BACKGROUND: Researchers can use a laser-based fiber-optic system to tell the difference between dangerously inflamed artery plaques from less dangerous deposits. In many cases the technique eliminates the need for an invasive biopsy. The same technique can also be used to detect brain tumors.
HOW IT WORKS: Surgeons take a fiber optic probe connected to a laser to access the desired area inside the body. The probe shines laser light on tissue, which glows (or fluoresces) in response. The way it glows tells the surgeon the chemical composition of the tissue. Inflamed artery plaque is rich in lipids, while the less dangerous variety has more collagen. Lipids and collagen fluoresce differently under laser light. The technique is called time-resolved laser-induced fluorescence spectroscopy.
WHAT ARE OPTICAL FIBERS: An optical fiber is made of ultra-thin strands of glass -- as thin as a human hair -- bundled together into cables. Optical fibers can transmit pulses of light at tremendous speeds, and are also small enough to be used as probes in a variety of medical imaging techniques. The thin glass center of the fiber where light travels is called the core. It is surrounded by a material that reflects light back into the core, called the "cladding." The cladding is covered with a plastic coating that protects the fiber from damage and moisture. The entire cable is contained in a covering called the jacket.
WHAT IS ARTERY PLAQUE: Plaque doesn't just grow on your teeth. It can also form inside your arteries -- the blood vessels that carry oxygen and blood to the heart, brain and other parts of the body. Arteries have an inner layer of muscle. When it is damaged, plaque can form, sometimes leading to a bulge in the wall of the artery. The bulges can grow big enough to cause the inner lining to rupture. The body responds by sending clotting fibers to the damaged site. Minerals, especially calcium, can become trapped in the net of fibers, and so can fats like cholesterol. The minerals and fats build up over time, causing the arteries to narrow. Blood can't flow so easily through the restricted arteries. The arteries can also become clogged, stopping blood flow completely.
The Optical Society of America contributed to the information contained in the TV portion of this report.