The diagnostic imaging ultrasound is different from the echo of the substance, liquid and gas tissues. When filling the bladder, it is a liquid dark area on the sound image. The uterus is a parenchymal organ with a cavity, and in the sound image, the normal uterus is located in the dark area of the bladder, and the uterine wall is the parenchyma dark area. In conclusion, if the bladder is not filled to the ultrasound examination, it will cause the gas in the bladder to overlap with the gas in the uterus, causing misdiagnosis and missed diagnosis. Therefore, the ultrasonography often requires the patient to have an empty stomach and hold urine, which is a prerequisite for smooth inspection and is very important.
But not all gynecologic abdominal B ultrasound need a hold back urine, such as the following condition is not: after eight weeks of pregnancy, the uterus grow up into the abdominal cavity, the association with nature to the above, the uterus in amniotic fluid, the fetus will no longer need to suppress the urine has been observed at this time.