Accuracy of ultrasonography compared with urography in detection of intrarenal dilatation in children.

Ultrasonography for detection of postoperative intrarenal dilatation following surgical intervention for vesicoureteral reflux was investigated in 102 children (0-14 years, mean age 4 years and 9 months) over a period of 5 years and was compared with urography. Ultrasonography had a high accuracy for demonstration of even slight intrarenal dilatation caused by postrenal obstruction, while slight and moderate non-obstructive dilatation often was overlooked. The results support the application of sonography for repeated controls of postrenal obstructive dilatation in children with a known medical record in order to diminish their exposure to radiation. The high accuracy does not apply to single sonograms in examination of possible obstruction of unknown origin where some alternative method should be added.