title: Subjective image quality of solid-state and photostimulable phosphor systems for digital intra-oral radiography.
abstract: OBJECTIVE
  To compare subjectively the image quality of intra-oral radiographs from six digital systems.
  
  
  METHODS
  Two generations of two different solid-state detectors; Visualix-1 and -2 (Gendex Dental Systems, Milan, Italy), Computed Dental Radiography (CDR) and CDR Active Pixel Sensor (APS) (Schick Technologies Inc., Long Island City, NY, USA), and two photostimulable phosphor (PSP) systems; Digora (Soredex, Orion Corporation, Helsinki, Finland) and DenOptix (Gendex Dental Systems, Milan, Italy) were compared. Tooth-containing specimens from different areas of dried mandibles were radiographed at exposures between 91-9400 microGy. Images were transferred to a personal computer, displayed in random order and evaluated in their original form and after applying a histogram equalisation algorithm. Eight observers graded subjective image quality using a 5-point scale.
  
  
  RESULTS
  Both CDR systems scored highest for image quality but within the narrowest exposure range. The Visualix images received the lowest scores. The PSP systems produced acceptable image quality at both lower and higher exposures than the solid-state systems. Enhanced images were generally considered to be inferior to the original images, except for those produced by the four solid-state systems at very low exposures.
  
  
  CONCLUSIONS
  (i) the PSP systems provided a clinically acceptable image quality over a wide exposure range; (ii) the CDR systems had the best image quality but over the narrowest exposure ranges; (iii) the Visualix systems had the lowest image quality; and (iv) histogram equalisation did not generally improve image quality.
authors.affiliation: Department of Oral Diagnostic Radiology, Faculty of Odontology, Göteborg University, Göteborg, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Borg
authors.forename: A
authors.initials: A
authors.lastname: Attaelmanan
authors.forename: H G
authors.initials: HG
authors.lastname: Gröndahl
mesh_terms: D000465:Algorithms; D001641:Bicuspid / Q000000981:diagnostic imaging; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D007180:Incisor / Q000000981:diagnostic imaging; D008334:Mandible / Q000000981:diagnostic imaging; D008838:Microcomputers; D008963:Molar / Q000000981:diagnostic imaging; D015588:Observer Variation; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D019252:Radiography, Dental, Digital / Q000295:instrumentation / Q000379:methods*