Robert L. Lebowitz, M.D. Children' s Hospital, Harvard Medical School Boston, Massachusetts

Diagnosis of Posterior Urethral Valves

A baby boy was found to have hydronephrosis in utero and after delivery at another hospital, was thought to have bilateral hydronephrosis, left worse than right, and a thick-walled bladder (Figure 1). Review of studies here showed that there was only mild left renal pelvic fullness. The right side was normal. The bladder wall looked thick but the blader was almost empty. It is well known that there is an inverse relationship between bladder wall thickness and the degree of intravesical obstruction in filling ¹.

Evaluation here showed that the bladder and urethra were normal (Figure 2) except that there was left Grade II reflux. An IVP showed a normal right kidney and mild fullness of the left renal pelvis (Figure 3).

Reference:
¹ Kaefer et al. The sonographic diagnosis of infravesical obstruction in children: evaluation of bladder wall thickness indexed to bladder filling. J Urol 1997; 157:989-991