P042 Significant correlation between intestinal ultrasound and magnetic resonance enterography for assessing disease activity and complications in Crohn’s disease

Abstract

Abstract Background The advantages of intestinal ultrasound (IUS) over magnetic resonance enterography (MRE) include wide availability, low cost, and the possibility of being point-of-care. We here aimed to compare the performance of IUS with MRE for assessing disease activity and complications in Crohn’s disease (CD). Methods Prospective longitudinal study of CD patients starting anti-TNF therapy. IUS and MRE were performed at baseline (W0) and after 1 year of infliximab therapy (W54). Bowel wall thickness (BWT) of the most affected segment (MAS) was measured in both exams (average of 4 measurements) and compared. Transmural response (TR) was defined as a reduction in 25% of BWT. All MRE were centrally reviewed by a blinded radiologist. Results We included 48 CD patients (48% male; median age 31 years, IQR 26-44). Ileum was the most commonly affected segment in 63% of the patients. At baseline the agreement between the two methods to select the most affected segment was moderate (k=0.581, p<0.001). At W54, 50% of patients had TR in IUS and 40% in MRE. After 1 year of therapy there was a significant decrease in median BWT in both methods (IUS: 4.88mm vs 3.22mm, MRE: 8.21mm vs 4.91mm, both p<0.001). We found a significant association between the two methods in detecting intestinal complications (stricturing or penetrating disease) on both timepoints (W0: 31.25% vs 21.73%; p<0.001; W54: 17.78% vs 20.83% ; p=0.004), and also a significant moderate to high correlation between BWT measured by IUS and MRE on both timepoints (W0:r=0.34, p=0.02; W54:r=0.58; p<0.001). The correlation was higher when the MAS was the ileum (W0 and W54: r=0.65, p<0.001). Conclusion We found a moderate to good agreement in the selection of MAS between IUS and MRE. There was also a moderate correlation between BWT measurements and detection of complications between the two methods, which increased when the MAS was the ileum. Our results suggest that IUS, a readily available and inexpensive tool, is accurate to evaluate disease activity and treatment response, particularly in patients with ileal disease.