In the presence of a magnetic field, magnetic atoms can have different energy levels, plus an energy (RF magnetic field), and this energy is equal to the adjacent 2-level energy difference, then the atoms absorb energy transition (resonance), from low level jump to the high energy level, level transition energy of RF magnetic fields than the number range. Nuclear magnetic resonance can be simply stated as research material on energy absorption of RF magnetic fields.
This technique is used to image the internal structure of the human body, producing a revolutionary diagnostic tool in medicine. Rapid changes in gradient magnetic field application, greatly accelerating the speed of magnetic resonance imaging, application of this technology in clinical diagnosis, research becomes a reality, greatly promoted the medicine, neurophysiology and the rapid development of cognitive neuroscience.
From nuclear magnetic resonance phenomena found during MRI technology over the decades, in three research areas related to nuclear magnetic resonance field (physics, chemistry, Physiology or medicine) won 6 Nobel prizes, will suffice to illustrate the importance of this area and its derivative technologies.