Febrile urinary tract infections in infants: renal ultrasound remains necessary

Current guidelines from the American Academy of Pediatrics recommend voiding cystourethrography (VCUG) and renal ultrasound for the radiographic evaluation of infants after a febrile urinary tract infection. Some recent studies have suggested that ultrasound is not necessary in the era of prenatal ultrasound. We reviewed our experience to ascertain the influence that ultrasound has on the treatment of these infants.

We reviewed retrospectively the charts of 282 consecutive patients (5 days to 6 months old, 98 males and 184 females) who underwent radiographic evaluation for a febrile urinary tract infection between October 1995 and August 2001. All patients were evaluated at our institution with VCUG and renal ultrasound.

Of 203 patients with normal VCUG ultrasound was abnormal in 32 (16%). Subsequent evaluation demonstrated 1 case each of significant ureteropelvic junction obstruction, ectopic ureter in a bilaterally duplicated system, renal duplication, renal duplication with calculus, ectopic ureter, renal cysts, multicystic dysplastic kidney and renal scarring. In addition, there were 3 cases of ureterovesical obstruction. No significant renal pathology was identified in the other cases. Two of these patients underwent operative intervention. Treatment or parental counseling was altered in 7 others, for a total of 9 of the 203 patients (4.4%).

In our population renal ultrasound adds information to the radiographic evaluation of infants after a febrile urinary tract infection. This information alters treatment and parental counseling in a significant number of patients.