title: Potential impact of pediatric MR urography on the imaging algorithm in patients with a functional single kidney.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the potential of MR urography in the assessment of children with a suspected "functional single kidney."
  
  
  METHODS
  Sixty patients (age range, 2.7 weeks to 15.7 years) who had been referred for assessment of a suspected functional single kidney underwent MR urography in addition to detailed sonography of the urinary tract and the currently indicated standard imaging. The results of the conventional imaging ((99m)Tc-dimer captosuccinic acid scintigraphy, voiding cystourethrography, and genitography) were compared with the results of sonography and MR urography; surgical findings served as the gold standard if available.
  
  
  RESULTS
  Twenty-six patients had a single kidney. The other diagnoses were six contralateral multicystic dysplastic kidneys, two normal ectopic kidneys, one crossfused double system, and 25 ectopic or dysplastic renal buds. Scintigraphy detected all normal kidneys, two ectopic kidneys, and two dysplastic renal buds. Detailed sonography missed two ectopic kidneys and two orthotopic dysplastic renal buds, but one additional renal bud that could not be confirmed on other imaging techniques (accuracy, 91.7%; sensitivity, 88.2%; specificity, 96.2%) was suspected. MR urography results were correct in all patients and verified in all 13 with surgical correlation.
  
  
  CONCLUSIONS
  MR urography allows a reliable assessment of renal and ureteral anatomy and of dysplastic or ectopic renal buds, even in non- or poorly functioning systems. MR urography therefore has the potential to replace the currently used excretory urography and scintigraphy. In patients with a suspected functional single kidney a detailed sonographic study and MR urography should be considered the diagnostic algorithm of choice.
authors.affiliation: Department of Radiology, Division of Pediatric Radiology, LKH-University Hospital, Auenbruggerplatz, Graz A-8036, Austria. michael.riccabona@klinikum-graz.at
authors.forename: Michael
authors.initials: M
authors.lastname: Riccabona
authors.forename: Andrea
authors.initials: A
authors.lastname: Ruppert-Kohlmayr
authors.forename: Ekkehard
authors.initials: E
authors.lastname: Ring
authors.forename: Cornelia
authors.initials: C
authors.lastname: Maier
authors.forename: Lukas
authors.initials: L
authors.lastname: Lusuardi
authors.forename: Marcus
authors.initials: M
authors.lastname: Riccabona
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D014567:Urography / Q000379:methods*