Effectiveness of color Doppler ultrasound and shear-wave elastography for characterization of intestinal inflammation and fibrosis in Crohn's disease: A comparison with surgical histopathology analysis

Background & aims: Differentiation between predominantly inflammatory or fibrous strictures is particularly important to decide the optimal therapy in patients with refractory symptoms in Crohn's disease. The purpose of this research was to evaluate the accuracy of color Doppler US and Shear Wave Elastography in differentiating the degree of inflammation or fibrosis in ileal strictures in patients with Crohn's disease by comparing with resected bowel samples. Materials and methods: Preoperative ultrasound examination, including SWE, was performed in 30 consecutive patients with Crohn's disease undergoing elective bowel resection. Ultrasound variables, Shear Wave Elastography quantitative analysis and visual elastographic color map, were prospectively evaluated. Histopathology grading of acute inflammation using the acute inflammatory score and the degree of fibrostenosis was performed. Results: In pathology analysis there were 21 segments with severe fibrosis. The mean Shear Wave Elastography value of the stenotic bowel wall was significantly higher in severe fibrosis (3.56 ± 1.4 m/s) than in mild fibrosis (1.89 ± 0.75 m/s) (P = 0.004). Using 2.5 m/s as the cut-off value to discriminate between mild and severe fibrosis, the sensitivity and specificity was 76.2% and 100% with an area under the curve (AUC) of 0.889. The sensitivity and specificity of the visual assessment of the elastographic color map in differentiating severe from mild fibrosis was 82.4% and 88.9%. Conclusions: this study suggests that Shear Wave Elastography is accurate for detecting severe intestinal fibrosis in Crohn's disease patients. This information may be useful in the treatment strategy for CD.