Ultrasonography as predictor of permanent renal damage in infants with urinary tract infection.

AIM: To evaluate the ability of ultrasound (US) in infants (<1 year) with acute urinary tract infection (UTI), to identify those with permanent renal damage (PRD) at scintigraphy 1 year later.

METHODS: US, dimercaptosuccinic acid scintigraphy and voiding cystourethrography were performed in 191 infants.

RESULTS: US was abnormal in 46 infants (24%). PRD was found in 46 infants (24%); 19 of these had abnormal US (sensitivity 41%). In 145 infants without PRD, 27 had abnormal US (specificity 81%). Dilating reflux or verified obstruction occurred in 21 (11%) infants, of whom 18 (86%) had PRD while 28 of 170 (16%) without such diagnoses had PRD. Of 16 infants with dilating reflux, 9 (sensitivity 56%) had abnormal US and 14 (88%) PRD. Dilatation at US was seen in 27 children; 7 of these had dilating reflux and 5 verified obstruction.

CONCLUSION: US performed in association with acute UTI had limited ability to identify children with PRD at (99m)Tc-dimercaptosuccinic acid (DMSA) 1 year later, although abnormal renal size was a strong indicator of renal damage. The ability of US to identify children with dilating reflux was also limited. However, once detected at US, dilatation of the urinary tract was associated with dilating reflux or obstruction in half of the cases. Our study confirms that dilating reflux and obstruction are strong indicators of PRD but only half of those who developed PRD had such diagnoses.