title: Significance of MR angiography in the diagnosis of aberrant renal arteries as the cause of ureteropelvic junction obstruction in children.
abstract: OBJECTIVE
  To determine the importance of MRI with contrast-enhanced MRA for the detection or exclusion of aberrant or obstructing renal arteries in ureteropelvic junction obstruction in children.
  
  
  METHODS
  Key word-based search in RIS database (ureteropelvic junction obstruction/ MRI) and retrospective comparison of arterial findings from preoperative contrast -enhanced MRA and intra-operative inspection. From 2007 to 2013, 19 children with ureteropelvic junction obstruction underwent contrast-enhanced MRA. Based on the results of the MRI scan and MAG3 scintigraphy, the children were referred to surgery (Anderson-Hynes-pyeloplasty).
  
  
  RESULTS
  An aberrant renal artery was diagnosed with MRI in 14 of 19 children, and intra-operative inspection confirmed 13 of those 14. In the remaining 5 children, no aberrant vessel could be observed in MRI and this was confirmed intra-operatively in 3 of the 5 cases, while in the remaining 2, an aberrant vessel was found. Of the 14 children with aberrant vessels, 12 underwent surgery due to assumed ureteral obstruction, which was confirmed by surgery in 11 cases. In one case, an aberrant artery was found intra-operatively, but obstruction could not be confirmed. In one of the 14 children, the vessel was found in MRI, but its obstructing character was negated via MRA, which was confirmed intra-operatively. In the diagnosis of aberrant and obstructing renal arteries, contrast-enhanced MRA presents 85% sensitivity and 80% specificity, with a positive predictive value of 0.8.
  
  
  CONCLUSIONS
  MRI with contrast-enhanced MRA is suitable to detect aberrant and obstructing renal arteries. An obstructive effect of the aberrant vessel is to be assumed if the vessel has a close relationship to the ureteropelvic junction and if it is linearly stretched.
  
  
  CONCLUSIONS
  • MRI with contrast-enhanced MRA is a sure method for the detection of aberrant renal arteries in children with ureteropelvic junction obstruction. • The obstructive effect of the aberrant vessel can be derived from the close proximity of the vessel to the ureteropelvic junction and from the streched course of the vessel.
authors.affiliation: Department of Pediatric Radiology, University of Leipzig.
authors.forename: L
authors.initials: L
authors.lastname: Ritter
authors.affiliation: Department of Pediatric Surgery, University of Leipzig.
authors.forename: G
authors.initials: G
authors.lastname: Götz
authors.affiliation: Department of Pediatric Radiology, University of Leipzig.
authors.forename: I
authors.initials: I
authors.lastname: Sorge
authors.affiliation: Department of Pediatric Surgery, University of Leipzig.
authors.forename: T
authors.initials: T
authors.lastname: Lehnert
authors.affiliation: Department of Pediatric Radiology, University of Leipzig.
authors.forename: F W
authors.initials: FW
authors.lastname: Hirsch
authors.affiliation: Department of Pediatric Surgery, University of Leipzig.
authors.forename: U
authors.initials: U
authors.lastname: Bühligen
authors.affiliation: Department of Pediatric Radiology, University of Leipzig.
authors.forename: A
authors.initials: A
authors.lastname: Vieweger
authors.affiliation: Department of Pediatric Surgery, University of Leipzig.
authors.forename: C
authors.initials: C
authors.lastname: Geyer
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007223:Infant; D007275:Injections, Intravenous; D007682:Kidney Pelvis / Q000473:pathology / Q000601:surgery; D018810:Magnetic Resonance Angiography; D008297:Male; D008536:Meglumine; D009942:Organometallic Compounds; D012077:Renal Artery / Q000002:abnormalities* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014517:Ureteral Obstruction / Q000175:diagnosis* / Q000209:etiology* / Q000601:surgery
chemical_list: D009942:Organometallic Compounds; C090600:gadobutrol; D008536:Meglumine; C072417:gadoterate meglumine