The digital radiographic image capture method that uses an X-ray absorber material coupled with a thin film transistor, CMOS, or a CCD to form the digital image is:

• A. Flat-panel detector (FPD)
• B. Image intensifier
• C. Film-screen radiography
• D. PSP plate

Answer: (A)

Digital radiography relies on a flat-panel detector that combines an X-ray absorber with an active readout matrix, typically a thin-film transistor (TFT) array, or imaging sensors like CMOS or CCD. When X-rays hit the absorber, they are converted to a signal that the TFT/CMOS/CCD array reads out pixel by pixel and converts into a digital image. In indirect conversion, the X-rays first strike a scintillator (such as CsI or gadolinium oxysulfide) that emits light, which is then detected by photodiodes linked to the TFTs. In direct conversion, materials like amorphous selenium directly convert X-rays into charge collected by the TFT array. This approach is distinct from an image intensifier system, which uses a vacuum tube to convert X-rays to light and then to a video signal, and from film-screen radiography or PSP plate systems, which involve film or laser-readout phosphor plates rather than a direct electronic detector array.