Final answer:
Cone beam artifacts in images appear as star-like streaks around high-density materials or at the edges of images, and are prevalent in imaging systems when high CT number materials like metals are present.
Step-by-step explanation:
A cone beam artifact typically appears in images as streaks or star-like artifacts radiating from a point. Such artifacts are visible in images where high CT number materials are present and can cause streaking artifacts. These artifacts are usually more pronounced around the edges of an image where there are large differences in tissue density or when structures with a high atomic number are present. An example is when metallic objects such as dental fillings or hip prosthesis are imaged, resulting in star-shaped artifacts emanating from the high-density material.