RT Journal Article SR Electronic T1 Exploring the role of CT densitometry: a randomised study of augmentation therapy in alpha-1 antitrypsin deficiency JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society DO 10.1183/09031936.00159408 A1 A. Dirksen A1 E. Piitulainen A1 D.G. Parr A1 C. Deng A1 M. Wencker A1 S.B. Shaker A1 R.A. Stockley YR 2009 UL http://erj.ersjournals.com/content/early/2009/02/05/09031936.00159408.abstract AB