The value of indium-labelled leucocytes in clinical practice.

Following intravenous injection, autologous 111In labelled-leucocytes migrate to sites of inflammation, where they can be imaged with the gamma camera. The principle underlining the labelling technique is exposure of a population of leucocytes or purified granulocytes to a lipophilic 111In complex, such as 111In oxine or 111In tropolonate. As a result of cell activation, the in vitro manipulation to which the leucocytes are subjected modifies their biodistribution early after re-injection. Separation and labelling in plasma-enriched media, however, limits this activation and promotes early migration into inflammatory foci.