In a flat-panel detector, which component acts as a switch to read charge from detector elements (DELs) and route it to the readout electronics?

In a flat-panel detector, which component acts as a switch to read charge from detector elements (DELs) and route it to the readout electronics?

• A. ADC
• B. TFT array
• C. Photodiode
• D. Scintillator

Answer: (B)

The switching and routing of charge in a flat-panel detector is handled by the thin-film transistor (TFT) array. Each detector element holds a small charge, stored on a capacitor, and the TFTs act as individual switches that connect that charge to the readout bus when addressed. This allows the charge from every pixel to be sequentially read out to the readout electronics and then digitized. The other components serve different roles: the scintillator converts X-rays to light, the photodiode collects that light and forms the initial charge, and the ADC converts the analog signal to digital after readout.

The switching and routing of charge in a flat-panel detector is handled by the thin-film transistor (TFT) array. Each detector element holds a small charge, stored on a capacitor, and the TFTs act as individual switches that connect that charge to the readout bus when addressed. This allows the charge from every pixel to be sequentially read out to the readout electronics and then digitized. The other components serve different roles: the scintillator converts X-rays to light, the photodiode collects that light and forms the initial charge, and the ADC converts the analog signal to digital after readout.