FIG 1. Diffusion tensor tractography of the fornix and cingulum in a healthy individual.

3D fiber tracking of the fornix (green) and cingulum (orange) overlaid on an anatomical, T1-weighted 3D–magnetization-preparation rapid gradient echo (MPRAGE) volume. The anatomy of these 2 fiber bundles can be thought as 2 nested semicircles. The tracts shown were selected by brute force for display purposes only. The labeled portions of the tracts (indicated by yellow lines for the cingulum and black lines for the fornix) were analyzed subsequently by using judicious tract selection regions, as shown in Figs 2 and 3.