title: Computer assisted electromagnetic navigation improves accuracy in computed tomography guided interventions: A prospective randomized clinical trial.
abstract: OBJECTIVE
  To assess the accuracy and usability of an electromagnetic navigation system designed to assist Computed Tomography (CT) guided interventions.
  
  
  METHODS
  120 patients requiring a percutaneous CT intervention (drainage, biopsy, tumor ablation, infiltration, sympathicolysis) were included in this prospective randomized trial. Nineteen radiologists participated. Conventional procedures (CT group) were compared with procedures assisted by a navigation system prototype using an electromagnetic localizer to track the position and orientation of a needle holder (NAV group). The navigation system displays the needle path in real-time on 2D reconstructed CT images extracted from the 3D CT volume. The regional ethics committee approved this study and all patients gave written informed consent. The main outcome was the distance between the planned trajectory and the achieved needle trajectory calculated from the initial needle placement.
  
  
  RESULTS
  120 patients were analyzable in intention-to-treat (NAV: 60; CT: 60). Accuracy improved when the navigation system was used: distance error (in millimeters: median[P25%; P75%]) with NAV = 4.1[2.7; 9.1], vs. with CT = 8.9[4.9; 15.1] (p<0.001). After the initial needle placement and first control CT, fewer subsequent CT acquisitions were necessary to reach the target using the navigation system: NAV = 2[2; 3]; CT = 3[2; 4] (p = 0.01).
  
  
  CONCLUSIONS
  The tested system was usable in a standard clinical setting and provided significant improvement in accuracy; furthermore, with the help of navigation, targets could be reached with fewer CT control acquisitions.
authors.affiliation: Department of Imaging, Radiology and Medical Imaging, University Hospital, Grenoble, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Durand
authors.affiliation: Laboratory of Techniques for biomedical engineering and complexity management - informatics, mathematics and applications, University Grenoble Alpes, Grenoble, France.|Laboratory of Techniques for biomedical engineering and complexity management - informatics, mathematics and applications, National Center for Scientific Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, National Institute of Health and Medical Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Department of Public Health, University Hospital, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Research Department, University Hospital, Grenoble, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Moreau-Gaudry
authors.affiliation: Clinical Investigation Center - Innovative Technology 1406, National Institute of Health and Medical Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Department of Public Health, University Hospital, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Research Department, University Hospital, Grenoble, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Silvent
authors.affiliation: Department of Imaging, Radiology and Medical Imaging, University Hospital, Grenoble, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Frandon
authors.affiliation: Clinical Investigation Center - Innovative Technology 1406, National Institute of Health and Medical Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Department of Public Health, University Hospital, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Research Department, University Hospital, Grenoble, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Chipon
authors.affiliation: Clinical Investigation Center - Innovative Technology 1406, National Institute of Health and Medical Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Department of Public Health, University Hospital, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Research Department, University Hospital, Grenoble, France.
authors.forename: Maud
authors.initials: M
authors.lastname: Médici
authors.affiliation: Department of Imaging, Radiology and Medical Imaging, University Hospital, Grenoble, France.|Laboratory of Techniques for biomedical engineering and complexity management - informatics, mathematics and applications, University Grenoble Alpes, Grenoble, France.|Laboratory of Techniques for biomedical engineering and complexity management - informatics, mathematics and applications, National Center for Scientific Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, National Institute of Health and Medical Research, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Department of Public Health, University Hospital, Grenoble, France.|Clinical Investigation Center - Innovative Technology 1406, Research Department, University Hospital, Grenoble, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bricault
mesh_terms: D004574:Electromagnetic Fields; D006801:Humans; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*