Introduction

Crohn disease is a chronic, relapsing inflammatory bowel disease that requires lifelong monitoring. Because symptoms correlate poorly with the true burden of intestinal inflammation, objective imaging has become essential for assessing disease activity and guiding treatment. MR enterography (MRE) is central to that effort: it is noninvasive, radiation-free, and shows both the bowel wall and the complications beyond it, such as strictures, fistulas, and abscesses. Patients are imaged repeatedly over the course of their disease, so the efficiency of each examination matters. The standard protocol uses intravenous gadolinium and an antiperistaltic agent, which add time and cost and require intravenous access. That raises a practical question: can we shorten the examination by omitting contrast without losing the information clinicians depend on?

Background / Clinical Context

A standard MRE protocol combines T2-weighted and balanced steady-state free precession (SSFP) sequences with contrast-enhanced T1-weighted imaging obtained before and after gadolinium, usually after an antiperistaltic agent. The contrast-enhanced sequences are valued for showing how the bowel wall enhances after gadolinium, which can help gauge active inflammation.

Abbreviated, noncontrast protocols — typically T2 and balanced SSFP alone — have been proposed to simplify the examination, and prior work suggests that omitting gadolinium may not meaningfully reduce accuracy for detecting inflammation. Less clear has been reproducibility: whether different radiologists interpret an abbreviated protocol consistently, and whether the same radiologist reaches the same conclusion with and without contrast. This question of reproducibility matters most for serial monitoring and for structured scoring systems such as the simplified Magnetic Resonance Index of Activity (sMaRIA), which are used to track disease over time.

Study Overview

Citation. Rimola J, Anupindi SA, Dane B, et al. Comparison of Conventional versus Abbreviated MR Enterography: Assessing Disease Activity and Complications in Crohn Disease. Radiology. 2026;319(2):e252039.

Purpose. To compare reader agreement — both between radiologists (inter-reader) and within the same radiologist (intra-reader) — when detecting Crohn disease activity and complications using an abbreviated, contrast-free protocol (A-MRE) versus the full contrast-enhanced protocol (CE-MRE). A secondary aim assessed the diagnostic accuracy of the sMaRIA score against ileocolonoscopy.

Methods. This was a retrospective, single-center secondary analysis of 60 patients and 80 examinations (51 before biologic therapy, 29 at the week-46 follow-up). The abbreviated examinations were simulated: rather than being acquired separately, the axial and coronal T2-weighted and balanced SSFP images were extracted from each full CE-MRE study, so the two versions differed only in whether the T1 sequences, acquired before and after gadolinium, were available. Ten abdominal radiologists from the United States, Europe, and Iran — five with eight or fewer years of experience and five with more — read every examination, blinded to clinical data, in two rounds at least one month apart. Agreement on binary findings was measured with Gwet’s AC1; continuous scores used the intraclass correlation coefficient. Diffusion-weighted imaging was not included.

Results. For detecting active disease, inter-reader agreement was almost perfect and comparable between protocols — 0.91 for CE-MRE and 0.87 for A-MRE — with overlapping confidence intervals, and it did not differ meaningfully between less- and more-experienced readers. By feature, agreement was highest for wall thickening, substantial for edema and penetrating disease, and lower for ulcers and fat stranding in both protocols. Intra-reader concordance was high throughout (0.86–1.00). The sMaRIA score showed comparable reliability across protocols; against ileocolonoscopy, its accuracy was high in the terminal ileum but lower in the colon — a pattern that tracked the bowel segment rather than the protocol. Omitting the contrast sequences reduced scanning time by about 39.5%.

Clinical Implications

For routine surveillance, a contrast-free protocol is appealing: it shortens the examination, removes the need for intravenous access and gadolinium, and could make frequent monitoring more feasible. The reproducibility data are reassuring — abbreviated reads were as consistent as contrast-enhanced reads across an international, mixed-experience panel.

Two cautions temper the interpretation of these findings. First, the primary endpoints measured agreement, not accuracy; high agreement means readers were consistent, not necessarily correct, because most comparisons lacked an independent reference standard. Where accuracy was tested, sMaRIA performed less well in the colon. Second, contrast enhancement still carries important diagnostic information — it can aid in distinguishing inflammation and fibrosis and the detection of subtle penetrating disease. Taken together, these findings suggest that abbreviated MRE may have a role in routine disease monitoring, while contrast-enhanced examinations may remain valuable in selected clinical scenarios, particularly when complications are  equivocal cases.

Key Takeaways

• Abbreviated, contrast-free MRE achieved almost-perfect inter-reader agreement, comparable to contrast-enhanced MRE, for detecting active Crohn disease.
• Agreement held across reader experience and an international panel, and intra-reader concordance was high (0.86–1.00).
• Where accuracy was assessed, sMaRIA was strong in the terminal ileum but weaker in the colon, reflecting the segment rather than the protocol.
• Dropping contrast cut scanning time by roughly 40%, supporting a possible tiered, contrast-when-needed approach.

Conclusion

In this study, an abbreviated, contrast-free MRE protocol was read as reproducibly as the full contrast-enhanced protocol for assessing Crohn disease activity and complications, while cutting examination time substantially. That is an encouraging result for streamlining routine monitoring. Because the work was single-center and the abbreviated exams were drawn from the full studies rather than acquired on their own, prospective, multicenter validation will be the natural next step, ideally incorporating diffusion-weighted imaging and independent reference standards. Contrast will likely remain valuable for selected questions, but a leaner, contrast-free protocol may represent a promising approach for routine disease monitoring pending.  is a credible direction for everyday monitoring.

References

1. Rimola J, Anupindi SA, Dane B, et al. Comparison of Conventional versus Abbreviated MR Enterography: Assessing Disease Activity and Complications in Crohn Disease. Radiology. 2026;319(2):e252039.
2. Ohliger MA. Is Contrast Necessary? Radiology. 2026;319(2):e261101.
3. Fernàndez-Clotet A, Sapena V, Capozzi N, et al. Avoiding contrast-enhanced sequences does not compromise the precision of the simplified MaRIA for the assessment of non-penetrating Crohn’s disease activity. Eur Radiol 2022;32(5):3334–3345.
4. Jhaveri KS, Sagheb S, Guimaraes L, Krishna S, Ahari AF, Espin-Garcia O. Evaluation of Crohn disease activity using a potential abbreviated MRE protocol consisting of balanced steady-state free precession MRI only versus full-protocol MRE. AJR Am J Roentgenol 2021;216(2):384–392.
5. Jannatdoust P, Valizadeh P, Razaghi M, Rouzbahani M, Abbasi A, Arian A. Role of abbreviated non-contrast-enhanced MR-enterography in the evaluation of Crohn’s disease activity and complications as an alternative for full protocol contrast-enhanced study: a systematic review and meta-analysis. Res Diagn Interv Imaging 2023;6:100030.