Crohn's disease related strictures in cross‐sectional imaging: More than meets the eye?

Abstract

Strictures in Crohn's disease (CD) are a hallmark of long‐standing intestinal damage, brought about by inflammatory and non‐inflammatory pathways. Understanding the complex pathophysiology related to inflammatory infiltrates, extracellular matrix deposition, as well as muscular hyperplasia is crucial to produce high‐quality scoring indices for assessing CD strictures. In addition, cross‐sectional imaging modalities are the primary tool for diagnosis and follow‐up of strictures, especially with the initiation of anti‐fibrotic therapy clinical trials. This in turn requires such modalities to both diagnose strictures with high accuracy, as well as be able to delineate the impact of each histomorphologic component on the individual stricture. We discuss the current knowledge on cross‐sectional imaging modalities used for stricturing CD, with an emphasis on histomorphologic correlates, novel imaging parameters which may improve segregation between inflammatory, muscular, and fibrotic stricture components, as well as a future outlook on the role of artificial intelligence in this field of gastroenterology.

Fibro-Stenosing Crohn’s Disease: What Is New and What Is Next?

“…Despite substantial heterogeneity in defining fibro-stenotic strictures, the fundamental elements for radiological definition are luminal narrowing, bowel wall thickness, and the presence of pre-stenotic dilation [28][29][30]. The CrOhN's disease anti-fibrotic STRICTure therapies (CONSTRICT) group provided accurate criteria for each item, defining the luminal narrowing as >50% compared to an adjacent healthy bowel tract, the bowel wall thickening as a 25% increase in wall thickness compared to the adjacent healthy bowel Additionally, this process self-perpetuates through intense epithelial-to-mesenchymal transition: it has been demonstrated that endothelial and epithelial cells can change phenotype and contribute to the ECM deposition [20].…”

Changing paradigms in management of inflammatory bowel disease

“…In this field, Wang et al 8 provided an update on cross-sectional imaging advances including magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) for IBD management, including extraluminal lesion detection, evaluation of complications, therapeutic response assessment, and outcome prediction. In addition, Sleiman et al 9 emphasized the novel cross-sectional imaging parameters used for the characterization of stricturing CD, including differentiation between inflammatory, muscular, and fibrotic stricture components.…”

“…It is expected that IBD management will soon benefit from the advances in the field of artificial intelligence (AI), which has a powerful ability in information processing and has already revolutionized many areas of medicine 10 . The modalities and impact of the implementation of AI in endoscopy and cross‐sectional imaging modalities on the clinical management of IBD have been already discussed in several invited reviews 7–9 …”

“…In addition, Sleiman et al. 9 emphasized the novel cross‐sectional imaging parameters used for the characterization of stricturing CD, including differentiation between inflammatory, muscular, and fibrotic stricture components.…”

“… 10 The modalities and impact of the implementation of AI in endoscopy and cross‐sectional imaging modalities on the clinical management of IBD have been already discussed in several invited reviews. 7 , 8 , 9 …”