Genitourinary Radiology > Anatomy > Male Pelvis

Male Pelvis


The testis measures 3.5-4 cm in length and 2-3 cm in width and is covered by the fibrinous tunica albuginea. The spermatic cord enters the testis along the posterosuperior margin, known as the mediastinum testes. The testis is divided into lobules arrayed radially around the mediastinum testes; each lobule being composed of branching seminiferous tubules.

The epididymis is 6-7 cm in lenth, 7-8 mm diameter at the globus major (head of epididymis at mediastinum testis) and 1-2 mm at the tail where it continues as the vas deferens. The vas deferens courses through the spermatic cord and exits via the deep inguinal ring. At the base of the prostate, it joins the seminal vesicle to form the ejaculatory duct.

20-30 ducts form the prostate gland, draining into the prostatic urethra at the verumontanum, located between the internal and external urethral sphincters. 3 zones of ductular drainage subdivide the prostate: the peripheral zone, the central zone, and the transitional zone.

Gray scale ultrasound of testis. Normal homogeneous echogenicity is finding that characterizes normal testicle. The linear echogenic band running through the testis is a normal structure called the mediastinum testis (arrow).

Transverse view of both testicles on gray scale ultrasound. Showing bilaterally symmetric testicles is useful in excluding a focal process. This view is sometimes called the "Dolly Parton" view.

Duplex ultrasound of testis. In this patient with suspected torsion, normal color flow (red and blue represents flow) and spectral analysis (arrows) show both venous and arterial flow thereby excluding torsion.

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