title: Setting up MR compatibility of a commercial stereo-localization system for low-field open MR interventional procedures.
abstract: BACKGROUND
  Surgical and interventional procedures increasingly rely on spatial measurement systems. One of the most popular is NDI's Polaris Vicra. Unfortunately, this system cannot be used for magnetic resonance imaging (MRI) procedures because of the image artifacts that it produces.
  
  
  METHODS
  Here, a simple method for hardware electrical shielding is presented which makes the Polaris Vicra MR-compatible for a low-field open-magnet MR scanner. The shielding is achieved by placing the cable linking the sensor to the USB converter inside a copper braid tube.
  
  
  RESULTS
  Tests performed with a variety of MR sequences show the absence of image artifacts, image distortion or grey-level uniformity degradation. In the same way, 3D localization accuracy of the spatial measurement system is not modified by the MR environment. A rough safety check shows that the system does not pose hazards with normal condition of use.
  
  
  CONCLUSIONS
  This minor adaptation makes the system suitable for various applications in low field MR environments, such as intraoperative and interventional MRI.
authors.affiliation: Inserm, U703, Institute of Medical Technology, University Hospital of Lille, Pavillon Vancostenobel, CHRU de Lille, 59037 Lille, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Viard
authors.forename: Maximilien
authors.initials: M
authors.lastname: Vermandel
authors.forename: Jean
authors.initials: J
authors.lastname: Rousseau
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003300:Copper; D004867:Equipment Design; D004869:Equipment Safety; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D011835:Radiation Protection / Q000295:instrumentation*; D015641:Radiography, Interventional / Q000295:instrumentation*; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*
chemical_list: D003300:Copper