Background: Myocardial 18F-deoxyglucose (18F-FDG) uptake has been observed to be enhanced in patients with coronary artery disease (CAD) under fasting conditions. However, whether the increased 18F-FDG is induced by myocardial ischemia and how to discriminate ischemic from physiological 18F-FDG uptake have rarely been investigated.
Methods: Under fasting conditions, 18F-FDG PET imaging was performed in 52 patients with suspected CAD. Two 18F-FDG imaging sessions were conducted within two hours after a single administration of 18F-FDG (dual-time-point imaging), and with an intervention of an exercise test after the first imaging. Abnormal 18F-FDG uptake was determined by the classification of the 18F-FDG distribution pattern, and the changes of the 18F-FDG distribution between the two PET imaging sessions were analyzed. 99mTc-sestamibi was injected at peak exercise and myocardial perfusion imaging (MPI) was conducted after 18F-FDG imaging. Coronary angiography was considered the reference for diagnosing CAD.
Results: Overall, 54.8% (17/31) of CAD patients and 36.2% (21/58) of stenotic coronaries showed exercise-induced abnormal uptake of 18F-FDG. Based on the classification of the 18F-FDG distribution pattern, the sensitivity and specificity of exercise 18F-FDG imaging to diagnose CAD was 80.6% and 95.2% by patient analysis, 56.9% and 98.0% by vascular analysis, respectively. Compared with MPI, 18F-FDG imaging had a tendency to have higher sensitivity (80.6% vs 64.5%, P = 0.06) on the patient level.
Conclusion: Myocardial ischemia can induce 18F-FDG uptake. With the classification of the 18F-FDG distribution pattern, dual-time-point 18F-FDG imaging under fasting conditions is efficient in diagnosing CAD.
Keywords: 18F-FDG; Coronary artery disease; Dual-time-point imaging; Myocardial ischemia.