Clinical Report: ESR Guidelines on Imaging in Luminal Crohn’s Disease Diagnosis and Treatment

Overview

Cross-sectional imaging, particularly MR Enterography (MRE) and intestinal ultrasound (IUS), plays a pivotal role in diagnosing and monitoring luminal Crohn’s disease (CD). These modalities accurately assess disease activity, phenotype, and treatment response, facilitating a treat-to-target approach and multidisciplinary communication.

Background

Crohn’s disease is a chronic, relapsing inflammatory condition affecting any part of the gastrointestinal tract, most commonly the terminal ileum. Traditional endoscopy, while the reference standard, has limitations in assessing transmural and extramural disease. Cross-sectional imaging techniques such as MRE, IUS, and CT provide comprehensive evaluation of bowel wall and surrounding tissues, enabling better disease characterization and monitoring. The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) guidelines emphasize standardized imaging protocols and reporting to optimize patient management.

Data Highlights

Key Findings

• MRE and IUS are accurate, well-tolerated first-line imaging modalities for luminal CD diagnosis and monitoring, with MRE superior for assessing disease extent.
• CT is reserved mainly for acute or emergency settings due to ionizing radiation exposure.
• Validated imaging signs of active inflammation include bowel mural thickening, mural and perimural oedema, ulceration, and hypervascularity.
• Chronic disease features such as fibrosis, fat deposition, and smooth muscle changes often coexist with active inflammation, requiring phenotypic assessment to guide management.
• Standardized reporting using ECCO-ESGAR terminology (transmural remission, significant response, stable disease, progressive disease) is recommended to enhance multidisciplinary communication.
• Cross-sectional imaging enables transmural and peri-enteric evaluation beyond the reach of endoscopy, supporting the treat-to-target strategy in CD management.

Clinical Implications

Clinicians should prioritize MRE and IUS for initial diagnosis and ongoing assessment of luminal Crohn’s disease to obtain accurate, objective measures of disease activity and phenotype. Structured imaging reports using standardized terminology facilitate clear communication within multidisciplinary teams, aiding treatment decisions and monitoring response. CT should be reserved for acute scenarios to minimize radiation exposure.

Conclusion

Cross-sectional imaging is integral to the diagnosis, phenotyping, and treatment monitoring of luminal Crohn’s disease. Adherence to ESGAR guidelines ensures optimal imaging selection, standardized reporting, and improved patient outcomes through a treat-to-target approach.

References

1. ESGAR 2024 -- Key Insights on ESR: Evaluating Diagnosis and Treatment Response in Luminal Crohn’s Disease