Age dependent changes of water exchange rate across the blood-brain barrier (BBB) in 115 subjects with age ranging from 8 to 87 years

We studied age-related BBB water exchange rate (kw) changes in a wide range of age groups with 115 subjects using diffusion prepared pseudo-continuous arterial spin labeling (DP-pCASL). We observed a significant trend of decreasing kw with age (slow when ≤50 years old and fast when >50 years old) and large spread of kw values in subjects >50 years, which may indicate compromised BBB function in some ageing populations. The inverted U-shaped correlations between kw versus age suggest a more complex age dependent changes in hippocampus and PHG regions.