Transrectal ultrasound: diagnosis and staging of prostatic carcinoma

Transrectal ultrasound has developed into a sophisticated technology since its first clinical application, and ultrasound imaging is now widely accepted. When 7 MHz scanning was introduced in 1986, improved resolution depicted an infrastructure of the prostate that corresponded to McNeal's 1968 concept of zonal prostate anatomy. McNeal's definition of three glandular zones (i.e., transition, central, and peripheral) and one nonglandular region (i.e., anterior fibromuscular stroma) has allowed us to identify areas of anatomic weakness through which cancer may escape the prostate. These glandular zones have sites of anatomic weakness through which cancer may easily extend to the extraprostatic space, thus affecting eventual staging. Highly accurate, easy to perform, and readily accepted by patients, strategic ultrasound-guided transrectal biopsy can accurately sample all areas within the prostate, including areas of anatomic weakness.