Radiolabeled leukocyte imaging in inflammatory bowel disease: a prospective blinded evaluation

Nuclear medicine scintigraphies have been reported to assist in making the diagnosis of inflammatory bowel disease. This work aimed to assess the role of radiolabeled leukocyte scintigraphy for the diagnosis of suspected inflammatory bowel disease.

Forty-six adult patients were referred for labeled leukocyte scintigraphy for the evaluation of active abdominal pain. The patient population included inpatients and outpatients, with known or suspected inflammatory bowel disease. The nuclear medicine staff was blinded to the patient's specific complaints.

The labeled leukocyte scintigraphy was positive in 11 of the 15 patients eventually determined to have Crohn's disease. Four of the 15 were false negatives. All four of the ulcerative colitis patients had normal scans. There were no false-positive scans. The positive predictive value was thus 100%, the negative predictive value was 77%, and the sensitivity and specificity were 58% and 100% respectively for Crohn's disease.

We found radiolabeled leukocyte scintigraphy helpful in prospective, blinded assessments of patients with non-stricturizing or non-fistulizing forms of Crohn's disease. Scintigraphy may be more justified for reassessments rather than in making an initial diagnosis. The scans were of value in Crohn's disease but not for ulcerative colitis.