title: Sonographic diagnosis of intestinal malrotation in infants: importance of the relative positions of the superior mesenteric vein and artery.
abstract: OBJECTIVE
  An abnormal relative position of the superior mesenteric vein and artery can be present in patients with intestinal malrotation. We undertook this retrospective study to see how often we could determine the relative position of these vessels on abdominal sonograms in infants and how often abnormal position of the vessels was associated with malrotation.
  
  
  METHODS
  We reviewed the radiology files and medical records of 337 infants with vomiting who were referred for sonography because of possible pyloric stenosis. We used sonograms and written reports to determine the position of the superior mesenteric vessels. The position was considered normal when the superior mesenteric vein was to the right of the superior mesenteric artery on transverse sonograms. The position was considered abnormal when the vein was directly ventral to the artery or when the vein was to the left of the artery. Sonographic findings were compared with results of upper gastrointestinal series when possible and with clinical outcome.
  
  
  RESULTS
  The relative positions of the superior mesenteric vein and artery were evident in 249 (74%) of the 337 patients. Abnormal orientation of the mesenteric vessels was detected in nine patients. In five patients, the superior mesenteric vein was located to the left of the artery, and all five had intestinal malrotation. In four patients, the superior mesenteric vein was directly ventral to the artery, and one of these had malrotation.
  
  
  CONCLUSIONS
  Sonographic assessment of the relative positions of the mesenteric artery and vein is an important adjunct in the examination of infants with suspected pyloric stenosis. Patients in whom sonograms show an abnormal position of the vessels should have further examination to detect malrotation.
authors.affiliation: Department of Radiology, University of Washington, School of Medicine, Seattle 98195.
authors.forename: E
authors.initials: E
authors.lastname: Weinberger
authors.forename: W D
authors.initials: WD
authors.lastname: Winters
authors.forename: R M
authors.initials: RM
authors.lastname: Liddell
authors.forename: D M
authors.initials: DM
authors.lastname: Rosenbaum
authors.forename: D
authors.initials: D
authors.lastname: Krauter
mesh_terms: D000013:Congenital Abnormalities / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007422:Intestines / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008297:Male; D008638:Mesenteric Arteries / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008642:Mesenteric Veins / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011707:Pyloric Stenosis / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D014463:Ultrasonography