Which conversion method does a selenium-based flat panel system utilize for digital imaging?

A selenium-based flat panel system employs direct conversion for digital imaging. In this method, the selenium material directly converts incoming x-ray photons into electrical charges. This is achieved through the photoelectric effect, where x-ray photons are absorbed by the selenium layer, resulting in the generation of electron-hole pairs. These charges are then collected by an array of electrodes, which translates them into a digital image.

The direct conversion process is advantageous because it maintains high spatial resolution and minimizes the need for intermediate steps that might reduce image quality. This stands in contrast to indirect conversion systems, which typically utilize a two-phase process involving a scintillator that first converts x-ray photons into visible light, followed by a photodetector that converts the light into an electrical signal. Understanding the specifics of how direct conversion works is integral to comprehending the functionality and efficiency of selenium-based systems in digital imaging.