Value of indium-111 granulocyte scintigraphy in the assessment of Crohn's disease of the small intestine: prospective investigation.

The present study was undertaken to determine the value of indium-111 granulocyte scintigraphy in Crohn's disease of the small bowel by comparing the results with those of radiology, endoscopy and surgery. Twenty-one patients with Crohn's disease of the small bowel, 9 patients with Crohn's disease of the colon, 1 patient with both localizations and 8 with ulcerative colitis were studied by indium-111 granulocyte scanning. Eighteen patients had evidence of active small intestinal disease based on clinical, radiologic, and/or endoscopic, and/or histopathological features. Thirteen of them had a true positive scan (sensitivity 72%), but accurate assessment of localization and extent of disease was often difficult. Five patients had a false negative scan and 4 a true negative. No false positive scans were found. The diagnostic accuracy was 77%. In contrast, from 18 patients with colonic disease, 16 had a true positive scan corresponding in localization and extent with standard investigations, 1 patient had a false negative scan (sensitivity 94%), and 1 a true negative (diagnostic accuracy 95%). This study also showed that 3-5 h scanning after injection of indium-111-labeled granulocytes is the optimal timing for this test. The patient's acceptability of this procedure was definitely superior to radiology and endoscopy. In conclusion, this technique has a definite place in evaluating localization and extent of active colonic disease, but it does not replace good small bowel radiology and should not be recommended in the routine diagnostic workup of Crohn's disease of the small intestine.