New HD brain scanner traces damage at neural level

Researchers from the University of Pittsburgh have developed a new powerful imaging technique that allows doctors to trace the extent of traumatic brain injury (TBI) damage with unprecedented clarity.

 

The researchers said the "High Definition Fiber Tracking (HDFT)" will let doctors clearly see broken neural connections and other neurological disorders.

 

“In our experiments, HDFT has been able to identify disruptions in neural pathways with a clarity that no other method can see. With it, we can virtually dissect 40 major fiber tracts in the brain to find damaged areas and quantify the proportion of fibers lost relative to the uninjured side of the brain or to the brains of healthy individuals. Now, we can clearly see breaks and identify which parts of the brain have lost connections,” said co-senior author Walter Schneider, professor of psychology at Pitt’s Learning Research and Development Center.

 

Schneider led the team that developed the technology.

 

Under the system, data from sophisticated MRI scanners is processed through computer algorithms to reveal the wiring of the brain in vivid detail.

 

It also pinpoints breaks in the cables, called fiber tracts. Each tract contains millions of neuronal connections.

 

Case study

 

In the report, the researchers describe the case of a 32-year-old man who was not wearing a helmet when his all-terrain vehicle crashed.

 

His initial 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.

 

“There are about 1.7 million cases of TBI in the country each year, and all too often conventional scans show no injury or show improvement over time even though the patient continues to struggle,” said co-senior author and UPMC neurosurgeon David Okonkwo, associate professor of the Department of Neurological Surgery, Pitt School of Medicine.

 

“Until now, we have had no objective way of identifying how the injury damaged the patient’s brain tissue, predicting how the patient would fare, or planning rehabilitation to maximize the recovery,” he added.

 

HDFT scans of the study patient’s brain were performed four and 10 months after he was injured.

 

The patient 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 HDFT, the injury site was compared to the healthy side of his brain, as well as to HDFT brain scans from six healthy individuals.

 

But 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.

 

Memory loss, language problems, personality changes and other brain changes occur with TBI, which the researchers are exploring with HDFT in other research protocols.

 

Complement to conventional imaging

 

Robert Friedlander, professor and chair of the Department of Neurological Surgery at Pitt School of Medicine, and UPMC Endowed Professor of Neurosurgery and Neurobiology, said UPMC neurosurgeons also have used the technology to supplement conventional imaging.

 

“I have used HDFT scans to map my approach to removing certain tumors and vascular abnormalities that lie in areas of the brain that cannot be reached without going through normal tissue,” he said.

 

He added it showed him "where significant functional pathways are relative to the lesion, so that I can make better decisions about which fiber tracts must be avoided and what might be an acceptable sacrifice to maintain the patient’s best quality of life after surgery.”

 

Okonkwo noted the patient and his family were relieved to learn that there was evidence of brain damage to explain his ongoing difficulties.

 

The team continues to evaluate and validate HDFT’s utility as a brain imaging tool, so it is not yet routinely available.

 

“We have been wowed by the detailed, meaningful images we can get with this technology,” Okonkwo said. “HDFT has the potential to be a game-changer in the way we handle TBI and other brain disorders.”

 

Co-authors of the study include lead author Samuel Shin, Allison Hricik, Megan Maserati, and Ava Puccio, all of the Department of Neurological Surgery; Timothy Verstynen, Sudhir Pathak, and Kevin Jarbo, all of LRDC; and Sue Beers, of the Department of Psychiatry, all of the University of Pittsburgh.

 

The study was funded by the Defense Advanced Research Projects Agency. — TJD, GMA News