Location and activity of ulcerative and Crohn's colitis by indium 111 leukocyte scan. A prospective comparison study.

A prospective blinded study comparing the indium 111 leukocyte scan to barium enema, colonoscopy, or surgery or a combination of these, was carried out in 15 patients (10 with active ulcerative colitis and 5 with active Crohn's colitis). Correlation of disease location to colonic regions between indium scan and other diagnostic studies was excellent in 11 instances, good in 2, and poor in 3. In 2 of the 3 studies where major disagreement occurred, the comparative barium enema was performed greater than 2 mo after the indium scan. Disease activity, estimated by the intensity of radionuclide uptake, was compared to clinical disease activity assessed by the Crohn's Disease Activity Index for both forms of colitis. The relative degree of inflammation estimated by the indium scan correlated well with the independent clinical assessment (correlation coefficient = 0.81). The indium 111 leukocyte scan appears to be an accurate, noninvasive method for assessing the extent and the severity of the inflammation in patients with acute ulcerative or Crohn's colitis.