title: Image quality and radiation dose on digital chest imaging: comparison of amorphous silicon and amorphous selenium flat-panel systems.
abstract: OBJECTIVE
  The aim of this study was to compare the image quality and radiation dose in chest imaging using an amorphous silicon flat-panel detector system and an amorphous selenium flat-panel detector system. In addition, the low-contrast performance of both systems with standard and low radiation doses was compared.
  
  
  METHODS
  In two groups of 100 patients each, digital chest radiographs were acquired with either an amorphous silicon or an amorphous selenium flat-panel system. The effective dose of the examination was measured using thermoluminescent dosimeters placed in an anthropomorphic Rando phantom. The image quality of the digital chest radiographs was assessed by five experienced radiologists using the European Guidelines on Quality Criteria for Diagnostic Radiographic Images. In addition, a contrast-detail phantom study was set up to assess the low-contrast performance of both systems at different radiation dose levels. Differences between the two groups were tested for significance using the two-tailed Mann-Whitney test.
  
  
  RESULTS
  The amorphous silicon flat-panel system allowed an important and significant reduction in effective dose in comparison with the amorphous selenium flat-panel system (p < 0.0001) for both the posteroanterior and lateral views. In addition, clinical image quality analysis showed that the dose reduction was not detrimental to image quality. Compared with the amorphous selenium flat-panel detector system, the amorphous silicon flat-panel detector system performed significantly better in the low-contrast phantom study, with phantom entrance dose values of up to 135 muGy.
  
  
  CONCLUSIONS
  Chest radiographs can be acquired with a significantly lower patient radiation dose using an amorphous silicon flat-panel system than using an amorphous selenium flat-panel system, thereby producing images that are equal or even superior in quality to those of the amorphous selenium flat-panel detector system.
authors.affiliation: Department of Medical Physics and Radiation Protection, Ghent University, Proeftuinstraat 86, Gent B9000, Belgium. klaus.bacher@ugent.be
authors.forename: Klaus
authors.initials: K
authors.lastname: Bacher
authors.forename: Peter
authors.initials: P
authors.lastname: Smeets
authors.forename: Ludo
authors.initials: L
authors.lastname: Vereecken
authors.forename: An
authors.initials: A
authors.lastname: De Hauwere
authors.forename: Philippe
authors.initials: P
authors.lastname: Duyck
authors.forename: Robert
authors.initials: R
authors.lastname: De Man
authors.forename: Koenraad
authors.initials: K
authors.lastname: Verstraete
authors.forename: Hubert
authors.initials: H
authors.lastname: Thierens
mesh_terms: D001331:Automation; D006801:Humans; D011786:Quality Control; D013902:Radiography, Thoracic / Q000295:instrumentation* / Q000592:standards*; D011874:Radiometry; D012643:Selenium; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012825:Silicon
chemical_list: D012643:Selenium; D012825:Silicon