INSTANT TECHNETIUM 99M HEXAMETHYL PROPYLENAMINE OXIME-LABELED LEUKOCYTE SCAN COMPARED WITH COLONOSCOPY IN EARLY ASSESSMENT OF DISEASE EXTENT AND ACTIVITY IN ACUTE COLITIS

AIM: This study was undertaken to evaluate technetium 99m (Tc 99m) hex amethyl propylenamine oxime (HMPAO)-labeled leukocyte scintigraphy for assessment of disease extent and activity in acute colitis. PATIENTS AND METHODS: Twenty-seven patients, hospitalized because of acute wate ry and/or bloody diarrhea, were investigated using both total colonosc opy and Tc 99m HMPAO-labeled leukocyte scintigraphy within 48 hours af ter admittance. RESULTS: Final diagnoses were ulcerative colitis in 14 patients, Crohn's disease in 7 patients, and infectious colitis in 6 patients. Using colonoscopy as the reference method, the maximum exten t of colitis was correctly assessed by the leukocyte scan in 18 patien ts (67 percent), although rectal engagement was not visualized in 5 (1 9 percent). In six additional patients, there was almost complete agre ement between the two methods. One other patient, with left-sided ulce rative colitis, was erroneously assessed as having total extent. Two o ther patients (one with Crohn's colitis and one with infectious coliti s) had different segments incorrectly assessed. Sensitivity, specifici ty, and diagnostic accuracy of scintigraphy in detecting active inflam matory segments were 0.85, 0.83, and 0.85, respectively. Intensity of inflammatory activity assessed by the leukocyte scan correlated signif icantly with colonoscopic assessment (r = 0.719; P < 0.0001). CONCLUSI ON: Information regarding extent, localization, and disease activity i n patients with acute colitis of inflammatory or infectious origin may be satisfactorily obtained using Tc 99m HMPAO-labeled leukocyte scann ing. The noninvasive nature of the method makes it an attractive early alternative to other investigational procedures such as total colonos copy or barium examination, particularly in cases with an established diagnosis of inflammatory bowel disease.