Low-grade vesicoureteral reflux. Variability in grade on sequential radiographic and nuclear cystograms

Paired voiding cystourethrogram (VCU) and nuclear cystogram (NC) studies in 68 children with vesicoureteral reflux (VUR) were analyzed to determine the variability of VUR on sequential studies. Sequential paired examinations included 82 studies where a VCU was followed by a repeat VCU study and 128 studies where a VCU was followed by a NC study. Grade I VUR on the initial VCU was difficult to duplicate on repeat cystography, regardless of the follow-up modality. When the initial VCU showed no VUR, 20% of follow-up studies demonstrated VUR. Follow-up VCU and NC studies showed similar results in detecting increases and decreases in the grade of VUR. Low-grade VUR may be intermittent, and clinical therapeutic decisions should take this variability into account.