title: Electromagnetic navigation versus fluoroscopy in aortic endovascular procedures: a phantom study.
abstract: OBJECTIVE
  To explore the possible benefits of electromagnetic (EM) navigation versus conventional fluoroscopy during abdominal aortic endovascular procedures.
  
  
  METHODS
  The study was performed on a phantom representing the abdominal aorta. Intraoperative cone beam computed tomography (CBCT) of the phantom was acquired and merged with a preoperative multidetector CT (MDCT). The CBCT was performed with a reference plate fixed to the phantom that, after merging the CBCT with the MDCT, facilitated registration of the MDCT volume with the EM space. An EM field generator was stationed near the phantom. Navigation software was used to display EM-tracked instruments within the 3D image volume. Fluoroscopy was performed using a C-arm system. Five operators performed a series of renal artery cannulations using modified instruments, alternatingly using fluoroscopy or EM navigation as the sole guidance method. Cannulation durations and associated radiation dosages were noted along with the number of cannulations complicated by loss of guidewire insertion.
  
  
  RESULTS
  A total of 120 cannulations were performed. The median cannulation durations were 41.5 and 34.5 s for the fluoroscopy- and EM-guided cannulations, respectively. No significant difference in cannulation duration was found between the two modalities (p = 0.736). Only EM navigation showed a significant reduction in cannulation duration in the latter half of its cannulation series compared with the first half (p = 0.004). The median dose area product for fluoroscopy was 0.0836 [Formula: see text]. EM-guided cannulations required a one-time CBCT dosage of 3.0278 [Formula: see text]. Three EM-guided and zero fluoroscopy-guided cannulations experienced loss of guidewire insertion.
  
  
  CONCLUSIONS
  Our findings indicate that EM navigation is not inferior to fluoroscopy in terms of the ability to guide endovascular interventions. Its utilization may be of particular interest in complex interventions where adequate visualization or minimal use of contrast agents is critical. In vivo studies featuring an optimized implementation of EM navigation should be conducted.
authors: Faculty of Medicine, Institute of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. kjetil.tystad.lund@gmail.com.
authors: Kjetil
authors: http://orcid.org/0000-0002-1792-1135
authors: K
authors: Tystad Lund
authors: Faculty of Medicine, Institute of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.|National Competence Centre for Ultrasound and Image-Guided Therapy, Trondheim, Norway.|Operating Room of the Future, St. Olavs Hospital, Trondheim, Norway.|Department of Medical Technology, SINTEF, Trondheim, Norway.
authors: Geir Arne
authors: http://orcid.org/0000-0003-0032-8500
authors: GA
authors: Tangen
authors: Faculty of Medicine, Institute of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.|National Competence Centre for Ultrasound and Image-Guided Therapy, Trondheim, Norway.|Operating Room of the Future, St. Olavs Hospital, Trondheim, Norway.|Department of Radiology, St. Olavs Hospital, Trondheim, Norway.
authors: Frode
authors: http://orcid.org/0000-0002-4899-0248
authors: F
authors: Manstad-Hulaas
mesh_terms: D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D002404:Catheterization; D054893:Cone-Beam Computed Tomography; D055590:Electromagnetic Phenomena; D057510:Endovascular Procedures / Q000379:methods*; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional; D059346:Magnets; D008953:Models, Anatomic; D061330:Multidetector Computed Tomography; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: 3D tracking; Abdominal aorta; Electromagnetic navigation; Endovascular procedures; Fluoroscopy