Table 1.
Definitions of criteria used to categorize cardiac sarcoidosis likelihood based on fluorodeoxyglucose positron emission tomography and cardiac magnetic resonance imaging findings.
| Likelihood Probability | FDG PET Likelihood | Cardiac MRI Likelihood |
|---|---|---|
|
CS Unlikely (<10%) |
-No perfusion defects and no FDG uptake | -No LGE -LGE present but clear alternative diagnosis (e.g. arrhythmogenic cardiomyopathy, coronary artery disease) |
|
CS Possible (10-50%) |
-Single perfusion defect without associated FDG uptake -No perfusion defects, but non-specific FDG uptake* |
-One focal area of LGE but alternative diagnosis more likely (e.g. pulmonary hypertension) |
|
CS Probable (50-90%) |
-Multiple, non-contiguous perfusion defects without associated FDG uptake -Single perfusion defect with associated focal or focal on diffuse FDG uptake -No perfusion defects, but focal or focal on diffuse FDG uptake |
-Multifocal LGE in a pattern that is likely consistent with CS, but cannot rule out other diagnosis (e.g. myocarditis) |
|
CS Highly Probable (>90%) |
-Multiple, non-contiguous perfusion defects with associated FDG uptake -Multiple areas of focal FDG uptake and extracardiac FDG uptake present |
-Multifocal LGE in a pattern strongly consistent†with CS with no alternative diagnosis |
Non-specific FDG uptake includes the following: (1) diffuse FDG uptake of the left ventricular myocardium and (2) focal FDG uptake with signal intensity that is only minimally increased when compared to background/blood pool uptake. †Features on cardiac MRI strongly consistent with CS: intense signal of LGE and/or prominent involvement of insertion points with direct and contiguous extension across the septum into the right ventricle. CS, cardiac sarcoidosis. FDG, fluorodeoxyglucose. LGE, late gadolinium enhancement. MRI, magnetic resonance imaging. PET, positron emission tomography. Adapted from Vita T et al. Circ Cardiovasc Imaging. 2018 Jan;11(1):e007030.13