Final answer:
An insufficient amount of mAs in digital imaging leads to a grainy image appearance known as quantum noise, caused by inadequate X-ray photon exposure to the digital detector.
Step-by-step explanation:
An insufficient amount of mAs in digital imaging will produce an image with quantum noise. In digital radiography, mAs (milliampere-seconds) is a measurement of the electric current used in conjunction with exposure time to produce an X-ray. If the mAs is too low, there won't be enough X-ray photons to expose the digital detector adequately. This underexposure leads to an image that may have a grainy appearance due to the random nature of X-ray photon distribution, which is referred to as quantum noise. Unlike underexposure in photography, which results in a dark, flat, and dull image, or chromatic aberration, which causes image distortion and fuzzy appearance, quantum noise is distinct in its presentation of an image with visible random fluctuation in its pixel values.