Novel MRI Technique Shows Secondhand Smoke Dam...(nd sacs in the lungs which can break dow...),Health

"With this technique, we are able to assess lung structure on a microscopic level," Dr. Wang said.

For the study, measurements were translated into scores called apparent diffusion coefficient (ADC) values for each of the participants. An increased ADC value indicates that the helium atoms were able to travel farther during the measurement time. Fifty-seven percent of the smokers and 33 percent of the nonsmokers with high exposure to secondhand smoke had ADC values greater than 0.024, suggesting that early lung damage was present. In addition, 14 percent of smokers, 67 percent of high-exposure nonsmokers, and 39 percent of low-exposure nonsmokers had ADC values below 0.0185. Relatively low ADC values in adults are a possible indication of a developing respiratory problem, such as chronic bronchitis or asthma.

"These findings suggest that breathing secondhand smoke can injure your lungs," Dr. Wang said. "Since legislation to limit public exposure to secondhand smoke is still being considered in many states, we hope that our work can be used to add momentum to the drive to pass such legislation."

Co-authors are T.A. Altes, M.D., G.W. Miller, Ph.D., E.E. de Lange, M.D., K. Ruppert, Ph.D., J.F. Mata, Ph.D., and G.D. Cates, Ph.D.

AT A GLANCE

-- Helium-3 diffusion MRI shows lung damage caused by secondhand smoke.

-- One-third of nonsmokers with high levels of exposure to secondhand

smoke exhibited structural changes in the lung similar to those in

smokers.

-- Thirty-five percent of U.S. children live in homes where regular

smoking occurs.

Note: Copies of RSNA 2007 news releases and electronic images will be available online at RSNA.org/press07 beginning
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