CT urograms in pediatric patients with ureteral calculi: do adult criteriawork?

Background. Secondary signs of urinary obstruction associated with ureteral calculi are useful adjuncts to diagnosis in adults with renal colic evalua ted by unenhanced helical CT. Objective. Our purpose was to evaluate the frequency of secondary signs of obstruction in children with renal colic undergoing unenhanced helical CT. Materials and methods. Ureteral calculi were identified in 20 of 61 childre n with acute flank pain examined by unenhanced helical CT. Each imaging stu dy was evaluated for the presence of secondary signs of urinary obstruction . The frequencies of individual signs were compared with each other by mean s of the McNemar test. Results. Six children had no secondary sign identified. In the remaining 14 children, proximal ureteral dilatation was seen in 10, renal enlargement i n 10, hydronephrosis in 9, tissue rim sign in 6, decreased kidney attenuati on in 5, and perinephric stranding in 1. Comparison of the frequencies stro ngly suggested that perinephric stranding occurs less frequently than proxi mal ureteral dilatation (P = 0.004), hydronephrosis (P = 0.008), or renal e nlargement (P = 0.012). Conclusion. Perinephric stranding, a common secondary sign in adults with u reteral calculi, occurs less frequently in children than other reported sec ondary signs.