title: Magnetic resonance urography in the evaluation of prenatally diagnosed hydronephrosis and renal dysgenesis.
abstract: OBJECTIVE
  We present our experience with dynamic contrast enhanced magnetic resonance urography for evaluation and treatment in infants born with prenatally recognized hydronephrosis. We determined the characteristics of renal dysgenesis in this population.
  
  
  METHODS
  We reviewed magnetic resonance urography images done within the first 6 months of life in 67 infants born with prenatally recognized hydronephrosis. High resolution imaging was used to establish a morphological diagnosis. Functional evaluation was used to assess obstruction and individual renal function. Voiding cystourethrography was performed in 62 patients.
  
  
  RESULTS
  Our study included 67 infants (87 renal units). There were 54 boys and 13 girls with a mean age of 2.8 months (range 0.9 to 4.6). Of these 87 renal units 30 (35%) had ureteropelvic junction obstruction, 18 (21%) had primary megaureters, 10 (11%) had nondilating vesicoureteral reflux, 10 (11%) had fetal folds, 8 (9%) had posterior urethral valves, 6 (7%) had ectopic ureters, 4 (5%) had multicystic dysplastic kidneys and 1 (1%) had a normal study. Magnetic resonance urography revealed renal dysgenesis in 24 renal units (28%), consisting of loss of corticomedullary differentiation, renal cystic changes distinct from multicystic dysplastic kidneys, solid renal dysplasia, hypoplasia and dysmorphic calyces.
  
  
  CONCLUSIONS
  Magnetic resonance urography is an excellent addition to our armamentarium for evaluating neonatal hydronephrosis and renal dysgenesis. Due to its comprehensiveness magnetic resonance urography has the potential to become the study of choice for evaluating infants with significant prenatally recognized hydronephrosis. However, further prospective, comparative studies in larger patient populations are needed to justify the cost and the need for sedation in infants.
authors.affiliation: Department of Pediatric Urology, Children's Healthcare of Atlanta, Emory University School of Medicine, 5445 Meridian Mark Road, Atlanta, GA 30342, USA.
authors.forename: Leah P
authors.initials: LP
authors.lastname: McMann
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Kirsch
authors.forename: Hal C
authors.initials: HC
authors.lastname: Scherz
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Smith
authors.forename: Richard A
authors.initials: RA
authors.lastname: Jones
authors.forename: Bahig M
authors.initials: BM
authors.lastname: Shehata
authors.forename: Rafal
authors.initials: R
authors.lastname: Kozielski
authors.forename: J Damien
authors.initials: JD
authors.lastname: Grattan-Smith
mesh_terms: D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000150:complications / Q000151:congenital* / Q000175:diagnosis*; D007223:Infant; D007668:Kidney / Q000002:abnormalities* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014551:Urinary Tract / Q000473:pathology*