Gastric and small bowel Crohn's disease assessed with leukocytes-Tc99m scintigraphy

We reviewed 312 Tc-99m leukocyte Tc-99m-WBC studies to evaluate the sensitivity and specificity of Tc-99m-WBC for identifying small-bowel and gastric inflammation in children with Crohn's disease. The Tc-99m-WBC scans were interpreted blindly and compared to the results of colonoscopy with biopsies and surgical specimens. In 46 children, total colonoscopy was done within a few days of a Tc-99m- WBC scan and in 13 others surgical specimens were available. Of the 37 children in whom the terminal ileum was visualized endoscopically (24) or surgically (13), the WBC-Tc-99m scan showed a similar degree of inflammation in 33. The sensitivity of Tc-99m-WBC scanning was 91% and the specificity 96%. The scans allowed evaluation of inflammation in the terminal ileum in 22 children in whom the endoscopist did not cannulate it; the scans were abnormal in 10 of these 22 children. In the children with no ileoscopy the results of the Tc-99m-WBC scan were consistent with the laboratory values, the gastroenterologist's clinical assessment, and long-term clinical follow-up. Finally, the scans of 46 controls did not reveal any false-positive findings in the terminal ileum. Five children with gastritis documented by gastroscopy had normal Tc-99m-WBC scans and upper gastrointestinal barium studies. This study demonstrates in a large number of normal and abnormal children with different pre-test probabilities of having inflammatory bowel disease that scintigraphy is reliable in identifying small-bowel inflammation.