Quantification of tissue properties in the cerebral cortex and in pericortical white matter. Two surfaces were defined from the T1-weighted anatomical images (left column): in mid-gray matter (red) and 2 mm below the gray-white matter boundary (blue). White matter fractional anisotropy (middle) was quantified 2-mm below the gray/white boundary and mean diffusivity (right) was quantified in both the cortical gray matter and the white matter surfaces. Parasagittal (left hemisphere) and axial (above the lateral ventricles) cross-sections from the TBI patient's first imaging session are shown. High intensity regions on the FA map correspond to major fiber bundles running parallel to the cortical surface. Cerebrospinal fluid surrounding the cortex appears bright on the MD map.