Normal US anatomy of the prostate.

Recent concepts on prostate anatomy are first emphasized. The sonographic approaches to the prostate and the seminal vesicles are then described. They are the external suprapubic and transperineal and the transrectal and transurethral approaches. The most detailed images were obtained with transrectal sonography by using a radial then a linear-array probe. The various views of the prostate and seminal vesicles are shown according to the approach and scan orientation. Their advantages and drawbacks are discussed. Our routine protocol includes suprapubic, transperineal and transrectal scanning with a radial and a linear-array probe. Linear-array probes also allow the voiding study of the bladder neck and prostatic urethra.