CHAPTER 5: Magnetic Field Gradients

Magnetic field gradients are an integral component in all MRI and NMR systems. The first part of this chapter describes the different design methods that can be used to produce gradients with high linearity, high efficiency and low eddy currents. Challenges that have to be faced include heating from the very large currents present in the gradient coils and strong Lorenz forces. Interfacing with gradient power amplifiers is also discussed. Finally, four different specific gradient projects are described, including the highest strength gradients for human MRI, which were specifically designed for the human connectome project.