Do ultrasound hold urine commonly used to check the urinary system, transabdominal gynecological ultrasound and transabdominal early pregnancy ultrasound, other parts of the ultrasound do not need to hold urine, as follows: 1, urinary system examination: the urinary system, including the bladder, ureters and prostate, especially to observe bladder lesions, you must have a good full bladder in order to see the wall of the bladder and the structure of the lumen; 2, transabdominal gynecological examination: such as uterus, accessory examination or early pregnancy ultrasonography All need to hold urine, so that the bladder is moderately full, the examination can be pushed away from the lower abdominal bowel, so as to avoid the bowel gas affect the image display. A full bladder is anechoic and serves as a good window of sound transmission, which improves visual resolution. In order to better display the clarity of the image, the bladder, prostate, uterus, adnexa and early pregnancy ultrasound need to hold urine, other parts of the ultrasound examination can not hold urine.