Evaluation of hyperacute cerebral ischemia with MR diffusion-weighted imaging in rats

Objective:To assess the diagnostic value of MR diffusion-weighted imaging (DWI) in hyperacute cerebral ischemia using rat model. Methods:Twelve male Wistar rats were performed right middle cerebral artery occlusion mode1 (MCAO). DWI,T2WI and T1WI were performed after one hour and six hours,respectively,the values of infarction volume and apparent diffusion coefficient (ADC) were measured. Triphenyltetrazolium chloride (TTC) stainings were executed and compared with DWI. Results:Abnormal hyperintensity was found in the right cerebral ischemic region on DWI after one hour. But there was no abnormal change on T2WI and T1WI. The extent of infarction was larger and the value of ADC was lower after six hours (P0.01). The abnormal hyperintensity was found on T2WI,and the abnormal hypointensity was found on T1WI in ischemic region. Infarction lesion on TTC staining was consistent with the abnormal on DWI. Conclusion:DWI is superior to conventional MRI for the diagnosis of hyperacute cerebral ischemia.