The Efficacy of Imaging Studies after a First Febrile Urinary Tract Infection in Young Children with Normal Prenatal Ultrasonographic Findings

Abstract

Purpose: The primary purpose for imaging the urinary tract of children with urinary tract infection is to detect congenital anomalies that may predispose the children to persistent or recurrent infection and also to prevent progressive renal deterioration. We evaluated the efficacy of imaging studies after a first febrile urinary tract infection in young children with normal prenatal ultrasonographic findings. Materials and Methods: We retrospectively reviewed 52 young children who were treated due to their first febrile urinary tract infection between 2001 and 2003. In all cases, urine specimens were collected via suprapubic aspiration. An the ultrasonogram and dimercaptosuccinic acid(DMSA) renal scans were obtained within 48 and 72 hours after hospitalization. Contrast voiding cystourethrograms were obtained within 1 to 4 week later after controlling the urinary tract infection. Results: On the ultrasonographic studies, 43 children(90%) were normal and 9 children(10%) were abnormal, and all of these abnormalities were upper tract dilatation that was not due to obstructive uropathy. DMSA renal scans revealed acute pyelonephritis in 34 children(65%) and normal findings in 18(35%). Voiding cystourethrogram revealed reflux in 15 children(31%). 4 children had Grade II reflux, 1 child had III reflux and 9 children had grade IV reflux. Conclusions: After the first febrile urinary tract infection in young children with normal prenatal ultrasonographic findings, an ultrasonogram performed at the time of acute illness is of limited value for the clinical decision about further treatment. A DMSA renal scan is useful for identifying pyelonephritis and renal scar, but its effect on the outcomes is unclear. Voiding cystourethrogram is most useful imaging study for identifying the reflux that needs antimicrobial prophylaxis for reducing reinfections and to prevent renal scarring.