Direct radionuclide cystography (DRC) with cyclic imaging is a sensitive method used for the detection of vesicoureteral reflux (VUR). Radionuclide cystography is generally recommended for follow-up evaluation of VUR. The aim of this study was to evaluate cyclic DRC with DMSA scan results during the follow-up period in children with a prior diagnosis of VUR.
Patients and methods
DRC findings of 85 children with VUR were evaluated together with DMSA findings during follow-up. VUR grade was classified anatomically as grades I, II, and III reflux. Reflux grades of II and III were regarded as high-grade reflux. Reflux was also graded functionally as transient and continuous on the basis of the presence of reflux on either filling or voiding phases (transient) or both phases (continuous) of at least one cycle.
Among 85 children, 32 (38%) exhibited reflux. In five patients, reflux was observed on both sides, and a total of 37 refluxing units (RUs) were evaluated. According to the highest grade attained in either cycle, 31 (84%) units had grade II, five had grade I and one had grade III reflux. Reflux was continuous in 23 (62%) and transient in 14 (38%) RUs. The incidence of an abnormal scan result was higher in continuous reflux group (78%) than in high-grade anatomic reflux group (59%). The addition of a second cycle resulted in the diagnosis of continuous reflux in six (26%) more RUs. DMSA scan findings correlated significantly with functional reflux classification (P<0.05), but not with anatomic reflux classification (P>0.05).
Functional classification of VUR into continuous and transient reflux resulted in higher correlation with DMSA scan findings compared with anatomic reflux grading in follow-up patients with VUR. Cyclic imaging contributed to continuous reflux diagnosis. The significance of functional information obtained from cyclic DRC in initial diagnostic workup, management, and follow-up of children with urinary tract infection needs to be determined with further studies.