title: [Magnetic resonance diffusion tensor imaging for diagnosis of pyramidal tract damage in rats].
abstract: OBJECTIVE
  To explore the applicability of magnetic resonance diffusion tensor imaging (DTI) for diagnosis of pyramidal tract damage in rats.
  
  
  METHODS
  Marmarou's model was set up, followed by DTI scanning at 3, 12, 24 and 72 h post trauma to acquire the dispersion parameter of bilateral pyramidal tracts. Moreover, axonal varicosities per square millimeter and the percentage of positive area of axons demonstrated by beta-amyloid precursor protein (beta-APP) immunostaining were obtained, as well as the mean density and sum density of neurofilament (NF) 68 immunostaining.
  
  
  RESULTS
  Axial diffusivity (AD), fraction anisotropy (FA) and relative anisotropy (RA) in the pyramidal tract were significantly and continuously reduced and reached to the bottom at 72h post trauma (P < 0.05) in accord with the gradient of axonal damage verified by beta-APP and NF68 immunostaining. Furthermore, the changes of AD, FA and RA showed a significant negative correlation with the beta-APP immunohistochemical results.
  
  
  CONCLUSIONS
  DTI has important value for early diagnosis in pyramidal tract damage.
authors.affiliation: Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. lishangxun@gmail.com
authors.forename: Shang-Xun
authors.initials: SX
authors.lastname: Li
authors.forename: Dai
authors.initials: D
authors.lastname: Shan
authors.forename: Yi-Jie
authors.initials: YJ
authors.lastname: Duan
authors.forename: Jing-Jun
authors.initials: JJ
authors.lastname: Xing
authors.forename: Yang
authors.initials: Y
authors.lastname: Ding
authors.forename: Yi-Wu
authors.initials: YW
authors.lastname: Zhou
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D000818:Animals; D016880:Anisotropy; D001369:Axons / Q000473:pathology; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D001930:Brain Injuries / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004195:Disease Models, Animal; D007091:Image Processing, Computer-Assisted; D008297:Male; D016900:Neurofilament Proteins / Q000378:metabolism; D011712:Pyramidal Tracts / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D016564:Amyloid beta-Protein Precursor; D016900:Neurofilament Proteins; C066858:neurofilament protein NF 68