摘要目的 探讨左右利手 成年人脑白质结构差异及差异脑区各指标之间的相关性.方法 对23名左 利手和32名右利手成年人进行结构磁共振成像(structural magnetic resonance imaging,sMRI)和弥散张量成像(diffusion tensor imaging,DTI)扫描,采用基于体素的形态测量学方法(voxelbased morphometry,VBM)、基于体素分析(voxel-based analysis,VBA)和基于感兴趣区(region of interest,ROI)的确定性纤维束追踪方法,比较脑白质体积、各向异性分数(fractional anisotropy,FA)和平均弥散系数(mean diffusivity,MD)的组间差异,并分析有差异脑区内各指标之间的关系.结果 (1)与右利手组相比,左利手组双侧胼胝体压部(左侧:x=-15,y=-57,z=13.5,t=-5.160;右侧:x=18,y=-42,z=12,t=-3.654)白质体积减小(P＜0.001);左侧中央后回下部(x=-24,y=-46,z=54)、左侧岛叶上缘(x =-36,y=-12,z=20)的FA值增高(P＜0.001)及通过其脑区纤维束的平均FA值、平均长度和纤维条数增加(P＜0.05);右侧海马(x=24,y=-34,z=-2)的MD值降低(P＜0.001)及通过该脑区纤维束的平均MD值降低、平均长度增加(P＜0.05).(2)左右利手组脑白质体积差异脑区右侧胼胝体压部白质体积与FA值(左利手组r=0.716,右利手组r=0.471)均呈正相关(P＜0.05);左右利手组FA差异脑区左侧中央后回下部(左利手组r=-0.769,右利手组r=-0.841)、左侧岛叶上缘(左利手组r=-0.775,右利手组r=-0.744);左右利手组MD差异脑区右侧海马(左利手组r=-0.842,右利手组r=-0.742)FA与MD值均呈负相关(P＜0.05).结论 左利手与右利手人群的脑白质存在宏观体积和微观结构差异,差异分布于多个脑区及纤维束,且不同差异指标间存在一定的关联性.

abstractsObjective To explore the differences of macrostructural and microstructural and their correlations in brain white matter (WM) between left-and right-handed adults.Methods Structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI) were performed on twenty-three left-handed (LH) and thirty-two right-handed (RH) healthy subjects.The WM volume,fractional anisotropy (FA) and mean diffusivity (MD) were mearsured and compared between the two groups by using the voxel-based morphometry (VBM) and voxel-based analysis (VBA) methods.Results (1) LH adults showed lower WM volume than RH adults in bilateral splenium of corpus callosum (SC) (Left:x=-15,y=-57,z =13.5,t=-5.160;Right:x=18,y=-42,z=12,t=-3.654;P＜0.001).Compared with the RH adults,the FA values in WM of the left postcentral gyrus (PoCG) (x =-24,y =-46,z =54) and the above left insula (INS) (x =-36,y =-12,z =20) increased (P＜ 0.001),as well as the average FA values,the average length and number of streamlines in WM tracts increased (P＜0.05) in LH adults.Compared with the RH adults,the MD values in the right HIP (x=24,y=-34,z=-2) decreased(P＜0.001),as well as the average MD values decreased,and the average length in WM tracts increased (P＜0.05) in LH adults.(2)There was positive correlation between FA and the volume of right splenium of corpus callosum in LH and RH adults (LH:r=0.716,RH:r=0.471,P＜0.05).There was negative correlation between FA and MD in the left PoCG (LH:r=-0.769,RH:r=-0.841),left INS (LH:r=-0.775,RH:r=-0.744) and right HIP (LH:r=-0.842,RH:r=-0.742) in LH and RH adults (all P＜0.05).Conclusion There are differences in both macrostructure and microstructure of white matter in several brain regions and WM tracts between left-handed and right-handed people,and correlations between these measures were also observed.