title: The Objective Identification and Quantification of Interstitial Lung Abnormalities in Smokers.
abstract: Previous investigation suggests that visually detected interstitial changes in the lung parenchyma of smokers are highly clinically relevant and predict outcomes, including death. Visual subjective analysis to detect these changes is time-consuming, insensitive to subtle changes, and requires training to enhance reproducibility. Objective detection of such changes could provide a method of disease identification without these limitations. The goal of this study was to develop and test a fully automated image processing tool to objectively identify radiographic features associated with interstitial abnormalities in the computed tomography scans of a large cohort of smokers.
  
  
  
  An automated tool that uses local histogram analysis combined with distance from the pleural surface was used to detect radiographic features consistent with interstitial lung abnormalities in computed tomography scans from 2257 individuals from the Genetic Epidemiology of COPD study, a longitudinal observational study of smokers. The sensitivity and specificity of this tool was determined based on its ability to detect the visually identified presence of these abnormalities.
  
  
  
  The tool had a sensitivity of 87.8% and a specificity of 57.5% for the detection of interstitial lung abnormalities, with a c-statistic of 0.82, and was 100% sensitive and 56.7% specific for the detection of the visual subtype of interstitial abnormalities called fibrotic parenchymal abnormalities, with a c-statistic of 0.89.
  
  
  
  In smokers, a fully automated image processing tool is able to identify those individuals who have interstitial lung abnormalities with moderate sensitivity and specificity.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115. Electronic address: syash@partners.org.
authors.forename: Samuel Y
authors.initials: SY
authors.lastname: Ash
authors.affiliation: Laboratory of Mathematics in Imaging, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: Rola
authors.initials: R
authors.lastname: Harmouche
authors.affiliation: Laboratory of Mathematics in Imaging, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: James C
authors.initials: JC
authors.lastname: Ross
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115.
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Diaz
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Hunninghake
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115.
authors.forename: Rachel K
authors.initials: RK
authors.lastname: Putman
authors.affiliation: Laboratory of Mathematics in Imaging, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: Jorge
authors.initials: J
authors.lastname: Onieva
authors.affiliation: Department of Medicine, Weil Cornell Medical College, New York, New York 10065.
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Martinez
authors.affiliation: Department of Medicine, Weil Cornell Medical College, New York, New York 10065.
authors.forename: Augustine M
authors.initials: AM
authors.lastname: Choi
authors.affiliation: Department of Radiology, National Jewish Health, Denver, Colorado 80206.
authors.forename: David A
authors.initials: DA
authors.lastname: Lynch
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hatabu
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115.
authors.forename: Ivan O
authors.initials: IO
authors.lastname: Rosas
authors.affiliation: Laboratory of Mathematics in Imaging, Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115.
authors.forename: Raul San Jose
authors.initials: RSJ
authors.lastname: Estepar
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., PBB, CA-3, Boston, MA 02115.
authors.forename: George R
authors.initials: GR
authors.lastname: Washko
mesh_terms: D000368:Aged; D000073865:Cigarette Smoking / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D000072356:Parenchymal Tissue / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000074285:Smokers; D014057:Tomography, X-Ray Computed
keywords: CT scanner; Pulmonary fibrosis; cigarettes; diffuse parenchymal lung diseases; idiopathic; interstitial; pneumonia; x-ray