Grade I – reflux into non-dilated ureter
Grade II – reflux into the renal pelvis and calyces without dilatation
Grade III – mild/moderate dilatation of the ureter, renal pelvis and calyces with minimal blunting of the fornices
Grade IV – dilation of the renal pelvis and calyces with moderate ureteral tortuosity
Grade V – gross dilatation of the ureter, pelvis and calyces; ureteral tortuosity; loss of papillary impressions