ORIGINAL RESEARCH Carotid Atherosclerotic Plaque Progression and Change in Plaque Composition Over Time: A 5-Year Follow-Up Study Using Serial CT Angiography

RESULTS: One-hundred-ninety-three carotid arteries were analyzed. Plaque volume decreased in 31% and increased in 69% of vessels (range 5.6–10.1%/year). Overall, plaque volume increased 1.2% per year (95% CI, 0.8–1.6, P .001). Plaque composition changed significantly from BL (fibrous 66.4%, lipid 28.8%, calcifications 4.8%): fibrous tissue decreased by 1.5%, lipid decreased by 1.8%, and calcification increased by 3.3% (P .001). Intraobserver reproducibility of all volume and proportion measurements was good (ICC 0.78–1.00) and interobserver reproducibility was moderate (ICC 0.76–0.99). CONCLUSIONS: Changes in carotid plaque burden and plaque composition can be quantified by using serial MDCTA. Plaque burden development is a heterogeneous and slow process. ABBREVIATIONS: BL baseline; CCA common carotid artery; CLL central lumen line; CoV coefficient of variation; ECA external carotid artery; FU follow-up; HU Hounsfield unit; ICC intraclass correlation coefficient; IQR interquartile range; MDCTA multidetector CT angiography