Detecting active inflammation and fibrosis in pediatric Crohn’s disease: prospective evaluation of MR-E and CT-E

Abstract

Symptoms of Crohn’s disease (CD) can be due to active inflammation or fibrosis. Differentiating these based on clinical presentation, endoscopy, laboratory parameters, and clinical scoring methods can be inaccurate and/or invasive. As therapy decisions are often directed based on whether active disease or fibrosis is present, a reliable and non-invasive test to distinguish these two etiologies would be a powerful clinical tool. CT enterography (CT-E) and MR enterography (MR-E) are two non-invasive imaging modalities tailored to evaluate the small bowel. The purpose of our study was to compare the ability of MR-E and CT-E to assess for active inflammation and mural fibrosis in patients with known CD as compared to a histologic reference standard. After obtaining MR-E and CT-E on the same day, a total of 61 histologic samples were obtained from twelve subjects aged 12–20 years via full-thickness bowel resection or endoscopy. These were evaluated by the pathologist for active inflammation and fibrosis. We found that while CT-E and MR-E were similar in their accuracies of depicting active inflammation, MR-E was significantly more sensitive in detecting fibrosis. Because of this and the lack of ionizing radiation from MR-E, we believe that MR-E rather than CT-E should serve as the primary imaging modality for the assessment of CD pediatric patients with non-acute clinical exacerbations.

MR enterography in Crohn’s disease: current consensus on optimal imaging technique and future advances from the SAR Crohn’s disease-focused panel

“…First, MRE has been shown to correlate with response to therapy and Abdominal Imaging mucosal healing and can be used serially to assess treatment response [8]. Additionally, although MRE and CTE detect active inflammation with equal efficacy, MRE has higher sensitivity for the detection of fibrosis, an essential differentiation that may affect patient management [9].…”

Role of imaging in the evaluation of inflammatory bowel disease: How much is too much?

“…MRE is the preferred study for evaluation of perianal disease and possible fistulas [34,35] . There is not a statistically significant difference between CTE and MRE in diagnostic accuracy for detecting active inflammation in IBD [36] . However, MRE is superior to CTE for differentiating bowel fibrosis from active inflammation (sensitivity 57% and 42%, specificity 82% and 68% respectively) [36] .…”

“…There is not a statistically significant difference between CTE and MRE in diagnostic accuracy for detecting active inflammation in IBD [36] . However, MRE is superior to CTE for differentiating bowel fibrosis from active inflammation (sensitivity 57% and 42%, specificity 82% and 68% respectively) [36] . The addition of diffusion weighted imaging on MRE has been shown to aid in identifying colonic inflammation and improve diagnostic confidence among children with IBD without the need for IV contrast [37,38] .…”

Quantitative apparent diffusion coefficient (ADC) values as an imaging biomarker for fibrosis in pediatric Crohn’s disease: preliminary experience

“…The majority of prior studies examining imaging evaluation of Crohn's disease focus on detecting active disease [2][3][4][5]. However, accurate imaging detection of mural fibrosis is just as important, not only because it is refractory to medical therapy [2], but also because it is an indication for mechanical therapy via endoscopy or surgery.…”