Monitoring of atherosclerosis evolution by detection of inflammatory states of aortae in a rabbit model using 18F-FDG -PET/CT

Aim. In vivo dynamic evaluation of atherosclerosis could be clinically significant in the prevention of cardiovascular events. We aimed to monitor Fluorine-18 fluorodeoxyglucose (F-18-FDG) uptake in different stages of atherosclerosis, and investigate the feasibility of detecting vulnerable plaques using positron emission tomography/computed tomography (PET/CT) angiography. Methods. Twenty-two male NZW rabbits were divided into two groups: atherosclerosis group (group A, N.=11) and atherosclerosis and statin group (group S, N.=11). The rabbits underwent two pharmacological triggerings to induce thrombus at the 18th week. In vivo PET/CT scans were performed on four time points: before cholesterol diet (baseline, N.=6), at 8th week (the middle-of-feeding, N.=4), at 18th week (the end-of-feeding, N.=22) and after triggering (post-triggering, N.=15). 18F-FDG uptake by the aorta was expressed as maximal standardized uptake value (SUVmax) and mean SUV (SUVmean). SUVs were measured on serial 7.5 mm arterial segments. Results. SUVmean and SUVmax were 0.449 +/- 0.108 and 0.550 +/- 0.132 at baseline, 0.694 +/- 0.117 and 0.754 +/- 0.129 at the middle-of-feeding, 0.788 +/- 0.121 and 0.861 +/- 0.139 in group A, and 0.651 +/- 0.194 and 0.736 +/- 0.243 in group S at the end-of feeding before triggering. SUVmean and SUVmax were 1.128 +/- 0.420 and 1.302 +/- 0.489 in thrombosis group, 0.774 +/- 0.159 and 0.859 +/- 0.191 in non-thrombosis group after triggering. Thrombus were identified in 10 of 22 rabbits (45.5%): 8 of 11 (72.3%) in group A, and 2 of 11 (18.2%) in group S (P<0.001). Conclusion. The inflammatory states of atherosclerosis and vulnerable plaque can be detected by quantitative analysis of F-18-FDG uptake. PET/CT may be used for predicting thrombosis events in patients with atherosclerotic disease.