基于B样条拟合与回归模型的脑神经纤维聚类方法
Brain Fiber Clustering Method Based on B-Spline Fitting and Regression Model
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摘要: 针对现有的神经纤维聚类技术通常依赖于纤维束的空间位置,缺乏对神经纤维走向信息考量的问题,提出一种基于B样条拟合与回归模型的脑神经纤维聚类方法,将神经纤维进行B样条拟合与采样,标准化,使用线性回归方程进行神经纤维描述,构造出每根神经纤维的高斯密度函数与神经纤维分布的极大似然函数,使用EM聚类算法进行聚类.将该算法与QB聚类算法应用到真实医学数据(PPMI影像数据跟踪出的脑神经纤维)上,并对聚类结果与QB聚类结果进行评估,定性地判断分类结果在解剖学空间上的相似性,定量地比较聚类后脑神经纤维的数目.实验结果表明,该方法在功能区层面的聚类可以更有效地分割出具有解剖学结构的脑神经纤维.Abstract: Brain fiber clustering technologies can effectively segment different levels of fibers bundles and have great vitality during the analysis process.However,the existing fiber clustering technologies usually depend on the spatial location of the fiber tracts and lack the consideration of the brain fiber trend information. This paper proposes a novel brain fiber clustering method based on B-spline fitting and regression model, which performs B-spline fitting, sampling, and standardization of brain fibers, uses linear regression equation to describe brain fibers, con-structs Gaussian density function for each fiber tract and maximum likelihood function for fiber distribution, and then uses EM clustering algorithm for clustering. The algorithm and QB clustering algorithm are applied to real medical data (Brain fibers tracked by PPMI image data). The clustering results are evaluated to qualitatively judge the spatial similarity of the results in anatomical space and quantitatively compare brain fiber tract numbers. The experimental results show that the proposed method can segment brain fiber bundles with anatomical identification at the brain functional region level.