18F-F.D.G. PET imaging of infection and inflammation: intestinal, prosthesis replacements, fibrosis, sarcoidosis, tuberculosis.

Nuclear medicine plays an important role in the evaluation of infection and inflammation. A variety of diagnostic methods are available for imaging this inflammation and infection, most notably computed tomography, 68Ga scintigraphy or radionuclide labeled leucocytes. Fluorine 18 fluorodeoxyglucose (18F-F.D.G.) is a readily available radiotracer that offers rapid, exquisitely sensitive high-resolution images by positron emission tomography (PET). Inflammation can be acute or chronic, the former showing predominantly neutrophilic granulocyte infiltrates, whereas in the latter, macrophages predominate. F.D.G. uptake in infection is based on the fact that mononuclear cells and granulocytes use large quantities of glucose by way of the hexose monophosphate shunts. 18F-F.D.G. PET accurately helps diagnose spinal osteomyelitis, diabetic foot and in inflammatory conditions such as sarcoidosis and tuberculosis.(it appears to be useful for defining the extent of disease and monitoring response to treatment). 18F-F.D.G. PET can also help localize the source of fever of undetermined origin, thereby guiding additional testing. 18F-F.D.G. PET may be of limited usefulness in postoperative patients and in patients with a failed joint prosthesis or bowel inflammatory disease. In this review, we will focus on the role of 18F-F.D.G. PET in the management of patients with inflammation or suspected or confirmed infection