Imaging of inflamed and vulnerable plaque in coronary arteries with 18F-FDG PET/CT in patients with suppression of myocardial uptake using a low-carbohydrate, high-fat preparation

Abstract

PET/CT imaging with 18F-FDG has been used to detect inflammation in carotid and aortic plaque; its use in detecting coronary plaque has been limited by avid 18F-FDG uptake by the myocardium. We investigated whether 18F-FDG PET/CT could be used to image inflammation in coronary arteries as a potential noninvasive method to detect vulnerable plaque. Methods: We retrospectively studied 32 patients treated for malignancy who underwent 18F-FDG PET/CT and concomitant cardiac catheterization. As part of the recently described protocol, all patients were instructed to eat a low-carbohydrate, high-fat meal the night before and drink a vegetable oil drink the morning of the study. We reviewed the patients' baseline characteristics and their 18F-FDG PET/CT scans for adequacy of myocardial uptake suppression and correlated the presence of angiographically apparent plaque with 18F-FDG uptake in the major coronary arteries. Two independent observers assessed the angiographic images and 18F-FDG PET scans. Results: A total of 95% of patients had 2 or more coronary disease risk factors, and 25% had unstable symptoms; 30% of index catheterizations resulted in intervention. In 20 of 32 patients (63%), myocardial suppression was good (12) or adequate (8). Inadequate suppression was due to self-reported dietary nonadherence. Patients with good, adequate, and poor suppression had maximal myocardial standardized uptake values of 2.8 ± 0.7, 5.0 ± 1.3, and 17.0 ± 9.7, respectively. We identified 18F-FDG uptake in 15 patients in 1 or more coronary segments. A trend to significance in correlation between presence of angiographic disease and signal in the vessel was observed (P=0.07; 80 vessels examined). A total of 7 patients with significant coronary artery disease had aortic 18F-FDG uptake. Conclusion: In this retrospective study, we demonstrated the potential use of 18F-FDG PET in imaging of inflammation in coronary arteries. The potential of 18F-FDG PET is also being investigated in a prospective study. COPYRIGHT © 2009 by the Society of Nuclear Medicine, Inc.