Ultrasonic characteristics of posterior urethral valves.

Thickening of the bladder wall and dilatation of the prostatic urethra can be shown by ultrasound in infants with posterior urethral valves. This can be helpful in the diagnosis of hydroureter. Marked hypertrophy of the bladder muscle can appear as solid echogenic mass and simulate a pelvic tumor. Ultrasonic findings in 5 infants with posterior urethral valves are reviewed.