The seminal vesicles are a pair of small, elongated glands located behind the urinary bladder and above the prostate gland. They produce a significant portion of the fluid that makes up semen. On transrectal ultrasound (TRUS), the seminal vesicles appear as paired, elongated, hypoechoic structures with a characteristic honeycomb or grape-like internal pattern. They can also be seen on transabdominal ultrasound when the bladder is full. Sonography of the seminal vesicles is performed to evaluate for cysts, dilation, calcifications, or masses, and to assess for invasion by prostate cancer or other pelvic malignancies. Absent or hypoplastic seminal vesicles may be found in the workup for male infertility.
Sonography Term