Evaluation of Crohn's Disease Activity: Development of an Ultrasound Score in a Multicenter Study

Abstract

Objective: Our goal in this multicentric prospective study was 2-fold: first, to test the diagnostic accuracy of ultrasound, color Doppler imaging (CDI), and contrast-enhanced ultrasound (CEUS) in identifying disease activity in patients with Crohn's disease (CD) compared with endoscopy as the reference standard; and, second, to construct a sonographic score that allows disease activity to be detected.

Materials and methods: Seventy-two patients with CD from 3 hospitals underwent within a 30-day period both colonoscopy and ultrasound (US), including mural thickness, CDI, and CEUS, prospectively as part of clinical care. A multivariate analysis was carried out to assess the influence of each of the ultrasound variables in predicting endoscopic activity. We then developed a predictive ultrasound score for disease activity, and a receiver operating characteristic (ROC) curve was constructed to determine the area under the ROC curve (AUC) and the best cut-off score value to discriminate between active and inactive disease.

Results: Sonographic findings that were independent predictors of the presence of active disease at endoscopy were wall thickness, color grade, and contrast parameters. A score based on those variables showed high accuracy in predicting active disease, with an area under the ROC curve of 0.972. A simpler index, without contrast parameters, also showed high accuracy in detecting disease activity (AUC, 0.923).

Conclusion: A score based on wall thickness, color Doppler grade, and contrast parameters showed high accuracy in predicting active disease. A score without including the use of contrast agent had practically similar results and is easier to use in monitoring response to treatment.

Keywords: CEUS; Crohn’s disease; activity score; contrast-enhanced ultrasound; ultrasound.