FDG PET Imaging of Large-Vessel Vasculitis.

Diagnosis of vasculitis is challenging given the nonspecific manifestations of the diseases. [(18)F]Fluorodeoxyglucose (FDG) positron emission tomography (PET) has been increasingly used for vasculitis in clinic and has been shown to have a potential role in diagnosing large-vessel vasculitis such as giant cell vasculitis and Takayasu vasculitis, in monitoring treatment response, and in predicting disease progression. However, the exact clinical role of FDG PET for vasculitis has not been determined. Diagnosis of vasculitis should not be made solely based on PET. It is also worth noting that FDG PET has limited role in small-size vasculitis, although case reports have shown some success.