Regional coupling of macrovascular flow velocity and cerebrovascular reactivity amplitude and delay in healthy adolescents

In a preliminary sample of healthy adolescents, we evaluated the relationship between hemodynamic function in large cerebral arteries and smaller cortical vessels. Specifically, we investigated correlations between 4D flow MRI-derived systolic blood velocity in the anterior, middle, and posterior cerebral arteries and BOLD cerebrovascular reactivity (CVR) in associated vascular territories. Both the amplitude and delay of CVR were negatively correlated with systolic velocity. These results provide new insights into the mechanism of CVR and measures of macrovascular flow, but more work is needed to better understand these relationships. Our work establishes important normative data for future comparisons in cerebrovascular pathology.