title: What You See Is What You Get: Lead Location Within Deep Brain Structures Is Accurately Depicted by Stereotactic Magnetic Resonance Imaging.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI)-verified deep brain stimulation relies on the correct interpretation of stereotactic imaging documenting lead location in relation to visible anatomic target. However, it has been suggested that local signal distortion from the lead itself renders its depiction on MRI unreliable.
  
  
  OBJECTIVE
  To compare lead location on stereotactic MRI with subsequent location of its brain track after removal.
  
  
  METHODS
  Patients underwent deep brain stimulation with the use of MRI-guided and MRI-verified Leksell frame approach. Infection or suboptimal efficacy required lead removal and subsequent reimplantation by using the same technique. Postimplantation stereotactic MR images were analyzed. Lateral (x) and anteroposterior (y) distances from midcommissural point to center of the lead hypointensity were recorded at the anterior commissure-posterior commissure plane (pallidal electrode) or z = -4 (subthalamic electrode). Stereotactic MRI before the second procedure, x and y distances from the center of the visible lead track hypointensity to midcommissural point were independently recorded. Vectorial distance from center of the lead hypointensity to the center of its track was calculated.
  
  
  RESULTS
  Sixteen electrode tracks were studied in 10 patients. Mean differences between lead artifact location and lead track location were: x coordinate 0.4 mm ± 0.2; y coordinate 0.6 mm ± 0.3. Mean vectorial distance was 0.7 mm ± 0.2.
  
  
  CONCLUSIONS
  Stereotactic distance between lead location and subsequent brain track location on MRI was small. The mean discrepancy was approximately half the deep brain stimulation lead width. This suggests that lead hypointensity seen on postimplantation MRI is indeed an accurate representation of its real location within deep brain structures.
authors.affiliation: *Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, Queen Square, London, United Kingdom; ‡Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom; §Department of Clinical Neuroscience, Umeå University, Umeå, Sweden.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Hyam
authors.forename: Harith
authors.initials: H
authors.lastname: Akram
authors.forename: Thomas
authors.initials: T
authors.lastname: Foltynie
authors.forename: Patricia
authors.initials: P
authors.lastname: Limousin
authors.forename: Marwan
authors.initials: M
authors.lastname: Hariz
authors.forename: Ludvic
authors.initials: L
authors.lastname: Zrinzo
mesh_terms: D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D046690:Deep Brain Stimulation / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D005917:Globus Pallidus / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010300:Parkinson Disease / Q000601:surgery; D015203:Reproducibility of Results; D013238:Stereotaxic Techniques; D020531:Subthalamic Nucleus / Q000033:anatomy & histology; D025321:Surgery, Computer-Assisted