title: Corticospinal tract modeling for neurosurgical planning by tracking through regions of peritumoral edema and crossing fibers using two-tensor unscented Kalman filter tractography.
abstract: OBJECTIVE
  The aim of this study was to present a tractography algorithm using a two-tensor unscented Kalman filter (UKF) to improve the modeling of the corticospinal tract (CST) by tracking through regions of peritumoral edema and crossing fibers.
  
  
  METHODS
  Ten patients with brain tumors in the vicinity of motor cortex and evidence of significant peritumoral edema were retrospectively selected for the study. All patients underwent 3-T magnetic resonance imaging (MRI) including functional MRI (fMRI) and a diffusion-weighted data set with 31 directions. Fiber tracking was performed using both single-tensor streamline and two-tensor UKF tractography methods. A two-region-of-interest approach was used to delineate the CST. Results from the two tractography methods were compared visually and quantitatively. fMRI was applied to identify the functional fiber tracts.
  
  
  RESULTS
  Single-tensor streamline tractography underestimated the extent of tracts running through the edematous areas and could only track the medial projections of the CST. In contrast, two-tensor UKF tractography tracked fanning projections of the CST despite peritumoral edema and crossing fibers. Based on visual inspection, the two-tensor UKF tractography delineated tracts that were closer to motor fMRI activations, and it was apparently more sensitive than single-tensor streamline tractography to define the tracts directed to the motor sites. The volume of the CST was significantly larger on two-tensor UKF than on single-tensor streamline tractography ([Formula: see text]).
  
  
  CONCLUSIONS
  Two-tensor UKF tractography tracks a larger volume CST than single-tensor streamline tractography in the setting of peritumoral edema and crossing fibers in brain tumor patients.
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.|Department of Neurosurgery, Jinling Hospital, Southern Medical University, Nanjing, 210002, Jiangsu, China.
authors.forename: Zhenrui
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Tie
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors.forename: Olutayo
authors.initials: O
authors.lastname: Olubiyi
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Mehrtash
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Rigolo
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Pegah
authors.initials: P
authors.lastname: Kahali
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
authors.forename: Isaiah
authors.initials: I
authors.lastname: Norton
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.|Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Ofer
authors.initials: O
authors.lastname: Pasternak
authors.affiliation: Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
authors.forename: Yogesh
authors.initials: Y
authors.lastname: Rathi
authors.affiliation: Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA. agolby@bwh.harvard.edu.|Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA. agolby@bwh.harvard.edu.
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: Golby
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA. odonnell@bwh.harvard.edu.
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: O'Donnell
mesh_terms: D000328:Adult; D000465:Algorithms; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D004487:Edema / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
keywords: Corticospinal tract; Crossing fibers; Diffusion tensor imaging; Neurosurgical planning; Peritumoral edema; Tractography