MR enterography in small bowel diseases, adding multipoint Dixon sequence, is it worth?

Abstract

Abstract Background MR enterography (MRE) has been increased in the last decade as a modality of choice in diagnosis and evaluation of small bowel diseases in both children and adults. Lacking ionizing radiation, non-invasiveness, excellent soft tissue resolution, adequate luminal distension of small bowel loops are the advantages of this technique. Acquisition of images was used to be: T2WI, steady-state free precession, and T1WI, fat-suppressed gadolinium contrast-enhanced sequences. Multipoint Dixon sequence was added recently to the routine MR enterography protocol. The current study aimed to evaluate the added value of multipoint Dixon sequence as a valuable modification of MR enterography protocol for better assessment of small bowel lesions as activity of Crohn’s disease, small bowel polyps, fibrotic strictures, with modification of MRE protocol in the future with less time consumption and better radiological evaluation. Methods The current research was a prospective cross-sectional study. Data were collected prospectively after getting ethical approval from the ethical committee of the faculty of medicine, in our university. Study population The sample size was 69 adult patients with suspected small bowel lesions, within the period from January 2022 to 30th December 2022. Written informed consent was obtained from all studied cases before the study, who were enrolled in this study. This number was calculated by using MedCalc 19 program by setting alpha error significance of 0.05%, 95% confidence level, and 80% power sample. Results This study enrolled 69 patients with recurrent abdominal pain and/or bleeding in stool. The patients’ age ranged from 18 to 50 years, with a mean of 32.6 ± 8.8. There is slightly higher female prevalence. The most common positive imaging findings in the studied patients were mucosal thickening in terms of submucosal fat deposition (36.23% of the MRE examination and 39.13% of the MRE with added Dixon sequence). Adding Dixon sequence yielded significantly higher AUC (97.2% vs. 90.5%, p = 0.047), higher sensitivity (100% vs. 92.16%), specificity (94.4% vs. 88.89%), accuracy (98.55% vs. 91.3%), positive predictive value (98.08% vs. 95.92%), and negative predictive value (100% vs. 80%). Conclusions MRE is an excellent imaging modality in the assessment of small bowel diseases without the use of ionizing radiation. Developing MR-based sequences as multi-point Dixon sequence have the potential to improve the ability of MRE to image the subtle changes as Crohn’s accompanying early inflammatory changes and fibrosis, as well as small intestinal polyps. Familiarity with MR enterography is essential for radiologists and gastroenterologists who participate in the clinical management of small intestinal diseases.

Keywords

• MR enterography
• Crohn’s disease
• Small bowel diseases
• Polyps
• Dixon sequence
• Inflammatory bowel diseases (IBD)