title: Biplane three-dimensional augmented fluoroscopy as single navigation tool for ablation of atrial fibrillation: accuracy and clinical value.
abstract: BACKGROUND
  We developed new methods for real time biplane integration of three-dimensional (3D) left atrial models with fluoroscopic images to assist in catheter ablation of atrial fibrillation (AF).
  
  
  OBJECTIVE
  The purpose of this study was to quantitatively assess the accuracy of 3D fluoroscopy integration and to evaluate its clinical value when used as a single navigation tool for AF ablation.
  
  
  METHODS
  Sixty patients underwent AF ablation under biplane fluoroscopic guidance after selective angiography of the four pulmonary veins. Computed tomography [CT]-based 3D models were integrated in the fluoroscopic framework using visual matching and landmark-based registration approaches. Integration accuracy was quantitatively assessed according to registration approach and different CT acquisition parameters (electrocardiogram [ECG] gating, respiratory phase). In 30 of the 60 patients (3D+ group), the integrated 3D model was used for real time 3D-augmented fluoroscopic catheter navigation, and the effects on procedural parameters and patient radiation dose were evaluated.
  
  
  RESULTS
  Landmark-based registration resulted in superior 3D fluoroscopy integration accuracy compared with the visual matching approach (P <.001 for alignment error and alignment score). The effects of ECG gating and respiratory phase during CT acquisition on integration accuracy were small and clinically irrelevant. The use of 3D-augmented fluoroscopy in the 3D+ group was gauged as extremely helpful by the operator. It resulted in a significant reduction of fluoroscopy time (61 +/- 18 minutes vs. 77 +/- 26 minutes; P = .009) and a trend toward shorter procedure duration (230 +/- 67 minutes vs. 257 +/- 58 minutes; P = .06) versus conventional procedures. The systematic use of nongated cardiac CT in the 3D+ group resulted in an important reduction in total effective patient radiation dose due to CT+fluoroscopy (4 + 14 = 18 +/- 8 mSv vs.17 + 16 = 33 +/- 13 mSv; P <.001).
  
  
  CONCLUSIONS
  Biplane 3D-augmented fluoroscopy can be used as a safe and accurate stand-alone method to guide AF ablation procedures. The use of nongated cardiac CT substantially reduces total patient radiation dose without a relevant reduction in integration accuracy.
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium, Europe. Joris.Ector@uz.kuleuven.ac.be
authors.forename: Joris
authors.initials: J
authors.lastname: Ector
authors.forename: Stijn
authors.initials: S
authors.lastname: De Buck
authors.forename: Wim
authors.initials: W
authors.lastname: Huybrechts
authors.forename: Dieter
authors.initials: D
authors.lastname: Nuyens
authors.forename: Steven
authors.initials: S
authors.lastname: Dymarkowski
authors.forename: Jan
authors.initials: J
authors.lastname: Bogaert
authors.forename: Frederik
authors.initials: F
authors.lastname: Maes
authors.forename: Hein
authors.initials: H
authors.lastname: Heidbüchel
mesh_terms: D001281:Atrial Fibrillation / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed