Diagnostic Value of Gastrointestinal Ultrasound (GIUS), Including Doppler and Contrast-Enhanced Ultrasound (CEUS), in the Assessment of Inflammatory Bowel Disease Activity: A Scoping Review

Background/Objectives: Treat-to-target management of inflammatory bowel disease (IBD) requires frequent, accurate assessment of disease activity. Endoscopy remains the reference standard, but its invasiveness limits repeated use, which has increased interest in gastrointestinal ultrasound (GIUS). To map the evidence on the diagnostic value of GIUS, including Doppler and contrast-enhanced ultrasound (CEUS), for IBD activity, with reference to endoscopy and serological/immunological biomarkers. Methods: This scoping review followed PRISMA-ScR. PubMed, Scopus, Web of Science and Embase were searched from January 2018 to March 2026, supplemented by reference-list screening. Two reviewers screened records independently. No formal risk-of-bias assessment was performed, and the synthesis was narrative. Results: Of 1284 records, 15 primary studies were included. Published meta-analyses report sensitivity of 85–91% and specificity of 83–96% for GIUS versus endoscopy; these are ranges from published sources, not estimates pooled by us. Bowel wall thickness (BWT) > 3 mm was the most frequently evaluated parameter. Color Doppler (Limberg grading) and CEUS added vascularity and perfusion information, and CEUS showed the highest reported accuracy in the meta-analytic literature, although data are limited. Combined GIUS–biomarker approaches reported accuracies of about 88–92% in single-center studies. Cytokine data (including IL-8) came mainly from non-GIUS studies and are hypothesis-generating. Conclusions: GIUS, alone or with biomarkers, is a promising complementary tool for monitoring IBD, mainly in moderate-to-severe disease. Because the evidence is heterogeneous, of unassessed quality and lacks randomized comparisons, it does not currently support replacing endoscopy or deferring it safely. Standardized protocols and randomized trials are needed.