Comprehensive ultrasound versus voiding cysturethrography in the diagnosis of vesicoureteral reflux

Abstract.

This study evaluates the accuracy of noninvasive renal ultrasound (US) in the detection of dilative vesicoureteric reflux (VUR) compared to voiding cysturethrography (VCUG), taking both sonographic morphology and kidney length into account. The data and images of 205 paediatric patients who had renal ultrasound and VCUG performed were reviewed. Abnormalities of renal length and kidney morphology were compared with degree of reflux on VCUG for each renal unit. A total of 407 renal units were evaluated. When the sonographic diagnosis of reflux was based solely on morphological criteria and degree of dilatation, correlation with VCUG results was poor. However, the fraction of kidneys of anomalous size increased markedly with grade of reflux, from 10% of non-refluxing renal units to 50% of renal units subjected to grade 4 and 5 VUR. Taking abnormal kidney length into account as well, dilative VUR was diagnosed by ultrasound with a sensitivity of 92% (95% CI 82%–100%) and a sensitivity of 67% (95% CI 63%–72%), P<0.001. Conclusion: the results of this study show that ultrasound cannot accurately diagnose vesicoureteric reflux by morphological changes alone, but requires the consideration of age-adjusted abnormalities in kidney length.