title: Three-dimensional endovascular navigation with electromagnetic tracking: ex vivo and in vivo accuracy.
abstract: OBJECTIVE
  To evaluate the accuracy of a 3-dimensional (3D) navigation system using electromagnetically tracked tools to explore its potential in patients.
  
  
  METHODS
  The 3D navigation accuracy was quantified on a phantom and in a porcine model using the same setup and vascular interventional suite. A box-shaped phantom with 16 markers was scanned in 5 different positions using computed tomography (CT). The 3D navigation system registered each CT volume in the magnetic field. A tracked needle was pointed at the physical markers, and the spatial distances between the tracked needle positions and the markers were calculated. Contrast-enhanced CT images were acquired from 6 swine. The 3D navigation system registered each CT volume in the magnetic field. An electromagnetically tracked guidewire and catheter were visualized in the 3D image and navigated to 4 specified targets. At each target, the spatial distance between the tracked guidewire tip position and the actual position, verified by a CT control, was calculated.
  
  
  RESULTS
  The mean accuracy on the phantom was 1.28±0.53 mm, and 90% of the measured distances were ≤1.90 mm. The mean accuracy in swine was 4.18±1.76 mm, and 90% of the measured distances were ≤5.73 mm.
  
  
  CONCLUSIONS
  This 3D navigation system demonstrates good ex vivo accuracy and is sufficiently accurate in vivo to explore its potential for improved endovascular navigation.
authors.affiliation: Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. frode.manstad.hulaas@ntnu.no
authors.forename: Frode
authors.initials: F
authors.lastname: Manstad-Hulaas
authors.forename: Geir Arne
authors.initials: GA
authors.lastname: Tangen
authors.forename: Lucian Gheorghe
authors.initials: LG
authors.lastname: Gruionu
authors.forename: Petter
authors.initials: P
authors.lastname: Aadahl
authors.forename: Toril A N
authors.initials: TA
authors.lastname: Hernes
mesh_terms: D000818:Animals; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000601:surgery*; D055590:Electromagnetic Phenomena; D057510:Endovascular Procedures / Q000295:instrumentation; D004867:Equipment Design; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D023421:Models, Animal; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000295:instrumentation; D034421:Sus scrofa; D014057:Tomography, X-Ray Computed / Q000295:instrumentation