Holding urine for b ultrasound is good for checking the bladder, and for women it is good for checking the uterus. Bladder examination needs to hold urine, after filling the bladder in addition to better examination of the pelvic organs and the internal structure of the bladder, but also through the examination process to let the patient urinate after observing the remaining urine to determine the function of the bladder, hold urine to the degree of to have to have the feeling of urination is good. Too much or too little urine in the bladder is a no-no and may affect the test results. The female uterus is located in the pelvis with the bladder in front of it and the bowel on either side. When the bladder is held, the bowel can be pushed open on both sides, and the urine in the bladder can form a good window of translucency, so that the uterus and adnexa behind the bladder can be shown more clearly. If the bladder is not full, the surrounding gas can mask the uterine signs and cannot truly reflect the uterus. In summary, some ultrasounds require urine holding for better examination of the bladder, uterus and other organs.