基于健康人皮质脊髓束模板分析脑卒中皮质脊髓束损伤  

Analysis of corticospinal tract injury in stroke based on a corticospinal tract template derived from healthy subjects

作　　者：魏彧 余秋蓉 尹大志 王鹤玮 孙莉敏[3] 徐国军 詹爽 王雪飞[1] 郭苗 刘凡 范明霞[1] WEI Yu;YU Qiurong;YIN Dazhi;WANG Hewei;SUN Limin;XU Guojun;ZHAN Shuang;WANG Xuefei;GUO Miao;LIU Fan;FAN Mingxia(Shanghai Key Laboratory of Magnetic Resonance,Department of Physics,East China Normal University,Shanghai 200062,China;School of Psychology and Cognitive science,East China Normal University,Shanghai 200062,China;Huashan Hospital,Fudan University,Shanghai 200040,China)

机构地区：[1]华东师范大学上海市磁共振重点实验室,上海200062 [2]华东师范大学心理与认知科学学院,上海200062 [3]复旦大学附属华山医院,上海200040

出　　处：《磁共振成像》2021年第7期39-44,68,共7页Chinese Journal of Magnetic Resonance Imaging

基　　金：国家自然科学基金面上项目(编号:81471651);国家自然科学基金面上项目(编号:81974356);国家自然科学基金青年项目(编号:81401859);国家重点研发计划(编号:2020YFC2004200)。

摘　　要：目的运用磁共振扩散张量成像(diffusion tensor imaging,DTI)探究脑卒中皮质脊髓束(corticospinal tract,CST)扩散定量指标与运动功能的关系。材料与方法采集37例单侧皮质下脑卒中患者和30例健康被试的DTI数据,运用概率性纤维束成像追踪出健康被试的CST,获得健康对照组CST模板。基于健康对照组的CST模板测量两组被试双侧CST的各向异性分数(fractional anisotropy,FA)和平均扩散率(mean diffusivity,MD),进一步计算两组被试FA比率(FA ratio,rFA)、FA不对称性(FA asymmetry,FA_(asy))、MD比率(MD ratio,rMD)和MD不对称性(MD asymmetry,MD_(asy)),用这六个扩散参数相关指标来评估脑卒中患者CST完整性损伤,并与患者“手+腕”及上肢运动功能评分(Fugl-Meyer Assessment,FMA)作相关性分析。结果与健康对照组相比,卒中组病灶同侧CST的FA、rFA显著降低(分别为t=-15.775,t=-11.111,P<0.001),FA_(asy)显著增高(t=9.473,P<0.001);而MD、rMD显著增高(分别为t=9.553,t=7.733,P<0.001),MD_(asy)显著降低(t=-8.941,P<0.001);病灶对侧CST的FA和MD均无显著变化(P>0.05)。患者病程及病灶大小与各扩散指标间均无显著相关关系(P>0.05)。卒中组病灶同侧CST的FA和rFA与“手+腕”及上肢FMA呈显著正相关(分别为r=0.342,P=0.038;r=0.479,P=0.003;r=0.343,P=0.038;r=0.482,P=0.003),FA_(asy)与“手+腕”及上肢FMA呈显著负相关(分别为r=-0.353,P=0.032;r=-0.490,P=0.002)。分步回归分析进一步发现,相较于病灶同侧CST的FA和rFA,FA_(asy)与“手+腕”和上肢运动功能评分更加相关(分别为Beta=-0.353,P=0.032;Beta=-0.490,P=0.002)。结论基于健康对照组CST模板测得的FA相关指标能反映CST结构完整性。FA_(asy)与“手+腕”及上肢运动功能评分密切相关,或许可作为评估脑卒中患者手腕部和上肢运动功能障碍的重要参考指标。Objective:To explore the relationship between diffusion parameters of corticospinal tract(CST)and motor dysfunction in stroke using diffusion tensor imaging(DTI).Materials and Methods:DTI data were collected from 37 unilateral subcortical stroke patients and 30 healthy subjects(HCs).A CST template was generated from the CST of HCs which was tracked by using the probabilistic tractography.Based on the template,the diffusion parameters of fractional anisotropy(FA)and mean diffusivity(MD)were measured,further,the FA ratio(rFA),FA asymmetry(FAasy),MD ratio(rMD)and MD asymmetry(MDasy)were calculated to assess the CST impairments in stroke patients.Furthermore,the correlations of these CST diffusion parameters with Fugl-Meyer Assessment(FMA)were performed.Results:Compared with HCs,FA of the ipsilesional CST and rFA decreased significantly(t=-15.775,t=-11.111,P<0.001,respectively)while FAasyincreased significantly(t=9.473,P<0.001);MD of the ipsilesional CST and rMD increased significantly(t=9.553,t=7.733,P<0.001,respectively)while MDasydecreased significantly(t=-8.941,P<0.001);no significant differences of these diffusion parameters were observed in the contralesional CST(P>0.05).Neither disease duration nor lesion size was significantly correlated with these diffusion parameters(P>0.05).FA of the ipsilesional CST and rFA was positively correlated with"hand+wrist"and upper limb FMA(r=0.342,P=0.038;r=0.479,P=0.003;r=0.343,P=0.038;r=0.482,P=0.003,respectively),while FAasywas negatively correlated with"hand+wrist"and upper limb FMA(r=-0.353,P=0.032;r=-0.490,P=0.002,respectively).In addition,stepwise regression analysis revealed that the correlations between FAasyand"hand+wrist"and upper limb FMA was stronger than that with FA of the ipsilesional CST and rFA(Beta=-0.353,P=0.032;Beta=-0.490,P=0.002,respectively).Conclusions:FA parameters derived from CST template may reflect CST microstructural integrity impairments following stroke.FAasywas closely related to the"hand+wrist"and upper limb FMA implying an important reference

关 键 词：磁共振成像 扩散张量成像 脑卒中 皮质脊髓束 运动功能障碍 

分 类 号：R445.2[医药卫生—影像医学与核医学] R743.32[医药卫生—诊断学]