MR灌注成像在轻微缺血症状患者中的应用价值

Application Value of MR Perfusion Weighted Imaging in Patients with Mild Cerebral Ischemia Symptoms

目的对轻微缺血症状患者按时间飞跃磁共振血管成像(TOF-MRA)结果进行脑动脉狭窄程度分度,评估PWI在不同程度动脉狭窄的该类患者中的应用价值。方法弥散成像(DWI)排除急性脑梗塞的轻微脑缺血症状患者113例,按TOF-MRA结果分为颅内动脉重度狭窄组47例,轻中度狭窄组49例,无狭窄组17例,均行PWI检查,对采集图像进行后处理和分析。结果重度狭窄组PWI阳性率高于DWI,差异有统计学意义(P<0.001),且与MRA结果匹配;轻中度狭窄、无狭窄组PWI与DWI阳性率差异无统计学意义(P>0.05)。结论在轻微脑缺血症状患者中,MRA提示颅内动脉重度狭窄者的PWI对脑灌注异常的检出高于DWI,轻中度度狭窄和无狭窄组则无差别,因此对于前者应重视PWI检查。

Objective To assess the application value of perfusion weighted imaging（PWI） in degree of cerebral artery stenosis according to Time-Of-Flight MRA（TOF-MRA）in the patients with mild ischemic symptoms. Methods PWI were performed and the images were post-processing and analysis in 113 cases with mild symptoms of cerebral ischemia, which were excluded acute cerebral infarction by Diffusion imaging（DWI）. They were devided in 3 groups according to TOF-MRA：47 cases in severe intracranial arterial stenosis group , 49 cases in mild stenosis group and 17 cases in normal group. Results To compare the differences between DWI and PWI, positive rate were statistically significant （P〈0.001） in severe intracranial arterial stenosis group, and the results was well-match with MRA. The differences were statistically insignificant （P〉0.05） in mild stenosis and normal groups. Conclusion In patients with mild cerebral ischemia symptoms, PWI is more sensitive than DWI in detecting abnormal perfusion conditions in severe intracranial arterial stenosis patients according to TOF-MRA, but PWI is not sensitive than DWI in mild stenosis and normal patients. PWI should be performed in the former condision.