Systematic Review of Available Intestinal Ultrasound Scores for Inflammatory Bowel Disease and Update on Validation Studies

Background: Various intestinal ultrasound (IUS) scoring systems combining different measurable parameters have been designed for inflammatory bowel disease (IBD), both Crohn’s disease (CD) and ulcerative colitis (UC). We aimed to provide an extensive systematic review of all the IUS scores developed for both CD and UC, adding a particular focus on the subsequent validation studies. Methods: For the systematic search, the PubMed and EMBASE databases were screened from their inception until November 15, 2024. All articles proposing IUS scores for patients with IBD, both adults and children, were included. Results: A total of 6381 studies were identified, and 23 studies evaluating 23 scores were finally included in the systematic review. Fifteen and 6 studies included patients with CD and UC, respectively, while 3 included a pediatric IBD population. The gold standard for developing the IUS score was endoscopy in 83% of the studies. The most relevant parameters included into the scores were bowel wall thickness, vascularity, bowel wall stratification, and inflammatory fat. The pooled sensitivity, specificity, and accuracy of the included IUS scores were 68% to 100%, 57% to 100%, and 72% to 91%, respectively, in the development studies. Only 6 of 23 studies assessed the interrater agreement of the developed scores. Thirteen scores out of the 23 included in the systematic review underwent a validation, with only 7 having been validated in more than 2 different cohorts. Conclusions: IUS scoring systems are easy-to-use tools for standardizing communication among sonographers. Recent validation studies for a few scores have confirmed their applicability to daily IBD practice.