Carotid pulse wave velocity measured using a fast single‐slice oblique‐sagittal phase‐contrast MRI is associated with cognitive impairment

Abstract

AbstractBackgroundArterial stiffness is one of the earliest markers of vascular dysfunction1. Elevated arterial stiffness leads to the transmission of excessive pulsations into the downstream microvasculature, which may be linked to cognitive impairment in aged individuals. Pulse wave velocity (PWV) is an established surrogate of arterial stiffness. To date, PWV measurement at carotid arteries or above has been still limited. Previous work has introduced a fast MRI method to measure carotid PWV (cPWV) using single‐slice oblique‐sagittal phase‐contrast MRI (OS PC‐MRI)3. In this study, we evaluated the association between cPWV and cognitive impairment in an aged group.MethodThe MRI experiments were conducted on Siemens Prisma 3T MRI scanner. A 2min TOF MRI was performed to localize carotid arteries including CCA and ICA. The 3D MR angiogram was reformatted to determine an oblique slice to maximally cover both CCA and ICA (Figure 1a). A single‐slice retrospectively gated 2D OS PC‐MRI with a single in‐plane velocity encoding (CCA to ICA) (Venc = 80cm/s, temporal resolution = 14.22ms) was performed to simultaneously acquire blood velocity waveforms at each location along the CCA‐ICA segment. cPWV was calculated as the inverse slope of the line fitted to the transit time versus distance along the vessel (Figure 1b). 15 elderly participants (age: 71.4 ± 8.5 years) were enrolled in this study. Each participant underwent cognitive assessments including CDR and 13 out of 15 were conducted the MoCA.ResultThere was a significant difference (p = 0.0496) in cPWV between the participants with normal cognition (CDR = 0) and cognition impairment (CDR> = 0.5). Figure 3 shows the scatter plot of cPWV vs. MoCA. Overall, cPWV increased with lower MoCA. However, there was no significance (r = ‐0.5294, p = 0.0767) obtained between cPWV and MoCA given a small sample size and the presence of a suspicious data point indicated by a green circle in Figure 3. After excluding this potential outlier, a significant negative correlation between cPWV and MoCA was obtained (r = ‐0.8113, p = 0.0014).ConclusionThe pilot study demonstrates that increased cPWV is associated with cognitive impairment, suggesting cPWV measured using 2D OS PC‐MRI could be an imaging marker for cognitive impairment.