# Pulsatility Assessment of Cerebral Perforating Arteries Using Submillimeter‐Resolution Dual‐VENC Phase‐Contrast MRI at 3T

## TL;DR

This study introduces a new MRI technique at 3T to assess pulsatility in cerebral perforating arteries, showing it is reliable and comparable to 7T MRI.

## Contribution

The novel contribution is the development and validation of dual-VENC PC-MRI at 3T for high-fidelity pulsatility assessment of cerebral perforating arteries.

## Key findings

- 3T dual-VENC PC-MRI showed reproducibility with CV values of 10% and 14% for pulsatility index and number of perforators.
- 3T dual-VENC measurements were comparable to 7T dual-VENC in younger participants.
- Pulsatility index was significantly associated with age and vascular risk factors in older adults.

## Abstract

Dysfunction of cerebral perforating arteries is a major contributor to cerebral small vessel disease. Developing a reliable MRI technique for assessing cerebral perforating arteries on widely accessible 3T systems would be advantageous.

To evaluate the feasibility and reliability of dual‐velocity encoding (dual‐VENC) PC‐MRI at 3T for assessing pulsatility of cerebral perforating arteries.

Prospective.

Twelve healthy young adults (2 female, 24.0 ± 3.99 years) and 31 older adults with and without vascular risk factors (21 female, 67.72 ± 8.48 years).

Dual‐VENC 2D PC‐MRI at 3T and 7T.

The number of perforators (Nperforator) and pulsatility index (PI) measured using 3T dual‐VENC PC‐MRI were evaluated through test–retest and comparison against those by 7T dual‐VENC PC‐MRI on the younger participants. The associations of PI and Nperforator with age, cognition, and vascular risk factors were investigated in the elderly cohort.

Paired t‐tests, two‐sample t‐tests, Bland–Altman analysis, coefficient of variation (CV), Shapiro–Wilk Test, one‐way ANOVA, and multivariable regression models. Significance level: 0.05.

3T dual‐VENC PC‐MRI provided better reproducibility with CV values of 10% and 14% for PI and Nperforator, respectively, compared to single VENCs (high VENC: 21% and 21%, low VENC: 13% and 14%). 3T dual‐VENC PC‐MRI showed no significant difference in Nperforator and PI measurements with 7T dual‐VENC (p = 0.16, 0.38, respectively). Among the older participants, aging and cognitive impairment were both significantly associated with increased PI but not with Nperforator (p = 0.17 and 0.365); global vascular risk burden, as well as individual vascular risk factors, including pulse pressure and hypercholesterolemia, showed a significant association with PI but not with Nperforator (p = 0.858, 0.345, and 0.476).

3T dual‐VENC PC‐MRI provides high‐fidelity pulsatility assessment of cerebral perforating arteries and may be a useful tool at widely accessible 3T.

Level 2.

Stage 2.

Dysfunction of cerebral perforating arteries may be linked to cerebral small vessel disease. While 2D phase‐contrast MRI (PC‐MRI) at 7T has been successfully applied to assess flow pulsatility in these tiny arteries, 7T has not yet achieved widespread use. This study introduced a dual‐velocity‐encoding (dual‐VENC) PC‐MRI technique to assess cerebral perforating arteries at widely accessible 3T. 3T dual‐VENC provided good reproducibility and comparable pulsatility measurements to 7T. Our aging study showed that pulsatility index was associated with age and vascular risk factors. These results suggest that 3T dual‐VENC PC‐MRI can be a reliable imaging tool for assessing cerebral perforating arteries.