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 leukocyte scintigraphy (LS) and spiral CT for the detection of inflammatory activity was assessed; the extent of the inflammation and the complications were compared with the clinical and laboratory parameters and with the endoscopic and radiological findings in patients with clinically active Crohn's disease (CD).

METHODS

Twenty-eight patients (13 men, 15 women, average age 32.5 yr, range: 18-59 yr) with an acute exacerbation of CD were enrolled in the study. The disease behavior type and the maximum extent of inflammation were established by means of endoscopy (jejunoscopy and colonoscopy) and enteroclysis. Nine patients with severe complications (abscess and stenosis) underwent operation. The GI tract was divided into five segments (small bowel, ascending 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 76.1% and 71.8%, specificities of 91.0% and 83.5%, and accuracies of 82.6% and 77.5%, respectively, for detection of segmental inflammatory activity. With regard to the disease behavior type, the sensitivities of LS and CT were, respectively, 77% and 100% in the penetrating-fistulizing, 80% and 73% in the stricturing, and 68% and 64% in the inflammatory form of CD. CT detected all abdominal abscesses, whereas the diagnostic value of LS for the detection of the complications of CD was lower. The inflammatory activity scores measured by LS displayed a closer correlation than that of CT with the Best 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 level (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 segmental inflammatory activity, whereas CT displayed excellent suitability for the recognition of complications: abdominal abscesses were diagnosed with 100% efficiency.