title: Microstructural changes and atrophy in brain white matter tracts with aging.
abstract: Diffusion tensor (DT) magnetic resonance imaging (MRI) tractography was used to investigate microstructural and volumetric abnormalities of the major brain white matter (WM) tracts with aging in 84 healthy subjects. Linear relationships were found between age and mean diffusivity (MD) increase and fractional anisotropy (FA) decrease in all WM tracts, except the right cingulum and bilateral uncinate, where a linear correlation with age was found for FA only. Quadratic model fitted better MD and FA values of several tracts, including the corpus callosum, limbic pathways, and bilateral association, and corticospinal tracts. Age-related MD and FA abnormalities were associated with radial diffusivity increase in all WM tracts, while axial diffusivity changes were characterized by a considerable variation from a tract to another. A linear negative relationship with age was found for the volumes of the left cingulum and fornix, while the quadratic model fitted better age-related volume loss of corpus callosum and right inferior fronto-occipital fasciculus. Diffusion tensor magnetic resonance imaging may shed light into the complex pathological substrates of WM changes with aging.
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Sala
authors.forename: Federica
authors.initials: F
authors.lastname: Agosta
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pagani
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Copetti
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Massimo
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology*; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult