How does the size of the image intensifier input phosphor compare to that of the output phosphor?

The size of the image intensifier input phosphor is indeed much larger than that of the output phosphor. This design is fundamental to the functioning of an image intensifier. The larger input phosphor collects more photons produced by the fluoroscopic examination, which enhances the overall image quality. When the incoming x-ray photons strike the input phosphor, they emit electrons. These electrons then travel through a vacuum tube towards the smaller output phosphor, where they produce a corresponding amount of light photons.

This substantial difference in size between the input and output phosphors allows for the amplification of the image. The larger input phosphor captures a wide area of radiation, translating it into a more concentrated signal at the output. Hence, the increased size of the input compared to the output is a critical aspect of how the image intensification process operates to provide enhanced images for better diagnostic capabilities.