[Value of quantitative examination via contrast-enhanced ultrasonography in evaluating the activity of Crohn disease at endoscopy].

Objective: To evaluate the predictive value of quantitative examination via contrast-enhanced ultrasonography on the activity of Crohn disease at endoscopy.

Methods: A total of 59 cases with Crohn disease in People's Hospital of Lishui City between January 2009 and December 2010 were collected prospectively and underwent both colonoscopy and contrast-enhanced ultrasonography. According to the Simple Endoscopic Score, Crohn disease was divided into inactive and active disease by colonoscopy. To assess the vascularization of the involved bowel loop in a region expected to be seen at colonoscopy, the contrast agent uptake was measured by using quantitative analysis. Measurement of contrast enhancement was assessed as the percentage of increase in wall brightness in regions of interest (ROI). The receiver operating characteristic curve was used to evaluate the value of contrast agent uptake in predicting the severity determined at endoscopy.

Results: Colonoscopy showed active lesions in 45 cases and inactive lesions in 14 cases, in whom the percentages of increase of brightness were (90±32)% and (41±29)% respectively. At a threshold value of 45% for the percentage of increase of brightness, sensitivity, specificity and accuracy of predicting the severity at endoscopy were 95.6%, 78.6% and 91.5%, the Youden index was 0.74, and area under curve was 0.846.

Conclusions: Quantitative measurement of bowel enhancement by using contrast-enhanced ultrasonography can discriminate between active and inactive Crohn disease at endoscopy. Contrast-enhanced ultrasonography may be a useful technique to monitor the activity of Crohn disease.