Image detectors for digital fluoroscopy are primarily categorized into which groups?

Image detectors for digital fluoroscopy are primarily categorized into direct conversion and indirect conversion systems. Direct conversion detectors utilize materials that directly convert incoming X-ray photons into electrical signals without the need for an intermediate stage. This typically involves the use of photoconductive materials (like amorphous selenium) that absorb X-rays and generate a charge, which can then be read out as an image.

On the other hand, indirect conversion detectors operate using a two-step process. In these systems, X-ray photons are first converted into visible light by a phosphorescent layer, and then the visible light is converted into electrical signals by a photodetector (such as a charge-coupled device or CCD).

Understanding the distinction between direct and indirect conversion is crucial, as it affects the efficiency, speed, and quality of the imaging. Options referring to "direct translation" or "indirect translation" are not standard terminologies used in the categorization of digital fluoroscopy image detectors, which further confirms that the primary categories are indeed direct and indirect conversion.