What components make up remnant exit or imaging forming radiation?

The correct answer is that remnant exit or imaging forming radiation consists of both interacting photons and scattered photons, but it is particularly characterized by the presence of those photons that have successfully passed through the patient and contributed to the image.

Remnant radiation is the term used to describe the radiation that exits the patient after it has interacted with the body tissues. Interacting photons, which include those that have undergone various interactions such as absorption and scattering, ultimately contribute to the image formation on the film or digital detector.

In contrast, non-interacting photons do not play a role in the formation of a diagnostic image, as they either pass through without any interaction or are absorbed by the body. Small-angle scattered photons may lose energy and not significantly contribute to the image quality, while large-angle scattered photons are generally considered to disperse in such a way that they do not aid in forming the desired image.

Therefore, the remnant radiation that contributes to image formation is derived from photons that have interacted appropriately with the patient's tissues but enough to maintain their capacity to contribute to the imaging process.