18FDG-PET-CT: An Imaging Biomarker of High-Risk Carotid Plaques. Correlation to Symptoms and Microembolic Signals

BACKGROUND AND PURPOSE—We investigated whether uptake of fluoro-2-deoxy-d-glucose (18FDG) positron emission tomography–computed tomography (PET-CT) correlated to clinical symptoms and presence of microembolic signals (MES) detected by transcranial Doppler in patients with carotid stenosis. METHODS—18FDG-PET-CT and MES detection was performed in consecutive patients with 50% to 99% symptomatic or asymptomatic carotid stenoses. Uptake index was defined by a target to background ratio (TBR) between maximum standardized uptake value of the carotid plaque and the mean standardized uptake value of the jugular veins. End points for analysis were presence of symptoms and presence of MES. RESULTS—We included 123 stenosis derived from 110 patients, 60 symptomatic and 63 asymptomatic. MES positive (+) lesions were found in 16%. TBR values were higher in symptomatic compared with asymptomatic (median 2.07 versus 1.78; P