Comparison of Conventional versus Abbreviated MR Enterography: Assessing Disease Activity and Complications in Crohn Disease Rimola J, Anupindi S, Capozzi N, et al. Study group Radiology 2026; 319(2):e252039. https://doi.org/10.1148/radiol.252039
Crohn disease is a chronic inflammatory disease in which MR enterography (MRE) plays a vital role, both in diagnosis and in follow up (1). However, conventional MRE comes with long acquisition times, high cost, and a suboptimal patient experience, driven by dislike of oral contrast, issues associated with IV placement, contrast side effects, glucagon administration, and, not least, long scan times (2). As a result, there's been growing interest in stripping the protocol down to fewer sequences and omitting contrast altogether, since it is faster, cheaper, and easier on patients. Until now, however, there hasn't been strong evidence comparing this abbreviated approach (A MRE) to the full contrast enhanced protocol (CE MRE) in a real world, multireader setting. The study led by Rimola and colleagues, went a long way toward closing that gap. Ten abdominal radiologists, a mix of five novices and five experienced readers, were drawn from SAR's Small Bowel and Crohn's Disease Panel plus an international group. The A MRE protocol was built from three sequences extracted from the full exam, axial T2 weighted images with and without fat saturation, coronal T2 weighted single shot images, and coronal balanced steady state free precession images, leaving out the antiperistaltic injection and the pre and post gadolinium T1 weighted sequences. For each exam, readers scored eight bowel segments separately, three in the small bowel (jejunum, proximal or mid ileum, and terminal ileum) and five in the colon (rectum, sigmoid, descending, transverse, and cecum or ascending), for wall thickness, edema, ulcers, and fat stranding. Each reader read 80 MRE exams from 60 Crohn's patients twice, once as A MRE and once as full CE MRE, a month apart. Interreader agreement and intrareader concordance were evaluated to assess consistency between and within readers, respectively. Agreement for binary variables was quantified using the Gwet first agreement coefficient (AC1), which adjusts for prevalence effects, with corresponding two-sided 95% CIs. The results were reassuring, showing that the two protocols performed very similarly across the board. For detecting active disease, interreader agreement was essentially the same whether readers used contrast or not, with an AC1 of 0.91 for CE MRE versus 0.87 for A MRE, and the confidence intervals overlapped comfortably. Strictures and penetrating disease showed the same pattern with substantial agreement with either protocol, and no real advantage for contrast. Specific findings like ulcers and fat stranding had weaker agreement, but this held true across both protocols.The same radiologist reading a case twice, with and without contrast, showed barely any change, with concordance ranging from 0.86 to 1.00, suggesting interpretation wasn't driven by gadolinium. The study also tested the sMaRIA scoring system, which was particularly relevant since sMaRIA was designed to work without contrast in the first place. Against ileocolonoscopy, A MRE detected terminal ileal inflammation with 96.4% sensitivity, close to the 98.4% seen with CE MRE. Specificity was similar too, around 68% for A MRE and 71% for CE MRE. The colon showed the same overall pattern, with sensitivity lower there than in the ileum, but again roughly equal between A MRE and CE MRE. By skipping the antiperistaltic injection and post contrast sequences, A MRE cut scan time by roughly 39%, so patients spent noticeably less time in the gantry. The authors were candid about a few nuances worth noting. The A MRE arm was simulated by pulling a subset of sequences out of full CE MRE exams rather than being acquired as its own protocol, so prospective studies with a truly shortened acquisition would help confirm these findings in practice. They also cautioned against dropping contrast entirely in every case, since A MRE may not reliably distinguish a inflammatory mass from a fluid collection, a distinction that can significantly affect patient management (3). For radiology departments managing Crohn's patients, this study makes an interesting case for A MRE in routine assessment of disease activity. It was simpler for patients, sparing them the added burden of contrast, and radiologist read it just as reliably as the full protocol. CE MRE still has a place, especially when complications need closer evaluation. | References
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