"With this technology, we have shown that it is possible to measure the severity of emphysema and its progression through time without the radiation exposure of lung CT tests," said Sean B. Fain, Ph.D., lead author and assistant professor of medical physics and radiology at the University of Wisconsin, Madison.
Emphysema is a chronic, progressive lung disease, which permanently damages the air sacs in the lungs. As the size of the air sacs (or "airspaces") increase, cavities form in the lung tissue, hindering oxygen delivery. According to the American Lung Association, over 3 million people in the United States have been diagnosed with emphysema, and millions more are in the early stages of the disease before signs and symptoms appear. Smoking cigarettes triples the risk of developing the disease.
The researchers had 19 volunteers inhale a special kind of "hyperpolarized" helium before they performed two MRI tests of the lungs. Eleven of the volunteers were smokers with no symptoms of emphysema, and the remaining eight were nonsmokers. The first image the researchers acquired showed obstructed areas of the lungs, where the air was unable to pass. The second image they obtained is called an apparent diffusion coefficient (ADC) map, which shows the size of the airspaces in the lungs. Because emphysema increases airspace size, the ADC map shows the location and severity of the disease.
"The ADC maps are very sensitive to changes in the lung structure," Dr. Fain said. "With this tool, it was shown that even smokers
Contact: Heather Babiar
Radiological Society of North America