Differentiation between continuous and discontinuous colitis with white blood cells labeled with technetium in children

Studies have suggested that WBC-Tc^99m scan may be superior to contrast radiology in the assessment of the extent and activity of inflammatory bowel disease (IBD). We have retrospectively examined the ability of WBC-Tc^99m scan to differentiate between continuous and discontinuous colitis in pediatric IBD. Methods: We reviewed the charts of 214 children evaluated with WBC-Tc^99m scan. One investigator blinded to the diagnosis interpreted the scans. Results: There were 80 children with Crohn's Disease (CD), 34 with ulcerative colitis (UC), and 18 with indeterminate colitis. Fifty-two children had non-specific gastrointestinal complaints and negative diagnostic tests. Thirty children served as controls (children with no gastrointestinal disease, but underwent WBC-Tc^99m scanning for other medical problems). The male/female distribution was 100/115. Mean and median ages were 12 and 13 years, respectively. In 76 children with active CD, WBC-Tc^99m scan correctly identified discontinuous colitis in 65 children and continuous colitis in 11 children. WBC-Tc^99m scan incorrectly identified a discontinuous pattern in 2/29 children with active UC who had evidence of minimal inflammation throughout the colon. It was difficult to interpret the significance of the WBC-Tc^99m scan results of two patients because there were no available biopsies from the areas of greatest technetium accumulation. One patient had focal accumulation in the appendix and rectosigmoid, had endoscopic and histologic rectosigmoiditis, but no evidence of appendicitis and no appendiceal biopsies. Another had intense uptake in the terminal ileum, but no ileal biopsies were available. Scans of all control patients were normal. Conclusion: WBC-Tc^99m scanning is a reliable method of distinguishing discontinuous from continuous colitis, unless inflammation is mild.