E S P G H A N 32nd Annual Meeting; Warsaw, Poland, June 2-5, 1999
Background: 99mTcHMPAO scintigraphy has been proposed as a screening test for IBD. Although there are several reports of its use in children there are no satisfactory studies on the accuracy of this investigative technique for small bowel Crohn's disease. We previously reported a series of children with severe proximal Crohn's disease, which was not detected by scintigraphy, and so we questioned its reliability.
Aim: To compare the results of scintigraphy with those of the upper gastrointestinal and follow-through barium contrast study in children undergoing investigation for IBD.
Methods: A total of 71 paired studies were available for comparison. The diagnostic groups included Crohn's disease (n=40), ulcerative colitis (n=8), indeterminate colitis (n=5) and normal subjects (n=18). Using the barium contrast study as the gold-standard the sensitivity, specificity, positive and negative predictive values (PPV, NPV) and the likelihood ratios for positive (LRP) and negative (LRN) scintigraphic scans were calculated. These indicators of accuracy were determined separately for the proximal and distal segments of the small intestine as well as for the total small intestine. Finally they were also determined using two different criteria (lower and higher) for scan positivity.
Conclusion: Depending on the criteria employed for scintigraphic positivity either the sensitivity or specificity was unsatisfactory, particularly with proximal disease. Calculation of the predictive values and likelihood ratios highlighted the relative inaccuracy of the technique. In children with Crohn's disease involving the small intestine 99mTcHMPAO scintigraphy is an unsatisfactory screening test.