title: External and endoluminal analysis of left atrial anatomy and the pulmonary veins in three-dimensional reconstructions of magnetic resonance angiography: the full insight from inside.
abstract: BACKGROUND
  The detailed knowledge of the individual pulmonary vein (PV) anatomy may help to prevent serious complications during PV isolation (PVI). The purpose of this study was to determine the geometry of the PV ostia and their spatial relation to adjacent structures in external (ex 3D) and endoluminal (en 3D) three-dimensional reconstructions of magnetic resonance angiographies (MRAs).
  
  
  RESULTS
  Ex 3D and en 3D of the left atrium (LA) and the PVs of 28 patients were calculated. Diameters and the shape of PV ostia were assessed. In addition, the distances between ipsilateral PV ostia, the LA isthmus line, the roof line and the distance between the left PV and the LA appendage (LAA) were measured. Both ex 3D and en 3D are useful tools to determine the dimensions and the geometry of PVs. En 3D facilitates the identification of common PV ostia (15/28 patients). In en 3D, ipsilateral PV ostia are separated by a narrow myocardial ridge of less than 4 mm in 19/38 PVs (mean 4.3 +/- 1 mm; 4.6 +/- 2 mm with ex 3D). LAA and the LPV ostia are separated by a ridge of less than 4 mm in 12/28 PVs measured with en 3D (4.8 +/- 2 mm; 6.4 +/- 2 mm with ex 3D).
  
  
  CONCLUSIONS
  Both ex 3D and en 3D reconstructions of MRA precisely visualize the complex LA anatomy. Exact determination of PV ostial geometry is facilitated with en 3D and provides important anatomical information for the PVI strategy. According to our data, individual encircling of every PV is strongly discouraged.
authors.affiliation: Department of Cardiology, Allgemeines Krankenhaus St. Georg, Hamburg, Germany. boris.schmidt@uniklinik-freiburg.de
authors.forename: Boris
authors.initials: B
authors.lastname: Schmidt
authors.forename: Sabine
authors.initials: S
authors.lastname: Ernst
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
authors.forename: K R Julian
authors.initials: KR
authors.lastname: Chun
authors.forename: Thomas
authors.initials: T
authors.lastname: Broemel
authors.forename: Dietmar
authors.initials: D
authors.lastname: Bänsch
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kuck
authors.forename: Matthias
authors.initials: M
authors.lastname: Antz
mesh_terms: D000368:Aged; D004730:Endothelium, Vascular / Q000033:anatomy & histology*; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000033:anatomy & histology*