has intensified nuclei spin system can not be maintained in this state

If at this time the nuclear spin system subjected to external radio frequency effects,neodymium arc magnet such as a certain frequency excitation nuclei can cause resonance effects. After the RF pulse stops, has intensified nuclei spin system can not be maintained in this state, we will revert to the original arrangement of the magnetic field in the state, while the release of weak energy, become radio signals, these many signal detection, and When the spatial resolution,samarium magnets you get movement nuclei distribution image. MRI is characterized by the flow of the liquid does not generate a signal called flow effect blank or flow effects