Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
CT-defined subtypes of COPD. Most subjects with emphysema have significant airway disease. Airway-predominant disease represents subjects with minimal or no emphysema as defined at quantitative CT (QCT ). * =There is a group of subjects without visually defined emphysema who have more than 6% of pixels less than −950 HU at quantitative CT. Further work is needed to understand the importance of this finding, and these individuals cannot currently be classified. A1AT = α1-antitrypsin.
