1, liver, gallbladder, pancreas, abdominal cavity and retroperitoneal lymph nodes should be examined after fasting (12 hours of fasting and water fasting), otherwise the ultrasound image may not be displayed clearly due to eating, and the diagnosis may be missed and misdiagnosed. 2.For examination of bladder, pelvis and uterine ovaries, please drink 600-800ml of water first and then wait for the bladder to fill up before examination, otherwise the above organs will not be displayed well due to intestinal gas obscuration. 3, ultrasound examination needs to expose the skin of the examination area, for convenience, please do not wear a dress to perform the examination. Please wear low-neck underwear for neck examination.