COMPARING MAGNETIC RESONANCE ENTEROGRAPHY AND ENDOSCOPY FINDINGS TO QUANTATATIVE MAGENTIC RESONANCE IMAGING IN PEDIATRIC CROHN’S DISEASE

Abstract

Abstract BACKGROUND In pediatric Crohn’s disease, endoscopy has remained the gold standard for diagnosis; however, Magnetic Resonance Enterography (MRE) is able to show inflammation of the bowel that a gastroenterologist cannot reach with endoscopy. For a standard MRE, a patient needs to ingest oral contrast, receive intravenous (IV) contrast and a spasmolytic agent, and hold his/her breath during portions of the study, which can be challenging in younger children. As shown in previous studies, quantitative Magnetic Resonance Imaging (MRI) can evaluate bowel motility in children with Crohn’s disease, showing that as motility decreases in the bowel, inflammation increases. A motility score obtained from GIQuant software (Motilent, UK) may allow existing MRE protocols to be shortened and can be done with free-breathing techniques and without IV contrast and the spasmolytic agent. AIM Our primary aim is to demonstrate that quantitative MRI, which uses the cine image to develop a motility score from GIQuant software, is as effective as standard MRE in assessing inflammation of the bowel. We secondarily hypothesize that the motility score will inversely correlate to the Endoscopic Biopsy Acute Histologic Inflammatory Score (eAIS), the Crohn’s Disease Endoscopic Index of Severity (CDEIS) score, and the MR Index of Activity (MaRIA) score. METHODS This was a retrospective study of 50 pediatric patients from Children’s Wisconsin with ileal and/ or cecal Crohn’s disease who underwent endoscopy and MRE within 7 days of each other without exposure to therapy. Cine images were used from patients’ previously obtained MREs to obtain a motility score using GIQuant. A cine image and GIQuant map example is shown in Figure 1. The relationships between motility score and MaRIA, eAIS, and CDEIS were then calculated by Spearman’s rank correlation coefficient (ρ). RESULTS MaRIA and motility scores inversely correlated (ρ = -0.66, p <.0001), which is seen in Figure 2. MaRIA positively correlated with CDEIS (ρ = 0.30, p= 0.03) and eAIS (ρ = 0.26, p = 0.07). The motility score showed a non-significant negative correlation with CDEIS (ρ = -0.17, p = 0.24) and eAIS (ρ = -0.23, p =0.11). CONCLUSION Quantitative MRI is as effective as standard MRE in identifying inflammation of the bowel in Crohn’s disease. The cine image is obtained much faster than standard MRE and without the use of intravenous contrast, spasmolytic agent, and breath-holding techniques, which is crucial for children who are too young to cooperate with current MRE protocols. Figure 1 MRE cine image with the Region of Interest in the terminal ileum identified via the polygon and the resulting Motility Map produced by GIQuant Figure 2 MaRIA and Motility scores of each patient in our cohort