The value of renal ultrasound in children with a first episode of urinary tract infection.

Background: Urinary tract infection (UTI) is a common pediatric problem. Guidelines recommend obtaining a renal ultrasonogram (RUS) for young children after a first UTI. Our aim was to assess the value of routine RUS in the management of children hospitalized with a first episode of UTI.

Methods: We conducted a retrospective review of the medical records of 130 children 12 years of age or younger admitted with a first UTI. Children were excluded if they had a urinary tract abnormality before admission and/or had been treated with an antibacterial agent within 7 days before admission. The yield of RUS was measured by ability to detect renal abnormalities, by the sensitivity and specificity for detecting vesicoureteral reflux (VUR) using voiding cystourethrogram (VCUG) as a gold standard, and by its influence on UTI management.

Results: RUS was conducted in 130 children, but only 118 returned for a VCUG and were included in the study. The findings were positive for VUR in 20 of 40 patients (50%) with a confirmed VUR on VCUG and positive in 18 of 78 patients (23.1%) without VUR on VCUG. Of the 20 patients with a normal RUS who showed VUR, 2 had grade I reflux, 8 had grade II reflux, 7 had grade III reflux and 3 had grade IV reflux. The sensitivity, specificity, positive and negative predictive value of ultrasound in suggesting VUR was 50% and 76.9%, 52.6% and 75%, respectively. Except for one, the result of an abnormal RUS did not alter the management of our patients.

Conclusions: The results of our study show that the RUS has a little value in the management of children with a first UTI.