Purpose. To determine the diagnostic value of magnetic resonance enterocolonography using quantitative indices of inflammation (MaRIA, Clermont) in assessing the activity of the inflammatory process in the small and large intestine in Crohn's disease.

Materials and methods. In the study 34 patients with Crohn's disease aged 21 to 46 years were included. All patients underwent magnetic resonance enterocolonography with intravenous contrast and diffusion-weighted images. Based on MRI data, the activity indices of the inflammatory process in the small and large intestine of MaRIA and Clermont were determined. MRI data were compared with endoscopic examination and the endoscopic index activity of inflammation SES-CD.

Results. In moderate inflammatory activity in the small and large intestine, the diagnostic values of the MaRIA (segmental) and Clermont (segmental) indexes were: sensitivity 73.3% and 66.7%, specificity 94.7% and 94.7%, accuracy 85.3 % and 82.3%, respectively. In severe inflammatory activity in the small and large intestine, the diagnostic values of the Maria (segmental) and Clermont (segmental) index were: sensitivity 94.7% and 94.7%, specificity 93.3% and 100%, accuracy 94.1% and 97.1%, respectively. In a comparative analysis of the MaRIA (segmented) and Clermont (segmented) indices with moderate and severe inflammation activity using the McNemar test, no statistically significant differences were found (p> 0.05). An analysis of the correlation between the values of the inflammation indices MaRIA (general) and Clermont (general) with SES-CD (general) revealed a direct strong relationship between them (r = 0.94 and r = 0.82, respectively, p <0.001).

Conclusion. The obtained results demonstrated the high diagnostic value of magnetic resonance enterocolonography in assessing the activity of the inflammatory process in the small and large intestine. MRE can be used as a non-invasive diagnostic method to assess inflammatory changes in the small and large intestine, which will avoid the appointment of multiple endoscopic studies in patients receiving medication therapy for Crohn's Disease. MaRIA and Clermont inflammation activity indices showed comparable diagnostic value. The use of the Clermont index will allow to abandon the use of intravenous contrast without losing the informative value of magnetic resonance enterocolonography. However, the possibilities of the index Clermont should be studied on more clinical material, which requires further research.