3-D ‘map’ of brain developed at UNC
by Pavi Sandhu, The News and Observer
CHAPEL HILL — Consider navigating without a roadmap in an unfamiliar city with a complex maze of streets. That's what neurosurgeons do when they operate on the brain's complicated bundle of more than a hundred blood vessels.
For years, medical images of those blood vessels have been crude and inadequate, like a map with many streets missing or blurred. But because of an advance made by two researchers at the University of North Carolina at Chapel Hill, doctors should soon have an easier time finding their way.
The new technology — developed by Dr. Liz Bullitt, a neurosurgeon at NC's medical school and Dr Steve Pizer, a computer scientist — combines two existing techniques to produce three-dimensional images that are the sharpest and clearest that doctors have yet seen.
Once it becomes widely available, the new imaging technique will help physicians plan new surgical remedies and improve their understanding of the brain's structure.
For instance, doctors will be able to more easily identify aneurysms -- swelling in the brain's blood vessels -- and find the best path for treating them. "Navigation in the brain is hard enough," said Dr. Tony Bell, a neurosurgeon at Presbyterian Hospital in Charlotte. "Having a 3-D representation to guide us is really going to be great. That takes all the guesswork out of it."
Bullitt's work with Pizer is an example of the unusual collaborations that can form at research universities. Unlike their counterparts elsewhere, professors at UNC-CH and other research campuses can readily team up with researchers in other disciplines, often gaining an expertise in fields they had never considered.
Six years ago, for example, Bullitt was a computer novice. She then started tooling around at her terminal, and her hobby turned into an obsession. Before long, she was writing her own computer code, taking courses in differential geometry and spending hours in front of the screen.
"I realized it was taking up too much of my time. I wasn’t sleeping,” Bullitt recalled. “I decided I had to integrate it into my real life or I would get into trouble," Hoping to apply her computer skills in her work, Bullitt approached Pizer in 1992 with the idea of developing a 3-D medical imaging method for the brain.
Pizer, head of the university’s display and image processing group, previously had collaborated with doctors in many different fields. He was uncertain at first whether the brain project would work, but Bullitt was not easily dissuaded.
"She pounded on my door until she got my attention” Pizer said. “I said it’s a pretty damn hard problem. She said, 'I don’t care. I want to solve it.' "
Working together, the two scientists started writing software that would combine two common imaging techniques — X-ray angiography and magnetic resonance imaging (MRI). In recent decades, both techniques have helped doctors visualize the brain's network of blood vessels, but both have limitations.
Widely used by doctors, X-ray angiography involves injecting a radioactive tracer into the patient's blood. The tracer shows up as a dark stain when exposed to X-rays, producing very sharp, detailed pictures with even the smallest vessels clearly resolved.
But the image is limited to two dimensions, forcing doctors to estimate the spatial relationships of the blood vessels. Making such estimates, Bullitt said, is like trying to reconstruct the branches of a tree by looking at its shadow.
Compared to angiography, MRI is simpler and faster, but it produces relatively poor resolution, making it hard to detect the smallest blood vessels. Approximately 20 percent of the aneurysms in a patient’s brain can be missed in an MRI scan.
To combine the advantage of both techniques, Bullitt’s and Pizer’s method starts with the three-dimensional MRI image, then converts it into two dimensions. The flat, blurry image is then enhanced by using the X-ray image, which has much higher resolution. Information from the two scans is then combined to construct a final image that contains complete 3-D information of even the smallest blood vessels.
An added advantage is that the software is simple enough to be run on a desktop computer. Previous imaging techniques required much more powerful workstations that can cost as much as $100,000.
Surgeons can manipulate the image in several ways. Different sections of the brain’s network can be highlighted in different colors, in order to focus on the target area.
Bell, the Charlotte surgeon, said the 3-D imaging capability will be especially useful in endovascular surgery, a novel method in which a thin tube is inserted into the blood vessels to reach the aneurysm. This approach requires a much smaller incision and is less invasive than conventional brain surgery.
After overcoming some technical hurdles, Bullitt and Pizer hope to have their technique ready for clinical applications in a few years. In the meantime, the two scientists are being forced to think about marketing issues.
Bullitt said she has mixed feelings about patenting and licensing the technology. Royalty payments would help her continue her research, but they also would limit how quickly the software could be widely available.
“I hate talking to lawyers” she said. “I just want to play with my computer."
by Pavi Sandhu, The News and Observer
CHAPEL HILL — Consider navigating without a roadmap in an unfamiliar city with a complex maze of streets. That's what neurosurgeons do when they operate on the brain's complicated bundle of more than a hundred blood vessels.
For years, medical images of those blood vessels have been crude and inadequate, like a map with many streets missing or blurred. But because of an advance made by two researchers at the University of North Carolina at Chapel Hill, doctors should soon have an easier time finding their way.
The new technology — developed by Dr. Liz Bullitt, a neurosurgeon at NC's medical school and Dr Steve Pizer, a computer scientist — combines two existing techniques to produce three-dimensional images that are the sharpest and clearest that doctors have yet seen.
Once it becomes widely available, the new imaging technique will help physicians plan new surgical remedies and improve their understanding of the brain's structure.
For instance, doctors will be able to more easily identify aneurysms -- swelling in the brain's blood vessels -- and find the best path for treating them. "Navigation in the brain is hard enough," said Dr. Tony Bell, a neurosurgeon at Presbyterian Hospital in Charlotte. "Having a 3-D representation to guide us is really going to be great. That takes all the guesswork out of it."
Bullitt's work with Pizer is an example of the unusual collaborations that can form at research universities. Unlike their counterparts elsewhere, professors at UNC-CH and other research campuses can readily team up with researchers in other disciplines, often gaining an expertise in fields they had never considered.
Six years ago, for example, Bullitt was a computer novice. She then started tooling around at her terminal, and her hobby turned into an obsession. Before long, she was writing her own computer code, taking courses in differential geometry and spending hours in front of the screen.
"I realized it was taking up too much of my time. I wasn’t sleeping,” Bullitt recalled. “I decided I had to integrate it into my real life or I would get into trouble," Hoping to apply her computer skills in her work, Bullitt approached Pizer in 1992 with the idea of developing a 3-D medical imaging method for the brain.
Pizer, head of the university’s display and image processing group, previously had collaborated with doctors in many different fields. He was uncertain at first whether the brain project would work, but Bullitt was not easily dissuaded.
"She pounded on my door until she got my attention” Pizer said. “I said it’s a pretty damn hard problem. She said, 'I don’t care. I want to solve it.' "
Working together, the two scientists started writing software that would combine two common imaging techniques — X-ray angiography and magnetic resonance imaging (MRI). In recent decades, both techniques have helped doctors visualize the brain's network of blood vessels, but both have limitations.
Widely used by doctors, X-ray angiography involves injecting a radioactive tracer into the patient's blood. The tracer shows up as a dark stain when exposed to X-rays, producing very sharp, detailed pictures with even the smallest vessels clearly resolved.
But the image is limited to two dimensions, forcing doctors to estimate the spatial relationships of the blood vessels. Making such estimates, Bullitt said, is like trying to reconstruct the branches of a tree by looking at its shadow.
Compared to angiography, MRI is simpler and faster, but it produces relatively poor resolution, making it hard to detect the smallest blood vessels. Approximately 20 percent of the aneurysms in a patient’s brain can be missed in an MRI scan.
To combine the advantage of both techniques, Bullitt’s and Pizer’s method starts with the three-dimensional MRI image, then converts it into two dimensions. The flat, blurry image is then enhanced by using the X-ray image, which has much higher resolution. Information from the two scans is then combined to construct a final image that contains complete 3-D information of even the smallest blood vessels.
An added advantage is that the software is simple enough to be run on a desktop computer. Previous imaging techniques required much more powerful workstations that can cost as much as $100,000.
Surgeons can manipulate the image in several ways. Different sections of the brain’s network can be highlighted in different colors, in order to focus on the target area.
Bell, the Charlotte surgeon, said the 3-D imaging capability will be especially useful in endovascular surgery, a novel method in which a thin tube is inserted into the blood vessels to reach the aneurysm. This approach requires a much smaller incision and is less invasive than conventional brain surgery.
After overcoming some technical hurdles, Bullitt and Pizer hope to have their technique ready for clinical applications in a few years. In the meantime, the two scientists are being forced to think about marketing issues.
Bullitt said she has mixed feelings about patenting and licensing the technology. Royalty payments would help her continue her research, but they also would limit how quickly the software could be widely available.
“I hate talking to lawyers” she said. “I just want to play with my computer."