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 (N(perforator)) 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 N(perforator) 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 N(perforator), 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 N(perforator) 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 N(perforator) (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 N(perforator) (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.