Imaging atherosclerotic plaque inflammation with [18F]-fluorodeoxyglucose positron emission tomography

Background-Atherosclerotic plaque rupture is usually a consequence of inflammatory cell activity within the plaque. Current imaging techniques provide anatomic data but no indication of plaque inflammation. The glucose analogue [F-18]-fluorodeoxyglucose ((18)FDG) can be used to image inflammatory cell activity non-invasively by PET. In this study we tested whether (18)FDG-PET imaging can identify inflammation within carotid artery atherosclerotic plaques. Methods and Results-Eight patients with symptomatic carotid atherosclerosis were imaged using (18)FDG-PET and co-registered CT. Symptomatic carotid plaques were visible in (18)FDG-PET images acquired 3 hours post-(18)FDG injection. The estimated net (18)FDG accumulation rate (plaque/integral plasma) in symptomatic lesions was 27% higher than in contralateral asymptomatic lesions. There was no measurable (18)FDG uptake into normal carotid arteries. Autoradiography of excised plaques confirmed accumulation of deoxyglucose in macrophage-rich areas of the plaque. Conchisions-This study demonstrates that atherosclerotic plaque inflammation can be imaged with (18)FDG-PET, and that symptomatic, unstable plaques accumulate more (18)FDG than asymptomatic lesions.