Which of the following can lead to out-of-field artifacts?

Out-of-field artifacts in CT imaging occur when parts of the patient's body or other objects extend outside the detection area of the CT scanner, thereby influencing the quality of the captured images. When a patient is positioned improperly, it may result in certain body parts being positioned outside of the scan field of view, which causes incomplete data to be collected. This incomplete data results in artifacts during the reconstruction of the images, leading to distortions or unexpected features in the final image.

In contrast, fast pitch refers to the speed at which the scanner moves during a helical scan and typically affects the quality and resolution of the image but does not directly create out-of-field artifacts. Patient motion can introduce blurring and other motion-related artifacts but does not create the specific kinds of artifacts linked to out-of-field scenarios since the patient remains within the scanning range. Ring artifacts arise from imperfections within the CT detector system and do not involve the positioning of the patient or the field of view at all. Therefore, the correct identification of improper patient positioning as a cause of out-of-field artifacts highlights the importance of careful patient alignment to ensure optimal imaging conditions.