烟雾病导致皮质型分水岭梗死的低场MRI特征分析

Analysis of low field MR imaging characteristics of cortical-type watershed infarction due to moyamoya disease

目的分析烟雾病导致皮质型分水岭脑梗死(CWI)的低场磁共振成像(MRI)表现特征,探讨侧支循环异常和皮质型CWI的关系。方法搜集11例经MRI及临床证实为烟雾病导致皮质型分水岭梗死的MRI资料。采用西门子concerto型0.2T磁共振,常规梯度回波T1WI(GRE-T1WI)、T2WI液体衰减反转恢复序列(FLAIR)和增强GRE-T1WI、后文(TOF-MRA)检查(11例)以及增强FLAIR检查(4例),分析其影像特征。结果缺血病变位于皮层分水岭区及基底神经节区,包括皮质前型CWI(8例)和皮质后型CWI(6例),及基底节区皮质型CWI(2例)。MRI平扫显示分水岭区皮质萎缩(3例),分水岭区皮质水肿(8例),及基底神经节区水肿(2例)。FLAIR显示基底节区病变周围深穿支血管高信号征(2例)。增强FLAIR显示病变区柔脑膜增厚强化(4例)。增强T1WI显示病变区皮层强化(2例)。结论 皮质型分水岭脑梗死的MRI表现特征和侧支循环重建机制有关。微循环障碍及血流动力学障碍和皮质型分水岭梗死密切相关。皮质型分水岭脑梗死的MRI特征性表现对烟雾病的诊断具有重要意义。

Objective To analyze the characteristics of cortical-type watershed infaretion due to moyamoya disease on low field MR imaging,to explore the relationship between abnormity of collateral circulation and cortical-type CWI.Methods The MRI imaging data of 11 cases of cortical-type watershed infaretion due to moyamoya disease confirmed by MRI and clinic.With MR system（Siemens Concerto 0.2Tesla）,underwent MR examination through GRE-T1WI,T2WI,FLAIR and enhanced GRE-T1WI,TOF-MRA scan（11 cases）,as well as enhanced FLAR scan（4 cases） to analyzed the neuroimang characteristics.Results The ischaemic lesions limited to cortical borderzone area and basal ganglia area,infarct patterns including precortical CWI（8 cases） and postcortical CWI（6 cases）,as well as cortical-type CWI in basal ganglia（2 cases）.Plain MRI showed watershed cortical atrophy（3 cases）,watershed cortical edema（8 cases）,and edema in basal ganglia（2 cases）.FLAIR demonstrates hyperintense vessel signs of peripheral deep perforator branches in the ischaemic lesions（2 cases）.Contrast-enhanced FLAIR revealed leptomeningeal thicking and enhancement in the ischaemic lesions（4 cases）.Contrast-enhanced T1WI cortical enhancement in the ischaemic lesions（2 cases）.Conclusion The characteristics of cortical-type watershed infarction on MRI depends on mechanisms of reconstruction of collateral circulation.There is a close correlation between microcirculatory disturbance,as well as haemodynamics disturbance and cortical-type watershed infarction.The characteristics of cortical-type watershed infarction on MRI have important meaning to moyamoya disease.