Figure 4. ROC of important US features, including intramural gas, portal venous gas, thickness increase, thickness increase, bowel dilatation, reduced inflation, and undetectable intestinal peristalsis. The associated factors were selected to calculate a novel variable US prognostic (USPro; intramural gas, portal venous gas, intestinal wall thickness, thickness increase, bowel dilatation, reduced inflation, decreased intestinal peristalsis, undetectable intestinal peristalsis, intestinal wall thickness, and thickness increase were numerical variables expressed in millimeter, and the other variables were categorical data that were valued 0 or 1, with 0=no and 1=yes). USPro had a much higher AUC (0.861) than other single features. To predict the third outcome (deteriorated), USPro showed a cutoff value of 0.96, with a sensitivity of 0.67 and a specificity of 0.88.