What is the term for streaking that occurs when part of the patient is positioned outside the SFOV?

The term for streaking that occurs when part of the patient is positioned outside the scan field of view (SFOV) is known as "out of field artifacts." This phenomenon occurs because the CT system is unable to properly reconstruct data from areas that are not being adequately scanned, which can result in streaks or artifacts in the reconstructed images. Such artifacts can obscure important anatomical details and can be misleading in diagnostic interpretation.

While other types of artifacts exist in CT imaging, they are caused by different factors. Beam hardening refers to the phenomenon where lower energy photons are absorbed more than higher energy photons, leading to darker areas in images, especially near dense structures like bone. Motion artifacts arise when the patient moves during the CT scan, causing blurring or streaking due to inconsistent positioning. Edge gradient artifacts are related to sharp interfaces between materials with different densities, leading to erroneous boundaries in the images.

In contrast, out of field artifacts are specifically related to patient positioning and the limitations of the imaging system when it comes to capturing data from areas that are not included within the SFOV, making this the correct term for the described artifact.