title: A real-time flat-panel X-ray pixel imaging system for low-dose medical diagnostics and craniofacial applications.
abstract: The aim of this study was to evaluate on-line performance of a real-time digital imaging system based on amorphous silicon technology and to compare it with conventional film-screen equipment. The digital detecting imager consists of (1) a converter, which transforms the energy of the incident X rays into light; (2) a real-time digital detecting system, capable of producing as many as 10 pictures per second using a large-area pixel matrix (20 x 20 cm2) based on solid-state amorphous silicon sensor technology with a pitch of 400 microns; and (3) appropriate computer tools for control, real-time image treatment, data representation, and off-line analysis. Different phantoms were used for qualitative comparison with the conventional film-screen technique, with images obtained with both systems at the normal dose (used as a reference), as well as with dose reduction by a factor of 10 to 100. Basic image quality parameters evaluated showed that the response of the detector is linear in a wide range of entrance air kerma; the dynamic range is higher compared with the conventional film-screen combination; the spatial resolution is 1.25 lp per millimeter, as expected from the pixel size; and good image quality is ensured at doses substantially lower than for the film-screen technique. The flat-panel X-ray imager based on amorphous silicon technology implemented in standard radiographic equipment permits acquisition of real-time images in radiology (as many as 10 images per second) of diagnostic quality with a marked reduction of dose (as much as 100 times) and better contrast compared with the standard film technique. Preliminary results obtained with a 100-micron pitch imager based on the same technology show better quality but a less substantial dose reduction. Applications in craniofacial surgery look promising.
authors: University of Geneva, Department of Radiology, Genève, Switzerland.
authors: S
authors: S
authors: Chapuy
authors: D
authors: D
authors: Dimcovski
authors: Z
authors: Z
authors: Dimcovski
authors: E
authors: E
authors: Grigoriev
authors: E
authors: E
authors: Grob
authors: Y
authors: Y
authors: Ligier
authors: M
authors: M
authors: Pachoud
authors: F
authors: F
authors: Riondel
authors: D
authors: D
authors: Rüfenacht
authors: C
authors: C
authors: Sayegh
authors: F
authors: F
authors: Terrier
authors: J F
authors: JF
authors: Valley
authors: F R
authors: FR
authors: Verdun
mesh_terms: D000703:Analog-Digital Conversion; D004867:Equipment Design; D005145:Face / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D009862:Online Systems; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D012825:Silicon; D012886:Skull / Q000000981:diagnostic imaging*; D013679:Technology, Radiologic / Q000295:instrumentation; D014962:X-Ray Film; D014963:X-Ray Intensifying Screens
chemical_list: D012825:Silicon