Fig. 2.

Transrectal ultrasonography (TRUS) findings of the prostate tumor. A Grayscale TRUS image showing a well-defined round tumor (30 × 25 mm) at the right peripheral zone of the prostate with a heterogeneous internal echo (white arrowheads). The hypoechoic area in the center of the tumor indicates necrosis (white arrow). B TRUS color Doppler imaging did not reveal internal blood flow in the tumor, except for normal prostate blood flow. C TRUS with superb microvascular imaging (SMI) revealed low-velocity blood flow in the tumor (yellow arrowheads), hypervascularity in the urethra (red arrowheads), and Santorini plexus (white arrows). By comparing the negative blood flow signal in the tumor using conventional Doppler imaging (B), SMI clarified the relatively poor but definitive tumor blood supply