Not All Head Injury Scans Are Equal

MRIs are more accurate than CT for determining traumatic brain injury damage and outcomes

(RxWiki News) Although most people with mild traumatic brain injury (mTBI) make a good recovery, about 15 percent go on to have lasting symptoms. Doctors currently have no way of knowing for certain which head injury patients will have long term difficulties.

A recent study looked at the effects of two different scanning techniques on patients with mTBI.

This clinical trial suggested that magnetic resonance imaging (MRI) is more effective than early computed tomography (CT) for evaluating head injuries in the emergency room.

This means MRI may be a better predictor of long term injury than CT scans.

"Talk to your doctor about which scan is best."

Esther Yuh, MD, PhD, of the University of California, San Francisco (UCSF), and colleagues followed 135 people with mild TBI across three different trauma center emergency rooms.

mTBI is normally defined as a non-penetrating head injury where the patient experiences either confusion and disorientation, loss of consciousness for less than 30 minutes, amnesia lasting less than one day or seizures and other signs of neurological dysfunction.

Another way of understanding mTBI is to use the Glasgow Coma Scale. The Glasgow Coma Scale is a widely used tool for understanding patient function after a TBI. 

In this USCF study, patients received CT scans when they were first admitted to the hospital. One to two weeks later, the patients also received an MRI.

Scores on the Glasgow Outcome Scale were determined at three months after the injury.

The results of the CT scan showed 99 patients with no visible signs of injury. However, more than one quarter of those 99 had abnormal MRI scans.

The MRI scans revealed focal lesions, areas of microscopic bleeding in the brain. Researchers can use the presence of focal lesions to predict which patients are more likely to have ongoing neurological problems.

Factors like age, prior head injury, educational background and employment status often play an important role in mTBI outcomes. The researchers adjusted the results to account for differences caused by these socioeconomic factors.

In addition to finding that MRI was a better predictor of long term injury than CT, the study also showed that patients with early CT and MRI markers had twice as bad Glasgow Outcome Scale scores at three months.

Efforts like this study are underway to improve mTBI understanding and treatment. When doctors know exactly which patients are at risk, they are more equipped to help them make a recovery.

The study was published in the journal Annals of Neurology. Funding was provided by the National Institute of Neurological Disorders and Stroke. Authors report affiliations with several medical and educational entities, the Department of Defense and over half a dozen pharmaceutical companies.

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Review Date: 
December 30, 2012