Neurosurgeons Use Water to Map Connections in the Brain

See that walnut-like object in this brain scan? It's a tumor that needs to be removed. But to avoid damaging critical functions like speech and vision, surgeons have to see the brain's tangled web of connections. The solution? Just add water.

This brain scanning technique, called tractography or diffusion tensor imaging (DTI), has been around for a while now and is used by neuroscientists to investigate and diagnose strokes and conditions like Alzheimer's. But a surgical team from the UC San Diego Health System is the first to use the technique in preparation for surgery.

"The brain can be mapped by tracking the movement of its water molecules," noted neurosurgeon Clark Chen in a UCSD News statement. "Water molecules in brain nerves move in an oriented manner. However, outside the nerves, the molecules move randomly."

The surgeons can use these distinct properties to locate important connections and to guide where surgery should occur — and just as importantly, where they should not occur.

These scans reveal the tiny open paths between nerve fibers to reach brain tumors, and they're color coded to display the intricate neural connections. No other imaging technique — not computed tomography (CT), not magnetic resonance imaging (MRI) — can do this.

Indeed, when it comes to brain surgery, there's practically no margin for error. Every centimeter of brain tissue contains millions of neural connections. But with tractography, the surgeons can visualize the most important of these connections to avoid injury and preserve the quality of life of brain cancer patients.

In this case, it's recovering patient Anthony Chetti. He recently developed a tumor in his occipital lobe, the region responsible for processing visual information. Surgeons successfully removed the tumor without damaging his vision.

"When I woke up from surgery, I asked for my glasses immediately and began running systems checks. I could see the clock. I could read the words on a sign. It was immediately evident that there were no problems," said Chetti.

I love how they call it "systems checks." Yup, brain's back online and functioning within normal parameters...

[Via UCSD News]

Image: UC San Diego.