Tract Coherence Imaging (TCI): Quantifying the Intra-Voxel Fiber Tract Heterogeneity

Sjoerd B. Vos¹, Max A. Viergever¹, Alexander Leemans¹

Complementary to track-density imaging (TDI), we have proposed tract coherence imaging, TCI, as a new MRI contrast to investigate the local architectural configuration of tract pathways. TCI quantifies the local consistency of fiber tract orientations for a given voxel resolution, limited between 0 (random orientations) and 1 (perfectly aligned fibers), providing an elegant framework for quantitative evaluations that can be used in a super-resolution framework. TCI does not depend on voxel size in homogenous tract configurations, facilitating quantitative analyses. Furthermore, the peak fiber orientations can be extracted from the tract pathways in each voxel to further understand the architectural complexity.