[Clinical evaluation of 99mTc-HMPAO labeled leukocyte imaging in ulcerative colitis].

Inflammatory imaging using 99mTc-HMPAO-labeled mixed leukocytes was assessed for use in treating 11 cases diagnosed as ulcerative colitis: 10 cases with total colitis and 1 with left-sided colitis. They consisted of 8 patients with relapse-remitting type and 3 with chronic continuous type. Radionuclide abdominal images were obtained at 1 hr, 4 hr and 24 hr after intravenous injection of 200 MBq prepared 99mTc leukocytes. Obvious colonic activity noted at 4 hr served as the basis for positive comparative criterion in the present study. The diagnostic efficacy of radionuclide imaging was compared with endoscopic findings (based on Matts' classification) and the clinical manifestations as reference. The sensitivity and specificity of this imaging were 83.3% and 85.7%, respectively, these values being consistent with endoscopic findings and clinical manifestations at sites of disease activity. All of positive images changed to negative after treatment by leukocyte apheresis or glucocorticoid. Based on these results, 99mTc leukocyte imaging can be used to accurately evaluate severity and treatment response in ulcerative colitis. Leukocytes may be closely related to the pathogenesis of ulcerative colitis.