I. Introduction
MAgnetic resonance imaging (MRI) has been successfully used as a noninvasive diagnostic tool for imaging soft tissue. The patient is placed within a strong and very homogenous magnetic field (a few parts per million) in the imaging region, also known as the diameter of the spherical volume (DSV), to align the magnetic moments of (usually) protons in water molecules. A separate gradient coil set generates a strong and linear magnetic field in the DSV to decode the MR signal in the time and frequency domains in order to form an MR image. The radio-frequency (RF) coil transmits RF energy and receives the MR signal response.