Development and validation of a novel intestinal ultrasound score for predicting endoscopic activity of ileocecal ulcers in intestinal Behçet's disease.

BACKGROUND

No diagnostic criteria have been established to specifically evaluate the activity of intestinal lesions in Behçet's disease (BD). We aimed to identify intestinal ultrasound (IUS) parameters that were correlated with endoscopic ulcer activity, as well as develop and prospectively validate an IUS activity score for patients with intestinal BD.

METHODS

Patients who underwent colonoscopy and IUS within 2 weeks during 2007-2019 were retrospectively included in the development phase. Correlations between corresponding endoscopic activity and seven IUS parameters [bowel wall thickness (BWT), vascularity, bowel wall stratification, white-plaque sign, mesenteric lymphadenopathy, extramural phlegmons, and fistulas] based on 73 examinations and were assessed. We created an IUS activity score with a multivariate logistic regression model and inter-observer assessment. This score was prospectively validated in a new cohort (2020-2024).

RESULTS

Among seven IUS parameters, only BWT (p = 0.001) and vascularity (p = 0.004) were significantly associated with endoscopically active disease, with high inter-observer agreement confirmed (intraclass correlation = 0.98, weighted kappa = 0.83, respectively) in the development phase. The IUS score for ileocecal ulcers in intestinal BD (IUS-BD) was developed based on 2*BWT + 5*vascularity. With a cutoff ≥ 16 points, IUS-BD could detect active ileocecal ulcers (sensitivity 84.6%, specificity 91.2%, and accuracy 87.7%). In the validation cohort including 17 IUS examinations, the IUS-BD was significantly increased in the endoscopically active disease (p = 0.024), with high diagnostic performance (sensitivity 84.6%, specificity 100%).

CONCLUSIONS

We developed and preliminarily validated a novel ultrasonographic score for intestinal BD to identify endoscopically active disease.