Imaging infection/inflammation in the new millennium

In the closing half of the past century a wide variety of approaches were d eveloped to visualise infection and inflammation by gamma scintigraphy. Use of autologous leucocytes, labelled with indium-111 or technetium-99m, is s till considered the "gold standard" nuclear medicine technique for the imag ing of infection and inflammation. However, the range of radiopharmaceutica ls used to investigate infectious and non-microbial inflammatory disorders is expanding rapidly. Developments in protein/peptide chemistry and in radi ochemistry should lead to agents with very high specific activities. Recent ly, positron emission tomography with fluorine-18 fluorodeoxyglucose has be en shown to delineate infectious and inflammatory foci with high sensitivit y. The third millennium will witness a gradual shift from basic (non-specif ic) or cumbersome, even hazardous techniques (radiolabelled leucocytes) to more sophisticated approaches. Here a survey is presented of the different approaches in use or under investigation.