Abstract Background Accurately diagnosing intestinal fibrosis is a critical unmet need for patients with Crohn’s disease (CD). Spatial heterogeneity of fibrosis may affect imaging tools’ diagnostic accuracy. To develop and validate a novel diagnostic strategy based on sub-regionalization into mesenteric and anti-mesenteric borders on MR enterography (MRE), for addressing diagnostic challenge posed by fibrosis heterogeneity. Methods This study included two surgical cohorts and a follow-up cohort, involving 184 CD patients. First, 12 patients who underwent preoperative MRE and surgery between January 2023 and December 2023 was prospectively recruited. Co-registration of MRE with ileal specimen was achieved for 88 sections, using 3D-printing and creeping fat information. Optimal multivariable MRE models were constructed for mesenteric border, anti-mesenteric border, and whole-circle regions, using histological fibrosis as reference. Their diagnostic ability was evaluated using area under ROC curve (AUC) and validated in another prospective surgical cohort involving 21 patients. The impact of this sub-regionalization diagnostic strategy on disease progression was compared in a retrospective follow-up cohort from two hospitals including 151 patients, using multivariate Cox regression analysis. Results Histological fibrosis scores were higher in mesenteric border than anti-mesenteric border regions in both surgical cohorts (both p.05). After dividing into sub-regions, the optimal MRE models showed the highest diagnostic efficacy in fibrosis for mesenteric border (AUC=0.91), followed by anti-mesenteric border (AUC=0.84) and whole-circle (AUC=0.77) regions in surgical cohort 1. In surgical cohort 2, MRE also showed higher efficacy in mesenteric border (AUC=0.87) than anti-mesenteric border (AUC=0.77) regions. In follow-up cohort, baseline fibrosis measurements in mesenteric border region (HR = 9.25) had the greatest impact on disease progression compared to other bowel regions (HR = 0.28-2.09). Conclusion Intestinal fibrosis demonstrates spatial heterogeneity. Intestinal sub-regionalization into mesenteric and anti-mesenteric borders improves MRE’s diagnostic effectiveness and may aid in predicting CD progression. References: 1. Bettenworth D, Bokemeyer A, Baker M, et al. Assessment of Crohn’s disease-associated small bowel strictures and fibrosis on cross-sectional imaging: a systematic review. Gut. Jun 2019;68(6):1115-1126. doi:10.1136/gutjnl-2018-318081 2. Rieder F, Fiocchi C, Rogler G. Mechanisms, Management, and Treatment of Fibrosis in Patients With Inflammatory Bowel Diseases. Gastroenterology. 2017;152(2):340-350.e6. doi:10.1053/j.gastro.2016.09.047 3. Li XH, Mao R, Huang SY, et al. Characterization of Degree of Intestinal Fibrosis in Patients with Crohn Disease by Using Magnetization Transfer MR Imaging. Radiology. May 2018;287(2):494-503. doi:10.1148/radiol.2017171221 4. Bruining DH, Zimmermann EM, Loftus EV, Jr., et al. Consensus Recommendations for Evaluation, Interpretation, and Utilization of Computed Tomography and Magnetic Resonance Enterography in Patients With Small Bowel Crohn’s Disease. Radiology. Mar 2018;286(3):776-799. doi:10.1148/radiol.2018171737 Conflict of interest: Ms. Wu, Luyao: No conflict of interest Lin, Jinjiang: No conflict of interest Zheng, Weikai: No conflict of interest Zheng, Qingzhu: No conflict of interest Shen, Xiaodi: No conflict of interest Huang, Lili: No conflict of interest Zhang, Ruonan: No conflict of interest Feng, Shi-ting: No conflict of interest Li, Xuehua: No conflict of interest
Wu et al. (Thu,) studied this question.