title: Detection of lung cancer using single-exposure dual-energy subtraction chest radiography.
abstract: OBJECTIVE
  The aim of this study was to evaluate the detectability of lung cancer by chest radiography with a single-exposure dual-energy subtraction (ES) method.
  
  
  METHODS
  Five radiologists read two sets of chest radiographs from 77 patients (66.5 +/- 9.6 years old) with histologically proven lung cancer measuring <or=3.0 cm and those from 77 normal subjects (65.7 +/- 9.0 years old). The observer tests were performed in two sessions: standard computed radiography (CR) images only and a combination of CR and ES images. Receiver-operating characteristic analysis was used for statistical analysis. All tumors were classified into three groups according to the appearance on thin-section CT: (1) nonsolid: tumor shadow disappearance rate (TDR) was 100%; (2) partly solid: TDR was >or=50 but <100%; (3) solid: TDR was <50%.
  
  
  RESULTS
  Overall, detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7673 to 0.8265, P < 0.05). In the subgroup analysis of the nonsolid group and the solid group detectability did not change using the ES method, whereas in the partly solid group detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7162 to 0.8209, P < 0.005).
  
  
  CONCLUSIONS
  The ES method improves the detectability of lung cancer by chest radiography, especially of the partly solid group.
authors.affiliation: Department of Radiology, Shikoku Cancer Center, Ehime University Postgraduate School of Medicine, 454 Shitsukawa, Toon, 791-0295, Japan. sakana@m.ehime-u.ac.jp
authors.forename: Kana
authors.initials: K
authors.lastname: Ide
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mogami
authors.forename: Tadashi
authors.initials: T
authors.lastname: Murakami
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Yasuhara
authors.forename: Masao
authors.initials: M
authors.lastname: Miyagawa
authors.forename: Teruhito
authors.initials: T
authors.lastname: Mochizuki
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015588:Observer Variation; D012372:ROC Curve; D011856:Radiographic Image Enhancement / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D012189:Retrospective Studies; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden