Imaging Atherosclerotic Plaque Inflammation With [F]-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]-fluorodeoxyglucose (FDG) can be used to image inflammatory cell activity non-invasively by PET. In this study we tested whether FDG-PET imaging can identify inflammation within carotid artery atherosclerotic plaques. Methods and Results—Eight patients with symptomatic carotid atherosclerosis were imaged using FDG-PET and co-registered CT. Symptomatic carotid plaques were visible in FDG-PET images acquired 3 hours post-FDG injection. The estimated net FDG accumulation rate (plaque/integral plasma) in symptomatic lesions was 27% higher than in contralateral asymptomatic lesions. There was no measurable FDG uptake into normal carotid arteries. Autoradiography of excised plaques confirmed accumulation of deoxyglucose in macrophage-rich areas of the plaque. Conclusions—This study demonstrates that atherosclerotic plaque inflammation can be imaged with FDG-PET, and that symptomatic, unstable plaques accumulate more FDG than asymptomatic lesions. (Circulation. 2002;105:2708-2711.)