Evaluation of human brain aging via diffusion tensor imaging tract characteristics

Diffusion tensor imaging (DTI) is a kind of imaging technique and it has been widely used in the evaluation of white matter (WM) in aging brain. In our study, DTI fiber tracking (FT) reconstruct the 3D fiber tracts for two normal male cases aiming to investigate the changes of WM for brain aging. Eight geometric and diffusion tract characteristics, number of fibers (NF), average length (AL), fractional anisotropy (FA), relative anisotropy (RA), mean diffusivity (MD), linear tensor (Cl), number of voxels (NV) and volume ratio (VR), were measured for the tracts of corpus callosum (CC), corticospinal tract (CST) and whole brain tracts (WBT). After comparison in 2D and 3D views, the results showed that NF, AL, FA, RA, Cl, NV and VR decreases and MD shows marginal increase. It is concluded that our proposed scheme is robust for the study of brain aging and the chosen tract characteristics of NF, AL, FA, RA, Cl, NV and VR could explain the degenerative WM changes correlated with the brain aging and could be taken as markers for tract estimation.