PET/CT Imaging in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a potentially life-threatening disease, but diagnosing CS remains a challenge because of nonspecific clinical manifestations and significant proportion of asymptomatic patients. Also, there is no standardized work-up for early diagnosis and management of CS. In recent years, there has been increasing interest in the use of advanced imaging modalities for evaluation of CS, including cardiac magnetic resonance imaging (MRI) and positron emission tomography with 18f-fluorodeoxyglucose (FDG PET) integrated with computed tomography (PET/CT). The purpose of this review is to highlight the utility of PET/CT for diagnosis and management of CS. The advantage of PET/CT is that it can detect FDG accumulation in the activated inflammatory cells, allowing visualization of active sites and early diagnosis of CS. Special emphasis has been put toward the development of appropriate preparation protocols that minimize physiological FDG uptake in the myocardium and optimal imaging protocols that allow sensitive and accurate detection of CS. Aside from early diagnosis, FDG PET/CT may inform when to start the therapy and whether the patient responded to treatment. FDG PET/CT may also be useful for follow-up and risk assessment of patients with CS. The limitations of FDG PET/CT are discussed with respect to a radiation exposure and control of glucose metabolism and insulin levels to avoid nonspecific myocardial uptake of FDG. Despite the progress made, more studies are needed to further refine clinical applications of FDG PET/CT in patients with CS. © 2014, Springer Science+Business Media New York.