CT Scans Can Miss Minor Bleeds

Mild traumatic brain injury may damage brain in ways only seen by MRI scans

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) People with mild brain injuries may have normal scans, but still show symptoms of brain injury. More sophisticated scans can pick up abnormalities, but are more expensive.

A recent study tracked the progress of mild traumatic brain injury patients for 3 months. Researchers found over a quarter of patients with normal CT scans on the day of the injury actually had brain injuries on MRI scans 1 week later. Further testing showed those with brain injuries were not fully recovered after 3 months.

"Tell a doctor if you’re experiencing any problems after a head injury."

Geoffrey T. Manley, MD, PhD, vice-chair of the Department of Neurological Surgery, and Esther Yuh, MD, PhD, neuroradiologist, at the University of California at San Francisco, worked with a team for the investigation.

For the study, 135 people admitted to one of three level-one trauma centers for mild traumatic brain injury were evaluated.

Each of the patients had a computer tomography (CT) scan when they were first admitted to the emergency department and an early brain magnetic resonance imaging (MRI) scan 9-15 days later.

All participants were reevaluated 3 months later.

A total of 27 percent of the group showed normal CT results, but abnormal MRI results.

The abnormal MRI results showed "focal lesions", which are tiny brain bleeds. Patients with abnormal MRIs were 3.5 times more likely to have “poorer” outcomes on the Extended Glasgow Outcome Scale (GOS-E) at the 3-month mark.

Having one or more brain bruises increased the odds of a poorer outcome on the GOS-E by 4.5 times at the 3-month mark. Having 4 or more tiny brain bleeds increased the odds of a poorer outcome by 3.2 times at the 3-month mark.

Dr. Manley said, “This work raises questions of how we’re currently managing patients via CT scan. Having a normal CT scan doesn’t, in fact, say you’re normal.”

Further studies like this contribute to a base knowledge and could provide the foundation for a more standardized treatment protocol for mild TBI.

Dr. Manley said, “The treatment’s all over the place—if you’re getting treatment at all.”

A better understanding of who is at risk for brain bleeds and bruising, poorer recovery and the development of new treatment therapies could improve the quality of care for mild traumatic brain injury patients.

Brain CT scans run around $1,100 and brain MRI scans run around $2,500. Both costs vary by location and provider.

This study was published in December in the Annals of Neurology.

Funding was supported by a grant from the National Institute of Neurological Disorders and Stroke, a part of the National Institutes of Health.

No conflicts of interest were reported.

Reviewed by: 
Review Date: 
January 2, 2013
Last Updated:
January 6, 2013