How to identify cerebral edema on a brain CT scan

Check the CT scan for cerebral edema by observing whether there is a surrounding rim of low-density shadow around the lesions of cerebral infarction or hemorrhage. This edematous ring forms because, during the acute phase of cerebral infarction or hemorrhage, local ischemia places the brain cells surrounding the lesion in a state of ischemic hypoxia and near death. These cells shrink and leak fluid, resulting in an edematous zone, clinically known as the ischemic penumbra. In fact, when treating acute cerebral infarction or hemorrhage, we often aim to improve collateral circulation and rescue these濒临 dying cells, thereby maximizing the recovery of brain function.