Indium-111 leukocyte scanning of the abdomen. Analysis of its value for diagnosis and management of inflammatory bowel disease.

Indium-111 leukocyte scanning of the abdomen (IAS) was performed in 10 patients with ulcerative colitis and in 39 patients with Crohn's disease involving the small intestine (in 25 occasions) and/or the colon (17 cases). Radionuclide uptake by the gut was seen in 84% of the patients with active inflammation. We compared the extent of the disease displayed by IAS with the findings obtained by either radiological or endoscopic studies or at surgery. In two-thirds of the patients, the IAS gave an accurate evaluation of the extent of the disease (sensitivity 68%). False-positive IASs were not seen in small bowel disease (specificity 100%), but were observed on 4 occasions on the colon (specificity 86%). The intensity of the radionuclide uptake could not be correlated with the clinical activity of the disease as evaluated by the Crohn's disease activity index. These results suggest that IAS is not superior to the standard procedures used to detect and localize inflammatory bowel disease and that IAS cannot replace these techniques. However, the simplicity of IAS and the complete lack of complications associated with its use render it useful in the evaluation of the extent and distribution of inflammation in some patients, mainly those with severe disease in whom standard diagnostic procedures would be contraindicated.