Dual-time-point myocardial 18F-FDG imaging in the detection of coronary artery disease

Background: Myocardial F-18-deoxyglucose (F-18-FDG) uptake has been observed to be enhanced in patients with coronary artery disease (CAD) under fasting conditions. However, whether the increased F-18-FDG is induced by myocardial ischemia and how to discriminate ischemic from physiological F-18-FDG uptake have rarely been investigated. Methods: Under fasting conditions, F-18-FDG PET imaging was performed in 52 patients with suspected CAD. Two F-18-FDG imaging sessions were conducted within two hours after a single administration of F-18-FDG (dual-time-point imaging), and with an intervention of an exercise test after the first imaging. Abnormal F-18-FDG uptake was determined by the classification of the F-18-FDG distribution pattern, and the changes of the F-18-FDG distribution between the two PET imaging sessions were analyzed. Tc-99m-sestamibi was injected at peak exercise and myocardial perfusion imaging (MPI) was conducted after F-18-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 F-18-FDG. Based on the classification of the F-18-FDG distribution pattern, the sensitivity and specificity of exercise F-18-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, F-18-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 F-18-FDG uptake. With the classification of the F-18-FDG distribution pattern, dual-time-point F-18-FDG imaging under fasting conditions is efficient in diagnosing CAD.