Abstract: Abstract: Objective To explore the diffusion-weighted imaging (DWI) and apparent dispersion coefficient (ADC) value on the diagnostic value of brain ischemic infarction. Methods 78 cases of ischemic cerebral infarction cases according to the time, all groups doing MR T1WI, T2WI scan and DWI check, drawing ROI in the lesion and calculate ADC values through the software. Results The ischemic cerebral infarction lesions of hyperacute phase on conventional MRI examination showed no abnormalities, and DWI showed high signal, the average ADC values decreased to 0.512±0.07×10－3mm2/s, lower than that of normal brain tissue. The lesions of acute phase DWI showed high signal, the average ADC values decreased to a minimum of 0.423 ±0.13 ×10－3mm2/s. The lesions of subacute stage DWI showed low signal, average ADC values increased to 0.781±0.05×10－3mm2/s, close to the normal brain tissue. The lesions of chronic phase DWI showed obviously low signal, the average ADC values increased to 3.238±0.35×10－3mm2/s, was significantly higher than the brain tissue close to the cerebrospinal fluid. Conclusion DWI can effectively shows the hyperacute phase and the acute phase of ischemic cerebral infarction lesions, not only can be used for diagnosis, can also be used for the difference between the new and the old infarction, judge development period of disease.

Key words: diffusion-weighted imaging, apparent diffusion coefficient, ischemic infarction