title: Feasibility of stereotactic MRI-based image guidance for the treatment of vascular malformations: a phantom study.
abstract: OBJECTIVE
  Treatment of vascular malformations requires the placement of a needle within vessels which may be as small as 1 mm, with the current state of the art relying exclusively on two-dimensional fluoroscopy images for guidance. We hypothesize that the combination of stereotactic image guidance with existing targeting methods will result in faster and more reproducible needle placements, as well as reduced radiationexposure, when compared to standard methods based on fluoroscopy alone.
  
  
  METHODS
  The proposed navigation approach was evaluated in a phantom experiment designed to allow direct comparison with the conventional method. An anatomical phantom of the left forearm was constructed, including an independent control mechanism to indicate the attainment of the target position. Three interventionalists (one inexperienced, two of them frequently practice the conventional fluoroscopic technique) performed 45 targeting attempts utilizing the combined and 45 targeting attempts utilizing the standard approaches.
  
  
  RESULTS
  In all 45 attempts, the users were able to reach the target when utilizing the combined approach. In two cases, targeting was stopped after 15 min without reaching the target when utilizing only the C-arm. The inexperienced user was faster when utilizing the combined approach and applied significantly less radiation than when utilizing the conventional approach. Conversely, both experienced users were faster when using the conventional approach, in one case significantly so, with no significant difference in radiation dose when compared to the combined approach.
  
  
  CONCLUSIONS
  This work presents an initial evaluation of a combined navigation fluoroscopy targeting technique in a phantom study. The results suggest that, especially for inexperienced interventionalists, navigation may help to reduce the time and the radiation dose. Future work will focus on the improvement and clinical evaluation of the proposed method.
authors.affiliation: ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland. marius.schwalbe@artorg.unibe.ch.
authors.forename: Marius
authors.initials: M
authors.lastname: Schwalbe
authors.affiliation: Division of Clinical and Interventional Angiology, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Axel
authors.initials: A
authors.lastname: Haine
authors.affiliation: Division of Clinical and Interventional Angiology, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Schindewolf
authors.affiliation: Institute of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Hendrik
authors.initials: H
authors.lastname: von Tengg-Kobligk
authors.affiliation: ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
authors.forename: Tom
authors.initials: T
authors.lastname: Williamson
authors.affiliation: ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.affiliation: Division of Clinical and Interventional Angiology, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Iris
authors.initials: I
authors.lastname: Baumgartner
authors.affiliation: Division of Clinical and Interventional Angiology, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Torsten
authors.initials: T
authors.lastname: Fuss
mesh_terms: D001132:Arm; D005240:Feasibility Studies; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted / Q000379:methods; D054079:Vascular Malformations / Q000000981:diagnostic imaging* / Q000601:surgery
keywords: MR imaging; Percutaneous needle insertions; Stereotactic image guidance; Vascular malformations