扩散张量磁共振成像数据集的多纤维扩散各向异性研究

Multi-fiber Diffusion Anisotropy Study for DT-MRI Dataset

目的研究扩散各向异性与单体素多纤维分叉的关系。方法提出了一种基于表观扩散系数和球谐函数的多纤维扩散各向异性分析方法对扩散各向异性进行分类。通过对5例孤独症患者和5例正常儿童的扩散张量成像数据分析,从而有效地解释了部分各向异性改变与体素内多纤维分叉现象之间的关系。结果1)单体素内多纤维分叉可能会导致部分各向异性FA值降低;2)单体素内多纤维分叉异常不一定会影响白质纤维的部分各向异性;3)部分各向异性降低也可能由其他原因产生。结论多纤维分叉异常是导致部分各向异性降低的原因之一,但多纤维分叉现象并不一定影响部分各向异性FA值。该方法为进一步研究精神疾病脑白质扩散各向异性的异常改变提供了一种有效的工具。

Objective To investigate the relationship between diffusion anisotropy and multiple fiber crossing within a single voxel. Methods Diffusion anisotropy was classified with a method based on apparent diffusion coefficient and spherical harmonic function. DT-MRI data of 5 children with autism and 5 matched healthy children were calculated to obtain fractional anisotropy （FA） changes and fiber characterizations. Results 1） Multi-fiber within a voxel might lead to the decrease of FA; 2） Multi-fiber within a voxel might not result in white matter abnormalities; 3） Some other potential reasons might influence the FA values. Conclusion Abnormal crossing of multi-fiber within a voxel is one of reasons to cause diffusion anisotropy change. Abnormal crossing of multi-fiber may not affect the FA value. The proposed method is a valuable measure for further clarifying the anisotropy abnormal changes of white matter in psychiatric patient clinical studies.