Imaging is everything
Bioengineering Assistant Professor Karel Zuzak knows perfectly well how to read a map. He can get from place to place without becoming lost. But he also knows that a global positioning system attached to the dashboard can make the trip far simpler and reduce his drive time.
The same principle applies when a surgeon navigates the human body. The doctor knows the road, but a high-tech system that provides a clearer view can help deliver superior outcomes. And that's just what Dr. Zuzak, with his research in hyperspectral imaging (HSI), has developed.
In simple terms, the system uses light-radiation composed of different wavelengths-to "see" body parts based on their molecular structure.
"It's all chemistry," he explains. "Our bodily tissues and fluids have a molecular structure acting like pigments, and when light is focused on them, some of it gets scattered, some gets absorbed, and some gets reflected. Different molecules-different types of chemistry-absorb or reflect different wavelengths of light, leaving a spectroscopic signature. We measure the spectrum of reflected light, and based on the reflected wavelengths-the way they are absorbed or reflected-we can tell you about the chemistry of what you are ‘seeing.' "
The researchers have used this area of chemical physics, known as spectroscopy, to build their DLP (Digital Light Processing) Hyperspectral Imaging System-something doctors are now using to see more clearly into the human body. The project has been conducted with technical support and funding from Texas Instruments, the company that invented DLP-a technology that powers, among other things, data projectors, high-definition televisions, and digital cinema projectors.
In addition to providing highly defined, chemically encoded images, DLP also gives Zuzak's system speed, producing near-video-rate images, something so important in an operating room, where time is money. Imagine an MRI or X-ray being produced at near-video rate, without the need for injecting anything to improve the view.
The system, still being refined, is already used at UT Southwestern Medical Center at Dallas by urology surgeon Jeffrey Cadeddu. Simply by looking at the visual images provided, he can tell which areas of the kidney are receiving blood and which are not-vital information before excising a tumor.
Because different bodily organs and systems have different chemical makeup, the imaging system can clearly see details not visible to the eye. The technology can provide a clear path for the neurosurgeon who is removing a brain tumor, giving him a way around an important blood vessel and thus reducing the risk of a post-operative stroke. The ophthalmologist may use the system to detect and diagnose diabetic retinopathy or retinoblastoma, a cancer of the eye.
In the near future, HSI may be used to perform "optical" biopsies in colonoscopy patients. Rather than removing suspicious-looking, possibly cancerous polyps, surgeons will see their chemical makeup and determine whether they are cancerous without cutting.
Soon melanoma patients may enter an examination room equipped with a ceiling-mounted hyperspectral imaging system. Almost instantly, doctors will be able to see a full-body image, and the patient's cancer (or lack of it) will be mapped in complete detail. No biopsy needed.
Leigh Files, a business development manager with Texas Instruments, worked with Zuzak on the system. She believes the research will lead to the development of systems in diagnosis and surgical procedures. How much better for a patient to provide diagnostic information rather than waiting on a time-consuming series of blood-chemistry and other tests.
"Technology has to make the surgeon's life easier," Zuzak says. "That's where the DLP technology comes into the picture. It's fast and it's accurate. The technology has to work for the doctors, who, in turn, work to save lives."