Imaging findings of uncommon cardiac diseases on fasted FDG PET/CT and other imaging modalities

Learning Objectives 1. To review the imaging findings of uncommon cardiac diseases on FDG PET/CT under fasting condition (fasted FDG PET/CT), SPECT, ECG-gated CT, and cardiac MRI. 2. To discuss the possible role of the FDG PET/CT as a marker of disease activity and a predictive indicator for the prognosis of the patients with these diseases.

Although fasted FDG PET/CT has been widely used for the evaluation of neoplasms and inflammatory diseases, its usefulness in the diagnosis of cardiac diseases has been limited because of the physiologically increased myocardial FDG uptake that is frequently observed. However, combined with other imaging modalities, fasted FDG PET/CT can be useful diagnostic tool for the diagnosis of these diseases. That is, even with an increased FDG uptake, the myocardium with normal findings on other imaging modalities, including myocardial SPECT, ECG-gated CT, and cardiac MRI, is likely to be intact. In this exhibition, we review the multimodality imaging findings of uncommon cardiac diseases, including eosinophilic myocarditis, radiation myocarditis, cardiac sarcoidosis, focally hypertrophic cardiomyopathy, cardiomyopathy, myocardial densification failure, right ventricular cardiomyopahy, ANCA-associated disease, pacemaker lead infections. We also demonstrate the multimodality imaging findings of the benign and malignant cardiac masses, including myxoma, cardiac lipoma, lipomatous hypertrophy of the interatrial septum, angiosarcoma, and malignant lymphoma, with correlation to the histopathologic findings. To know the multimodality imaging findings of these uncommon cardiac diseases is important to improve confidence and accuracy in the diagnosis of the diseases. Finally, we discuss the possible role of the FDG PET/CT as a marker of disease activity and a predictive indicator for the prognosis of the patients with these diseases