After a head injury, the main tests that need to be performed are CT and MRI, which are more commonly done, but not all patients with head trauma need to undergo CT and MRI. If the head injury is mild, and the patient has no serious clinical symptoms and the trauma is relatively minor, the patient can be observed and then undergo CT and MRI if necessary. However, if the patient has obvious neurological dysfunction or impaired consciousness after the head injury, it is necessary to go to the hospital for examination by a specialist and then arrange for the corresponding CT and MRI examinations.