International system of radiographic grading of vesicoureteric reflux. International Reflux Study in Children.

The classification of grading of vesicoureteric reflux (VUR) agreed to by the participants in the International Reflux Study in Children is described. It combines two earlier classifications and is based upon the extent of filling and dilatation by VUR of the ureter, the renal pelvis and the calyces. A standardised technique of voiding cystography is also described to ensure comparability of results.