Figure 4:

The ODI and NDI images with the corresponding histology images (LFB and NeuN). Heavy myelinated white matter bundles (cc, ec, fi, ic, mt, and opt) exhibit lower ODI values, light myelinated region (neocortex) has higher ODI values. NDI shows lower values in Py and GrDG, corresponding to higher neuron contents in NeuN images. SLu shows slightly higher NDI than the surrounding tissues. Laminar appearance of neuron density is observed at the cortex area in NeuN staining, where the variation at cortex layer IV (internal granular layer) and V (large pyramidal layer) in NeuN staining is illustated in NDI image. The different contrast for NODDI and histology images in cc (black arrows), ic (red arrows), Py (white arrows) and neocortex (blue eclipse) are enlarged in Figure c-d. All the images are obtained from the right hemisphere. cc: corpus callosum; ec: external capsule; fi: fimbria; ic: internal capsule; mt: mammillothalamic tract; opt: optic tract; Py: pyramidal cell layer in hippocampus; GrDG: granule cell layer of dentate gyrus in hippocampus; SLu: Stratum lucidum of the hippocampus; AM: amygdala; TH: thalamus; HY: hypothalamus.