一种种子点聚类与方向修正的纤维追踪算法  

A Fiber Tracking Algorithm with Seed Point Clustering and Orientation Correction

作　　者：李浩东 王远军[1] LI Haodong;WANG Yuanjun(Institute of Medical Imaging Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学医学影像工程研究所,上海200093

出　　处：《波谱学杂志》2024年第4期430-442,共13页Chinese Journal of Magnetic Resonance

基　　金：上海市自然科学基金项目(18ZR1426900).

摘　　要：纤维追踪算法能通过纤维方向分布函数对脑部纤维进行追踪.考虑到水分子间的弥散作用是相互的,通过扫描数据重建的纤维方向分布函数可能存在误差,本文在传统流线型追踪算法的基础上,结合最大余弦相似度,提出了一种方向修正优化的纤维追踪算法.同时,考虑到人脑内存在各向异性弥散和各向同性弥散的水分子,且后者占比较大,使用最大期望算法对具有相同性质的种子点进行聚类,减少各向同性弥散体素点的追踪.最后分别使用模拟数据和真实数据进行实验,结果表明,本文提出算法追踪所需时间更少,相较于传统流线型纤维追踪算法纤维平均长度更长,错误追踪纤维簇数量显著少于传统纤维追踪算法,正确追踪纤维束比率显著高于传统纤维追踪算法,在大部分特定纤维束的追踪上也有着更高的重叠率与更低的过度估计率,更能体现实际情况下纤维的结构分布.The fiber tracking algorithm can track the brain fibers through the fiber orientation distribution function.Considering that the dispersion of water molecules is mutual and the fiber orientation distribution function reconstructed from scanned data may have errors,this paper proposes a fiber tracking algorithm optimized by direction correction based on the traditional streamline tracking algorithm combined with the maximum cosine similarity.Meanwhile,considering the existence of anisotropically dispersed and isotropically dispersed water molecules in the human brain,and that the latter accounts for a larger proportion,the maximum expectation algorithm is used to cluster the seed points with the same properties to reduce the tracking of isotropically dispersed voxel points.Finally,the experiments were conducted using simulated and real data respectively,and the results show that the proposed algorithm takes less time for tracking,the average fiber length is longer compared to the traditional streamline tracking streamline tracking(STT)algorithm,the number of incorrectly tracked clusters is significantly less and the ratio of correctly tracked bundles significantly higher than that of the traditional fiber tracking algorithm.Additionally,it demonstrates a higher overlap rate and a lower overestimation rate in the tracking of most specific fiber bundles,better reflecting the structural distribution of fibers in practical scenarios.

关 键 词：纤维追踪 最大期望聚类 移动最小二乘法 流线型纤维追踪算法 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]