【摘要】 目的　评价各种MRI检查方法在早期脑缺血动物模型中的诊断价值。方法　线栓法制备大鼠局灶性大脑中动脉闭塞 /再通模型。应用弥散加权成像 (DWI)、超顺磁氧化铁 (SPIO)灌注T2WI和常规MRI检查 ,在不同时间点对模型进行观察。结果　DWI在脑缺血的 3 0～ 90min可显示高信号区 ,但缺血范围显示不清 ;SPIO灌注T2WI在缺血 1h时可显示脑血流低灌注区 ,无法观察病理改变 ;T2WI上高信号在脑缺血后 6～ 12h ,可确切观察缺血范围 ;T1WI无异常发现。结论　早期脑缺血的MRI诊断应综合应用不同的成像方法更多还原

【Abstract】 Objective To study the value of different MRI examination on early cerebral ischemia in rats. Methods Fifty-two Wistar rats were randomly divided into 6 groups, 46 rats were created focal cerebral ischemia model in middle cerebral artery territory by Zea Longa method, the other 6 rats were used as normal control group and sham-operated group. Apply diffusion weighted imaging (DWI), superparamagnetic iron oxide (SPIO) perfusion T2WI and general MRI separately to observe the models at different time. Results DWI showed high signal 30-90 minutes after the occlusion of middle cerebral artery (100%), but the range of the lesions was not clear. SPIO perfusion T2WI could detect low perfusion area within 1 h after cerebral artery occlusion, but couldn’t reflect the pathological changes. T2WI showed abnormal signal intensity in 6-12 h after cerebral ischemia (70%) and could show the boundary of ischemic area precisely. No abnormal signal intensity could be found on T1WI within time of observation. Conclusion DWI and SPIO perfusion T2WI can provide useful imaging information for diagnoses of hyperacute cerebral ischemia. T2WI is helpful in localizing and judging the range of cerebral ischemia. No abnormality could be identified on T1WI at early cerebral ischemia. The application of different MRI methods is recommended in diagnosing early cerebral ischemia.更多还原