Higher spatial resolution at ultra-high field (≥7T) magnetic resonance imaging (UHF MRI), with consequent reduction of partial volume effects, enables diffusion tensor imaging (DTI) to visualize sharp turns of the white matter (WM) fibers into grey matter cortex (CTX), which are challenging to see in the lower main magnetic field data. More, UHF DTI data also recover rather high fractional anisotropy (FA) in several CTX regions, which may help to minimize the strong gyral bias in tractography that are found even in the relatively high resolution 3T DTI. In this work we analyse statistical properties of DTI major eigenvectors at UHF as in WM-CTX interface as in medial CTX to understand fiber orientation characteristics in the whole human brain in vivo and allow connectivity analysis from
white matter into the cortex.
