Widespread age-related differences in the human brain microstructure revealed by quantitative magnetic resonance imaging.
A pressing need exists to disentangle age-related changes from pathologic neurodegeneration. This study aims to characterize the spatial pattern and age-related differences of biologically relevant measures in vivo over the course of normal aging. Quantitative multiparameter maps that provide neuroimaging biomarkers for myelination and iron levels, parameters sensitive to aging, were acquired from 138 healthy volunteers (age range: 19-75 years). Whole-brain voxel-wise analysis revealed a global pattern of age-related degeneration. Significant demyelination occurred principally in the white matter. The observed age-related differences in myelination were anatomically specific. In line with invasive histologic reports, higher age-related differences were seen in the genu of the corpus callosum than the splenium. Iron levels were significantly increased in the basal ganglia, red nucleus, and extensive cortical regions but decreased along the superior occipitofrontal fascicle and optic radiation. This whole-brain pattern of age-associated microstructural differences in the asymptomatic population provides insight into the neurobiology of aging. The results help build a quantitative baseline from which to examine and draw a dividing line between healthy aging and pathologic neurodegeneration.
['Callaghan|Martina F|MF|', 'Freund|Patrick|P|', 'Draganski|Bogdan|B|', 'Anderson|Elaine|E|', 'Cappelletti|Marinella|M|', 'Chowdhury|Rumana|R|', 'Diedrichsen|Joern|J|', 'Fitzgerald|Thomas H B|TH|', 'Smittenaar|Peter|P|', 'Helms|Gunther|G|', 'Lutti|Antoine|A|', 'Weiskopf|Nikolaus|N|']
D000328:Adult D000368:Aged D000375:Aging D001921:Brain D005260:Female D006801:Humans D007501:Iron D019189:Iron Metabolism Disorders D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D019150:Neuroaxonal Dystrophies D059906:Neuroimaging D055815:Young Adult
Quantitative Aging 3T MT Magnetization transfer R1 R2* Relaxation T1 T2* VBQ Water content