Computed radiography
Updates to Article Attributes
Computed radiography (CR) is the use of photostimulable phosphor as an image receptor. The image receptor is held in a similar casing (cassette) to that of the traditional film screen. Computed radiography harnesses the absorption of radiation, trapping electrons at energy levels via the process of photostimulable luminescence.
CR enables the transition of conventional radiography to digital radiography, by using existing x-ray equipments for conventional radiography 3.
Electron storage
The computed radiography plate has a thin layer of phosphor grains, known as a photostimulable phosphor. The plate is exposed to x-ray radiation exciting the phosphor, exciting the electrons to be trapped in the lattice until inevitably they are stimulated by the second round of illumination.
AnalogAnalogue to digital conversion
The computed radiography plate is exposed to a small, high-intensity laser resulting in the previously trapped electrons to return to their respective valence bands, letting off violet light.
A photomultiplier tube will interpret this light and convert it into an electric signal that, via an analoganalogue-to-digital converter (ADC) is digitised and mapped onto a pixel matrix.
Using a white light, the computed radiography plate can be 'reset', thus they can be reused repeatedly if carefully handled.
See also
-<p><strong>Computed radiography (CR) </strong>is the use of <a href="/articles/photostimulable-phosphors">photostimulable phosphor</a> as an image receptor. The image receptor is held in a similar casing (cassette) to that of the traditional film screen. Computed radiography harnesses the absorption of radiation, trapping electrons at energy levels via the process of photostimulable luminescence. </p><h5>Electron storage</h5><p>The computed radiography plate has a thin layer of phosphor grains, known as a photostimulable phosphor. The plate is exposed to <a href="/articles/x-rays-1">x-ray radiation</a> exciting the phosphor, exciting the electrons to be trapped in the lattice until inevitably they are stimulated by the second round of illumination. </p><h5>Analog to digital conversion</h5><p>The computed radiography plate is exposed to a small, high-intensity laser resulting in the previously trapped electrons to return to their respective valence bands, letting off violet light.</p><p>A photomultiplier tube will interpret this light and convert it into an electric signal that, via an analog-to-digital converter (ADC) is digitised and mapped onto a pixel matrix.</p><p>Using a white light, the computed radiography plate can be 'reset', thus they can be reused repeatedly if carefully handled.</p><h4>See also</h4><ul><li><a title="Digital radiography" href="/articles/digital-radiography">digital radiography</a></li></ul>- +<p><strong>Computed radiography (CR) </strong>is the use of <a href="/articles/photostimulable-phosphors">photostimulable phosphor</a> as an image receptor. The image receptor is held in a similar casing (cassette) to that of the traditional film screen. Computed radiography harnesses the absorption of radiation, trapping electrons at energy levels via the process of photostimulable luminescence. </p><p>CR enables the transition of conventional radiography to digital radiography, by using existing x-ray equipments for conventional radiography <sup>3</sup>.</p><h5>Electron storage</h5><p>The computed radiography plate has a thin layer of phosphor grains, known as a photostimulable phosphor. The plate is exposed to <a href="/articles/x-rays-1">x-ray radiation</a> exciting the phosphor, exciting the electrons to be trapped in the lattice until inevitably they are stimulated by the second round of illumination. </p><h5>Analogue to digital conversion</h5><p>The computed radiography plate is exposed to a small, high-intensity laser resulting in the previously trapped electrons to return to their respective valence bands, letting off violet light.</p><p>A photomultiplier tube will interpret this light and convert it into an electric signal that, via an analogue-to-digital converter (ADC) is digitised and mapped onto a pixel matrix.</p><p>Using a white light, the computed radiography plate can be 'reset', thus they can be reused repeatedly if carefully handled.</p><h4>See also</h4><ul><li><p><a href="/articles/digital-radiography" title="Digital radiography">digital radiography</a></p></li></ul>
References changed:
- 3. Allisy-Roberts P & Williams J. Digital Radiography. Farr's Physics for Medical Imaging. 2008;:79-90. <a href="https://doi.org/10.1016/b978-0-7020-2844-1.50009-0">doi:10.1016/b978-0-7020-2844-1.50009-0</a>