title: Dynamic registration of preablation imaging with a catheter geometry to guide ablation in a Swine model: validation of image integration and assessment of catheter navigation accuracy.
abstract: BACKGROUND
  Catheter ablation of atrial and ventricular tachyarrhythmia involves anatomically based cardiac ablation strategies. CT and MRI images provide the most detailed cardiac anatomy available. Integration of these images into a mapping system should produce detailed and accurate models suitable to guide ablation.
  
  
  OBJECTIVE
  The purpose of this study was to validate and assess the accuracy of a novel CT and MRI image integration algorithm designed to facilitate catheter navigation and ablation.
  
  
  METHODS
  Using a lateral thoracotomy, markers were sutured to the epicardial surface of each cardiac chamber in 12 swine. Detailed CT/MRI anatomy was imported into the mapping system. The CT/MRI image was then integrated with a detailed catheter geometry of the relevant chamber using a new image integration algorithm. The epicardial markers, identified from the CT/MRI images, were then displayed on the surface of the integrated image. Guided only by the integrated CT/MRI, a single RF lesion was directed at the corresponding endocardial site for each epicardial marker. At autopsy, the distance from the endocardial RF lesion to the target site was assessed.
  
  
  RESULTS
  The mean position error (CT/MRI) for the left atrium was 2.5 +/- 2.4 mm/5.1 +/- 3.9 mm, for the right atrium 6.2 +/- 6.5 mm/4.3 +/- 2.2 mm, for the right ventricle 6.2 +/- 4.3 mm/6.6 +/- 5.3 mm, and for the left ventricle 4.7 +/- 3.4 mm/3.1 +/- 2.7 mm. There was no cardiac perforation or tamponade.
  
  
  CONCLUSIONS
  CT and MRI images can be effectively utilized for catheter navigation when integrated into a mapping system. This novel registration module with dynamic registration provides effective guidance for ablation.
authors.affiliation: University of Virginia Division of Cardiovascular Medicine, St. Paul, Minnesota, USA.
authors.forename: J Jason
authors.initials: JJ
authors.lastname: West
authors.forename: Amit R
authors.initials: AR
authors.lastname: Patel
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Kramer
authors.forename: Adam S
authors.initials: AS
authors.lastname: Helms
authors.forename: Eric S
authors.initials: ES
authors.lastname: Olson
authors.forename: Vamsee
authors.initials: V
authors.lastname: Rangavajhala
authors.forename: John D
authors.initials: JD
authors.lastname: Ferguson
mesh_terms: D000818:Animals; D013504:Cardiovascular Surgical Procedures / Q000379:methods*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D009206:Myocardium / Q000473:pathology*; D011300:Preoperative Care / Q000379:methods; D013382:Subtraction Technique; D025321:Surgery, Computer-Assisted / Q000379:methods; D013552:Swine; D018511:Systems Integration; D013812:Therapeutics; D014057:Tomography, X-Ray Computed / Q000379:methods*