Purpose or Case Report: The objective of this prospective study was to determine the accuracy of MR Enterography (MRE) in the assessment of mucosal healing in patients with Pediatric Crohn’s Disease (PCD) after starting treatment. MARIA and Clermont scores are MRE scores that were originally developed in adult population for the assessment of severity of Crohn's Disease (CD) in correlation to Crohn's Disease Endoscopic Index of Severity (CDEIS). MARIA score has shown close correlation to disease severity of colonic CD and Clermont score has shown close correlation to terminal ileum disease. A few reports have shown correlation of mucosal heling when assess by MRE scores and CDEIS in Adult population, but not work is available in pediatrics.
Methods & Materials: 16 patients with PCD underwent ileocolonoscopy (IC) and immediately after MR Enterography (MRE) at the time of diagnosis or when biological treatment was going to be started (time 1). Each patient had a 12-week follow up with IC and MRE (time 2), in the same settings as was performed at time 1. MRE included multiphase fiesta, 3 planes SSFSE, 2 planes DWI b1000 and pre-contrast and post-contrast dynamic multiphase T1-fat sat weighted sequences. Endoscopic activity was evaluated based in the Short Endoscopic Score for CD (SES-CD). MRE scores were calculated based in the independent readings performed by two experimented Pediatric Radiologists who were blinded to the SES-CD. The assessment of the terminal ileum (TI) was separated from the large bowel that was divided in 6 segments. ICC for Maria and Clermont scores were calculated as well as ROC when compare with SES-CD. Correlation of the variation of MRE scores and variation of SES-CD between T1 and T2 where calculated for the assessment of mucosal healing.
Results: ICC in the TI was 0.33 for MARIA and 0.34 for Clermont. ICC in colon were 0.16-0.87 for MARIA and 0.27 - 0.96 for Clermont. No significant correlation was found between SES-CD and MRE scores in the colon. Spearman coefficient in the TI was 0.54 (p: 0.0039) for MARIA and SES-CD and 0.50 (p:0.0039) for SES-CD and Clermont. Spearman coefficient in the TI for assessing interval healing changes for MARIA was 0.47 (p: 0.069) and for Clermont was 0.48 (p:0.062).
Conclusions: Developed MRE severity scores are only valid for the assessment PCD in the terminal ileum. Assessment for mucosal healing is close to be significant, further recalculation in the ponderation of values for both scores may be beneficial for adequate assessment of healing in pediatric population.