Vesicoureteral reflux in children with urinary tract infection: comparison of diagnostic accuracy of renal US criteria.

PURPOSE

To directly compare various renal ultrasonography (US) criteria for vesicoureteral reflux (VUR) with voiding cystography, the reference method, for diagnostic accuracy in helping to determine an intermediate strategy of screening children who require cystography.

MATERIALS AND METHODS

Institutional review board approval and parental consent were obtained for this prospective hospital-based cohort study involving children with urinary tract infections (UTIs). Renal length, ureteral dilatation, pelvic dilatation, and corticomedullary differentiation were analyzed and compared. One hundred seventeen patients (median age, 0.8 year; age range, 0.0-13.9 years) were included: 46 (39%) boys (median age, 0.3 year; age range, 0.5-13.9 years) and 71 girls (median age, 1.2 years; age range, 0.0-11.5 years). A two-level logistic regression model was used to analyze data, and diagnostic accuracy calculations were performed.

RESULTS

Thirty-two (27%) children had all-grade VUR, and eight (7%) had VUR of grade 3 or higher. Only ureteral dilatation was significantly related to all-grade VUR (odds ratio [OR], 7.5; 95% confidence interval [CI]: 1.0, 58.2; P = .05), with 25% sensitivity (95% CI: 15%, 39%) and 88% specificity (95% CI: 83%, 92%). Ureteral, pelvic, and urinary tract dilatations were significantly associated with VUR of grade 3 or higher, with ORs of 20.2 (95% CI: 3.5, 118.2; P = .001), 13.7 (95% CI: 4.1, 46.0; P < .001), and 20.0 (95% CI: 4.4, 90.1; P < .001), respectively. The best compromise between sensitivity and specificity was achieved by using the ureteral dilatation criterion, which had 73% sensitivity (95% CI: 43%, 90%) and 88% specificity (95% CI: 84%, 92%) for high-grade VUR.

CONCLUSION

Ureteral dilatation may yield the best accuracy for the US-based diagnosis of both all-grade and high-grade VUR. This US criterion, perhaps in combination with other predictors, might find a place in an evidence-based selective strategy for limiting cystography in children with UTIs.