If the patient is having a CT scan of the liver, the patient does not need special preparation, as long as he or she has not had a barium meal contrast within the last week, in addition, when doing the examination, he or she should cooperate with the muzzle of the machine, requiring the patient to cooperate with good inhalation and closure of breath, if he or she is having a CT enhanced liver examination, the meal before the examination needs to be fasted. In addition, we need to clarify the patient’s medical history and allergy history, we need to clarify whether the patient has severe hyperthyroidism or allergy to iodine contrast agent, if the patient has these two conditions, then you can not do the liver enhancement CT. in addition, patients taking metformin drugs, generally need to stop the drug 48 hours before you can do the liver enhancement CT, specific examination technical details, it is recommended to consult the CT room medical staff.