THE ROLE OF DIRECT RADIONUCLIDE CYSTOGRAPHY IN EVALUATION OF VESICOURETERAL REFLUX

The validity of voiding cystourethrography (VCUG) for detecting vesico ureteral reflux in children and assessing its extent was compared with that of direct radionuclide cystography (DRNC). Of 131 patients with recurrent urinary tract infection, all underwent DRNC and most also VC UG. Vesicoureteral reflux was found at DRNC in nine renal units (9 pat ients) in which VCUG was negative. In 17 renal units (15 patients) VCU G showed reflux to the ureter, but not to the renal pelvis, whereas DR NC revealed backflow from the bladder up to the renal pelvis. Reflux v isualized at DRNC but not at VCUG was defined as grade Io. In all case s with reflux of grade I according to current classifications, DRNC sh owed reflux up to the renal pelvis. These observations make the distin ction between grades I and II reflux in presently used classification less relevant and indicated the possible pathway of renal infection in patients with grade I vesicoureteral reflux and in so-called ''elusiv e'' reflux. We propose the addition of an extra grade (Io) of vesicour eteral reflux.