The Change in the Renal Pelvis Anterior-Posterior Diameter between Prevoiding and Postvoiding Status, and Its Correlation with Vesicoureteral Reflux

In this study, our aim was to evaluate the significance of the change in renal pelvis anterior-posterior diameter (RPAPD) before and after micturition between vesicoureteral reflux (VUR)-positive and-negative patients to whom had voiding cystourethrography (VCUG) was performed. In this study, 69 children, age ranging from 0 to 12 years, were included. Before the VCUG imaging, the RPAPD was measured first with a full bladder and then after urination via ultrasound (US). The differences between in RPAPD measurements were noted and values compared made among VUR-positive and-negative children. Data distribution was inhomogeneous, and the Wilcoxon Sign Rank test was utilized instead of Student t test. There was no statistically significant difference in prevoiding and postvoiding RPAPD in VUR (+) and VUR (-) patients (P = 0.672). There was no statistically significant relation between VUR and the presence of hydronephrosis (P = 0.126). Vesicoureteral reflux is more common in patients with urinary tract infections (UTI) (P = 0.001). There was no statistically significant relationship between prevoiding and postvoiding RPAPD change and VUR diagnosis (P = 0,164). Ultrasound is the modality of choice for urinary system evaluation. Diagnosis of hydronephrosis via US is not sufficient in predicting VUR; however, indirect findings may reveal the diagnosis. A decrease in RPAPD in postvoiding US evaluation may not rule out the VUR diagnosis for this reason further imaging modalities, such as VCUG, should be taken into consideration for the patients with clinical suspicion.