title: Global tracking in human gliomas: a comparison with established tracking methods.
abstract: OBJECTIVE
  Global tracking (GT) is a recently published fibre tractography (FT) method that takes simultaneously all fibres into account during their reconstruction. The purpose of this study was to compare this new method with fibre assignment by continuous tracking (FACT) and probabilistic tractography (PT) for the detection of the corticospinal tract (CST) in patients with gliomas.
  
  
  METHODS
  Tractography of the CST was performed in 17 patients with eight low grade and nine anaplastic astrocytomas located in the motor cortex or the corticospinal tract. Diffusions metrics as fractional anisotropy (FA), mean (MD), axial (AD) and radial diffusivity (RD) were obtained. The methods were additionally applied on a physical phantom to assess their accuracy.
  
  
  RESULTS
  PT was successful in all (100 %), GT in 16 (94 %) and FACT in 15 patients (88 %). The case where GT and FACT, both, missed the CST showed the highest AD and RD, whereas the one where FACT algorithm, alone, was not successfully showed the lowest AD and RD of the group. FA was reduced on the pathologic side (FApath 0.35 ± 0.16 (mean ± SD) versus FAcontralateral 0.51 ± 0.15, pcorr < 0.03). RD was increased on the pathologic side (RDpath 0.67 ± 0.29 × 10(-3) mm(2)/s versus RDcontralateral 0.46 ± 0.08 × 10(-3) mm(2)/s, pcorr < 0.03). In the phantom measurement, only GT did not detect false positive fibres at fibre crossings.
  
  
  CONCLUSIONS
  PT performed well even in areas of increased diffusivities indicating a severe oedema or disintegration of tissue. FACT was also susceptible to a decrease of diffusivities and to a susceptibility artefact, where GT was robust.
authors: Department of Neuroradiology, University Medical Centre Freiburg, Breisacher St. 64, 79106, Freiburg, Germany, nguyen.thanh.thao@hue-radiology.com.
authors: T
authors: T
authors: Nguyen-Thanh
authors: M
authors: M
authors: Reisert
authors: C
authors: C
authors: Anastasopoulos
authors: F
authors: F
authors: Hamzei
authors: T
authors: T
authors: Reithmeier
authors: M S
authors: MS
authors: Vry
authors: V G
authors: VG
authors: Kiselev
authors: A
authors: A
authors: Weyerbrock
authors: I
authors: I
authors: Mader
mesh_terms: D000465:Algorithms; D001932:Brain Neoplasms / Q000473:pathology*; D058948:Cell Tracking / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D010363:Pattern Recognition, Automated / Q000379:methods; D011712:Pyramidal Tracts / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity