Which type of digital imaging detector converts x-ray photons directly into an electric signal?

Direct conversion detectors are designed to convert x-ray photons directly into an electric signal without the need for an intermediate step. This process typically involves a layer of a semiconductor material, such as amorphous selenium, which absorbs the x-rays and generates charge carriers (electrons and holes) when exposed to the radiation. These charge carriers are then collected and translated into an electric signal that can be processed to create a digital image.

This direct conversion process enhances image quality and improves efficiency compared to systems that require intermediate steps, such as the use of light emitted by a scintillator to then create an electric signal. In contrast, indirect conversion detectors utilize a two-step process involving a scintillator to convert x-rays into visible light before converting that light into an electrical signal, which inherently involves some loss of resolution or detail. Computed radiography detectors and screen-film systems are not digital detectors in the same capacity as direct or indirect conversion detectors, as they rely on analog processes or physical film rather than direct conversion to an electric signal.