18F-FDG -PET/CT in cardiac sarcoidosis: Diagnosis, therapy monitoring, and future directions

Sarcoidosis represents a multisystem granulomatous disease of unknown etiology that is described by the formation of non-caseating granuloma in various organs. One out of four patients may have cardiac involvement or even isolated form that confers an increased mortality rate in these patients. 18F-fluorodeoxyglucose- positron emission tomography (18F-FDG-PET) is increasingly performed for the identification and description of systemic and cardiac sarcoid disease. Notably, 18F-FDG-PET may identify early and inflammatory cardiac sarcoid disease before myocardial structural alterations such as fibrosis and/or scarring may ensue. 18F-FDG-PET is not only advantageous for the detection of early inflammatory disease but also for commencing and guiding immune-suppressive therapy to improve cardiovascular outcome as demonstrated by more recent clinical trials. 18FDG- PET, is likely to advance image-guided and personalized preventive medical care in cardiac sarcoidosis patients needing further large-scale clinical trials.