title: Focal lesions of the corticospinal tract demonstrated by diffusion tensor imaging in patients with diffuse axonal injury.
abstract: OBJECTIVE
  Diffusion tensor imaging (DTI) with fiber tractography (FT) could be useful for exploration of the state of the corticospinal tract (CST) at the subcortical white matter level. The purpose of this study was to demonstrate focal lesions of the CST in patients with diffuse axonal injury (DAI), using DTI with FT.
  
  
  METHODS
  Two patients with DAI and six normal control subjects were recruited to this study. DTI was performed using 1.5-T with a synergy-L Sensitivity Encoding (SENSE) head coil. Fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were measured using a region of interest (ROI) method. FTs were obtained with FA <0.3 and an angle change >45 degrees as termination criteria.
  
  
  RESULTS
  On the DTI with FT, the focal lesions, which could not observed using routine brain MRI, were detected in the left brainstem of patient 1 and in the right pons and the left and right medulla of patient 2. The patients showed significantly decreased FA values in the focal lesions compared to normal controls.
  
  
  CONCLUSIONS
  DTI with FT demonstrated focal lesions at the brainstem that had not been revealed by conventional brain MRI; these focal lesions explained the weaknesses of the patients. We conclude that DTI with FT may be a useful modality for use in investigating the status of CST in patients with DAI.
authors.affiliation: Department of Neurosurgery, School of Medicine, Ajou University, Suwon city, Republic of Korea.
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Ahn
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Kim
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Han
authors.forename: Oh Lyong
authors.initials: OL
authors.lastname: Kim
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Ahn
authors.forename: Yoon Woo
authors.initials: YW
authors.lastname: Cho
authors.forename: Yong-Hyun
authors.initials: YH
authors.lastname: Kwon
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Jang
mesh_terms: D000328:Adult; D016880:Anisotropy; D020833:Diffuse Axonal Injury / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011712:Pyramidal Tracts / Q000473:pathology*