Radioactive Defect on I-123 MIBG Myocardial SPECT Imaging in a Patient with Cardiac Sarcoidosis

Sarcoidosis is a disease of undetermined cause and characteristic by noncaseating epitheloid granulomas in multiple organs. Cardiac involvement produces arrhythmias, heart failure, or both and sometimes leads to sudden death. TI-201 myocardial scintigraphy is useful for the diagnosis of cardiac sarcoidosis with its distribution defects. It is possible that defects are also detected on I-123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy, because not only myocytes but also the sympathetic nerve system can be damaged in cardiac sarcoidosis. The authors describe a patient with pathologically proved sarcoidosis who had I-123 MIBG myocardial defects.