Adjunctive role of 18FDG-PET imaging in the diagnosis of cardiac sarcoid

1877 Learning Objectives 1. To understand the utility of 18FDG-PET imaging as compared with other imaging modalities in the diagnosis of cardiac sarcoidosis. 2. To understand the recommended procedure for optimizing and performing 18FDG-PET for detection of cardiac sarcoidosis. Sarcoidosis is a non-infectious, non-necrotizing, idiopathic granulomatous disease affecting multiple organ systems, and occurring predominantly in the 20-50 year old age group, with female to male preponderance. In the U.S., it is prevalent in African-americans (35 per 100,000 population) versus Caucasians (10 per 100,000 population), with lifetime risk of 2.4% (African-americans) versus 0.8% (Caucasians). The lungs are the most commonly affected organs with concurrent involvement of lymphatic, gastrointestinal, dermatologic, and ocular systems. Concurrent cardiac involvement is seen in 5-10%; however, occult cardiac sarcoid has been observed in >20%. Cardiac involvement may present as asymptomatic conduction abnormalities, to sudden death from fatal arrhythmias which constitutes approximately 65-70% of deaths from cardiac sarcoid. Diagnosis of cardiac sarcoid has largely been based on clinical guidelines by the Japanese Ministry of Health and Welfare (revised 2006) using criteria based on abnormal findings in ECG, endomyocardial biopsy, echocardiogram, cardiac MRI, nuclear MPI and gallium scans. Although 18FDG PET imaging has not been included in these criteria, there have been several published studies that have demonstrated the utility and value of 18FDG PET for detection of cardiac sarcoid disease. Its sensitivity of 80-100% is superior to echocardiogram, myocardial perfusion imaging and gallium imaging. It is closely comparable in sensitivity to cardiac MRI with delayed enhancement, but with added advantages of detecting coexistent extra-cardiac sarcoidosis using whole body imaging, and use in patients with implantable cardiac devices. This educational exhibit will discuss and illustrate the adjunctive role of 18FDG-PET imaging in the diagnosis of cardiac sarcoid disease.