title: Accuracy of diffusion tensor magnetic resonance imaging-based tractography for surgery of gliomas near the pyramidal tract:  a significant correlation between subcortical electrical stimulation and postoperative tractography.
abstract: BACKGROUND
  Diffusion tensor (DT) imaging-based fiber tracking is a noninvasive magnetic resonance technique that can delineate the course of white matter fibers.
  
  
  OBJECTIVE
  To evaluate the accuracy and usefulness of this DT imaging-based fiber tracking for surgery in patients with gliomas near the pyramidal tract (PT).
  
  
  METHODS
  Subjects comprised 32 patients with gliomas near the PT. DT imaging-based fiber tracks of the PT were generated before and within 3 days after surgery in all patients. A tractography-integrated navigation system was used during the operation. Cortical and subcortical motor-evoked potentials (MEPs) were also monitored during resection to maximize the preservation of motor function. The threshold intensity for subcortical MEPs was examined by searching the stimulus points and changing the stimulus intensity. Minimum distance between the resection border and the illustrated PT was measured on postoperative tractography.
  
  
  RESULTS
  In all subjects, DT imaging-based tractography of the PT was successfully performed, preoperatively demonstrating the relationship between tumors and the PT. With the use of the tractography-integrated navigation system and intraoperative MEPs, motor function was preserved postoperatively in all patients. A significant correlation was seen between threshold intensity for subcortical MEPs and the distance between the resection border and PT on postoperative DT imaging.
  
  
  CONCLUSIONS
  DT imaging-based fiber tracking is a reliable and accurate method for mapping the course of subcortical PTs. Fiber tracking and intraoperative MEPs were useful for preserving motor function in patients with gliomas near the PT.
authors.affiliation: Department of Neurosurgery, Ehime University Graduate School of Medicine, Toon, Ehime, Japan. sohue@m.ehime-u.ac.jp
authors.forename: Shiro
authors.initials: S
authors.lastname: Ohue
authors.forename: Shohei
authors.initials: S
authors.lastname: Kohno
authors.forename: Akihiro
authors.initials: A
authors.lastname: Inoue
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamashita
authors.forename: Hironobu
authors.initials: H
authors.lastname: Harada
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kumon
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Miki
authors.forename: Takanori
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005910:Glioma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000379:methods*; D011712:Pyramidal Tracts / Q000033:anatomy & histology; D025321:Surgery, Computer-Assisted / Q000379:methods*; D055815:Young Adult