Prasad Gautam, Jahanshad Neda, Aganj Iman, Lenglet Christophe, Sapiro Guillermo, Toga Arthur W, Thompson Paul M
Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, USA.
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA.
Proc IEEE Int Symp Biomed Imaging. 2011 Apr;2011:276-280. doi: 10.1109/ISBI.2011.5872405.
High angular resolution diffusion imaging (HARDI) allows analysis of the white matter structure and connectivity. Based on orientation distribution functions (ODFs) that represent the directionality of water diffusion at each point in the brain, tractography methods can recover major axonal pathways. This enables tract-based analysis of fiber integrity and connectivity. For multi-subject comparisons, fibers may be clustered into bundles that are consistently found across subjects. To do this, we scanned 20 young adults with HARDI at 4 T. From the reconstructed ODFs, we performed whole-brain tractography with a novel Hough transform method. We then used measures of agreement between the extracted 3D curves and a co-registered probabilistic DTI atlas to select key pathways. Using median filtering and a shortest path graph search, we derived the maximum density path to compactly represent each tract in the population. With this tract-based method, we performed tract-based analysis of fractional anisotropy, and assessed how the chosen tractography algorithm influenced the results. The resulting method may expedite population-based statistical analysis of HARDI and DTI.
高角分辨率扩散成像（HARDI）可用于分析白质结构和连通性。基于表示大脑中每个点水扩散方向性的方向分布函数（ODF），纤维束成像方法可以重建主要的轴突通路。这使得基于纤维束的纤维完整性和连通性分析成为可能。对于多受试者比较，可以将纤维聚集成在不同受试者中一致发现的束。为此，我们使用4T的HARDI对20名年轻成年人进行了扫描。从重建的ODF中，我们使用一种新颖的霍夫变换方法进行了全脑纤维束成像。然后，我们使用提取的三维曲线与共同配准的概率性扩散张量成像（DTI）图谱之间的一致性度量来选择关键通路。使用中值滤波和最短路径图搜索，我们得出了最大密度路径，以紧凑地表示人群中的每个纤维束。使用这种基于纤维束的方法，我们进行了基于纤维束的分数各向异性分析，并评估了所选纤维束成像算法如何影响结果。所得方法可能会加快基于人群的HARDI和DTI统计分析。
