CT of the brain can detect cerebral infarction, but the positive rate of CT of the brain for acute cerebral infarction, especially diagnosed within 24 hours of onset, is low. MRI is needed, and functional brain imaging of MRI can be revealed for acute cerebral infarction within 2 hours. CT of the brain is clinically unrevealing for acute cerebral infarction in part. At the same time, for posterior circulation cerebral infarction, especially for medulla oblongata and pontine infarction, the cranial artifacts at the base of the skull are not particularly clear, so MRI is needed to confirm the diagnosis when necessary. Most of the lesions in post-infarction patients can be visualized on CT, and because they can become cerebral softening foci after infarction as the disease changes, CT can show cerebral softening foci. CT of the brain will be more sensitive to cerebral hemorrhage and can be visualized in the acute stage. Patients with symptoms of neurological deficits need to undergo CT examination to rule out brain hemorrhage, and further MRI can be done.