Table 2. Systematic biopsy, 3D-GS TRUS and 3D-PDS detection of prostate cancer by PSA level in 112 patients.

PSA (ng ml−1)	Cancer detection rate
	Systematic biopsy	3D-GS TRUS	3D-PDS
<4	5.6% (1/18)	0	0 (0/2)
4–10	25% (10/40)	45.5% (5/11)	60% (3/5)
>10	55.6% (30/54)	88.9% (24/27)	80.6% (25/31)
>20	72.4% (21/29)	85% (17/20)	90% (18/20)

3D-GS TRUS, three-dimensional greyscale transrectal ultrasound; 3D-PDS, three-dimensional power Doppler sonography; PSA, prostate-specific antigen.