Flow Overview - Video Lesson

Hey everybody. Welcome to today's lesson on artifacts in MRI. This lesson focuses on flow as it relates to MRI, in particular understanding how flow behaves. In MRI we often assume that anatomy is stationary during image acquisition. In reality many tissues most notably blood and cerebrospinal fluid are in constant motion. Flow related motion is one of the most important sources of both image contrast and image artifacts in MRI. Understanding how flow behaves and how MRI systems respond to motion is essential for accurate image interpretation, protocol optimization, and quality control. Let's get started. First, let's define flow as it relates to MRI. Flow in MRI refers to the movement of spins through space during image acquisition, most commonly involving blood or CSF. Unlike stationary tissue, flowing spins may enter or exit the imaging slice, change position between RF excitation and signal readout, or experience different magnetic field gradients over time.