Intestinal ultrasound in inflammatory bowel disease: current evidence and future directions.

Abstract

Purpose of review: Intestinal ultrasound (IUS) as a noninvasive tool for assessment and longitudinal monitoring of inflammatory bowel disease (IBD) is gaining attention. This review examines current evidence supporting the diagnostic performance and utility of IUS in IBD and explores expanding applications, use in special populations, and remaining gaps in knowledge.

Recent findings: Evidence supports its diagnostic accuracy in Crohn's disease (CD) and ulcerative colitis (UC). Bowel wall thickness (BWT) and vascularity through color Doppler signal (CDS) are among the most reliable markers of inflammation. IUS demonstrates utility for disease monitoring, assessment of treatment response, and prediction of long-term outcomes. Activity indices have been externally validated, demonstrating reproducibility. Beyond luminal assessment, transmural remission (TR) is emerging as a therapeutic target. Advanced techniques, including contrast-enhanced ultrasound (CEUS) and small-intestine contrast ultrasound (SICUS), may provide additional value in selected clinical scenarios, although their use remains limited to specialized settings.

Summary: IUS is an important practical tool in IBD, complementing endoscopy and biomarkers. Although diagnostic performance is well established, future work should focus on IUS-driven treatment strategies, validation of meaningful endpoints, and addressing barriers to implementation.