CT for Adult Minor Head Trauma
A closed head injury results from hitting your head on something. Even a small minor blow to the head can be dangerous and should be evaluated by a doctor for a possible concussion, bleeding on the brain, or skull fracture. Most minor head injuries do not require imaging tests.
A test called the Glasgow Coma Scale helps assess a person's level of consciousness after a minor or mild closed head injury. If the test result is equal to or more than 13, additional guidelines are used to see if an imaging test is recommended. A CT scan without contrast is used if the guidelines say a test is needed to find out the seriousness of the head injury. People with moderate or severe closed head injuries are also recommended to have a CT scan without contrast.
The results of a noncontrast head CT may read as normal despite an existing brain injury. Follow-up imaging tests are recommended for people whose brain injury symptoms are not getting better or are getting worse. CT without contrast is usually the best test for follow-up. MRI is used in cases of chronic (ongoing) suspected traumatic brain injury. If blood vessel injury is suspected then CT angiography or MR angiography is used for arterial injury and CTV or MRV for vein injuries.
CT scans expose people to radiation. MRI tests do not.
For more information, see the Head Injury page.
This page was reviewed on December 15, 2021