title: Diffusion tensor tractography of residual fibers in traumatic spinal cord injury: a pilot study.
abstract: OBJECTIVE
  In clinical studies, evaluating residual fiber tracts in spinal cord injuries poses serious difficulties, whereas diffusion tensor imaging (DTI) can assess alterations in fiber structural integrity. For this reason, this study aimed to determine changes in the structural integrity of residual fiber tracts via fractional anisotropy (FA) variations and fiber-tracking patterns in patients with chronic traumatic spinal cord injury (SCI).
  
  
  METHODS
  T2-weighted and diffusion-weighted imaging was performed on four traumatic SCI patients and three healthy volunteers using a 3.0-T MR scanner. After obtaining fiber-tracking maps, FA values were measured and analyzed in residual and remote normal and healthy cords.
  
  
  RESULTS
  Diffusion tensor tractography showed obvious destruction of fiber tracts in injured cords. In the healthy control subjects, averaged FA values ranged from 0.545 to 0.601, whereas all SCI patients had decreased FA values in both residual (0.220 ± 0.121) and remote normal fibers (0.535 ± 0.101). There were also statistically significant differences in FA values between residual and remote normal fibers in patients (P = 0.000) and between their residual and healthy control fibers (P = 0.000). No significant difference was found between remote normal and healthy cords (P = 0.312).
  
  
  CONCLUSIONS
  Specific FA variations were observed in residual fibers, suggesting that DTI may be a useful tool for evaluating residual tracts in SCI patients.
authors: Department of Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, 37# Xueyuan Road, 100191 Beijing, China.
authors: Jia-Sheng
authors: JS
authors: Rao
authors: Can
authors: C
authors: Zhao
authors: Zhao-Yang
authors: ZY
authors: Yang
authors: Shu-Yu
authors: SY
authors: Li
authors: Tao
authors: T
authors: Jiang
authors: Yu-Bo
authors: YB
authors: Fan
authors: Xiao-Guang
authors: XG
authors: Li
mesh_terms: D000328:Adult; D056324:Diffusion Tensor Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology*; D010865:Pilot Projects; D013119:Spinal Cord Injuries / Q000503:physiopathology*
keywords: ASIA; American Spinal Injury Association; CNS; DTI; DW; Diffusion tensor imaging; FA; FOV; Fiber tracking imaging; Fractional anisotropy; MRI; N; No; ROI; Residual fiber tracts; SCI; SD; SE-EPI; SNR; T; Traumatic spinal cord injury; Y; Yes; central nervous system; diffusion tensor imaging; diffusion-weighted; field of view; fractional anisotropy; magnetic resonance imaging; regions of interest; signal-to-noise ratio; spin-echo echo-planar imaging; spinal cord injury; standard deviation; thoracic segment