Centering the patient improperly on the CT gantry can lead to which type of artifact?

Centering the patient improperly on the CT gantry leads to out-of-field artifacts. When the patient is not correctly aligned with the isocenter of the gantry, parts of the anatomy may fall outside the effective imaging area, resulting in data that is not accurately captured. This can create artifacts where structures that are supposed to be included in the image are either poorly represented, distorted, or not visible at all. The out-of-field artifact is frequently characterized by the appearance of additional noise and a loss of image quality in the regions where anatomy is excluded from the detector's field of view.

On the other hand, partial volume averaging involves the averaging of different tissue types within a single voxel, which occurs regardless of patient centering, and beam hardening artifacts result from the variation in X-ray beam intensity as it traverses denser tissues. Motion artifacts arise from patient movement during scanning and are not related to improper centering.