title: Efficacy of MRI in complicated congenital heart disease with visceral heterotaxy syndrome.
abstract: OBJECTIVE
  The authors' goal was to assess the diagnostic accuracy and clinical effect of MRI compared with echocardiography and catheterization in the evaluation of cardiac defects with situs ambiguous.
  
  
  METHODS
  Twenty-two patients with visceral heterotaxy syndrome were included.
  
  
  RESULTS
  Because situs determined by the relation between the pulmonary artery and bronchi showed most predominantly a tendency toward lateralization, this was regarded as the standard reference of situs determination. For the purpose of this study, patients were classified as having right isomerism (n = 13) or left isomerism groups (n = 9). MRI has several advantages compared with echocardiography or cardiac angiography for examining patients with situs ambiguous. (1) The bronchial, pulmonary arterial, and splenic situs can be readily determined, and discrepancies (n = 2) can be assessed easily. (2) Venoatrial connections are adequately imaged. In particular, all types of total and partial anomalous pulmonary venous return are delineated, regardless of whether restrictions of pulmonary blood flow or pulmonary venous obstructions are involved (n = 4). The courses of vertical veins were easily identified, and the prearterial position was revealed in only one of seven right isomerisms with total anomalous pulmonary venous return. The drain pattern of the hepatic vein can be visualized using three-dimensional spatial information and is useful for total cavopulmonary connection design. (3) Associated complicated cardiac anomalies, particularly the size or peripheral stenosis of the pulmonary arteries, may be evaluated, and this information is useful for palliative shunt operations.
  
  
  CONCLUSIONS
  Because of its wide field of view and imaging, which is not restricted by associated anomalies, a thorough understanding of the cardiovascular anatomy of the situs ambiguous can be achieved using MRI, which is of considerable value in the surgical correction of this complicated anomaly. MRI can obviate or facilitate catheterization in these critically ill patients.
authors.affiliation: Department of Diagnostic Radiology, Yonsei University, College of Medicine, Seoul, Korea.
authors.forename: Y K
authors.initials: YK
authors.lastname: Hong
authors.forename: Y W
authors.initials: YW
authors.lastname: Park
authors.forename: S J
authors.initials: SJ
authors.lastname: Ryu
authors.forename: J W
authors.initials: JW
authors.lastname: Won
authors.forename: J Y
authors.initials: JY
authors.lastname: Choi
authors.forename: J H
authors.initials: JH
authors.lastname: Sul
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: B K
authors.initials: BK
authors.lastname: Cho
authors.forename: K O
authors.initials: KO
authors.lastname: Choe
mesh_terms: D000015:Abnormalities, Multiple / Q000473:pathology*; D000790:Angiocardiography; D006328:Cardiac Catheterization; D002675:Child, Preschool; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000002:abnormalities; D006330:Heart Defects, Congenital / Q000150:complications / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D014781:Viscera / Q000002:abnormalities*