A traumatic brain injury (TBI) is the result of a blow to the head or a foreign object penetrating the skull and causing a head injury. The injury disturbs normal brain function and can range from mild to severe in nature. The ensuing problems can have short or long-term complications or cause death.
- 1.4 million people in the United States suffer from TBI every year
- 50,000 people die each year as the result of a traumatic brain injury
The causes of TBI are varied and innumerable. A fall, a car accident, a blunt blow to the head, a bullet wound or a blast, as in a military war zone, can cause TBI. The lasting results of a TBI can be short or long-term. It can affect a person’s ability to think, learn and/or speak as well as their overall behavior, which can include memory, stress, temper and general emotions. TBI can sometimes cause epilepsy and can predispose a patient to other serious and chronic neurological conditions like Alzheimer’s disease and Parkinson’s disease.
Brain scans are a valuable diagnostic tool used to assess a patient for traumatic brain injury. The options include computerized axial tomography (CT or CAT scans) and magnetic resonance imaging (MRI) studies. For a variety of reasons, a CT scan is the diagnostic study of choice for most TBI patients.
This is the primary neuro-imaging choice for evaluating an acute brain trauma. The cross-section images of the brain are invaluable to assess a brain injury. A CT scan assesses physical changes of the brain like edema or swelling, hemorrhage, hematomas or blood clots, contusions or bruised brain tissue and/or skull fractures. A patient is exposed to x-ray radiation during CT scan.
Why is a CT scan such a valuable diagnostic tool?
- CT scanning is fast
- It is a painless study
- The test is readily available at most hospitals
- This is the best study to identify intracranial bleeding
- It is a more sensitive study than an MRI
An MRI evaluates the brain using magnetic fields, not x-ray radiation. While it is a good diagnostic tool, it does have a drawback for some patients -- MRI scanning requires the patient to lie perfectly still in an enclosed tube, and some patients are not comfortable being enclosed in small spaces. An MRI is often the diagnostic tool used to reassess a patient once their condition has stabilized.
Why is MRI a good diagnostic tool?
- The study is painless
- There is no radiation exposure during the exam
- MRI images of brain structures are high resolution
MRI scan drawbacks include:
- An MRI takes longer to complete than a CT scan
- A patient must lie perfectly still for the duration of the test
- MRI is more difficult to tolerate than a CT scan because it is very confining within the MRI machine
- An MRI cannot be performed if a patient has a pacemaker or IV line in place because of the machine’s magnetic fields
Time is crucial when evaluating and subsequently treating a patient with TBI. A brain scan is a critical component in diagnosing the effects of traumatic brain injury. It is a fast, precise, well-tolerated and informative diagnostic tool.