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

Abstract

Background: 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. Purpose: To evaluate the feasibility and reliability of dual-velocity encoding (dual-VENC) PC-MRI at 3T for assessing pulsatility of cerebral perforating arteries. Study Type: Prospective. Subjects: 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). Field Strength/Sequence: Dual-VENC 2D PC-MRI at 3T and 7T. Assessment: 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. Statistical Tests: 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. Results: 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). Data Conclusion: 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 of Evidence: Level 2. Technical Efficacy: Stage 2.