title: Value of sonographic anterior-posterior renal pelvis measurements before and after voiding for predicting vesicoureteral reflux in children.
abstract: OBJECTIVE
  Voiding cystourethrography (VCUG) is the gold standard for diagnosing vesicoureteral reflux (VUR), but it is important to minimize the use of VCUG because of the urinary catheterization and radiation exposure required. Ultrasound (US) observations suggest that pelvicalyceal dilatation varies according to the degree of bladder fullness in children with urinary tract infection. The aim of this study was to assess whether anterior-posterior (AP) measurements of the renal pelvis on US before and after voiding can be used as a screening tool while predicting the presence of VUR in children.
  
  
  METHODS
  The subjects were toilet-trained children older than 4 years who required VCUG. Two groups were established based on the VCUG results: a VUR group of 40 kidney units (each unit defined as calyces and ureter) that exhibited different severities of reflux, and a control group of 68 kidney units unaffected by VUR. Prior to VCUG, US AP measurements of the renal pelvis of each kidney unit were recorded when the urinary bladder was full and again after bladder emptying. The change in AP measurement from before to after voiding was compared between the two groups.
  
  
  RESULTS
  The mean change in AP measurements from before to after voiding in the VUR group was significantly greater than that in the control group (p = 0.003).
  
  
  CONCLUSIONS
  Comparing US AP measurements of the renal pelvis before and after voiding is useful for identifying children who are suspected to have VUR and thus require immediate VCUG.
authors.affiliation: Baskent University Faculty of Medicine, Radiology, Adana, Turkey.
authors.forename: Senay
authors.initials: S
authors.lastname: Demir
authors.affiliation: Baskent University Faculty of Medicine, Radiology, Adana, Turkey.
authors.forename: Naime
authors.initials: N
authors.lastname: Tokmak
authors.affiliation: Baskent University Faculty of Medicine, Pediatric Nephrology, Adana, Turkey.
authors.forename: Nurcan
authors.initials: N
authors.lastname: Cengiz
authors.affiliation: Baskent University Faculty of Medicine, Pediatric Nephrology, Adana, Turkey.
authors.forename: Aytul
authors.initials: A
authors.lastname: Noyan
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003974:Diatrizoate Meglumine; D005260:Female; D006801:Humans; D007682:Kidney Pelvis / Q000000981:diagnostic imaging*; D008297:Male; D011237:Predictive Value of Tests; D014463:Ultrasonography; D014567:Urography; D014718:Vesico-Ureteral Reflux / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D003974:Diatrizoate Meglumine
keywords: children; renal pelvis; ultrasonography; vesicoureteral reflux