Dual neuroimaging technique optimizes surgical outcomes

June 11, 2007

The intraoperative combination of functional MRI and diffusion-tensor tractography can improve the functional abilities of patients who undergo brain surgery, according to researchers who used a brain navigation system to apply the data during surgery.

The intraoperative combination of functional MRI and diffusion-tensor tractography can improve the functional abilities of patients who undergo brain surgery, according to researchers who used a brain navigation system to apply the data during surgery.

The researchers from the Neuroscience Institute at the University of Cincinnati and University Hospital presented preliminary data June 9 to 13 at the Society of Neuroradiology meeting in Chicago, demonstrating the value of the real-time combination of these tools in the operating room.

Dr. James Leach, an associate professor of radiology at Cincinnati and a neuroradiologist with University Hospital, and colleagues combined fMRI with tractography data to outline areas of the brain and their connections prior to surgery. They then transferred the data to the OR to monitor those areas during surgery.

BrainLab technology incorporates fMRI data to identify brain areas linked to speech, movement, and vision and diffusion-tensor imaging data to map critical white matter tracts that connect different parts of the brain. The detailed images serve as a map indicating areas of the brain to be avoided during surgery and a guide to help patients understand how the surgery will be conducted.

"We can show patients a color-coded picture of their brain and explain to them where their tumor is in relation to areas that control critical functions like expressive speech, movement and vision," Leach said. "This can help alleviate the patient's apprehension and help explain what will happen during surgery."

The team tracked critical regions of the brain using BrainLab's surgical navigation system in 20 cases at Cincinnati's University Hospital, finding that data obtained using the two imaging techniques not only optimize surgical approaches to treating brain tumors but ultimately improve patient outcomes, according to Leach.

Combining standard visual, sound, and voice-based tests measured by fMRI performed on a 3T scanner with BrainLab's intraoperative guidance system can improve patients' postoperative speech, movement, and memory, according to Leach. It can also optimize quality of life for those with brain tumors and other neurological conditions.

The researchers expect this dual-imaging technique to become standard practice across the U.S. in the next five years. But there will be limitations. Patients with limited vision may not demonstrate as much activity in the brain in areas linked to vision during fMRI testing, for example.

"That doesn't necessarily mean that there's no function there. It may just be that fMRI is not sensitive enough to detect it," Leach said.