CT and ^99mTc-WBC vs colonoscopy in the evaluation of inflammation and complications of inflammatory bowel diseases

Background.

The goal of this study was to evaluate the accuracy of computerized tomography (CT) and ^99mTc-white blood cell (WBC) scintigraphy versus colonoscopy in assessing inflammatory bowel diseases (IBD) in a large population of children. Methods. In a patient population of 313 consecutive children who had a ^99mTc-WBC scan, 106 colonoscopies were done within a median time interval of 8 days of the ^99mTc-WBC scan. One hundred and three CT scans were performed on 84 patients. Results. Of the 42 CT scans obtained within a short time interval after the ^99mTc-WBC scan, 21 (50%) were normal. In the 21 children with a positive ^99mTc-WBC scan, 62% (13/21) of the CT scans underestimated the bowel wall inflammation in at least one segment. In the children with a negative ^99mTc-WBC study, there were 17 negative CT examinations and 4 examinations showing an abnormal terminal ileum. When CT was compared with colonoscopy in assessing inflammation, there were five true-negative CT, two true-positive CT, no false-positive, and seven false-negative CT examinations. When ^99mTc-WBC scintigraphy was compared with colonoscopy in assessing inflammation, there were seven true-positive, two false-negative, five true-negative, and no false-positive ^99mTc-WBC studies. The ^99mTc-WBC scan was positive in five patients with a false-negative CT examination. Of the total 103 CT scans obtained, 53 (51%) were normal. Four abscesses (3.8%) were demonstrated by CT. Conclusions. ^99mTc-WBC scintigraphy is more sensitive than CT for detecting inflammation of the bowel wall. The incidence of complications from IBD in this retrospective study was much lower than had been previously reported.