Researchers at University of Pittsburgh have developed a brain imaging method, called high-definition fiber tracking (HDFT), that detects axonal damage in the brain, effectively pinpointing exactly where there’s damage after a traumatic injury. The technique might one day allow clinicians to better select treatment options and predict how the injury will affect the patient.
The method involves special algorithms that analyze MRI scans and create images of the brain that look like colorful spaghetti, on which neuronal disconnections can be readily seen and correlated to the functions of the corresponding parts of the brain.
In the report, the researchers describe the case of a 32-year-old man who wasn’t wearing a helmet when his all-terrain vehicle crashed. Initially, his CT scans showed bleeding and swelling on the right side of the brain, which controls left-sided body movement. A week later, while the man was still in a coma, a conventional MRI scan showed brain bruising and swelling in the same area. When he awoke three weeks later, the man couldn’t move his left leg, arm and hand.
HDFT scans of the study patient’s brain were performed four and 10 months after he was injured; he also had another scan performed with current state-of the-art diffusion tensor imaging (DTI), an imaging modality that collects data points from 51 directions, while HDFT is based on data from 257 directions. For the latter, the injury site was compared to the healthy side of his brain, as well as to HDFT brain scans from six healthy individuals.
Only the HDFT scan identified a lesion in a motor fiber pathway of the brain that correlated with the patient’s symptoms of left-sided weakness, including mostly intact fibers in the region controlling his left leg and extensive breaks in the region controlling his left hand. The patient eventually recovered movement in his left leg and arm by six months after the accident, but still could not use his wrist and fingers effectively 10 months later.
Abstract in Journal of Neurosurgery: High-definition fiber tracking for assessment of neurological deficit in a case of traumatic brain injury: finding, visualizing, and interpreting small sites of damage