A head MRI is relatively simple. The patient simply needs to cooperate with the physician by lying on the MRI machine platform and keeping his or her head as still as possible. If the patient’s head moves, the accuracy of the MRI will be affected and artifacts may be produced. MRI is very commonly used in clinical practice. Compared to CT, it shows lesions in the posterior cranial fossa more clearly, especially in early cerebral infarction, and the image is more adequate than CT. The non-invasive examination of MRI can clarify whether the patient has cerebral infarction, whether there are new lesions, intracranial occupations, and can make a rapid diagnosis of brain demyelination diseases. However, the environment is relatively loud and similar to an airtight environment when doing MRI, so patients must be psychologically prepared and avoid mental tension. Patients must not bring iron products to the MRI, and if they have a pacemaker or dentures, they must inform the doctor in advance.