Updates on the Role of Imaging in Cardiac Sarcoidosis

The non-specific symptom profile and subclinical nature of disease along with variable region of cardiac involvement in systemic sarcoidosis make the diagnosis particularly challenging. The yield of endomyocardial biopsy, a gold standard for diagnosis, is not high unless coupled with additional imaging modalities to detect regional involvement. This review is focused on highlighting the major recent advances in imaging modalities and diagnosis of cardiac sarcoidosis.

There has been much interest and increasing research focused on developing newer and improved imaging modalities to establish diagnosis. CMR and ¹⁸F- FDG-PET are now considered imaging modalities of choice in most centers worldwide, but the data comparing both methodologies head-to-head is limited. Nevertheless, novel radiotracers (i.e. ⁶⁸Ga-DOTANOC, ¹⁸F-Flurpiridaz, ¹³N-Ammonia) and hybrid combination PET/CMR imaging are coming to spotlight with improved sensitivity and specificity for earlier detection of myocardial sarcoid. As CMR and PET are showing increased utilization in cardiac sarcoidosis, ²⁰¹Th-SPECT, ^99mTc MDP SPECT, ⁶⁷Ga Scintigraphy, and ⁸²Rb PET are falling out of favor. Newer imaging modalities, radionuclide tracers, and hybrid PET/CMR combinations have been promising in better detecting cardiac sarcoidosis and are currently being evaluated in larger trials.