Computed tomographic and magnetic resonance imaging classification of head injury.

Neuroimaging with CT and MRI is a basis for decision making in individual head-injured patients and also provides a classification of patients according to severity of damage, patterns of injury, pathophysiologic mechanisms and prognosis. Such classifications can be based on the intracranial lesions identified: subdural, extradural, and intracerebral hematomas, contusions, and shearing lesions, or indirect indications of raised intracranial pressure and brain swelling: shift, obliteration of the third ventricle and basal cisterns, and signs of ischemia. The appropriate classification for early diagnosis and acute decision making may differ from the assessment of severity of damage, prognosis and late sequelae. Parallel systems of classification, suitable for these purposes, are proposed.