"In a traumatic brain injury, it's not one specific area that is affected but multiple areas of the brain connected with axons," Dr. Lipton said.
Using DTI, the researchers measured the uniformity of water flow (called fractional anisotropy or FA) throughout the brain, pinpointing areas with low FA, which are indicative of axonal injury, and areas with abnormally high FA, as compared to healthy brains.
"Abnormally low FA within white matter has been associated with cognitive impairment in patients with TBI," Dr. Lipton said. "We believe that high FA is evidence not of axonal injury, but of brain changes that are occurring in response to the trauma."
One year after their brain injury, the patients completed two standard questionnaires to assess their post-concussion symptoms and evaluate their health status and quality of life.Comparing the DTI data to the patient questionnaires, the researchers found that the presence of abnormally high FA was a predictor of fewer post-concussion symptoms and higher functioning. The results suggest that in patients who exhibit areas of high FA on DTI, the brain may be actively compensating for its injuries. "These results offer us a new opportunity for treatment by finding ways to enhance the brain's compensatory mechanisms," Dr. Lipton said. Coauthors are Sara B. Rosenbaum, B.A., Namhee Kim, Ph.D., Tova M. Gardin, B.A., Richard B. Lipton, M.D., and Molly E. Zimmerman, Ph.D. Note: Copies of RSNA 2012 news releases and electronic images will be available online at RSNA.org/press12 beginning Monday, Nov. 26. RSNA is an association of more than 50,000 radiologists, radiation oncologists, medical physicists and related scientists, promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Ill. ( RSNA.org) Editor's note: The data in these releases may differ from those in the published abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.