Figure 7. Environmental Contributions to Tract Anisotropy.
Variations in diffusion parameters along tracts during normative development are likely a combination of tract specific (myelin content, axonal integrity) and local environment contributions. Voxel A contains a tract of interest (yellow) as well as a crossing tract (gray), resulting in low anisotropy measurements at this point. Voxel B contains only the tract of interest and exhibits high anisotropy. Within voxel C axons from nearby gray matter join the tract and some axons break off heading towards gray matter targets. The result would be a drop in anisotropy measurements at this point in the tract.