Abstract
White matter fiber tracts demonstrate heterogeneous vulnerabilities to aging effects. Here, we estimated age-related differences in tract properties using UK Biobank diffusion magnetic resonance imaging data of 7167 47- to 76-year-old neurologically healthy people (3368 men and 3799 women). Tract properties in terms of generalized fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity were sampled on 76 fiber tracts; for each tract, age-related differences were estimated by fitting these indices against age in a linear model. This cross-sectional study demonstrated 4 age-difference patterns. The dominant pattern was lower generalized fractional anisotropy and higher axial diffusivity, radial diffusivity, and mean diffusivity with age, constituting 45 of 76 tracts, mostly involving the association, projection, and commissure fibers connecting the prefrontal lobe. The other 3 patterns constituted only 14 tracts, with atypical age differences in diffusion indices, and mainly involved parietal, occipital, and temporal cortices. By analyzing the large volume of diffusion magnetic resonance imaging data available from the UK Biobank, the study has provided a detailed description of heterogeneous age-related differences in tract properties over the whole brain which generally supports the myelodegeneration hypothesis.
Original language | English |
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Pages (from-to) | 160-172 |
Number of pages | 13 |
Journal | Neurobiology of Aging |
Volume | 98 |
Early online date | 13 Nov 2020 |
DOIs | |
Publication status | Published - 1 Feb 2021 |
Bibliographical note
AcknowledgementsThis research was approved by the UK Biobank (application number: 24089) and was supported by the Roland Sutton Academic Trust (grant number: 0039/R/16) and Taiwan National Health Research Institute (NHRI-EX109-10928NI). We acknowledge the valuable contributions of members of the UK Biobank Imaging Working Group and the UK Biobank coordinating center. The UK Biobank (including the imaging enhancement) was supported by the UK Medical Research Council and the Wellcome Trust. The authors are grateful for the provision of simultaneous multislice (multiband) pulse sequence and reconstruction algorithms by the Center for Magnetic Resonance Research, University of Minnesota. Finally, the authors are extremely grateful to all UK Biobank study participants, who have generously donated their time to make this resource possible. This article was edited by Wallace Academic Editing.
Keywords
- Brain aging
- White matter
- Fiber degeneration
- Magnetic resonance imaging
- UK Biobank
- diffusion MRI
- Diffusion MRI