title: Novel Logistic Regression Model of Chest CT Attenuation Coefficient Distributions for the Automated Detection of Abnormal (Emphysema or ILD) Versus Normal Lung.
abstract: OBJECTIVE
  We evaluated the role of automated quantitative computed tomography (CT) scan interpretation algorithm in detecting interstitial lung disease (ILD) and/or emphysema in a sample of elderly subjects with mild lung disease. We hypothesized that the quantification and distributions of CT attenuation values on lung CT, over a subset of Hounsfield units (HUs) range (-1000 HU, 0 HU), can differentiate early or mild disease from normal lung.
  
  
  METHODS
  We compared the results of quantitative spiral rapid end-exhalation (functional residual capacity, FRC) and end-inhalation (total lung capacity, TLC) CT scan analyses of 52 subjects with radiographic evidence of mild fibrotic lung disease to the results of 17 normal subjects. Several CT value distributions were explored, including (1) that from the peripheral lung taken at TLC (with peels at 15 or 65 mm), (2) the ratio of (1) to that from the core of lung, and (3) the ratio of (2) to its FRC counterpart. We developed a fused-lasso logistic regression model that can automatically identify sub-intervals of -1000 HU and 0 HU over which a CT value distribution provides optimal discrimination between abnormal and normal scans.
  
  
  RESULTS
  The fused-lasso logistic regression model based on (2) with 15-mm peel identified the relative frequency of CT values of over -1000 HU and -900 and those over -450 HU and -200 HU as a means of discriminating abnormal versus normal lung, resulting in a zero out-sample false-positive rate, and 15% false-negative rate of that was lowered to 12% by pooling information.
  
  
  CONCLUSIONS
  We demonstrated the potential usefulness of this novel quantitative imaging analysis method in discriminating ILD and/or emphysema from normal lungs.
authors.affiliation: Department of Statistics and Actuarial Science, University of Iowa, Schaeffer Hall 241, Iowa City, IA 52242. Electronic address: kung-sik-chan@uiowa.edu.
authors.forename: Kung-Sik
authors.initials: KS
authors.lastname: Chan
authors.affiliation: Department of Occupational and Environmental Health, University of Iowa, USA.
authors.forename: Feiran
authors.initials: F
authors.lastname: Jiao
authors.affiliation: Department of Occupational and Environmental Health, University of Iowa, USA.
authors.forename: Marek A
authors.initials: MA
authors.lastname: Mikulski
authors.affiliation: Department of Internal Medicine, University of Iowa, USA.
authors.forename: Alicia
authors.initials: A
authors.lastname: Gerke
authors.affiliation: Department of Radiology and Biomedical Engineering, University of Iowa, USA.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Radiology and Biomedical Engineering, University of Iowa, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Newell
authors.affiliation: Department of Radiology and Biomedical Engineering, University of Iowa, USA; Departments of Radiology, Internal Medicine and Biomedical Engineering, University of Iowa, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Hoffman
authors.affiliation: Department of Radiology, University of Iowa, USA.
authors.forename: Brad
authors.initials: B
authors.lastname: Thompson
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Occupational and Environmental Health and Department of Epidemiology, University of Iowa, USA.
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Fuortes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D045853:Exhalation; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005652:Functional Residual Capacity / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000000981:diagnostic imaging*; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000592:standards; D013902:Radiography, Thoracic / Q000706:statistics & numerical data*; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D014109:Total Lung Capacity / Q000502:physiology
keywords: Fused lasso; computer assisted; interstitial lung disease; quantitative Computed Tomography