磁共振DWI和FLAIR序列对判断脑梗塞期龄的作用

目的：评价DWI和FLAIR序列在脑梗塞后不同时期内的应用价值。方法：通过对65例不同发病时间脑梗塞的连续追踪的MRI－DWI和FLAIR序列扫描，分析病灶的异常信号出现的时间、范围、信号强度的差异。结果：超急性期DWI序列病灶出现明显的高信号改变，而FLAIR序列未能显示；急性期DWI序列和FLAIR序列均能显示病灶的高信号，但以DWI序列更佳；亚急性期DWI的高信号在后半程开始下降，而FLAIR像则对病灶显示得很好；慢性早期DWI信号降至等信号，FLAIR像信号开始下降，至慢性后期（30d后）大部分病灶信号降至正常，其中部分病灶降至低信号。结论：在脑梗塞发病的超急性期应常规使用DWI序列扫描，才能准确而全面地反映病灶的范围；FLAIR序列对于急性期以后的脑梗塞病灶能清楚显示其变化过程，对于多发性脑梗塞可以鉴别不同病灶的新旧程度。

An evaluation of MRI-DWI and FLAIR on staging the cerebral infarction

Objective It's an evaluation of MRI-DWI and FLAIR on staging the cerebral infarction. Methods Serial MRI-DWI and FLAIR scan were performed in 65 patients with cerebral infarction. The appearing time, extent and FLAIR scan were performed signals were analyzed. Results In super-acute stage apparent hyper-intense lesions were revealed on DWI, while no abnormality was found on FLAIR in demonstrating the hyper-intensity of lesions. In the later sub-acute stage the lesion signal began to decline. In the early chronic stage the lesions presented iso-intensity on DWI, when the lesion signal started to decline on FLAIR. After 30 day of episode, the lesions were iso-intense in most of the cases except hypo-intense lesions revealed in several cases. Conclusion DWI is a routine study in super-acute stag of cerebral infarction because of the good demonstration of the lesion extent, FLAIR is superior to DWI in investigation of the lesion in sub-acute and chronic stage, and FLAIR is also helpful in staging lesions in a case with multiple cerebral infarctions.