磁敏感加权成像在脑梗死再灌注损伤的临床应用研究

Clinical application of susceptibility-weighted imaging in the reperfusion of ischemic stroke

目的：探讨磁敏感加权成像（SWI）技术对脑梗死再灌注损伤的临床应用价值。方法：对54例脑梗死各期患者进行MR及随诊检查,超急性期（〈6h）9例,急性期（7－24h）18例,亚急性期（1.5－7天）18例,稳定期（8－14天）3例,慢性期（〉15天）6例。对其中21例大面积脑梗死病例行SWI随诊。观察脑梗死内有无出血、出血程度及梗死区周围小血管的改变,并与患者的临床NIHSS评分进行相关性分析。结果：21例大面积脑梗死随访中,SWI发现梗死后出血为16例,占76.8%。梗死后重度出血程度与临床NIHSS评分改变具有显著正相关性（rs=0.765,P=0.001）。14例发现梗死灶周边有增多的微小血管,明显显示10例（占47.6%）,显示程度与临床NIHSS评分改变无明显相关性（rs=0.408,P=0.066）。结论：SWI能够敏感检测梗死灶内的出血灶,预测梗死后再灌注损伤的程度与发展趋势;SWI通过显示梗死灶周围微小血管的影像改变,有助于判断其周围血流再灌注情况,对临床的治疗及预后起到一定的预测作用。

Objective：To investigate the imaging evolution of the ischemic stroke in SWI,and evaluate the role of SWI in assessment of reperfusion after ischemic stroke.Methods：Fifty-four patients（30 males,24 females,age 20-83 years,average 67 years） with cerebral infarction were performed with conventional MRI and SWI.Nine cases of hyperacute infarction（6 hours）,18 cases of acute infarction（7-24 hours）,18 cases of subacute infarction（1.5-7days）,3 cases of stable stage（8-14days）,and 6 cases of chronic infarction（〉15days） were recruited in this study.Twenty-one cases with large area of infarction were followed up by SWI in this study.The presence of hemorrhage within the infarction,the extent of hemorrhage and microvascular changes around the ischemic area were observed in the follow-up images.The correlation between the extent of hemorrhage in the infarction region,the number of surrounding microvessels and the NIHSS changes were analyzed.Results：① Hemorrhage was revealed by SWI in 16 out of 21 massive cerebral infarctions.There was a significant positive correlation between the severe hemorrhage and the NIHSS scores（rs=0.765,P=0.001）.②Among the 21 cases of large area of infarctions,increased microvessels were observed in 10 patients（47.6%）.There was no significant correlation between the microvessels and the NIHSS scores changes（rs=0.408,P=0.066）.Conclusion：SWI is sensitive in detecting the microbleeds in the infarction,which can be used to predict the evolution of reperfusion injury after ischemic stroke.The microvascular changes reflected on SWI can be used to assess the reperfusion status after stroke,which is helpful in guiding the clinical treatment.