基于体素分析的磁共振弥散张量成像在多系统萎缩的应用研究

目的 利用磁共振弥散张量成像（diffusion tensor imaging，DTI）技术，联合基于体素分析方法（voxel-based analysis，VBA），探讨多系统萎缩（multiple system atrophy，MSA）患者白质的改变。方法 选取15例小脑型多系统萎缩（MSA-C）患者（病例组）及11例志愿者（对照组），分别行全脑常规MRI及DTI扫描，采用SPM8（http：//www.fil.ion.ucl.ac.uk/spm/software/spm8/）生成部分各向异性（fractional anisotropy，FA）图和平均弥散率（mean diffusivity，MD）图。结果 与对照组比较，病例组FA减少累及双侧脑干、脑桥、小脑（小脑后叶、山坡）、额叶（额上回）、扣带回、边缘叶及白质，差异有统计学意义（P=0.000），MD升高累及双侧小脑（小脑后叶、小脑蚓）、额叶（额上、中回、中央前回）、颞叶（颞上、中回、颞横回）、岛叶、顶叶（缘上回、角回），差异有统计学意义（P=0.000）。结论 基于体素分析的磁共振弥散张量成像可以用于显示全脑微结构改变，对MSA有一定诊断意义。

Voxel-based Analysis of Diffusion Tensor Imaging in Multiple System Atrophy

Objective To explore the brain white matter changes in MSA patients with voxel-basedanalysis of diffusion tensor imaging. Methods Routine MRI and DTI imaging was performed in 15 patients with MSA with predominant cerebellar symptoms(case group) and 11 healthy subjects(control group).SPM8 was used to generate FA maps and MD maps. Results Compared with the control group,MSA-C patients showed significant FA decrease bilaterally inbrainstem, pons,cerebellum(posterior lobe and clivis), frontal lobe(superior frontal gyrus), cingulate gyrus,limbic lobe and white matter (P=0.000). MD increase in MSA-C patients could be seen in bilateral cerebellum (posterior lobeand vermis),frontal lobe (superior frontal gyrus,middlefrontal gyrus, precentral gyrus), temporal lobe (temporal gyrus, middle temporal gyrus, transverse temporal gyrus),insula and parietal lobe (supramarginalgyrus, angular gyrus,P=0.000). Conclusion VBA of DTI is helpful to show the changes of the whole brain microstructure, which has a certain diagnostic value for MSA.