Which imaging artifact is most commonly associated with MRIs?

Motion artifacts are the most commonly encountered imaging artifacts in MRIs due to their reliance on the patient's ability to remain still during the scanning process. When a patient moves even slightly, it can result in blurring or ghosting of the images. This artifact can affect any MRI scan but is particularly problematic in sequences that have longer acquisition times or where high spatial resolution is required.

While chemical shift artifacts, phase cancellation artifacts, and susceptibility artifacts are significant in MRI imaging, they occur under more specific conditions. For instance, chemical shift artifacts typically arise due to differences in resonance frequency between fat and water, which can lead to misregistration of fat and water images. Phase cancellation artifacts can occur in certain conditions when fat and water signals cancel each other out, while susceptibility artifacts are mainly associated with differences in magnetic field strength in the presence of materials that distort the field, such as metal implants or air/tissue interfaces.

In practice, addressing motion artifacts often involves techniques such as instructing patients clearly before the scan, using shorter scan times, or employing specialized sequences designed to correct for motion, emphasizing their prevalence and importance in MRI safety and image quality management.