Clinical value of technetium-99m-HMPAO-labeled leukocyte scintigraphy and spiral computed tomography in active Crohn's disease

OBJECTIVES: The diagnostic accuracy of technetium-99m-HMPAO-labeled leukocy te scintigraphy (LS) and spiral CT for The detection of inflammatory activi ty was assessed; the extent of the inflammation and the complications were compared with the clinical and laboratory parameters and with the endoscopi c and radiological findings in patients with clinically active Crohn's dise ase (CD). METHODS: Twenty-eight patients (13 men, 15 women, average age 32.5 yr, rang e: 18-59 yr) with an acute exacerbation of CD were enrolled in the study. T he disease behavior type and the maximum extent of inflammation were establ ished by means of endoscopy (jejunoscopy and colonoscopy) and enteroclysis. Nine patients with severe complications (abscess and stenosis) underwent o peration. The GI tract was divided into five segments (small bowel, ascendi ng colon, transverse colon, descending colon, and rectosigmoid), the LS, CT , endoscopic, and radiological pictures of all segments were graded (range: 0-3) and the scores were summed and compared. RESULTS: The investigations indicated that LS and CT had sensitivities of 7 6.1% and 71.8%, specificities of 91.0% and 83.5%, and accuracies of 82.6% a nd 77.5%, respectively, for detection of segmental inflammatory activity. W ith regard to the disease behavior type, the sensitivities of LS and CT wer e, respectively, 77% and 100% in the penetrating-fistulizing, 80% and 73% i n the stricturing, and 68% and 64% in the inflammatory form of CD. CT detec ted all abdominal abscesses, whereas the diagnostic value of LS for the det ection of the complications of CD was lower. The inflammatory activity scor es measured by LS displayed a closer correlation than that of CT with the B est index (r = 0.71, p < 0.0005 vs r = 0.63, p < 0.001), the van Hees index (r = 0.61, p < 0.005 vs r = 0.59, p < 0.005), the serum fibrinogen level ( r = 0.67, p < 0.005 vs r = 0.59, p < 0.005), or the C-reactive protein leve l (r = 0.64, p < 0.005 vs r = 0.51, p < 0.01). CONCLUSIONS: Both LS and CT are valuable noninvasive diagnostic methods in cases involving severe, active CD. LS seemed better for the detection of se gmental inflammatory activity, whereas CT displayed excellent suitability f or the recognition of complications: abdominal abscesses were diagnosed wit h 100% efficiency. (C) 2001 by Am. Cell. of Gastroenterology.