Acute cerebral hemorrhage is usually a little larger than the estimated amount of bleeding in the CT when the surgery is opened, because the brain is a closed environment after the hemorrhage, the bleeding itself has a compressive effect on the bleeding vessels to stop bleeding, when the cranial pressure disappears, the bleeding vessels will continue to bleed, which leads to the image bleeding is often less than the amount of cranial opening. Our common method is that if the lesion is still regular, the epidural hematoma bleeding volume (ml) = the maximum level of the lesion length × width × layer spacing × lesion layer × 0.5 (cubic centimeters), if irregular, then layer by layer calculation, layer by layer sum, to get the results, so then more accurate, but in the workload to be a little larger. Intracerebral, epidural hematoma hemorrhage (ml) = maximum lesion length × width × layer spacing × number of layers × 0.5 (cm3), if the layer spacing is 10 MM, then the formula can be simplified to hemorrhage = maximum lesion length × width × number of layers × 0.5. The measurement should not include the extent of edema. This formula cannot be used for subdural, intracerebroventricular, or subarachnoid hemorrhage.