Table 2.
Summary of results
| Trend with age | Regions | Interpretation |
|---|---|---|
|
| ||
| Conventional view | ||
| Increased MD | Association fibers; anterior corpus callosum | Decreased integrity of primarily single fiber bundles |
| Decreased FA | ||
| Increased MD | Projection fibers crossing secondary association fibers | FA = unsuitable metric |
| Inconsistent FA | ||
| Revised view | ||
| Increased MD | Association fibers; Genu of corpus callosum | Decreased integrity of primarily single fiber bundles |
| Decreased NA | ||
| Decreased MO | ||
| Increased MD | Projection fibers crossing secondary association | Selective degeneration of secondary crossing fibers |
| Increased NA | fibers; Splenium of corpus callosum | |
| Increased MO | ||
| Increased MD | Body of corpus callosum | Dual degeneration of primary fibers and secondary crossing fibers |
| Increased NA | ||
| Decreaseda MO | ||
Key: MD, mean diffusivity; MO, mode of anisotropy; FA, fractional anisotropy; NA, norm of anisotropy.
a
Refers to decreased or no significant age associations of MO.