PET Imaging of Carotid Atherosclerosis: Methodology, Implications, and Applications in Neurovascular Disease

Figures

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  Figure 1.. Tracer uptake in symptomatic disease. A, Axial computed tomography angiography (CTA). B, Axial positron emission tomography (PET)/CTA. C, Axial PET showing a symptomatic right carotid artery (purple arrow) and an asymptomatic left carotid artery (green arrow). Adapted with permission from Evans et al.14 Copyright © 2020 The Authors. This is an open access article under the terms of the Creative Commons License CC BY 4.0 (https://creativecommons.org/licenses/by/4.0), which permits use and distribution in any medium, provided the original work is properly cited.

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  Figure 2.. Evaluating tracer uptake. A, Axial positron emission tomography (PET)/computed tomography angiography (CTA) with an example region of interest (ROI), showing standardized uptake value (SUV) data. B, coronal PET/CTA with arterial ROIs displayed around the carotid bifurcation (red lines), and ROIs in a proximal vein unaffected by spillover from adjacent structures (blue lines). Target-to-background ratio (TBR) statistics are calculated by taking the relevant arterial SUV statistic and dividing by the mean of the SUVmean obtained from the venous ROIs.

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  Figure 3.. Common approaches to measure arterial tracer uptake. A, Sagittal fluorodeoxyglucose (FDG)-positron emission tomography (PET) showing diffuse uptake in the symptomatic carotid (white arrows). B, Sagittal sodium fluoride (NaF)-PET showing focal uptake in the symptomatic carotid (black arrow). C, diagram demonstrating methods to quantify arterial uptake. Whole Vessel analysis uses the average region of interest (ROI) uptake value, and the Single Hottest Slice uses the maximum value of the segments being evaluated. The Most Diseased Segment uses the mean ROI uptake of the Single Hottest Slice and its adjacent 2 ROIs, while the Active Segment method takes all ROI uptake values above a prespecified limit—in this case ≥1.6. A and B adapted with permission from Evans et al.14 Copyright © 2020 The Authors. This is an open access article under the terms of the Creative Commons License CC BY 4.0 (https://creativecommons.org/licenses/by/4.0), which permits use and distribution in any medium, provided the original work is properly cited.