To do a head MRI, foreign objects in the head and on the body surface, such as earrings, dentures, braces, wigs, etc., are removed. Patients with electronic devices such as pacemakers, cochlear implants, etc., who are suspected of having a metallic foreign body in the eye should not have an MRI because it may damage the instrument. A metallic foreign body inside the eye may cause displacement and cause further damage to the eye. If there is a metallic foreign body in the body, such as a stent or a spring coil, inform your doctor so that the examining physician can evaluate whether an MRI can be done. MRI is not recommended for pregnant women in their third trimester of pregnancy, and MRI can be done in the middle and late stages of pregnancy. When doing magnetic resonance examination, the patient must cooperate, head motionless, otherwise it will produce motion effects, artifacts affect the examination effect. Enhanced scanning, because the patient has a certain allergic reaction, the requirement must be fasting, in order to prevent the occurrence of vomiting, vomit will be sucked into the trachea to cause choking, respiratory asphyxia and other adverse diseases. When you are done with the MRI, do not rush to leave, but observe for 20 minutes in case there is an allergic reaction. It is also required to make the patient drink a lot of water in order to get the contrast agent out of the body as soon as possible.