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

## TL;DR

This study uses 7T MRI to show that intracranial arterial calcification increases pulsatility in the middle cerebral artery but does not affect smaller downstream vessels in older adults.

## Contribution

The study provides new insights into the localized effects of intracranial arterial calcification on cerebrovascular function using high-resolution 7T MRI.

## Key findings

- Intracranial arterial calcification is associated with increased pulsatility in the middle cerebral artery.
- No significant association was found between calcification and function in downstream small perforating arteries.
- Cerebrovascular reactivity was not significantly affected by intracranial arterial calcification.

## Abstract

•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

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. βICAC 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.