Objective Intestinal ultrasound (IUS) and magnetic resonance enterography (MRE) are state-of-the-art modalities recommended for monitoring Crohn’s disease (CD) activity and treatment response. This study aimed to examine the intermodality agreement for determining transmural response to medical treatment. Methods IUS and MRE performed in a prospective, blinded, multicentre study were included in the analysis. Patients with endoscopically active CD completed IUS and MRE before and after medical treatment. Observers were blind to the result of the other modality. Findings and disease classification at baseline, as well as the intermodality agreement for transmural treatment response, were determined. Results 35 patients entered the analysis. IUS and MRE detected 59 (24.1%) and 42 (17.1%) segments with active CD at baseline, respectively (p=0.001). Disease location and behaviour were determined with a moderate intermodality agreement (κ=0.48 and κ=0.43, p<0.01). Global IUS and MRE activity scores decreased after medical treatment (p<0.05), and repeated measurement correlations were weak to moderate. The intermodality agreement for transmural treatment response was fair to moderate: IUS versus Magnetic Resonance Index of Activity κ=0.43 (95% CI 0.13 to 0.73, p=0.006) and IUS versus Clermont score κ=0.31 (95% CI 0.01 to 0.60, p=0.026). Normalisation of bowel wall thickness occurred in 12 (34.3%) patients with MRE and 11 (31.4%) patients with IUS. The intermodality agreement was moderate (κ=0.42, 95% CI 0.10 to 0.74, p=0.007). Conclusion Transmural response and healing are determined with considerable variability. Maintaining consistency in imaging modality between assessments is essential to ensure an accurate interpretation. Trial registration number NCT03435016 .
Brodersen et al. (Sun,) studied this question.