DWI／PWI在脑梗死缺血半暗带量化评定中的应用

目的评价磁共振弥散加权成像（DWI）和灌注加权成像（PWI）在界定超早期脑梗死缺血半暗带中的应用。方法25例发病时间在6h以内的超早期脑梗死患者行MRI检查，包括DWI和PWI，测量分析梗死中心区、缺血半暗带（IP）及对侧镜像区扩张变化和血流灌注。计算ADC值。结果超早期大面积脑梗死患者PWI上显示的脑灌注延长区域与DWI上显示的高信号急性脑梗死区域不匹配，PWI显示的病灶范围大于DWI显示；DWI定量分析显示，与梗死中心区比较，IP、梗死中心对侧镜像区ADC值均明显增高，有显著性差异（P〈0．01）；IP区fADe值高于梗死中心区，两者比较有显著性差异（P〈0．05）；PWI显示大面积梗死患者脑组织血流灌注明显减低，腔隙性脑梗死患者未见明显的灌注减低区。结论DWI与PWI的联合检查可准确诊断超早期脑梗死并预测IP。

Application of DWI/PWI to the quantitative assessment of cerebral infarc- tion ischemic penumbra

Objective To evaluate diffusion weighted imaging （DWI） and perfusion weighted imaging （PWI） applied in the I determination of ischemic penumbra in super-early stage cerebral infarction. Methods A total of 25 patients were carried out MRI examination, including DWI and PWI, within 6 hours onset of super-early stage cerebral infarction. Infarction central area, ischemic penumbra （IP）, expansion change to side mirror area, and blood perfusion were determined, and the values of ADC were calculated. Results Super-early stage large area cerebral infarction patients, the cerebral perfusion ex- tended area displayed by PWI did not match with the high signal acute cerebral infarction area displayed by DWI. Lesions range showed by PWI was bigger than by DWI. DWI quantitative analysis showed that ADC values of IP, infarction center to side mirror area were significantly increased in comparison with infarction central area significantly （P 〈 0.01）. The rADC value in IP area was higher than in infarction central area, which showed significant difference （P 〈 0.05）. PWI showed tissue perfusions of large infarction patients were significantly reduced and no obvious perfusion reduced area was found in the lacunar cerebral infarction patients. Conclusion Combined examinations of DWI and PWI can diagnose accurately su- per-early stage cerebral infarction and predict IP.