• To correlate the prognosis of acute ischemic stroke with the result of MRI-DTI. [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  

• To establish the DTI protocol as the biomarker for future research in neurological disorders, such as brain tumor, brain injury, brain developmental disorders, and Multiple Sclerosis. [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  

Stroke is the second leading cause of death in Taiwan. The morbidity and mortality of stroke is also very high worldwide. In the United States, about one third of 800,000 stoke patients became disabled; while in Taiwan, 13,000 out of 68,000 stroke patients died each year.

Diffusion tensor imaging (DTI) characterizes the three-dimensional distribution of water diffusion, which is highly anisotropic. Previous studies utilized DTI derived mean diffusivity (MD) and fractional anisotropy (FA) have found correlation between pathological changes of white matter and prognosis of stroke. However, the result was not specific due to the reason that any change at either axon or myelin sheath resulted in FA reduction. DTI, on the other hand, differentiate morphological change at axon and myelin sheath with axial and radial diffusivity, respectively. With this data, we hypothesized that the prognosis might relate to pathological change with axon post-stroke. Therefore, we conduct the study to use DTI derived axial diffusivity to evaluate the severity and to predict the functional outcome in acute ischemic stroke patient.