title: Comparison of an automatic versus a semiautomatic mode for gray-scale adaptation for digital chest radiography.
abstract: OBJECTIVE
  To compare image quality of digital chest radiographs using 2 modes of gradation adjustment.
  
  
  METHODS
  We compared image quality and visualization of anatomic landmarks of 50 chest radiographs after digital processing using a semiautomatic mode with a fixed gamma of 2.6 and an automatic mode with individual gamma adaptation.
  
  
  RESULTS
  The mean gamma was significantly higher (P < 0.001) with the automatic mode (3.0 vs. 2.6, respectively). Patient constitution had no impact on the automatically adapted gamma for PA but showed a significant correlation (P < 0.001) for lateral images. For PA, there was a preference (P < 0.016) of the semiautomatic mode in heavier patients whereas no difference was seen in slim patients. For the lateral projection, there was a general preference (P = 0.001) of the automatic mode.
  
  
  CONCLUSIONS
  For PA radiographs, the semiautomatic mode provides superior results for heavier patients without compromising the quality in slim patients. For lateral radiographs, the automatic mode provides generally superior results.
authors.affiliation: Department of Radiology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria. johannes.sailer@univie.ac.at
authors.forename: Johannes
authors.initials: J
authors.lastname: Sailer
authors.forename: Mathias
authors.initials: M
authors.lastname: Prokop
authors.forename: Ulrich
authors.initials: U
authors.lastname: Neitzel
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Philipp
authors.initials: P
authors.lastname: Peloschek
authors.forename: Cornelia
authors.initials: C
authors.lastname: Schaefer-Prokop
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000592:standards*; D013902:Radiography, Thoracic / Q000592:standards*; D013008:Somatotypes