Abstract:

Objective

To analyze the correlation between international bowel ultrasound segmental activity score （IBUS-SAS） and endoscopic disease activity in patients with Crohn’s disease （CD）to provide external validation for IBUS-SAS.

Methods

A retrospective analysis was performed on 113 patients admitted to Zhejiang Provincial People’s Hospital from January 2022 to June 2024 with a clinical diagnosis of CD by intestinal ultrasonography and intestinal endoscopy. Bowel wall thickness （BWT）， color Doppler sign （CDS）， inflammation signals at the mesentery （i-fat）， and bowel wall stratification （BWS） were measured to yield IBUS-SAS. According to the Chinese clinical practice guideline on the management of Crohn’s disease （2023， Guangzhou）， the patients with CD were divided into endoscopic remission group（SES-CD＜3）， endoscopic mild activity group （SES-CD≥3 and ＜7）， and moderate to severe endoscopic activity group （SES-CD≥7）. The differences in IBUS-SAS， BWT， CDS， i-fat， and BWS among the groups were compared and analyzed by ANOVA. Spearman correlation was used to analyze the correlation of IBUSSAS， BWT， CDS， i-fat， and BWS with endoscopic activity in patients with CD， and receiver operating characteristics （ROC） curve analysis was performed to assess the predictive value of the above indicators for different endoscopic disease activity levels in patients with CD.

Results

The values of different indexes in the endoscopic remission group （31 cases）， endoscopic mild activity group （47 cases）， and endoscopic moderate to severe activity group （35 cases） were： IBUS-SAS ［（29.46±13.20） vs （53.33±14.89） vs（78.78±14.16）］， BWT ［3.9 （3.5， 4.7） vs 4.5 （3.5， 5.0） vs 6.4 （5.3， 8.3）］， CDS ［1 （0， 1） vs 1 （1， 2） vs 2 （2， 3）］，i-fat ［0 （0， 1） vs 1 （1， 2） vs 2 （2， 2）］， and BWS ［0 （0， 0） vs 1 （0， 1） vs 2 （1， 3）］； there was an increasing trend in these indexes with the increase of endoscopic disease activity， and the differences were statistically significant （F=99.25， Z=44.44， 41.60， 56.98， and 33.95， respectively； P＜0.001）. IBUS-SAS， BWT， CDS，i-fat， and BWS were significantly positively correlated with SES-CD （r=0.846， 0.642， 0.731， 0.658， and 0.615， respectively； P＜0.001）， and IBUS-SAS was highly correlated with SES-CD. IBUS-SAS， BWT， CDS，i-fat， and BWS in CD patients showed significant positive correlations with endoscopic disease activity（r=0.803， 0.606， 0.710， 0.609， and 0.550， respectively； P＜0.001）， among which IBUS-SAS had the strongest correlation with endoscopic activity in CD patients. ROC curve analysis showed that IBUS-SAS， BWT， CDS，i-fat， and BWS had predictive value on whether patients with CD had endoscopic disease activity， moderate to severe endoscopic disease activity， and mild endoscopic disease activity. The diagnostic efficiency of IBUSSAS was significantly higher than that of BWT， CDS， i-fat， and BWS alone （P＜0.05）. In the stratification analysis of patients with endoscopic disease activity， IBUS-SAS， BWT， CDS， i-fat， and BWS had predictive value in distinguishing between mild and moderate to severe endoscopic disease activity in patients with CD， and the AUC of IBUS-SAS was significantly higher than that of CDS， i-fat， and BWS alone （P＜0.05），but had no significant difference with that of BWT （P＞0.05）.

Conclusion

IBUS-SAS is correlated with endoscopic disease activity in patients with CD， has high diagnostic value for endoscopic disease activity， and can be used as an early screening tool for disease activity in patients with CD. In CD patients with endoscopic disease activity， BWT can be used as a simple ultrasound indicator to evaluate disease activity in CD patients.

Key words: Crohn’s disease, Intestinal ultrasound, Score, International bowel ultrasound segmental activity score