Semi-Quantitative and Quantitative [(18)F]FDG-PET/CT Indices for Diagnosing Large Vessel Vasculitis: A Critical Review

To confirm the diagnosis of large vessel vasculitis (LVV) with high accuracy, one of the recommended imaging techniques is [(18)F]Fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography ([(18)F]FDG-PET/CT). Visual assessment of [(18)F]FDG uptake in the arterial wall compared to liver uptake is the mainstay for diagnosing LVV in routine clinical practice. To date, there is no consensus on the preferred semi-quantitative or quantitative parameter for diagnosing LVV. The aim of this review is to critically update the knowledge on the available evidence of semi-quantitative and quantitative [(18)F]FDG uptake parameters for diagnosing LVV and to provide future directions for methodological standardization and research.