The role of nuclear medicine in inflammatory bowel disease. A review with experiences of aspecific bowel activity using immunoscintigraphy with Tc-99m anti-granulocyte antibodies

The diagnosis of inflammatory bowel disease (IBD) needs a complex diagnosti c work-up. Beside verifying the disease itself, it is fundamental to assess disease extent and activity and to detect associated complications, to fin d the most effective treatment and for follow up. Scintigraphy with radiola belled leukocytes is able to provide a complete survey of the whole intesti nal tract, both the small and large bowel, and detects septic complications successfully with negligible risk. Radionuclide procedures are useful in e stablishing or ruling out IBD in patients with intestinal complaints, in as sessing disease severity, and in the evaluation of extraintestinal septic c omplications. Widely available radionuclide procedures are discussed, i.e. scintigraphy by (111)Indium oxime or (99m)Technetium HMPAO labelled white b lood cells and immunoscintigraphy with Tc-99m anti-granulocyte antibodies. Advantages and disadvantages of all three methods are stressed out. Patient s and methods: The immunoscintigraphies with Tc-99m anti-granulocyte antibo dies (ANTI-GRANULOCYTE (R) BW 250/183) of 27 patients with suspicion of IBD were retrospectively analysed. Planar anterior and posterior images were o btained 4 and 24 h postinjection, respectively. The bowel was divided into six segments and the activity was visually graded with reference to bone ma rrow in each segments. The scans were compared with the results of radiolog ical and endoscopical investigations. The diagnosis of IBD was proved or ru led out by means of enteroclysis, large bowel enema or endoscopy. Results: In the 27 patients, 74 bowel segments with increased activity were detected . In the case of 30 segments in 16 patients, bowel inflammation was reveale d by the other methods (true positives). In the case of 44 bowel segments, no underlying bowel inflammation could be verified, and these activities we re regarded as aspecific activity. We could not differentiate between true positive and aspecific activity based on scan pattern or intensity. Discuss ion: These findings of aspecific bowel activity using immunoscintigraphy ar e in contrast with the results of former studies, while the existence of no n-specific activity decreases the reliability of the method. Based on the l iterature and our experiences, we conclude that Tc-99m HMPAO labelling shou ld be the method of choice for the investigation of IBD patients. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.