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Principal Investigator
david wilson
M.D., M.P.H.
University of Pittsburgh
Position Title
Associate Professor
About this CDAS Project
NLST (Learn more about this study)
Project ID
Initial CDAS Request Approval
Oct 18, 2016
Validation of Emphysema in NLST CT scans
In continuation of our previously published findings about the relationships between airflow obstruction on spirometry, emphysema on CT scans and lung cancer, we are analyzing this relationship in 3 cohorts of lung screening subjects that also have spirometry available: the Pittsburgh Lung Screening Study (n=3638) (PLuSS), the Pamplona International Early Lung Cancer Action Project (n=2501) (PIELCAP) and the ACRIN sub-cohort of NLST (n=6564). Our preliminary review shows the prevalence of airflow obstruction in the 3 cohorts to be: 42.7 % PLuSS, 24.5 % PIELCAP and 33.4 % NLST. The presence of emphysema as interpreted by study radiologists is: 42.5 % PLuSS, 28.5 % PIELCAP and 55.8 % NLST. The large disparity in NLST between the finding of airflow obstruction and emphysema (33.4 v. 55.8 %) and the significantly higher prevalence of emphysema in NLST than PLuSS are very hard to reconcile, especially since PLuSS cohort is older and has more airflow obstruction. We believe emphysema has been overdiagnosed in NLST and would like to review the CT images to test this hypothesis.

1) Assess the accuracy of emphysema diagnosis by study radiologists in the ACRIN subcohort of NLST CT arm by qualitative emphysema assessment using our previously published guidelines
2) determine the relationship between airflow obstruction, emphysema and lung cancer risk in these 3 large cohorts


Dr. Juan Pablo de Torres Tajes, Dept of Medicine, Universidad de Navarro, Pamplona, Spain;
Dr. Carl Fuhrman, Dept of Radiology, Univ of Pittsburgh;