What random pattern of incident radiation is associated with "snow" or "mottle" in images?

The phenomenon referred to as "snow" or "mottle" in imaging is primarily a result of quantum noise. This type of noise occurs due to the statistical nature of photon detection in imaging systems. When the number of photons reaching the detector is low, which can happen in low-exposure or low-dose scenarios, variations in the detected signal contribute to a grainy appearance in the images. The random fluctuations in the number of photons result in a pattern that can be interpreted as noise, leading to the characteristic mottled appearance that resembles snow.

This is crucial in radiographic imaging since it can affect the quality of diagnostic images by decreasing the clarity and detail. Understanding quantum noise helps imaging professionals recognize and mitigate its effects by optimizing exposure settings and ensuring proper equipment performance, ultimately leading to higher quality diagnostic results.