摘要
目的运用白质纤维概率追踪技术,对颅内段运动传导通路进行定位研究,以确定其分别来自舌、面、手及足运动区的四个组成部分在穿过内囊后肢时的具体位置和相互关系。方法对20名志愿者的脑部磁共振弥散张量图像(DTI)进行回顾性分析。白质纤维概率追踪成像采用基于MATLAB软件的DTI&Fiber Tools工具包在个人电脑上离线处理得到舌、面、手及足运动功能皮层与脑桥白质纤维的连接概率图(ConMap)。确定相应运动皮层白质纤维束穿过内囊后肢的位置,并计算其相对于内囊后肢前内侧端点的纵向指数(PI)和横向指数(LI)。应用配对t检验对比各运动皮层纤维束平均位置的差异。结果本研究成功追踪了所有20名受检者双侧共计40组运动传导通路,全部穿过内囊后肢。在16组(40%)通路中,舌运动白质纤维束(舌束)位于面运动白质纤维束(面束)的内前方,同时前者双侧的PI和LI均低于后者(P<0.05)。在25组(62.5%)通路中,面束位于手运动白质纤维束(手束)的内前方,同时前者双侧的PI和LI均低于后者(P<0.05)。在14组(35%)通路中,手束位于足运动白质纤维束(足束)的内前方;在11组(27.5%)通路中,手束位于足束的前方。双侧手运动纤维的PI低于足(P<0.05),但两者的LI无显著差异(P>0.13)。结论本研究的结果表明运动传导通路在内囊后肢上是沿着其长轴由前内至后外排列的,在双侧大脑半球的排列是对称的。这个发现将有助于判断病灶位置与运动功能缺损症状的关系,并可指导神经外科手术。
Objective To trace the fibers from tongue, face, hand and foot motor cortices using probabilistic diffusion tractography and to define their somatotopic organization in the PLIC. Methods MRI data of twenty normal subjects were retrospectively studied. Fiber tracts were separately calculated between ROI in the cerebral peduncle and in the four different motor regions in the precentral gyrus. Probabilistic connectivity maps were generated and the voxel with the highest probability was designated as the position of the motor pathway. The PI and LI were defined as the relative anteroposterior and mediolateral locations of the motor pathways. Results Tongue pathways were located anteromedial to face pathways in 16 hemispheres （40%） with less PI and LI （P 〈 0.05 ）. Face pathways were located anteromedial to hand pathways in 25 hemispheres （62.5%） with less PI and LI （P 〈 0.05）. Hand pathways were anteromedial to foot pathways in 14 hemispheres （35%） and anterior in 11 hemispheres （27.5%） with less PI （P 〈 0.05）. Group analysis showed that the bilateral hemispheres somatotopic arrangement were symmetrical. Conclusion Probabilistic tractography demonstrated the anterior-posterior alignment of the motor pathways along the long axis in the PLIC.
出处
《影像诊断与介入放射学》
2012年第5期323-326,共4页
Diagnostic Imaging & Interventional Radiology
关键词
弥散张量成像
运动通路
内囊
概率追踪
Diffusion tensor tractography
Motor Pathways
Internal capsule
Probabilistic tracking
