It is better to use MRI for cerebral infarction because a portion of cerebral infarction within 48 hours is not visualized on CT. It is possible to assess the location and size of the lesion, and the corresponding treatment such as thrombolysis, antiplatelet aggregation, anticoagulation and blood circulation can be given according to the patient’s condition. At the same time, MRI is free of radiation, while CT uses the principle of X-ray imaging, which has a certain amount of radiation to the human body. CT is good for patients in the acute stage of cerebral infarction, and MRI is also clearer than CT for review in the post-infarction period. Because CT examination, especially the posterior cranial fossa lesions will have cranial artifacts, which are not sufficiently clear, while MRI can show the medulla oblongata, cerebral bridge and cerebellar lesions clearly.