What kind of effect or the size of the effect on the patient’s body is related to the patient’s physical condition and the basic state of the body. Because of the use of contrast agents on patients when doing enhanced CT, a small portion of them will have allergic reactions to contrast agents, which are not a big problem in mild cases and do not affect the examination, and these reactions will disappear soon after the examination, but if there is a moderately severe allergic reaction, then the patient needs to stop the examination immediately, and first aid treatment is needed. Since the contrast agent is metabolized by the kidneys, patients may develop contrast nephropathy, especially elderly patients and patients with underlying renal disease, so it is recommended that patients after an enhanced CT must drink a lot of water to promote the excretion of the contrast agent from the body as soon as possible. Before doing CT enhancement examination, it is recommended to do a renal function test is appropriate.