Imaging of acute head injury in the adult.

Head injury is a leading cause of trauma deaths. Prompt recognition of treatable injuries is critical to reduce mortality. Computed tomography (CT) of the head is readily obtainable in most medical centers, and is the cornerstone of rapid diagnosis. This article explains the important prognostic features of various forms of head trauma and their manifestations on noncontrast head CT. Intra-axial lesions are considered first, with explanation of diffuse axonal injury, contusions, and parenchymal hematomas. Extra-axial hemorrhages are also detailed, including subdural hematomas, epidural hematomas, and subarachnoid hemorrhage. Finally, extracranial manifestations of head trauma are explained, with descriptions of craniofacial fractures and orbital injuries. This article should help to place the imaging features of head trauma in clinical perspective for those involved in caring for trauma victims from a diagnostic or therapeutic standpoint.