Head trauma and CT with reference to epidural hematoma

Computed tomography (CT) is useful to detect lesions in patients with mild head trauma in its acute stage which may be followed by a lucid interval of hours to several days before exact diagnosis is made, or in serious patients with impairment in state of consciousness. Non-enhanced scan can determine the location of the lesion in 94% of patients with brain tumor, and enhanced scan can do in more than 98%. CT can reveal many anatomical changes due to trauma. Of these pathological changes, epidural hematoma is often caused by the damage of the middle meningeal artery or its branch. Therefore, CT should be performed if a bone-fracture line runs across the meningeal artery. CT is also applicable for the patients with some brain symptoms such as those who had not immediate post-traumatic unconsciousness but have developed impairment in state of consciousness after a lucid interval, or those who have persistent headache even if they have no impairment in stage of consciousness. In CT findings, the margin of hematoma and normal cerebral tissues is usually clear in acute causes but unclear in subacute cases. (Ueda, J.)