ABSTRACT
In this chapter the physical processes that lead to the generation of a signal in magnetic resonance imaging (MRI) are introduced. Although a complete description can be very complex, many of the details are not necessary for developing an understanding of how the processes are used in MRI. The description given here therefore is limited to the essential core of information. All MRI systems have three basic components, and these are introduced in this chapter. It is shown how the need for each of the three components can be linked to the physical processes that are involved. The first of the interactive programs-the Rotating Frame of Reference program-is used in this chapter.
