Eddy Currents - Video Lesson

Hey everybody and welcome back to our course on MRI artifacts. In this lesson, we will discuss Eddy currents, including what Eddy currents are and how they are produced. We will also discuss image artifacts associated with Eddy currents and identify system level and scan parameter strategies that can reduce Eddy current effects. Let's get started. First, let's discuss what Eddy currents are. Eddy currents are electrical currents induced in conductive materials when they are exposed to changing magnetic fields. In MRI, these currents are not part of the intended imaging process. Instead, they arise as a consequence of how spatial encoding is performed. Gradient coils rapidly switch magnetic fields on and off to encode spatial information along the X, Y and Z axises. According to Faraday's law of electromagnetic induction, any time varying magnetic field will induce an electrical current in nearby conductive structures. These structures include components such as the magnet bore, cryostat,