Image fusion between 18F-FDG PET and MRI in cardiac sarcoidosis: A case series

Background. Sarcoidosis is a systemic disorder of unknown etiology. It is distinguished by the presence of noncaseating epithelioid granulomas. This study demonstrates the use of image fusion between (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) and magnetic resonance imaging (MRI) to diagnose patients with cardiac sarcoidosis (CS). Methods. Seven patients diagnosed with sarcoidosis were retrospectively included. All patients underwent 18F-FDG PET/CT and cardiac MRI. Results. On the MRI scan, late gadolinium enhancement (LGE) was observed in five patients. T2-weighted images revealed areas with an increased signal consistent with myocardial edema in two patients and with hypointensity suggesting fibrosis in one patient. Increased 18F-FDG uptake was seen in the myocardial wall in three patients, indicating active inflammation. Conclusion. 18F-FDG PET and MRI image fusion allows clinicians to obtain complete morphofunctional cartography in patients with sarcoidosis. Our data show that 18F-FDG PET/MRI image fusion imaging can be useful in the diagnosis of CS.