Optimal Patient Preparation for Detection and Assessment of Cardiac Sarcoidosis by FDG-PET

Abstract

Abnormal uptake of ¹⁸F-fluorodeoxyglucose (FDG) in the heart on positron emission tomography (PET) was recently included in the major criteria of diagnostic guidelines for cardiac sarcoidosis (CS). The high sensitivity but great variability in specificity in the diagnosis probably due to variable preparation methodologies of FDG-PET was reported. There are three main methods which have been reported to minimize physiological FDG uptake in the normal myocardium. A low carbohydrate diet on the day before PET with an overnight fasting more than 18-h achieves almost complete suppression of myocardial FDG uptake. Use of heparin pre-injection or high-fat diet preparation may enhance the suppressive effect. Serum FFA levels before PET imaging might be a biomarker of predicting the physiological FDG uptake in the myocardium.