Michael Wahl1, Yi-Ou Li1, Joshua Ng1, Sara C. LaHue1, Shelly R. Cooper1, Elliott H. Sherr2, Pratik Mukherjee1
1Radiology, University of California, San Francisco, San Francisco, CA, United States; 2Neurology, University of California, San Francisco, San Francisco, CA, United States
In this 3T DTI study of 44 normal adult volunteers, we use quantitative fiber tracking to demonstrate that specific patterns of microstructural correlation exist between white matter tracts and may reflect phylogenetic and functional similarities between tracts. Inter-tract correlation matrices computed from tract-based measures of fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity, reveal that there are significant variations in correlations between tracts for each of these four DTI parameters. Data-driven hierarchical clustering of FA correlational distances show that neocortical association pathways grouped separately from limbic association pathways, and that projection pathways grouped separately from association pathways.