Age-Related Differences in White Matter: Understanding Tensor-Based Results Using Fixel-Based Analysis.

ABSTRACT: Aging is associated with widespread alterations in cerebral white matter (WM). Most prior studies of age differences in WM have used diffusion tensor imaging (DTI), but typical DTI metrics (e.g., fractional anisotropy; FA) can reflect multiple neurobiological features, making interpretation challenging. Here, we used fixel-based analysis (FBA) to investigate age-related WM differences observed using DTI in a sample of 45 older and 25 younger healthy adults. Age-related FA differences were widespread but were strongly associated with differences in multi-fiber complexity (CX), suggesting that they reflected differences in crossing fibers in addition to structural differences in individual fiber segments. FBA also revealed a frontolimbic locus of age-related effects and provided insights int

SUBMITTER: Kelley S 

PROVIDER: S-EPMC8440891 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature