ABSTRACT
In the last chapter it was seen that the net magnetization vector could be moved from its equilibrium state, aligned with the z direction, by supplying energy from radio frequency (RF) radiation. Furthermore, tipping the magnetization vector means that a signal can be detected. In this chapter the emphasis is on what happens when the RF is switched off. The system will revert back to its original state, in a way that affects the measured signal in a predictable manner. The relaxation mechanisms allow us to predict tissue contrast. In this chapter the Saturation Recovery program is used to help the reader gain familiarity with the effects of relaxation on signal size.
