[(18)F]fluorodeoxyglucose PET in large vessel vasculitis.

[(18)F]fluorodeoxyglucose (FDG) PET is a noninvasive metabolic imaging modality based on the regional distribution of [18F]FDG that is highly effective in assessing the activity and extent of giant cell arteritis and Takayasu's arteritis, respectively. Metabolic imaging using [18F]FDG-PET has been shown to identify more affected vascular regions than morphologic imaging with MRI in both diseases. The visual grading of vascular [18F]FDG uptake helps to discriminate arteritis from atherosclerosis and therefore provides high specificity. High sensitivity is attained by scanning during the active inflammatory phase. Thus, [18F]FDG-PET has the potential to develop into a valuable tool in the diagnostic workup of giant cell arteritis and Takayasu's arteritis.