18F-labelled fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging in experimental arthritis. (a) High-resolution CT provided detailed anatomical information of skeletal elements for accurate allocation of PET signalling. (b) Rapid 18F-FDG biodistribution via blood circulation in a time frame 0 to 10 seconds after tail vein injection, visualized by PET and CT image fusion. (c) PET imaging of mice before arthritis onset (day 2) revealed enrichment of 18F-FDG in tissue and organs (in particular, heart, bladder, kidneys, and eyes). (d) Acute inflammatory arthritis (day 13) caused additional accumulation of 18F-FDG at sites of pathological increased glucose metabolism (that is, inflamed carpal and tarsal joints) (arrowheads).