P643 Development of quantitative ultrasonographic activity score in ileal Crohn’s disease

M. Livne Margolin1, M. Amitai2, E. Klung2, B. Ungar1, R. Eliakim1, S. Ben-Horin1, D. Carter1, U. Kopylov1

1Department of Gastroenterology, Sheba Medical Center, Ramat Gan, Israel, 2Department of Diagnostic Imaging, Sheba Medical Center, Ramat Gan, Israel

Background

Intestinal ultrasound (IUS) is as an accurate bedside tool for monitoring Crohn’s disease (CD). However, there is no validated quantitative ultrasonographic score for evaluation of the activity of intestinal inflammation in CD. Such a score may facilitate the use of IUS-based monitoring in clinical practice and in clinical trials in CD. For magnetic resonance enterography (MRE), the magnetic resonance index of activity (MaRIA) is most commonly used. Thus, the aim of our study was to correlate IUS data for the terminal ileum with segmental MARIA score for the terminal ileum in order to devise a quantitative inflammatory index for IUS.

Methods

In this retrospective cohort study, the data of CD patients who were followed in the Gastroenterology Department at Sheba medical centre between January 2016 and December 2018 were extracted. Inclusion criteria were age >18 and an interval<3 months between MRE and IUS. MaRIA score for the terminal ileum was compared with ultrasonographic features of inflammation that included: bowel wall thickness (continuous variable), echogenicity of the bowel wall, pseudostratification of the bowel wall layers, inflammatory mesenteric fat and lymph nodes, hyperemia present on colour Doppler flow and complications (nominal variable). A linear regression model that included the significantly correlated variables was constructed.

Results

Forty-two patients with established Crohn’s disease were included. A stepwise multiple regression model was constructed to predict MaRIA score using US features. Two variables were found to be independently significant in the explanatory model, terminal ileum thickness (r = 0.68, p = 0.001) and US fat proliferation (r = 0.45, p = 0.019). A model was constructed as follows: MaRIA = 7 + 2.5 * TI US thickness (mm) + 7 * US fat proliferation (0 = no, 1 = yes). This model has an R2 of 0.51 for explaining the variability in the results.

Conclusion

Quantitative IUS measurements are significantly correlated with segmental MaRIA score in the terminal ileum; a simple computational model for prediction can be constructed; however,, the accuracy of such model to predict segmental MaRIA was moderate. Additional work to develop quantitative IUS parameters in CD is merited.