title: Pre- and intraoperative tractographic evaluation of corticospinal tract shift.
abstract: BACKGROUND
  Magnetic resonance with diffusion tensor image (DTI) may be able to estimate trajectories compatible with subcortical tracts close to brain lesions. A limit of DTI is brain shifting (movement of the brain after dural opening and tumor resection).
  
  
  OBJECTIVE
  To calculate the brain shift of trajectories compatible with the corticospinal tract (CST) in patients undergoing glioma resection and predict the shift directions of CST.
  
  
  METHODS
  DTI was acquired in 20 patients and carried out through 12 noncollinear directions. Dedicated software "merged" all sequences acquired with tractographic processing and the whole dataset was sent to the neuronavigation system. Preoperative, after dural opening (in 11) and tumor resection (in all) DTI acquisitions were performed to evaluate CST shifting. The extent of shifting was considered as the maximum distance between the preoperative and intraoperative contours of the trajectories.
  
  
  RESULTS
  An outward shift of CST was observed in 8 patients and an inward shift in 10 patients during surgery. In the remaining 2 patients, no intraoperative displacement was detected. Only peritumoral edema showed a statistically significant correlation with the amount of shift. In those patients in which DTI was acquired after dural opening as well (11 patients), an outward shifting of CST was evident in that phase.
  
  
  CONCLUSIONS
  The use of intraoperative DTI demonstrated brain shifting of the CST. DTI evaluation of white matter tracts can be used during surgical procedures only if updated with intraoperative acquisitions.
authors.affiliation: Department of Neuroradiology, S Andrea Hospital, University Sapienza, Rome, Italy. andrea.romano@uniroma1.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Romano
authors.forename: Giancarlo
authors.initials: G
authors.lastname: D'Andrea
authors.forename: Luigi Fausto
authors.initials: LF
authors.lastname: Calabria
authors.forename: Valeria
authors.initials: V
authors.lastname: Coppola
authors.forename: Camilla Rossi
authors.initials: CR
authors.lastname: Espagnet
authors.forename: Alberto
authors.initials: A
authors.lastname: Pierallini
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrante
authors.forename: Luigi
authors.initials: L
authors.lastname: Fantozzi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bozzao
mesh_terms: D000328:Adult; D000368:Aged; D001929:Brain Edema / Q000601:surgery; D001932:Brain Neoplasms / Q000601:surgery; D003399:Craniotomy; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D011712:Pyramidal Tracts / Q000473:pathology* / Q000601:surgery*; D012372:ROC Curve