The evolving role of PET/CT and PET/MRI in the management of sarcoidosis

Learning Objectives 1. To review current applications of PET/CT imaging in diagnosis, assessment, and management of sarcoidosis and its complications. 2. To discuss new horizons related to molecular imaging in the management of sarcoidosis and its complications including use of PET/MRI.

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. The diagnosis is based on clinical and radiographic findings as well as by histopathological findings. Molecular imaging in recent years has made important progress regarding the study of various inflammatory diseases including sarcoidosis. PET provides insight into metabolism of this disease. MRI is the current modality of choice for detection of cardiac sarcoidosis and neurosarcoidosis, but has some limitations that may be overcome with PET. This review article provides an overview of the applications of PET for evaluation of patients with sarcoidosis and following subjects will be reviewed: 1. PET’s role in detection and response assessment of pulmonary and nodal sarcoidosis. 2. PET’s role in neurosarcoidosis. 3. PET’s role in cardiac sarcoidosis. 4. PET’s utility for prognostication of patient outcome in sarcoidosis. 5. PET radiotracers beyond FDG for assessment of sarcoidosis. 6. Potential role of PET/MRI for evaluation of patients with sarcoidosis.