To look at the brain CT film: 1. we need to see whether the brain is symmetrical bilaterally, whether the midline is centered, and whether there is displacement. 2. we need to see whether there is widening or shallowing of the cortical sulcus and gyrus; if there is widening of the sulcus and gyrus, for young patients, the presence of brain atrophy may be considered; if there is shallowing of the sulcus and gyrus, it may be related to brain edema caused by increased intracranial pressure. 3. we also need to look at the brain parenchyma and The morphological structure of the ventricles and brain pools, whether there is pressure on the ventricles or brain parenchyma, and whether there are high-density or low-density lesions in the cortical area and white matter area on the CT film. If there are high-density lesions, brain hemorrhage may be present, and some patients may have calcified foci. If there are hypodense foci in the cortex or white matter of the brain, consider that the first one may have infarction and the second one is inflammation.