Findings in Magnetic Resonance Enterography and Experience With Maria Score Assessment in a Colombian Inflammatory Bowel Disease Referral Center: Observational Study

Background: Endoscopy has been considered one of the gold standards for diagnosis and follow-up in inflammatory bowel disease (IBD); however, it provides little access to the small bowel and is limited in identifying extra-luminal lesions. MR enterography has proven its value for the evaluation of IBD and is nowadays one of the imaging modalities of choice for the initial and follow-up evaluation of IBD, it has a sensitivity and specificity for IBD similar to CT enterography. The objective is to describe MR enterography findings in patients with IBD. Methods: Descriptive observational cross-sectional study in patients diagnosed with IBD evaluated with MR enterography. For MR enterography, we used a 1.5T resonator, oral contrast with a biphasic hyperosmolar agent, preparation with soft diet. Images were obtained in decubitus. We performed FIETA sequences, fast T2-weighted sequences with and without fat saturation, dynamic LAVA study after intravenous contrast administration, diffusion sequence and CINE sequences. We also used hyoscine N-butyl-b for antispasmodic effect during the study. For the reading of enteroresonance, a specific scheme was established for the signs of acute inflammation, dividing them into mural findings, extramural findings, chronic fibrostenotic signs and signs of chronic reparative-regenerative process, also including the extraintestinal findings within the description. The MARIAs index was applied in 12% of the patients taking into account the following items (MARIAs = (1 × thickness >3 mm) + (1 × edema) + (1 × fat striae) + (2 × ulcers)). Results: Of the 74 patients, MRI enterography was performed in 30% with suspected Crohn’s disease. Among the findings, mural involvement predominated, with greater involvement of the ileum (32%), followed by the sigmoid colon, with an average extension in the ileum of 37 mm and an average parietal thickening of 5.7 mm. For extramural findings, the presence of free fluid, alteration of the mesenteric fat signal, vascular alteration (comb sign) and mesenteric adenopathies were established, with predominance of mesenteric fat alteration and mesenteric adenopathies (57%). For chronic fibrostenotic signs, the most compromised intestinal segment was the ileum, with the main finding being diffuse parietal thickening, as well as mesenteric fibrotic changes (21%). Regarding chronic reparative-regenerative signs, the main findings were absence of connivent valves and mesenteric fibrotic changes (14%). In 36% there were no findings related to IBD. Calculadora del índice de actividad de resonancia magnética simplificada (MARIAs) para la enfermedad de Crohn was performed with punctuation of 0 in the 20%, 1 in the 20%, 3 in the and 20% with a score of 5. Conclusions: MR enterography is the imaging modality of choice for the initial and follow-up evaluation of IBD, in our cohort it allowed the study of mural and extramural findings differentiating active inflammatory pathology, chronic fibrostatic changes and signs of chronic reparative-regenerative processes, in addition to its complications, it also allows the evaluation of Crohn’s disease activity by means of the MARIASs index.