Intracranial arterial calcification and cerebrovascular function in the general aging population – A 7T MRI Study

• 195 community-dwelling subjects underwent 7T MRI to assess small vessel function • Vascular function was defined as pulsatility, flow velocity, and cerebrovascular reactivity • Intracranial arterial calcification influences pulsatility in the middle cerebral artery • Intracranial arterial calcification shows no detectable association with small vessel function downstream Intracranial arteriosclerosis may impair downstream cerebrovascular function, but the underlying mechanisms remain unclear. Using 7T MRI, we investigate the association between intracranial arteriosclerosis and cerebrovascular function in the middle cerebral artery (MCA) and in downstream small perforating arteries. We included 195 Rotterdam Study participants (43.6% female, average age 70.8 years (± 4.52 years)) who previously underwent a non-contrast CT on which we measured intracranial carotid artery calcification (ICAC) and vertebral artery calcification (VAC) as hallmarks of intracranial arteriosclerosis. Participants underwent a 7T brain MRI to assess blood flow velocity and pulsatility in the MCA and small perforating arteries as well as whole-brain cerebrovascular reactivity (CVR). We assessed the relationship between intracranial arteriosclerosis and vessel function using linear regression and linear mixed models. ICAC and VAC presence and burden were associated with higher pulsatility but not blood flow velocity in the MCA (e.g. β ICAC presence : 0.07 [95% Confidence interval: 0.02, 0.13]). There was no statistically significant association with CVR, pulsatility, and blood flow velocity in the small perforating arteries. In this cohort, intracranial arterial calcification was associated with increased MCA pulsatility, suggesting a localized impact on cerebrovascular hemodynamics. Associations with CVR and perforating artery flow velocity and pulsatility did not reach statistical significance. Thus, larger studies are needed to determine whether subtle effects exist.