Assessment of tissue viability with fluorine-18-fluoro-2-deoxyglucose (FDG) and carbon-11-acetate PET imaging

Abstract

Positron emission tomography allows noninvasive assessment of myocardial metabolic processes and perfusion. Myocardial F-18-2 deoxyglucose (FDG) uptake as assessed by PET imaging has been established as a metabolic tracer indicating myocardial viability, whereas N-13 ammonia uptake reflects myocardial perfusion. Furthermore, it has been shown that the clearance of C-11-acetate in normal and ischemic myocardium correlates closely with overall myocardial oxygen consumption (MVO2). Therefore, C-11-acetate PET imaging has been proposed as a tracer for myocardial viability. In contrast with myocardial FDG uptake, the clearance of C-11-acetate is independent from overall substrate utilization. In the present time the highly expensive PET studies should only be performed in patients with chronic advanced coronary artery disease resulting in severely impaired left ventricular function. Moreover, coronary anatomy has to be suitable for revascularization and there has to be an absence of reversible perfusion abnormalities on Tl-201-chloride reinjection SPECT scans. This review focuses on clinical studies employing C-11-acetate and FDG PET imaging in patients with advanced chronic coronary artery disease, acute myocardial infarction and after heart transplantation. Clinical applications of FDG and C-11-acetate PET imaging and prognosis of PET flow-metabolic imaging regarding recovery of myocardial function and clinical outcome after revascularization and thrombolytic therapy are summarized. Furthermore, PET results are compared to SPECT imaging with Tl-201 and Tc-99m-MIBI.