Positron emission tomography-computed tomography for imaging of inflammatory cardiovascular diseases.

Inflammation is a determinant of atherosclerotic plaque rupture, the event usually responsible for myocardial infarction and stroke. Possible causes of inflammatory cardiomyopathy include myocarditis, eosinophilic disease, and sarcoidosis. Although conventional imaging techniques can identify the site and severity of luminal stenosis, they do not provide information regarding inflammatory status. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for imaging of inflammatory cardiovascular diseases has been rapidly evolving. Integrated PET/computed tomography (CT) is becoming the method of choice for quantification of arterial inflammation across multiple vessels. Moreover, PET/CT provides information about the activation status of inflammatory cells in the vessel wall, thus allowing early diagnosis and risk stratification of patients. The Japanese health insurance system approved reimbursement for FDG-PET use to detect inflammation sites in cardiac sarcoidosis as of April 2012. This approval has necessitated a more detailed assessment of the clinical value of FDG-PET. Standardized preparation, imaging, and image interpretation protocols should be established to sufficiently suppress physiological FDG uptake in the normal myocardium, and thereby facilitate detection of early-stage cardiac inflammatory lesions with more favorable specificity. This review summarizes the background, clinical utility, state-of-the-art advances, and potential future applications of FDG-PET for imaging inflammatory cardiovascular diseases including cardiac sarcoidosis, large-vessel arteritis, and atherosclerosis.