intestine specimens

Table 1 Detection rate for the simulated polyps by ultrasound virtual endoscopy, computed tomography colonography and optical colonoscopy

Actual polyp size, mm	Referenced No. of polyps	OC		CTC		USVE
		No. of detected polyps	Sensitivity	No. of detected polyps	Sensitivity	No. of detected polyps	Sensitivity
≤ 5	9	9	100%	8	88.9%	9	100%
6-9	15	15	100%	15	100%	14	93.3%
≥ 10	6	6	100%	6	100%	6	100%
All	30	30	100%	29	96.7%	29	96.7%

USVE: Ultrasound virtual endoscopy; CTC: Computed tomography colonography; OC: Optical colonoscopy.

Table 2 Relationship between conspicuity grade and polyp size n (%)

Actual polyp size, mm	Conspicuity grade 2	Conspicuity grade 3	P value
≤ 5 (n = 9)	1 (11.1)	8 (88.9)	0.627
6-9 (n = 14)	2 (14.3)	12 (85.7)
≥ 10 (n = 6)	0 (0)	6 (100)
All (n = 29)	3 (10.3)	26 (89.7)

Table 3 Mean error of the optimized two-dimensional multiplanar reformatted measurement and the pooled standardized polyp size with ultrasound virtual endoscopy

Actual polyp size, mm	Mean measurementerror ± SD, mm	Pooled standardizedpolyp size ± SD, %
≤ 5 (n = 9)	1.9 ± 0.8	142.5 ± 18.7
6-9 (n = 14)	0.9 ± 1.2	111.2 ± 16.7
≥ 10 (n = 6)	1.0 ± 1.4	109.2 ± 12.2
≥ 6 (n = 20)	0.9 ± 1.3	110.5 ± 14.6