Transrectal ultrasonography for the detection and staging of carcinoma of the prostate.

Transrectal ultrasonography (TRUS) has become the most frequently used imaging modality for the prostate. The internal architecture of the prostate is readily detailed by TRUS, and the procedure allows an accurate measurement of prostate size. Carcinoma of the prostate has a characteristic hypoechoic pattern which is sometimes distinct from the normal echo pattern of the peripheral portion of the prostate. TRUS does not have sufficient sensitivity and specificity to support its use for routine screening for prostate cancer. In men with an abnormality of either digital rectal palpation of the prostate or serum prostate specific antigen, TRUS is useful for directing prostate biopsy. Transrectal core biopsies are obtained under ultrasound direction, and precise placement of the biopsy needles can be accomplished using TRUS.