INDIUM SCANNING IN ASSESSMENT OF ACUTE CROHNS-DISEASE - A PROSPECTIVE-STUDY OF SENSITIVITY AND CORRELATION WITH SEVERITY OF MUCOSAL DAMAGE

The aim of this study was to determine whether the sensitivity of indium-111 (In-111) scanning in the assessment of the activity and extent of Crohn's disease correlates with the severity of intestinal lesions as measured by the newly validated Crohn's disease endoscopic index of severity (CDEIS). Nineteen patients with active (CDAI > 200) colonic (N = 11) or ileocolonic (N = 8) Crohn's disease were assessed by colonoscopy and indium scanning. The intestine was divided into five segments in both studies (rectum, sigmoid and left colon, transverse colon, right colon, and ileum). Seventy of the 86 intestinal segments seen at colonoscopy presented macroscopic lesions of Crohn's disease. On third-hour scintigrams In-111 uptake was observed in 52 segments, 51 of which were found to be abnormal at colonoscopy. Predictive positive and negative values of scanning with respect to disease extent assessment were equal to 98% and 44%, respectively. Complete agreement between endoscopic and scintigraphic findings was observed in only six of the 19 patients (32%). Segmental endoscopic indexes of severity (SEIS) were significantly (P < 0.001) lower in false negative (7.9 +/- 4.2) (mean +/- SD) than in true positive (18.0 +/- 9.7) segments as defined by scintigraphy. SEIS values above which In-111 uptake was constantly observed did not differ in the different disease locations. When comparing macroscopically abnormal intestinal segments according to their In-111 uptake grade, the corresponding mean SEIS values increased significantly as the grade increased. Scintigraphic activity, as assessed by the fall in splenic activity, was equal to 23 +/- 11% (N = 19). It correlated significantly with CDEIS (r = 0.63, P < 0.005), but even more so when the highest SEIS of each patient had been taken into account (r = 0.75, P < 0. 0005). In conclusion, when considering disease extent and activity, scanning results correlate well with the endoscopic severity of intestinal lesions in active Crohn's disease. Nevertheless, minor endoscopic lesions can be missed by In-111 scanning.