单侧大脑中动脉狭窄或闭塞脑铁沉积的定量磁敏感图初步研究

Preliminary study of quantitative susceptibility mapping in the brain iron deposition of unilateral middle cerebral artery stenosis or occlusion

目的采用磁共振定量磁敏感图(quantitative susceptibility mapping,QSM)测量单侧大脑中动脉(middle cerebral artery,MCA)狭窄或闭塞患者大脑深部灰质核团的铁含量。材料与方法纳入33例单侧MCA狭窄或闭塞患者,采用GE 3.0 T MR进行QSM和常规MRI检查。将原始图像进行处理后得到QSM图像,分别测量病侧和对侧尾状核、壳核、苍白球及丘脑的磁敏感值,采用配对样本t检验比较两侧灰质核团间磁敏感值的差异。再根据管腔狭窄程度将33例患者分为轻中度狭窄组、重度狭窄组、闭塞组,采用单因素方差分析比较三组患者病侧灰质核团间磁敏感值的差异。结果33例受试者病侧尾状核、壳核和苍白球磁敏感值较对侧差异有统计学意义(P<0.05),丘脑两侧磁敏感值差异无统计学意义(P>0.05)。上述三组各组间差异均无统计学意义(P值均>0.05)。结论应用QSM技术发现一侧MCA狭窄或闭塞患者病侧灰质核团铁含量均较对侧增高,进一步加深对缺血性脑卒中病理生理过程的认识,从而为临床治疗和改善缺血性脑卒中预后提供指导。

Objective:The MR quantitative susceptibility mapping(QSM)was used to explore the iron deposition of brain gray matter nucleus in patients with unilateral middle cerebral artery(MCA)stenosis or occlusion.Materials and Methods:Thirty-three patients with unilateral MCA stenosis or occlusion underwent QSM and conventional MRI scan by GE 3.0 T MR.After processing the original images,QSM images were obtained.Susceptibility values of bilateral caudate nucleus,putamen,globus pallidus and thalamus were measured and compared between the lesion side and the contralateral side by paired sample t-test.According to the degree of lumen stenosis,the 33 patients were divided into mild and moderate stenosis group,severe stenosis group and occlusion group.One-way analysis of variance was used to compare the differences of susceptibility values of gray matter nucleus in the three groups.Results:There was significant difference in susceptibility values of caudate nucleus,putamen and globus pallidus between the lesion side and the contralateral side in 33 subjects(P<0.05),while there was no significant difference in susceptibility values of thalamus on both sides(P>0.05).And there was no statistical significance among the above three groups(P>0.05).Conclusions:The QSM technique found that the iron content in gray matter nucleus of the lesion side in patients with unilateral MCA stenosis or occlusion was higher than the contralateral side,which further deepens the understanding of the pathophysiological changes of ischemic stroke and provides guidance for clinical treatment and improvement of the prognosis of ischemic stroke.