Dense shadows are seen in the brain as a result of the patient’s brain CT, which may be due to the presence of hematomas, calcifications, etc. in the brain. 1. Hematoma: Epidural or subdural hematoma formed due to trauma may show high density shadow in brain CT. 2. Calcification: including physiological calcification and pathological calcification, physiological calcification can be seen in normal population, mainly in choroid plexus of lateral ventricle, pineal gland, pallidum, etc., which needs no treatment. Pathological calcification is due to lesions, such as parasites, old hemorrhage, etc. The location of calcification foci is not fixed, and it will be manifested in the brain parenchyma, so high density shadow is seen in brain CT examination, and the cause needs to be identified and treated. Brain see high density shadow of the patient is recommended to further examination, after clarifying the cause of the disease, according to the doctor’s guidance for standardized treatment.