Figure 4a. US images in a 77-year-old man with elevated PSA levels and pathologic findings of prostate cancer (Gleason score, 6). (a) Transverse gray-scale US image of the prostate apex shows a hypoechoic mass (arrow) on the left. This was identified as a cancer at pathologic examination. (b) Transverse color Doppler US image of the apex depicts increased blood flow (arrow) in the same area as in a.