Pulmonary blood flow assessment may identify early emphysema
MedWire News: A technique that assesses pulmonary blood flow may help identify smokers at high risk for developing emphysema, researchers have found.
Writing in the Proceedings of the National Academy of Sciences, Eric Hoffman (University of Iowa, Iowa City, USA) and colleagues explain: “Although it is known that emphysematous destruction leads to vasculature changes, less is known about early regional vascular dysfunction which may contribute to and precede emphysematous changes.”
To investigate, the team studied 17 non-smokers and 24 smokers aged between 21 and 57 years with normal lung function on spirometry tests. Of the smokers, 12 had subtle signs of centrilobular emphysema on lung imaging scans.
Using multidetector row computed tomography (MDCT) perfusion imaging, the researchers assessed pulmonary blood flow (PBF) and mean transit time (MTT) in the participants.
They found that there were no significant differences in mean PBF and MTT among the groups.
However, smokers with subtle signs of emphysema had significantly different coefficient of variation measurements for PBF and MTT compared with non-smokers and smokers without signs of emphysema.
The differences in coefficient of variation measurements of PBF and MTT between non-smokers and smokers without signs of emphysema were non-significant.
“Our data show a blood flow pattern of significantly increased heterogeneity, indicative of increased regional variability in PBF and MTT in a subset of smokers with minimal visual MDCT-based evidence of centrilobular emphysema and normal spirometry,” the researchers conclude.
Hoffman added: “We have developed a new tool to detect early emphysema-related changes that occur in smokers who are susceptible to the disease.
“Our discovery may also help researchers understand the underlying causes of this disease and help distinguish this type of emphysema from other forms of chronic obstructive pulmonary disease. This type of CT scan could even be a tool to test the effectiveness of new therapies by looking at the changes in lung blood flow."
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By Mark Cowen