What term describes the component of digital radiography receptors responsible for capturing the radiation signal transmitted through the patient?

• A. Picture Element (Pixel)
• B. Charge-Coupled Device
• C. Detector Element (DEL)
• D. Photostimulable Phosphor (PSP)

Answer: (C)

Digital radiography receptors capture x-ray energy with a grid of detector elements. Each detector element is the smallest physical unit that directly receives the transmitted radiation and generates an electrical signal that will become part of the image. In indirect DR, the x-ray energy is first absorbed by a scintillator that emits light, and the detector element’s photodiode then converts that light into an electrical charge, with a thin-film transistor routing that charge to the readout electronics. In direct DR, the conversion happens directly in a photoconductor material, again with a TFT to read the signal. Together, many detector elements form the image as a matrix of pixels, with each detector element corresponding to one pixel’s data. This is why the term detector element is the best description of the component capturing the radiation signal. A pixel is the image’s sample element, not the physical capture unit; the PSP plate belongs to computed radiography, and a CCD is a sensor used in some systems but not the standard DR detector element.