Ultrasound in Crohn's disease of the small bowel

Objective: The purpose of this work is to prospectively evaluate high resol ution ultrasonography with graded compression in the ability to detect Croh n's disease of the small bowel (CDSB) together with its complications and a ctivity signs, compared with enteroclysis, CT and immunoscintigraphy in the mirror of the final diagnosis. Methods and material: In a series of 73 con secutive patients, who were referred for enteroclysis with suspected Crohn' s disease of the small bowel computed tomography (CT), ultrasound (US), imm unoscintigraphy with Tc-99m labeled monoclonal antigranulocyte antibody (AG Ab) examinations were performed within 10 days from each other. For the fin al evaluation the diagnosis of CDSB was based on combination of clinical an d enteroclysis findings (73 cases) and in 17 cases additional surgical and pathological data were available. The results of other modalities were blin ded to the radiologists performing and reading out the exams. The diagnosti c values of each modality was assessed also in those 18 patients, who had e arly Crohn's disease. In the group of 43 patients with proven CDSB who had all the four imaging modalities, the modalities were compared in their abil ity to demonstrate various pathological conditions related to CD. Increased (> 500 ml/min) flow measured by Doppler US in the superior mesenteric arte ry and increased color signs in the gut wall seen by power Doppler sonograp hy were compared to CDAI. Results: Of the 73 patients the combination of en teroclysis and clinical tests demonstrated CDSB in 47. The sensitivity, spe cificity and accuracy of ultrasound were 88.4, 93.3 and 90.4%, respectively . Enteroclysis was the: most accurate method. CT was more sensitive than US , but less specific. The accuracy of US, CT and scintigraphy were similar. In the group of 18 patients, who had early CDSB, the sensitivity of US decr eased to only 67%, CT and scintigraphy had higher values. Intra- and perimu ral abscesses, and sinus tracts were also more frequently visualized by US, especially if they were small. US was superior than CT in detecting stenos es and skip lesions, but inferior to enteroclysis. US and CT detected more fistulas, than enteroclysis. Compared to CT, US detected more cases with me senteric lymphadenopathy, equal cases with abscesses and free peritoneal fl uids. In detecting mesenteric inflammatory proliferation CT. and in detecti ng colonic involvement CT and immunoscintigraphy were slightly superior tha n graded compression US. Patterns of mural stratification detected by ultra sound correlated well with the enteroclysis severity stages. There was only 59% agreement between increased superior mesenteric artery flow detected b y Doppler sonography and CDAI, and 60.5% agreement between increased number of Color pixels in the gut wall measured by power Doppler and increased CD AI. Conclusion: High resolution graded compression sonography is a valuable tool for detecting small intestinal Crohn's disease. It has similar diagno stic values as CT, However in early disease the sensitivity substantially d ecreases. In known Crohn's disease for following disease course, evaluating relapses and extramural manifestations US is an excellent tool. Doppler an d Power Doppler activity measurements do not correlate well with the more w idespread clinical activity index. (C) 2000 Elsevier Science ireland Ltd. A ll rights reserved.