title: Determination of the spatial orientation and shape of pulmonary vein ostia by contrast-enhanced magnetic resonance angiography.
abstract: OBJECTIVE
  For catheter ablation of atrial fibrillation (AF), proper catheter positioning is crucial and depends on knowledge of pulmonary vein (PV) anatomy. The aim of this study was to assess PV spatial orientation and ostial shape by contrast-enhanced magnetic resonance angiography (CE-MRA).
  
  
  RESULTS
  In 30 consecutive AF patients, CE-MRA was performed prior to ostial ablation. Using a centre-line technique, the PV ostium was defined perpendicular to this centre-line. Minimal and maximal ostial diameters, ostial perimeter, and angles in the anatomical frontal and transverse planes were measured. Twenty-one patients had four separate PVs. In four patients, there was a distinct right-middle PV and in five a common left common PV was found. Left-sided PV ostia were smaller and more elliptical than right-sided PVs. In the transverse plane, the ostia of both superior PVs were directed anteriorly (LS -15 +/- 13 degrees , RS -13 +/- 11 degrees ) and both inferior PV ostia were directed posteriorly (LI 23 +/- 15 degrees , RI 39 +/- 15 degrees ). In the frontal plane, both superior PV ostia pointed upwards (LS -27 +/- 14 degrees , RS -33 +/- 12 degrees ) while the inferior ostia were directed horizontally (LI 2 +/- 11 degrees , RI 3 +/- 13 degrees ).
  
  
  CONCLUSIONS
  PV ostial shape and spatial orientation are variable and can be visualized adequately by CE-MRA.
authors.affiliation: Department of Cardiology, Catharina Hospital PO Box 1350, 5602 ZA Eindhoven, The Netherlands. pepijn.vd.voort@catharina-ziekenhuis.nl
authors.forename: Pepijn H
authors.initials: PH
authors.lastname: van der Voort
authors.forename: Harrie
authors.initials: H
authors.lastname: van den Bosch
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Post
authors.forename: Albert
authors.initials: A
authors.lastname: Meijer
mesh_terms: D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000601:surgery*; D017115:Catheter Ablation; D003287:Contrast Media; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000033:anatomy & histology*
chemical_list: D003287:Contrast Media