Before the enhancement CT examination, it is usually necessary to do an iodine allergy test on the patient because some patients will have an allergic reaction to iodine contrast agent, and the patient’s allergy history should be asked in detail. Generally, 1mL of water-soluble organic iodine contrast agent is used, which is injected intravenously and observed for about 20 minutes, and the patient has no allergic reaction before the enhancement examination can be performed. The enhancement test is performed by selecting a certain amount of contrast agent according to the patient’s specific location and injecting it through the patient’s elbow vein or the vein on the back of the hand. A high-pressure syringe is used to inject the contrast agent, and the specific time, dose, and speed are chosen according to the injection site. After the contrast is injected, an enhancement scan is performed. After the scan, the patient is observed in the observation room for about 30 minutes and is allowed to leave when there are no abnormal symptoms.