ABSTRACT
Motion artifacts are very common in magnetic resonance imaging (MRI) and occur due to 'phase mismapping', which occurs because moving protons develop different phase shifts from static tissue and therefore are incorrectly spatially located during phase-encoding (PE). All MR images contain some artifacts and their recognition is important to avoid misdiagnoses and to allow diagnostic images to be obtained. While artifacts are visible on every MR image, they can be useful in allowing characterization of tissues or identification of lesions such as hemorrhage or thrombi. The appearance of flowing fluids on MRI is complex and depends on pulse sequence, imaging parameters, direction, profile, and velocity of the flow. Cerebrospinal fluid (CSF) flow artifacts occur due to altered magnetization of CSF as it moves. They are most commonly seen on T2W and T2-FLAIR images where areas of abnormal signal are seen within accumulations of CSF with turbulent flow.
