MR扩散加权成像对脑梗死缺血半暗带的诊断价值

目的探讨MR扩散加权成像在评价脑梗死缺血半暗带中的价值及临床意义。方法对首次发病的41例脑梗死患者进行常规MR及DWI扫描，并在治疗后复查MRI。对比分析患侧病灶中心区和缺血半暗带及对侧镜像区的表观扩散系数及表观扩散系数比率。结果与正常区比较缺血半暗带ADC值仅轻度下降，病灶中心区ADC值则明显下降。病灶中心区与缺血半暗带ADCR值随发病时间延长均有上升趋势。超急性期及急性期缺血半暗带区ADCR值高于病灶中心区，差异有高度统计学意义（P〈0．01）。结论DWI、ADC及ADCR可以发现急性期脑梗死和预测缺血半暗带，为指导患者的治疗提供影像学依据。

The value of diffusion-weighted imaging in the diagnosis of ischemic penumbra of the cerebral infarction

Objective To explore the value and clinical significance of diffusion weighted imaging（DWI） in the evalu- ation of ischemic penumbra of the cerebral infarction. Methods The first episode in 41 cases of cerebral infarction were examined with conventional MRI and DWI scans, and examined MRI again after clinical treatment. Comparative analysis of the apparent diffusion coefficient （ADC） values and the apparent diffusion coefficient ratio （ADCR） in the ipsilateral lesion center, the ischemic penumbra and the mirrored region. Results Compared with the normal area, the ADC value of the ischemic penumbra only slightly decreased, and the ADC values of the infarcted lesion core de- creased significantly. The ADCR value of the core and ischemic penumbra has rising trend with time of onset of ex- tension. Hyper acute and acute stage ADCR value of the penumbra was higher than the infarct region, the difference was very significant（P 〈 0.01 ）. Conclusion DWI and ADC, ADCR can find in hyper acute and acute stage of cerebral infarction and predict of ischemic penumbra , for guiding to treat with neuroimaging basis.