What is a ghosting artifact in CT imaging?

A ghosting artifact in CT imaging refers specifically to a shadow or phantom effect that appears within the image due to the presence of an object, which may not be in the exact focal plane of the scanner. This artifact arises when the imaging system captures residual signals from the object that may still affect the surrounding tissue, creating a visual ambiguity that can confuse interpretation.

This phenomenon can occur in various scenarios, often when there are structures or materials that are not properly aligned with the imaging plane, leading to an unexpected shadowing or overlay effect that misrepresents true anatomical structures. When preparing for CT imaging, understanding ghosting artifacts is essential for both technicians and radiologists to ensure accurate diagnosis and analysis, making it critical to recognize what may lead to such effects in order to mitigate them.

The other options describe different phenomena: reflections from external light sources typically result in artifacts unrelated to the imaging process itself; motion-induced errors are more associated with blurring rather than shadowing effects; and loss of detail around object edges relates to issues of resolution and contrast rather than the shadowing indicative of ghosting artifacts.