title: Routine skeleton radiography using a flat-panel detector: image quality and clinical acceptance at 50% dose reduction.
abstract: OBJECTIVE
  The purpose of this study was to evaluate image quality and clinical acceptance of a large-area, flat-panel X-ray detector for routine skeleton examinations at 50% dose reduction.
  
  
  METHODS
  A total of 153 examinations (307 images) of 100 consecutive patients were evaluated. The cesium iodide-amorphous silicon active-matrix imager had a panel size of 43 x 43 cm, a matrix of 3000 x 3000, and a pixel pitch of 143 microm. All images were obtained with a kilovoltage setting identical to conventional radiographies of speed class 400. The amperage values were reduced by 50% compared with standard dose. Images were presented to 3 radiologists, who subjectively rated image quality on a 4-point scale according to 5 criteria (bone cortex, bone trabecula, soft tissue, overall contrast, and overall impression). Three trauma surgeons rated the clinical acceptance on a 4-point scale. Clinical acceptance was defined as directly derived consequences or therapy based on the presented image quality. For both evaluations, 1 represented excellent, 2 represented good, 3 represented moderate, and 4 represented nondiagnostic image quality/clinical acceptance. Intermediate scores at 0.5 intervals were allowed.
  
  
  RESULTS
  The mean values for all 5 image quality criteria were rated good or excellent (< or = 2). A total of 4.2% (13 of 307) of the images were rated 2.5 to 3.5 concerning the overall impression. None of the imaging features was ranked more than 3.5 by any radiologist. The mean value of the clinical acceptance was between good and excellent (1.47). A total of 98.7% (151 of 153) of the examinations were rated < or = 2.5; 1.3% (2 of 153) of examinations were of moderate clinical acceptance (< or = 3.5). None of the examinations was of nondiagnostic image quality or clinical acceptance (>3.5); therefore, no study had to be repeated.
  
  
  CONCLUSIONS
  Routine skeleton images with 50% dose reduction yield good image quality and good clinical acceptance. In cases with abundant soft tissue, less dose reduction or standard dose is required.
authors.affiliation: Department of Diagnostic Radiology, University Hopital of Regensburg, Germany. markus.voelk@klinik.uni-regensburg.de
authors.forename: Markus
authors.initials: M
authors.lastname: Völk
authors.forename: Christian
authors.initials: C
authors.lastname: Paetzel
authors.forename: Peter
authors.initials: P
authors.lastname: Angele
authors.forename: Johannes S
authors.initials: JS
authors.lastname: Seitz
authors.forename: Bernd
authors.initials: B
authors.lastname: Füchtmeier
authors.forename: Reiner
authors.initials: R
authors.lastname: Hente
authors.forename: Stefan
authors.initials: S
authors.lastname: Feuerbach
authors.forename: Michael
authors.initials: M
authors.lastname: Strotzer
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D002586:Cesium; D005260:Female; D006801:Humans; D007454:Iodides; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D012825:Silicon; D014963:X-Ray Intensifying Screens
chemical_list: D007454:Iodides; D002586:Cesium; C040050:cesium iodide; D012825:Silicon