Impact of age and sex on regional white matter hemodynamics across the adult lifespan

White matter perfusion has been difficult to measure with arterial spin labeling (ASL) MRI due to the elongated arterial transit times of white matter. Here, we identified changes in white matter cortical hemodynamics associated with age and between sex for the first time using multi-delay pseudo-continuous ASL with tract-based analyses in a large typically aging cohort. We found reductions in white matter CBF and increases in white matter ATT with advancing age, as well as widespread sex differences across tracts. This work serves as the first step towards understanding the relationship between white matter physiology and age-related structural decline.