title: Selective effects of aging on brain white matter microstructure: a diffusion tensor imaging tractography study.
abstract: We examined age-related changes in the cerebral white matter. Structural magnetic resonance images (MRIs) and diffusion tensor images (DTIs) were acquired from 69 healthy subjects aged 22-84 years. Quantitative DTI tractography was performed for nine different white matter tracts to determine tract volume, fractional anisotropy (FA), mean diffusivity (MD), axial, and radial diffusivities. We used automated and manual segmentation to determine volumes of gray matter (GM), white mater (WM), cerebrospinal fluid (CSF), and intracranial space. The results showed significant effects of aging on WM, GM, CSF volumes, and selective effects of aging on structural integrity of different white matter tracts. WM of the prefrontal region was the most vulnerable to aging, while temporal lobe connections, cingulum, and parieto-occipital commissural connections showed relative preservation with age. This study was cross-sectional, and therefore, additional longitudinal studies are needed to confirm our findings.
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Stijn
authors.initials: S
authors.lastname: Michielse
authors.forename: Nick
authors.initials: N
authors.lastname: Coupland
authors.forename: Richard
authors.initials: R
authors.lastname: Camicioli
authors.forename: Rawle
authors.initials: R
authors.lastname: Carter
authors.forename: Peter
authors.initials: P
authors.lastname: Seres
authors.forename: Jennifer
authors.initials: J
authors.lastname: Sabino
authors.forename: Nikolai
authors.initials: N
authors.lastname: Malykhin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*