title: [Application of diffusion tensor imaging in judging infarction time of acute ischemic cerebral infarction].
abstract: OBJECTIVE
  To evaluate the clinical application value of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in judging infarction time phase of acute ischemic cerebral infarction.
  
  
  METHODS
  To retrospective analysis DTI images of 52 patients with unilateral acute ischemic cerebral infarction (hyper-acute, acute and sub-acute) from the Affiliated Yancheng Hospital of Southeast University Medical College, which diagnosed by clinic and magnetic resonance imaging. Set the regions of interest (ROIs) of infarction lesions, brain tissue close to infarction lesions and corresponding contra (contralateral normal brain tissue) on DTI parameters mapping of fractional anisotropy (FA), volume ratio anisotropy (VRA), average diffusion coefficient (DCavg) and exponential attenuation (Exat), record the parameters values of ROIs and calculate the relative parameters value of infarction lesion to contra. Meanwhile, reconstruct the DTT images based on the seed points (infarction lesion and contra). The study compared each parameter value of infarction lesions, brain tissue close to infarction lesions and corresponding contra, also analysed the differences of relative parameters values in different infarction time phases.
  
  
  RESULTS
  The DTT images of acute ischemic cerebral infarction in each time phase could show the manifestation of fasciculi damaged. The DCavg value of cerebral infarction lesions was lower and the Exat value was higher than contra in each infarction time phase (P<0.05). The FA and VRA value of cerebral infarction lesions were reduced than contra only in acute and sub-acute infarction (P<0.05). The FA, VRA and Exat value of brain tissue close to infarction lesions were increased and DCavg value was decreased than contra in hyper-acute infarction (P<0.05). There were no statistic differences of FA, VRA, DCavg and Exat value of brain tissue close to infarction lesions in acute and sub-acute infarction. The relative FA and VRA value of infarction lesion to contra gradually decreased from hyper-acute to sub-acute cerebral infarction (P<0.05), but there were no difference of the relative VRA value between acute and sub-acute cerebral infarction. The relative DCavg value of infarction lesion to contra in hyper-acute infarction than that in acute and sub-acute infarction (P<0.05), however there was also no difference between acute and sub-acute infarction. ROC curve showed the best diagnosis cut off value of relative FA, VRA and DCavg of infarction lesions to contra were 0.852, 0.886 and 0.541 between hyper-acute and acute cerebral infarction, the best diagnosis cut off value of relative FA was 0.595 between acute and sub-acute cerebral infarction, respectively.
  
  
  CONCLUSIONS
  The FA, VRA, DCavg and Exat value have specific change mode in acute ischemic cerebral infarction of different infarction time phases, which can be combine used in judging infarction time phase of acute ischemic cerebral infarction without clear onset time, thus to help selecting the reasonable treatment protocols.
authors.affiliation: Department of Radiology, Affiliated Yancheng Hospital of Southeast University Medical College, Yancheng 224001, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Dai
authors.affiliation: Email: shuibin1988@163.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Interventional Radiology, Affiliated Yancheng Hospital of Southeast University Medical College, Yancheng 224001, China, Email: ycsyylz@163.com.
authors.forename: Lizheng
authors.initials: L
authors.lastname: Yao
authors.forename: Congsong
authors.initials: C
authors.lastname: Dong
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Haicun
authors.initials: H
authors.lastname: Shi
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Zhang
authors.forename: Naizhong
authors.initials: N
authors.lastname: Yang
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Zhang
authors.forename: Yinggui
authors.initials: Y
authors.lastname: Dai
mesh_terms: D016880:Anisotropy; D001921:Brain; D002545:Brain Ischemia; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D020521:Stroke