Assessment of stricturing Crohn's disease: Current clinical practice and future avenues

Abstract

Crohn's disease (CD) is a chronic remittent idiopathic disease. Although the early phase of the disease is commonly characterized by inflammation-driven symptoms, such as diarrhea, the frequency of fibrostenotic complications in patients with CD increases over the long-term course of the disease. This review presents the current diagnostic options for assessing CD-associated strictures. In addition to the endoscopic evaluation of CD strictures, this review summarizes the currently available imaging modalities, including ultrasound and cross-sectional imaging techniques. In addition to stricture detection, differentiating between the primarily inflammatory strictures and the predominantly fibrotic ones is essential for selecting the appropriate treatment strategy (anti-inflammatory medical treatment vs endoscopical or surgical approaches). Therefore, recent imaging advances, such as contrast-enhanced ultrasound and ultrasound elastography, contribute to the development of non-invasive non-radiating imaging of CD-associated strictures. Finally, novel magnetic resonance imaging techniques, such as diffusion-weighted, motility and magnetization transfer imaging, as well as (18)F-FDG PET/CT, molecular imaging approaches and biomarkers, are critically reviewed with regard to their potential role in assessing stricturing CD.

Keywords: 18F-FDG PET/CT CEUS; Computed tomography; Crohn’s disease; Elastography; Endoscopy; Inflammatory bowel disease; Intestinal stricture; Magnetic resonance imaging; Ultrasound.

Figure 1

Examples of ileal strictures. A, B: MR-enteroclysis of an ileal stricture (A: T2-weighted gradient echo sequence with fat saturation showing thickening of the affected segment. The inner lumen is reduced; B: T1-weighted sequence with intravenous gadolinium application and fat saturation. The Crohn’s disease (CD) -affected segment is thickened and shows increased contrast enhancement. Additionally, the intestinal vessels are extended); C: Computed tomography-enteroclysis of ileal strictures. The vascular “injection” in the CD-affected area is depicted (“comb sign”).