Figure 6:

The relationship between ODI and fiber orientation distributions. Four selected areas showing hippocampus (1 and 2), neocortex (3), and subcortical white matter just posterior to the splenium of the corpus callosum (4) are enlarged in panels to the right. Throughout the brain, higher ODI regions show more crossing fibers, while lower ODI regions show few crossing fibers. Note the absence of resolved crossing fibers in the subcortical white matter (white arrow in 4) and the strong coherence of anisotropic voxels in the stratum radiatum of the hippocampus (green arrows in 2). The cortex showed complex fiber orientation distributions, where most areas have crossing fibers. However, neocortical layer II/III features lower ODI values (yellow arrow in 3), which presumably reflects the prominence of the apical dendrites of cortical pyramidal neurons passing through this region.