Aided by a powerful imaging technique, scientists have discovered they can detect smoking-related lung damage in healthy smokers who otherwise display none of the telltale signs of tobacco use.
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.