Despite well recognized limitations, conventional retrograde urethrography (RUG) has remained the standard imaging study for the diagnosis and management of urethral disease. Encouraged by my initial results with sonourethrography (SUG), I
reviewed
my
experience with its use in anterior urethral strictures in male patients.
Over a 6-year period, paired RUG and SUG were performed in 47 patients (50- strictures). In all cases, the urethra was subsequently evaluated either urethroscopically or at open operation.
In all cases, SUG correctly identified the stricture and its site. When the stricture length measured by RUG was compared with that measured by SUG, there was no good correlation between the two (r2=0.71, p<0.005). However, there was better
correlation
when the stricture was located in the penile urethra than in the bulbar urethra (r2=0.95 vs. 0.59, p<0.005). Because most of the strictures were evaluated operatively, a better assessment of each study's ability to predict the stricture length
was
available : SUG was more accurate than RUG (r2=0.97 vs. 0.75, p<0.005), and the shorter the stricture the more accurate it was. Although SUG certainly identifies periurethral tissue, it was unreliable in predicting the depth of spongiofibrosis
compared
with full-depth biopsies in 20 patients (r2=0.01).
SUG is a dynamic study that accurately identifies the stricture site, number and calibre. When compared with RUG it more accurately measures the stricture length and identifies periurethral tissue, making it a valuable adjunct in the evaluation
of
patients with suspected anterior urethral strictures.
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