Magnetic Resonance Imaging (MRI)
The process of signal generation and acquisition in magnetic resonance imaging consists of four stages.[more]
1. The magnetic gradient along the axis selects a slice of the object. The protons in this slice are excited by a radiofrequency pulse.
2. The magnetic gradient along the axis achieves phase encoding of the protons in the selected slice.
3. The magnetic gradient along the axis produces a frequency encoding.
4. The signals emitted by the protons are detected, and an image of the object is synthesized by a computer program.[less]
 S. A. Huettel, A. W. Song, and G. McCarthy, Functional Magnetic Resonance Imaging, 2nd revised ed., Sunderland, MA: Sinauer Associates Inc., 2008.
 Wikipedia. "Basic Physics of Nuclear Medicine/MRI & Nuclear Medicine." (Mar 11, 2014) en.wikibooks.org/wiki/Basic_Physics_of _Nuclear _Medicine/MRI_%26 _Nuclear _Medicine.