Chemical Shift Artifact - Video Lesson

Hey everybody. Welcome back to today's lesson on artifacts in MRI. This lesson focuses on chemical shift artifact, a common and predictable MRI artifact that arises from fundamental differences in the magnetic properties of fat and water. Because MRI relies on frequency and phase information to create spatial localization, even small frequency differences can lead to visible image distortions. Understanding chemical shift artifact is important because it can mimic pathology, obscure small lesions, and alter perceived anatomy at fat water interfaces such as the retro orbital fat boundaries. A technologist must recognize this artifact, understand why it occurs, and know how to manage it to preserve diagnostic accuracy. Let's get started. Chemical shift artifact occurs due to differences in precessional frequency between fat and water protons in a magnetic field. These differences in precessional frequency occur due to differences in how the hydrogen in fat and water are arranged. The hydrogen atoms in