title: Digital chest radiography: comparison of unprocessed and processed images in the detection of solitary pulmonary nodules.
abstract: OBJECTIVE
  To compare the accuracy with which simulated solitary pulmonary nodules can be identified on digital images of the chest that are unprocessed, processed with adaptive spatial filtering, or processed with global filtering.
  
  
  METHODS
  Six experienced chest radiologists evaluated 408 test radiographs (136 from each of the three types, half with simulated nodules) and judged whether a nodule was present. Data from the 2,448 observations were evaluated by means of a receiver operating characteristic curve with location methods.
  
  
  RESULTS
  Accuracy was significantly better with the adaptive filter technique than with the global technique (P < .05), and it was better with adaptive filtering than with no processing in the detection of pulmonary nodules in the mediastinal-subdiaphragmatic areas (P < .05). No significant difference was found between no processing and global filtering.
  
  
  CONCLUSIONS
  Adaptive filtration is superior to global filtration in the identification of solitary pulmonary nodules and is superior to no processing in nodules projected over the radiopaque areas of the thorax on digital images.
authors.affiliation: Department of Electronics, University of Santiago de Compostela, Hospital General de Galicia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Correa
authors.forename: M
authors.initials: M
authors.lastname: Souto
authors.forename: P G
authors.initials: PG
authors.lastname: Tahoces
authors.forename: K S
authors.initials: KS
authors.lastname: Malagari
authors.forename: D M
authors.initials: DM
authors.lastname: Tucker
authors.forename: J J
authors.initials: JJ
authors.lastname: Larkin
authors.forename: J
authors.initials: J
authors.lastname: Kuhlman
authors.forename: G T
authors.initials: GT
authors.lastname: Barnes
authors.forename: E A
authors.initials: EA
authors.lastname: Zerhouni
authors.forename: R G
authors.initials: RG
authors.lastname: Fraser
mesh_terms: D000465:Algorithms; D006801:Humans; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014963:X-Ray Intensifying Screens