2018 年 4 巻 1 号 p. 151-154
Since cardiac sarcoidosis (CS) portends adverse outcomes, early diagnosis of active inflammation in CS is essential for therapeutic and prognostic advantages. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) has been used for the clinical evaluation of active inflammatory lesions in CS. While myocardium can utilize both free fatty acids and glucose as the substrates of energy metabolism, the physiological myocardial 18F-FDG uptake often makes it difficult to detect the pathological 18F-FDG accumulation. Prolonged fasting and low-carbohydrate diet are most commonly used for suppressing physiological myocardial 18F-FDG uptake, and moreover unfractionated heparin administration is sometimes considered. Sufficient preparation allows for the establishment of increased 18F-FDG uptake in myocardium as active inflammatory lesions. Typical patterns of pathological 18F-FDG accumulation in myocardium are “focal” and “focal-on-diffuse” and these are often corresponded with myocardial perfusion abnormality. In case with inconclusive 18F-FDG uptake, the simultaneous interpretation with myocardial perfusion imaging is useful and helpful to evaluate clinically significant 18F-FDG uptake in CS.
