title: Improved detection of subtle lung nodules by use of chest radiographs with bone suppression imaging: receiver operating characteristic analysis with and without localization.
abstract: OBJECTIVE
  The purpose of this article is to evaluate radiologists' ability to detect subtle nodules by use of standard chest radiographs alone compared with bone suppression imaging used together with standard radiographs.
  
  
  METHODS
  The cases used in this observer study comprised radiographs of 72 patients with a subtle nodule and 79 patients without nodules taken from the Japanese Society of Radiological Technology nodule database. A new image-processing system was applied to the 151 radiographs to create corresponding bone suppression images. Two image reading sets were used with an independent test method. The first reading included half of the patients (a randomly selected subset A) showing only the standard image and the remaining half (subset B) showing the standard image plus bone suppression images. The second reading entailed the same subsets; however, subset A was accompanied by bone suppression images, whereas subset B was shown with only the standard image. The two image sets were read by three experienced radiologists, with an interval of more than 2 weeks between the sessions. Receiver operating characteristic (ROC) curves, with and without localization, were obtained to evaluate the observers' performance.
  
  
  RESULTS
  The mean value of the area under the ROC curve for the three observers was significantly improved, from 0.840 with standard radiographs alone to 0.863 with additional bone suppression images (p = 0.01). The area under the localization ROC curve was also improved with bone suppression imaging.
  
  
  CONCLUSIONS
  The use of bone suppression images improved radiologists' performance in the detection of subtle nodules on chest radiographs.
authors.affiliation: Department of Radiology, The University of Chicago, IL 60637, USA. feng@uchicago.edu
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hara
authors.forename: Junji
authors.initials: J
authors.lastname: Shiraishi
authors.forename: Roger
authors.initials: R
authors.lastname: Engelmann
authors.forename: Heber
authors.initials: H
authors.lastname: MacMahon
authors.forename: Kunio
authors.initials: K
authors.lastname: Doi
mesh_terms: D000368:Aged; D002983:Clinical Competence; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D011856:Radiographic Image Enhancement; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*