Giant cell arteritis (GCA) is the most common of the large vessel vasculitides, with [18F] fluorodeoxyglucose (FDG) PET/CT indicated for evaluation of suspected large vessel involvement. Advances in PET/CT technology, particularly with digital PET, have significantly improved the assessment of cranial artery involvement in GCA. Recent guidelines have been updated to incorporate [18F]FDG PET/CT imaging in the diagnosis of GCA. This review article provides a practical guide to the most recent recommendations regarding PET/CT study indications, image acquisition and interpretation criteria for GCA, while discussing potential pitfalls and future research directions in the field.