title: Evaluation of electrode position in deep brain stimulation by image fusion (MRI and CT).
abstract: BACKGROUND
  Imaging has an essential role in the evaluation of correct positioning of electrodes implanted for deep brain stimulation (DBS). Although MRI offers superior anatomic visualization of target sites, there are safety concerns in patients with implanted material; imaging guidelines are inconsistent and vary. The fusion of postoperative CT with preoperative MRI images can be an alternative for the assessment of electrode positioning. The purpose of this study was to assess the accuracy of measurements realized on fused images (acquired without a stereotactic frame) using a manufacturer-provided software.
  
  
  METHODS
  Data from 23 Parkinson's disease patients who underwent bilateral electrode placement for subthalamic nucleus (STN) DBS were acquired. Preoperative high-resolution T2-weighted sequences at 3 T, and postoperative CT series were fused using a commercially available software. Electrode tip position was measured on the obtained images in three directions (in relation to the midline, the AC-PC line and an AC-PC line orthogonal, respectively) and assessed in relation to measures realized on postoperative 3D T1 images acquired at 1.5 T.
  
  
  RESULTS
  Mean differences between measures carried out on fused images and on postoperative MRI lay between 0.17 and 0.97 mm.
  
  
  CONCLUSIONS
  Fusion of CT and MRI images provides a safe and fast technique for postoperative assessment of electrode position in DBS.
authors.affiliation: Department of Neuroradiology, Geneva University Hospital, Gabrielle Perret Gentil, 4, 1211, Geneva 14, Switzerland.
authors.forename: I
authors.initials: I
authors.lastname: Barnaure
authors.affiliation: Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Pollak
authors.affiliation: Department of Neurosurgery, Geneva University Hospital, Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Momjian
authors.affiliation: Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Horvath
authors.affiliation: Department of Neuroradiology, Geneva University Hospital, Gabrielle Perret Gentil, 4, 1211, Geneva 14, Switzerland.
authors.forename: K O
authors.initials: KO
authors.lastname: Lovblad
authors.affiliation: Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Boëx
authors.affiliation: Department of Radiology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Remuinan
authors.affiliation: Department of Neurology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Burkhard
authors.affiliation: Department of Neuroradiology, Geneva University Hospital, Gabrielle Perret Gentil, 4, 1211, Geneva 14, Switzerland. maria.i.vargas@hcuge.ch.
authors.forename: M I
authors.initials: MI
authors.lastname: Vargas
mesh_terms: D001931:Brain Mapping / Q000379:methods*; D046690:Deep Brain Stimulation; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000601:surgery*; D057234:Preoperative Period; D020531:Subthalamic Nucleus; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT; Deep brain stimulation; Electrode position; Image fusion; MRI