Researchers at the University of Wisconsin-Madison were able to probe deeper into smokers' lungs by tracking the movement in the respiratory organs of a harmless gas known as helium. Helium can be inhaled and visually detected via the widely used diagnostic technique known as magnetic resonance imaging (MRI), which produces high-contrast images of the body's soft tissues. The use of helium is a departure from traditional MRI, which typically distinguishes body tissues from one another by tracking differences in water content.
Writing in the journal Radiology, the UW-Madison scientists suggest that in comparison to existing imaging methods, the helium-based approach could enable doctors to assess lung health more accurately, as well as spot smoking-associated diseases much sooner.
"It's one thing to see a [lung] disease that was already diagnosed, but another to see changes that no one predicted were there," says lead author Sean Fain, a UW-Madison assistant professor of medical physics. "This approach allows us to look at lung micro-structures that are on the scale of less than a millimeter."
Cigarettes can contribute to the onset of respiratory conditions such as emphysema, bronchitis and asthma. In emphysema in particular, the alveoli - tiny sacs in the lungs that transfer oxygen to blood - gradually break down. Fain and his team therefore reasoned that helium gas molecules are likely to have more space to move around in lungs with fewer functioning alveoli.
Testing that theory among eight non-smokers and 11 healthy smokers with no obvious lung damage, Fain found that the movement or "diffusion coefficient" of helium gas molecules did indeed correlate with how much a person smokes, with greater movement indicating a highe
Contact: Sean Fain
University of Wisconsin-Madison