Ultrasound and MRI for Pediatric Crohn's Disease Assessment: Correlations of the MaRIA Score and IBUS-SAS with Endoscopic Disease Activity and Optimal Cutoff Values

Objectives To assess transmural damage in patients with Crohn's disease (CD), imaging techniques such as magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) are used. The Magnetic Resonance Index of Activity (MaRIA) and the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) are scoring systems for MRE and IUS, respectively. This study examined their correlation with the Crohn's Disease Endoscopic Index of Severity (CDEIS) in children with CD. Methods This was a retrospective analysis of children with new-onset CD who were treated from 2017–2022 at Zhejiang University Children's Hospital. Patients underwent IUS examination and IBUS-SAS scoring, MRE examination and MaRIA evaluation, colonoscopy and CDEIS calculation, and in addition, the PCDAI value was calculated. Blood samples were also collected for analysis. Nonnormally distributed data were analysed using Spearman's rank correlation coefficient. Results Forty-eight children were included in this study. The MaRIA and IBUS-SAS scores were positively correlated with the CDEIS value (r = 0.334 and r = 0.328, both p < 0.05). In the colon, the Spearman's rank correlation coefficient between the MaRIA score and the CDEIS value was 0.345 (P < 0.05), and that between the IBUS-SAS score and the CDEIS value was 0.501 (P < 0.05). The IBUS-SAS had an AUC of 0.655 for the prediction of moderate active disease (CDEIS ≥ 9), with a cut-off of 55.5. Conclusions Both the MaRIA and the IBUS-SAS scores are correlated with the CDEIS score in children with newly diagnosed CD. An IBUS-SAS score above 55.5 suggests moderate disease activity. IUS can serve as an alternative to MRE for disease activity assessment when MRE is not viable.