答案解析:D FeedBack: There are normally 5 layers of the gut wall identified on the US exam. In the cross-sectional view, the bowel segment will have a bull's eye appearance (in the normal or abnormal patient). 在超声检查中,肠壁通常可以分为5层。在横切面上,肠段将呈现出牛眼状外观(无论是在正常患者还是异常患者中) Graded compression techniques are used to document compressibility expected from a normal segment. Color Doppler can be used to document peristalsis of a normally functioning segment. 分级压缩技术用于记录正常肠段的可压缩性。彩色多普勒可用于记录正常功能肠段的蠕动。 While fluid within the lumen is usually normal, any fluid in the walls or outside the segment (ascites) would be a sign of an abnormality. 虽然管腔内的液体通常是正常的,但管壁内或肠段外的任何液体(如腹水)都是异常的迹象。