University of Virginia Health System

Contact: Sally H. Jones
434-924-9241
sallyhjones@virginia.edu

UVA Physicist Wins International Award for Novel MRI Technique
to Identify Microstructural Changes in Asthma

CHARLOTTESVILLE, VA, June 30, 2008 - A researcher at the University of Virginia Health System, Chengbo Wang, Ph.D., assistant professor of Radiology, has received the prestigious W.S. Moore Young Investigator Award for Clinical Science from the International Society for Magnetic Resonance in Medicine (ISMRM). Wang was chosen for his research in developing a novel magnetic resonance imaging (MRI) technique that - for the first time ever - identified microscopic structural damages deep in the lungs of patients with asthma.

"The award committee received a record number of applications this year, and Dr. Wang's work stood out for its innovative approach and excellent presentation," says Dr. Vivian Lee, president of ISMRM.

Wang says he and his research team used a special type of magnetic resonance imaging to detect microstructural changes in the lungs.  "We found structural alterations in asthmatics, which were not expected.  These findings contribute to a new understanding of the pathophysiology of asthma."

Wang's study, which will be published in the upcoming July issue of Journal of Magnetic Resonance Imaging, involved 14 healthy volunteers and 14 patients with difficult-to-treat asthma.

The research team polarized helium-3 to make it visible for MR imaging. Then the research subjects inhaled the polarized helium-3 gas, and MR images of the lung were obtained.  These images measured how far the helium atoms could move in the lung. 

Co-registered axial apparent diffusion coefficient (ADC) maps from: a healthy subject at diffusion times of 1 ms and 1.5 s; an asthma subject at diffusion times of 1 ms and 1.5 s; and a COPD subject at diffusion times of 1 ms and 1.5 s. The healthy subject has homogeneously low ADC values at both time scales. The asthmatic has focal areas of elevated ADC values anteriorly that are larger and more conspicuous on the long-time-scale ADC maps. The subject with COPD has diffusely, markedly elevated ADC values.

Researchers found that the helium-3 atoms moved a greater distance in the lungs of patients with asthma than in healthy subjects, indicating that there are subtle lung structural differences between asthmatics and healthy volunteers.  Wang previously used similar MRI techniques last year to show the first evidence of structural lung damage from secondhand cigarette smoke.

"We had expected to see the opposite effect in asthma due to narrowing of airways. Our unexpected results, however, may reflect alterations at the level of the alveoli or smallest bronchi," says Wang.  Although these findings require more study, he says, they may be the reason why some asthmatics are difficult to treat, and they may be related to "remodeling" in asthma - permanent alterations in lung tissue caused by the disease.

"This study raises new questions about our understanding of asthma," says Wang. "We hope our further research can help resolve some of these questions and help us better understand and manage this sometimes puzzling disease."

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