title: Method for minimizing observer variation for the quantitation of high-resolution computed tomographic signs of lung disease.
abstract: OBJECTIVE
  This study aimed to describe a method of reducing interobserver variation associated with the visual quantitation of high-resolution computed tomographic (HRCT) signs of airways and interstitial lung disease (ILD).
  
  
  METHODS
  The HRCT scans of 2 cohorts of patients with airways disease (n = 144) and ILD (n = 109) were evaluated by 2 observers. Selected signs of airways disease were evaluated: (1) bronchial wall thickness and (2) the extent of the decreased attenuation. In the ILD group, the total extent of disease was scored. These 3 HRCT signs were scored by 2 observers independently using a standard method. The observers rescored the CT scans with a new scoring system (continuous learning method, CLM).
  
  
  RESULTS
  Observer agreement for CT signs was superior for CLM: bronchial wall thickness κw increased from 0.51 to 0.76; for decreased attenuation, κw increased from 0.34 to 0.81; and for ILD extent, κw increased from 0.53 to 0.87.
  
  
  CONCLUSIONS
  The CLM reduces noise from observer variation in studies that require visual quantitation of HRCT signs of lung disease.
authors.affiliation: Department of Clinical Sciences, Section of Diagnostic Imaging, Padiglione Barbieri, University Hospital of Parma, Parma, Italy. nicolasve@tiscali.it
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.forename: Anand
authors.initials: A
authors.lastname: Devaraj
authors.forename: Sujal R
authors.initials: SR
authors.lastname: Desai
authors.forename: Maureen
authors.initials: M
authors.lastname: Quigley
authors.forename: Athol U
authors.initials: AU
authors.lastname: Wells
authors.forename: David M
authors.initials: DM
authors.lastname: Hansell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed / Q000379:methods*