Standardized Ketogenic Dietary Preparation for Metabolic PET Imaging in Suspected and Known Cardiac Sarcoidosis

A major limitation of cardiac positron emission tomography (PET) with F18-fluorodeoxyglucose (F18-FDG) for the evaluation of cardiac sarcoidosis (CS) is associated with physiologic myocardial glucose uptake. The optimal dietary protocol to suppress physiologic myocardial F18-FDG uptake is not well-established. We aimed to evaluate the diagnostic performance of a novel dietary preparation using a ketone-based infant formula. Between 2018 and 2021, consecutive studies using a ketogenic dietary preparation were identified (n=198). The rate of non-diagnostic studies due to failure to suppress myocardial glucose was 7.1% (n= 14) with a similar incidence in diabetics (n= 6, 8.1%). Among studies reported to have no inflammation (N= 137), 130 studies (66%) had mean myocardial SUV less than or equal to mean blood pool SUV. Patient preparation with a ketone-based infant formula resulted in low rate of inappropriate myocardial glucose suppression in patients undergoing F18-FDG cardiac PET to evaluate cardiac sarcoidosis.