P136. Contrast enhanced abdominal ultrasound in IBD. Comparison with Ileocolonoscopy and MR Enterography

C.S. Horjus1, R. Bruijnen2, L. Roovers1, D. de Jong3, F.B. Joosten2, M.J. Groenen1, P.J. Wahab1

1Rijnstate Hospital, Department of Gastroenterology, Arnhem, Netherlands; 2Rijnstate Hospital, Department of Radiology, Arnhem, Netherlands; 3Universitair Medisch Centrum St Radboud, Afd Maag–Darm Leverziekten, Nijmegen, Netherlands

Background: Contrast-Enhanced Ultrasound (CE-US) as a diagnostic tool in IBD may be a patient-friendly, easy applicable and less costly alternative for endoscopy and MR Enterography (MRE). CE-US measures tissue perfusion density which reflects the intensity of inflammation. We compared quantitative parameters of contrast-enhanced ultrasound (CE-US) examination of the small bowel with endoscopic inflammatory activity and findings at MRE in patients with Crohn's disease.

Methods: Thusfar, we prospectively evaluated 46 patients with Crohn's disease, performing ileocolonoscopy followed within 14 days by CE-US and MRE. The radiologists were blinded for the endoscopic disease activity. Standardized ultrasound examination, colour-coded duplex sonography and CE-US of the small bowel was performed using Sonovue®. Contrast-enhanced sonographic perfusion maps were generated to derive the peak intensity (PI) and the time to peak (TTP), by using the quantification software Qontrast®. We scored the endoscopic disease activity in the ileum as: none, moderate (aphthous ulcers with normal mucosa between lesions, or diffuse aphthae) and severe (large ulcers with diffuse inflamed mucosa, nodule and/or stenosis). The maximum enhancement at MRE was similarly scored as none, moderate and severe.

Results: The endoscopic disease activity was scored in 46 patients as: no lesions: 4 patients; mild: 14 patients; severe: 20 patients and stricturizing disease: 8 patients. A peak intensity value of 10% at CE-US had an overall sensitivity and specificity of 100% in predicting any inflammation at endoscopy. For the MRE the overall sensitivity and specificity were, 80% and 100%, respectively. A peak intensity value of 30% had a sensitivity of 86% and 80% in the prediction of moderate or severe grade of inflammation at endoscopy, respectively. The enhancement grade at the MRE showed a sensitivity of 50% and 65% in predicting moderate and severe inflammation at endoscopy, respectively.

Conclusions: Quantitative bowel enhancement of the terminal ileum obtained by using CE-US highly correlates with severity grade of inflammation determined at endoscopy. CE-US is more sensitive than MRE, in detecting moderate and severe inflammation of the small bowel in Crohn's disease.