The dilated urinary tract in children. Prospective analysis with correlation of radiological, isotope, pressure perfusion and surgical findings.

Moderate and even severe dilatation of the urinary tract in the absence of vesicoureteric reflux may remain stable or show spontaneous resolution. Two such cases are described. Twenty-five children with dilated urinary systems were studied to correlate the radiological, isotope, pressure perfusion and surgical findings. A positive Whitaker test correlated well with the surgical findings and post-operative improvement in renal function in all patients with pelviureteric junction (PUJ) and vesicoureteric junction (VUJ) obstruction. High flow rates of 8.6 and 12 ml are required even in neonates and infants in order to demonstrate obstruction by Whitaker testing.