Do full abdominal CT scan before to do some preparation, mainly in the following aspects: 1, in the day before the scan, the diet as far as possible to eat liquid diet, or vegetarian pasta, such as noodles, thin rice or bread, as little as possible to eat greasy things and vegetables, because these things are easy to accumulate, the gastrointestinal tract excretion is relatively difficult to do abdominal CT will be affected; 2, in the day of scanning fasting, must be as far as possible in the morning fasting to do the examination, because the fasting situation can put the gastrointestinal stuff excretion is relatively clean, so the whole abdomen CT scan in the morning fasting, so the whole CT scan in the morning fasting. The day of the scanning fasting, must as far as possible in the morning fasting to do the examination, because the case of fasting, can be inside the gastrointestinal excretion of things relatively clean, so the whole abdominal CT scan as far as possible to fasting in the morning, and in the scanning of the 40-50 minutes before to drink a large amount of water, generally drink one thousand to two thousand milliliters of water, the whole gastrointestinal tract to fill up; 3, if it is to see the pelvic examination should be held urine.