Diffusion-weighted imaging in Crohn’s disease

Background Diffusion-weighted MRI (DWI) is routinely used in abdominal imaging. In addition to neoplastic diseases, inflammatory changes can be delineated and diagnosed based on diffusion restriction in DWI. DWI is also increasingly used in the context of MRI of the small and large intestine. Objective This article focuses on the technical aspects of DWI and its role in the diagnosis of Crohn’s disease (CD) as well as in the grading of disease severity and in treatment monitoring. Materials and methods Guidelines, basic research papers, and review articles were analyzed. Results Diffusion-weighted MRI is a specialized MRI technique that visualizes the diffusion of water molecules in biological tissues. In the context of MRI of the small and large intestine, DWI facilitates the diagnosis of inflammatory bowel disease and assessment of treatment response. DWI enables detection of not only intra- and transmural changes, but also extramural pathologies and complications. However, DWI also has its limitations and challenges. Conclusion This article provides a comprehensive overview of the use of DWI for diagnostic evaluation of bowel wall changes and extramural complications in the setting of CD. It also summarizes the relevant evidence available in the literature.