The predictive value of ultrasonography in evaluation of infants with posterior urethral valves.

Between 1981 and 1989, 28 infants less than 6 months old with posterior urethral valves underwent ultrasound evaluation as part of the initial evaluation at our hospital. The single ultrasound feature that correlated with subsequent renal function was the status of corticomedullary differentiation. The presence of corticomedullary junctions in at least 1 kidney in 17 infants was always associated with a serum creatinine level of 0.8 mg./dl. or less in long-term followup. Of 11 patients with absent corticomedullary differentiation 7 had eventual creatinine levels of greater than 0.8 mg./dl. with 5 of them suffering clinically significant renal insufficiency. An association between vesicoureteral reflux and absent corticomedullary junctions was also found.