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Atherosclerosis is a dynamic inflammatory disorder. The biological composition and inflammatory state of an atherosclerotic plaque, rather than the degree of stenosis or its size are the major determinants of acute clinical events. A noninvasive technique to detect vulnerable atherosclerotic plaque is critically needed. FDG-PET/CT, a combined functional and structural whole-body imaging modality, holds great potential for this purpose. FDG uptake in large arteries has been frequently observed and is associated with cardiovascular risk factors. FDG accumulates in plaque macrophages and uptake is correlated with macrophage density. It is known that vascular FDG uptake and calcification do not overlap significantly and changes of FDG uptake are common, suggesting that FDG uptake may represent a dynamic inflammatory process. It has been reported that vascular FDG uptake can be attenuated by simvastatin in patients, and by the antiinflammatory drug probucol in rabbits. Vascular FDG uptake has been linked to cardiovascular events in some preliminary studies. Data from basic sciences, and animal and clinical studies support the emerging role of FDG-PET/CT in assessing atherosclerosis in large arteries in humans.

Purpose: The main aim of this research was to determine the changes of FDG uptake in large arteries with aging as visualized by FDG-PET imaging., Methods: We examined the presence of arterial FDG uptake in 149 subjects (61 males, 88 females; age range 5-83 years) who underwent whole-body PET scans for the assessment of non-cardiovascular disorders. The subjects were divided into eight age decade groups, with at least 12 subjects in each group. The presence of FDG uptake was recorded in the ascending, arch, descending thoracic and abdominal segments of the aorta, as well as in iliac and femoral arteries. We then calculated the percentage of segments with visible FDG uptake for each age group. Mean SUVs were calculated for each of the arterial segments and compared among the age groups., Results: Among 149 subjects, 145 were noted to have visible uptake in at least one segment of the large vessels. Percentage of segments with visible FDG uptake increased with age (p < 0.01). Mean SUVs of the ascending aorta, aortic arch, descending thoracic aorta, iliac arteries and femoral arteries increased with age (p < 0.01)., Conclusion: Prevalence and intensity of FDG uptake in large arteries generally increases with aging. Increased FDG uptake likely represents the presence of active inflammatory process of atherosclerotic plaque. The magnitude of inflammation within the wall of the large arteries increases with aging.