Ultrasound of the male anterior urethra

Abstract

Imaging of the anterior male urethra has traditionally been performed by fluoroscopic contrast urethrography. While providing easily interpretable images, this technique has a number of disadvantages associated with it. An alternative approach is to use ultrasound to assess the lumen of the urethra and the periurethral tissues. Here we describe the development of urethral ultrasound and the ascending and descending urethral ultrasound techniques employed in our institution with reference to commonly and uncommonly encountered pathologies. We also identify common pitfalls and how to avoid them.

Figure 1

Anatomy and technique of retrograde contrast urethrography [1].

Figure 2

Demonstration of comparative ultrasound (top) and contrast urethrography (bottom) images of the distal urethra.

Figure 3

(a) Posterior acoustic shadowing behind the tip of the catheter obscuring the distal urethra. (b) Better demonstration of the distal urethra following trimming of the distal catheter beyond the balloon.

Figure 4

Comparison of normal urethral anatomy as seen on ultrasound (left) and contrast urethrography (right). (a) Normal peno-scrotal junction and (b) normal bulbar urethra.

Figure 5

Normal urethra in transverse section. CC, corpus cavernosum; S, spongiosum surrounding urethra; U, urethral lumen.

Figure 6

Bulbar stricture on ultrasound (left) and urethrography (right).

Figure 7

The viral papilloma demonstrated on the ultrasound study (middle and bottom) was overlooked as a bubble on the contrast urethrogram (top).

Figure 8

Mucosal tag seen as filling defect on urethrography (top) and ultrasound (bottom).

Figure 9

(a) Urethral diverticulum seen on ultrasound with layering of debris within it and (b) urethrogram correlate.

Figure 10

Normal navicular fossa seen during voiding descending urethral ultrasound (left), with diagrammatic representation of navicular fossa (right).

Figure 11

Urethral stricture seen using the descending ultrasound technique in (a) longitudinal and (b) transverse planes.

Figure 12

Viral papilloma seen in (a) longitudinal and (b) transverse planes.

Figure 13

(a) Normal mucosa and periurethral tissues. (b) Periurethral fibrotic cuffing surrounding bulbar stricture.

Figure 14

Two examples of strictures within the fossa navicularis that could not be demonstrated on either contrast urethrography or ascending urethral ultrasound. The penile tip is to the left of the images.

Figure 15

Descending urethral ultrasound in hypospadias assessment demonstrating (a) a pinhole ventrally placed meatus and (b) a distal post-operative irregularity. The penile tip is to the left of the images.

Figure 16

Two attempts at performing descending urethral ultrasound in the same patient. (a) At the first attempt there was insufficient distension of the urethra. (b) This was rectified at the second attempt.

Figure 17

(a) Descending urethral ultrasound that fails to demonstrate a proximal stricture, which is identified on (b) perineal voiding images.