PET/CT holds great promise for the management of many types of infection and inflammation.  This issue discusses many of these uses, starting with arthroplasty-associated infection.  FDG PET/CT also has utility in inflammatory bowel disease.  This issue also discusses the utilization of FDG PET and PET/CT in the evaluation of diabetic foot, and in monitoring therapeutic effect in patients without malignancy.   PET/CT is reviewed regarding its use in patients with sarcoidosis or IgG4 disease.  Also covered is the application of FDG PET/CT in detecting the source of fever of unknown origin. Artherosclerosis and vasculitis can be assessed by PET/CT and FDG PET/CT can also be used in the management of severe infection in patients with malignancies.  Finally, the issue discusses the use of PET and PET/CT in the evaluation of osteomyelitis.