Optimization of technetium-99m-HMPAO leukocyte scintigraphy in evaluation of active inflammatory bowel disease

Although [Tc-99m]HMPAO-labeled leukocyte scintigraphy is widely used in the assessment of IBD, the time point chosen for imaging is still controversia l. The aim of the present study was to determine the optimal scanning seque nce to assess IBD extension and activity. Sixty-two consecutive patients wi th active and 18 with inactive IBD were prospectively studied. Clinical eva luation, colonoscopy, radiology, and scintigraphy were performed within thr ee days, without changes in the patient's treatment. Compared to early scan (45 min), late scan (3 hr) had a higher sensitivity (85% vs 100%) and accu racy (85% vs 95%) in identifying patients with active IBD and in defining I BD extension. Combinations of values from both scans did not improve accura cy of scintigraphy, which is lower in Crohn's disease than in ulcerative co litis and also in patients receiving steroid treatment. In conclusion, a si ngle late scintigraphy scan provides the best means to identify patients wi th active IBD and to assess disease extension.