There is a clear difference between new-onset cerebral infarction and old-onset cerebral infarction on cranial CT images. For new-onset cerebral infarction, early tissue ischemia and hypoxia can be manifested as intracellular edema, and the tissue surrounding the infarction is blurred and irregular due to the swelling of the tissue cells, which is expected to be recovered after active medication, and the foci of infarction will be reduced after the edema is reduced. However, in the case of old cerebral infarction, the infarcted foci are relatively old, and the disappearance of intracellular edema is often accompanied by the generation of scar tissue and the proliferation of glial cells, so that the edges of the tissues are more regular and the borders are clearer.