Digital Radiography And Pacs - Questions With Precise Solutions

Digital Radiography And Pacs - Questions With
Precise Solutions

Direct conversion Correct Answer - Use photoconductor(amorphous
selenium )
Thin film transistor
Image receptor made of DEL
DEL CONTAINS TFT switch & storage capacitor

Indirect conversion Correct Answer - First converts invisible Xray
photons into visible light photons, then are converted into an electrical system

Indirect conversion CCD Correct Answer - Scintillation layer is coupled
to each CCD sensor by lenses or fiber optics.
-cray photons strike scintillation layer and are converted into light photons
-CCD converts the light photons into electrical signals
-sent to ADC which sends the electrical signals to a computer for processing

TFT systems indirect conversion Correct Answer - -after scintillation
layers there's a photodiode layer ( amorphous silicon)
And TFT array
-Xray photons strike scintillation layer and converted into light photons
-Photodiode layer converts light photons into electrical signal that is
transferred to the TFT array
-TFT array sends electrical signal to ADC

TFT Correct Answer - thin film transistors
Composed of small Detector Elements where the electric charge is stored and
released to be sent to and analog to digital converter

Photodiode Correct Answer - Solid-state device that converts light into
an electric current.

charge-coupled device (CCD) Correct Answer - array of high-sensitivity
electronic detectors of electromagnetic radiation, used at the focus of a
telescope (or camera lens) to record an image or spectrum