The grainy appearance of a CT image is known as:

The grainy appearance of a CT image refers to image noise, which is the random variation of brightness or color in images that may obscure or distort the true image information. Noise can be caused by a variety of factors, including limitations in the detector technology, patient motion during the scan, or insufficient radiation dose. In the context of CT imaging, noise is particularly important to control because it can significantly affect the diagnostic capabilities of the images produced.

By understanding noise, imaging professionals can take steps to optimize image quality, such as adjusting the exposure parameters or utilizing advanced reconstruction techniques, to ensure the images are as clear and useful as possible for interpretation.