Carotid Artery Stenting Intervention to Enhance Global Brain Blood Flow and Cognition in Carotid Artery Disease: Preliminary Findings from a Prospective Follow-Up MRI Study

Figures

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  Figure 1. Flowchart showing the study sample. Data from the carotid arterial stenosis patient participants who had a carotid artery stenting procedure and completed both baseline and the first follow-up MRI scans were used in the analysis, as highlighted using gray boxes. Note: “n” represents number of participants; CNSVS represents Cognitive Nervous System Vital Signs.

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  Figure 2. Example MRI acquisition and processing for flow quantification. (a) Sagittal view showing the oblique plane of the imaging placement across the ICAs (orange line, with a circle showing the central point), overlaying on the T1-weighted anatomical image. (b) Sagittal view showing the oblique plane placement of the imaging placement (orange line) crossing the bilateral ICAs (red arrows). (c) Coronal view showing the imaging placement (orange line) crossing the bilateral ICAs (red arrows). (d) Axial view highlighting the bilateral ICAs. Red arrows indicate the bilateral ICAs. Regions of interest (ROIs) of the two ICAs were drawn on this plane for flow velocity calculation within the ICAs.

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  Figure 3. Individual changes in internal carotid artery (ICA) flow from baseline to follow-up. (a) Ipsilateral ICA flow; (b) Contralateral ICA flow; (c) Total ICA flow (sum of ipsilateral and contralateral). Note: Participants are color-coded by baseline stenosis severity group (blue = 70%, red = 80%, black = 90%); individuals are presented using unique marker shapes. Lines connecting data points in panels (a–c) are also color-coded by stenosis severity, as shown in the legend in panel (b).

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  Figure 4. Comparison of changes in ipsilateral and contralateral flows between baseline and follow-up scans. (a) Absolute change in flow rate (mL/min). (b) Relative change in flow rate (%). Note: Each marker represents an individual participant. Stenosis groups are shown in different colors (blue: 70%, red: 80%, black: ≥90%); each unique symbol corresponds to one individual. Axes are centered at the origin to highlight directional changes in flow. One subject exhibited an extraordinary relative increase in ipsilateral flow (216%) and is scaled down by a factor of 1/4 for visualization clarity on the axis scale in (b).

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  Figure 5. Group mean differences in cognitive scores with 95% confidence intervals. (a) Assessment scores pre-CAS (open bars) and post-CAS (filled bars). (b) Mean values of the absolute changes in the normalized scores for subject-wise differences between baseline and follow-up, where 100 represents the general population or group average. Lower scores indicate poorer performance. (c) Relative change in normalized scores. Note: Bars represent group means, with error bars indicating 95% confidence intervals. One outlier value (184.2%) for the simple attention domain of the 90% stenosis group is truncated on the axis scale for visualization clarity in (c).

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  Figure 6. Post-CAS changes in cognitive assessment scores in relation to post-CAS flow changes, stratified by the baseline carotid stenosis group. Note: The data represent mean values of relative changes for the baseline stenosis groups. Relative changes for each participant were calculated as follows: 100 × (post-CAS value − baseline value)/baseline value. The Neurocognitive Index was derived from the computerized cognitive assessment battery, Cognitive Nervous System Vital Signs (CNSVS). Symbols indicate changes in the cognitive items, bars indicate changes in the flow, with error bars showing the standard deviation for each stenosis group. The error bar for the ipsilateral flow change and the symbol representing simple attention change in the 90% stenosis group are visually scaled down by a factor of four to allow for visualization within the y-axis scale.