Which two components are part of a digital imaging system that converts x-ray photons directly into an electrical signal?

The correct choice identifies the thin-film transistor (TFT) array and amorphous selenium (a-Se) as integral components of a digital imaging system that is capable of converting x-ray photons directly into an electrical signal.

The thin-film transistor (TFT) array plays a critical role in this system by acting as the electronic switch that reads out the signal generated when x-ray photons interact with the amorphous selenium layer. This layer is a photoconductive material that absorbs the x-ray photons and produces charge carriers in response to the radiation. When x-rays strike the amorphous selenium, it converts the photon energy into electrical charge, which is then transferred through the TFT array for image processing. This direct conversion process is crucial for creating high-quality digital images in radiography.

The other options focus on different technologies and components that are not directly involved in this specific method of conversion. For instance, charge-coupled devices (CCDs) and photomultiplier tubes, while important in other imaging systems, utilize different mechanisms for image capture and signal conversion. Similarly, the image intensifier and conductive layer pertain to older imaging technologies or indirect conversion methods and do not reflect the direct conversion typically achieved with TFT arrays and amorphous