title: Automatic patient-instruction devices in thin-section CT of the thorax: impact on image quality.
abstract: OBJECTIVE
  To determine what influence automatic patient-instruction (API) devices have on image quality of chest computed tomographic (CT) scans and whether the qualitative outcome justifies their routine use.
  
  
  METHODS
  Thin-collimation CT scans of two age- and sex-matched groups of 64 patients each were evaluated prospectively for the presence of breathing artifacts and for concomitant deterioration of image quality. Breathing commands in group 1 were given with the API device and in group 2 with technologist-performed patient instruction. Cardiac motion artifacts were not evaluated. The frequency of scans repeated owing to breathing artifact was determined.
  
  
  RESULTS
  Image quality was worse in group 1 compared with that of group 2. The percentage of scans repeated was higher with API (38%) than without API (16%).
  
  
  CONCLUSIONS
  API devices cannot be recommended for thin-section CT of the thorax. The large number of scans that must be repeated leads to a considerable increase in patient irradiation, scanning time, and cost.
authors.affiliation: Department of Radiology, University of Vienna, Austria.
authors.forename: A A
authors.initials: AA
authors.lastname: Bankier
authors.forename: D
authors.initials: D
authors.lastname: Fleischmann
authors.forename: K
authors.initials: K
authors.lastname: Dantendorfer
authors.forename: M N
authors.initials: MN
authors.lastname: Wiesmayr
authors.forename: M
authors.initials: M
authors.lastname: Kontrus
authors.forename: P
authors.initials: P
authors.lastname: Hübsch
authors.forename: C J
authors.initials: CJ
authors.lastname: Herold
mesh_terms: D000328:Adult; D016477:Artifacts; D001331:Automation; D016022:Case-Control Studies; D003194:Computer-Assisted Instruction; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D017063:Outcome Assessment, Health Care; D010353:Patient Education as Topic; D011369:Professional-Patient Relations; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D013902:Radiography, Thoracic; D012119:Respiration; D012984:Software; D013679:Technology, Radiologic; D014057:Tomography, X-Ray Computed