title: PHYSIOLOGIC AND QUANTITATIVE COMPUTED TOMOGRAPHY DIFFERENCES BETWEEN CENTRILOBULAR AND PANLOBULAR EMPHYSEMA IN COPD.
abstract: BACKGROUND
  The purpose was to define the differences between centrilobular (CLE) and panlobular emphysema (PLE) phenotypes in cigarette smokers with COPD by a combined qualitative-quantitative computed tomography (CT) analysis.
  
  
  METHODS
  Chest CT scans of 116 cigarette smokers were visually scored by 22 chest radiologists and 29 pulmonologists in a single setting for the predominant emphysema phenotype (e.g. CLE or PLE) and automatically quantified for emphysema{% low attenuation area (LAA) ≤ -950 HU - %LAAinsp-950, gas trapping extent and bronchial metrics{wall area % for segmental (%WAsegm) and subsegmental (%WAsubsegm) bronchi}. These quantitative CT indexes were compared and related to FEV1, FEV1/FVC, and smoking history as stratified for emphysema phenotype.
  
  
  RESULTS
  Although more frequent than CLE in GOLD stages 3 and 4 (p = 0.01), PLE was also scored in 38.2% of combined GOLD stages 1 and 2. PLE was positively associated with %LAAinsp-950(OR = 1.18, 95% CI: 1.12 to 1.27, β coefficient = 0.17, p = <0.0001) and negatively associated with pack-years of smoking (OR = 0.97, 95% CI: 0.95 to 0.99, β coefficient = -0.02, p = 0.03). Both %WAsegm and %WAsubsegm were more strongly associated with FEV1% (R2= 0.6 for both measures, p< 0.001) in CLE as compared to PLE (R2= 0.15, p = 0.02; R2= 0.26, p< 0.001).
  
  
  CONCLUSIONS
  PLE likely represents a more advanced phase of emphysema, which may also occur in earlier COPD stages and show different interplay with airway disease as compared to CLE.
authors.affiliation: Department of Surgery, Section of Diagnostic Imaging, University of Parma, Parma, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.affiliation: Division of Radiology, National Jewish Health, Denver, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
authors.affiliation: Section of Respiratory Medicine, Department of Internal Medicine, University of Florence, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Pistolesi
authors.affiliation: Diagnostic and Interventional Radiology, University Clinic Heidelberg, Germany.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: Service de Radiologie Polyvalente, Diagnostique and Interventionelle, Hospital Pitie-Salpetriere, Paris, France.
authors.forename: P A
authors.initials: PA
authors.lastname: Grenier
authors.affiliation: Division of Biostatistics and Bioinformatics, National Jewisj Health, Denver, Denver, USA.
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, National Jewish Health, Denver, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Crapo