Anatomical subcortical estimates are highly consistent over time but significantly different for midlife adults compared to older adults

Motivation: Longitudinal MRI is used to quantify brain atrophy over time, yet more work is needed to understand factors that contribute these trajectories. Goal(s): To use repeat anatomical MRI to predict subcortical volume changes at follow-up and test whether these data are more consistent in midlife adults than older adults. Approach: We estimated subcortical MRI volumes in 100 midlife and 132 older adults and compared consistency between the two groups. Results: We found strong associations between initial and repeat MRI. The midlife group showed higher consistency in subcortical volume estimates than the older group. Impact: We demonstrated that we could use baseline MRI estimates to predict subcortical anatomical change over 2.3 years within UK Biobank midlife and older populations, while the older adults showed lower consistency in MRI anatomical estimates than midlife adults.