title: Progress of emphysema in severe alpha 1-antitrypsin deficiency as assessed by annual CT.
abstract: OBJECTIVE
  To assess serial CT as a measure of the progress of emphysema in patients with severe alpha 1-antitrypsin deficiency (phenotype PiZ).
  
  
  METHODS
  In a randomized placebo-controlled study of alpha 1-antitrypsin augmentation therapy, 22 patients with moderate emphysema were followed for 2-4 years with an annual lung CT. The images were analysed by means of semiautomatic lung detection, and the degree of emphysema was quantitated by the density-mask and the percentile methods. The influence of lung volume was standardised by a regression model.
  
  
  RESULTS
  A highly significant decline in Hounsfield units (HU) was found in low-density areas, corresponding to a mean (SE) annual loss of lung tissue of 2.1 (0.4) g/l lung volume. Analysis of a single slice at 5 cm below the level of the carina gave comparable results: 2.4 (0.4) g/l.
  
  
  CONCLUSIONS
  Serial CT is a sensitive measure of the progress of emphysema in patients with severe alpha 1-antitrypsin deficiency.
authors.affiliation: Department of Respiratory Medicine, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Dirksen
authors.forename: M
authors.initials: M
authors.lastname: Friis
authors.forename: K P
authors.initials: KP
authors.lastname: Olesen
authors.forename: L T
authors.initials: LT
authors.lastname: Skovgaard
authors.forename: K
authors.initials: K
authors.lastname: Sørensen
mesh_terms: D000208:Acute Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology; D012044:Regression Analysis; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D014361:Trypsin Inhibitors / Q000627:therapeutic use; D000515:alpha 1-Antitrypsin / Q000627:therapeutic use; D019896:alpha 1-Antitrypsin Deficiency / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology
chemical_list: D014361:Trypsin Inhibitors; D000515:alpha 1-Antitrypsin