A 1935 paper published by Lev Landau and Evgeny Lifshitz predicted the existence of ferromagnetic resonance of the Larmor precession, which was independently verified in experiments by J . H . E . Griffiths ( UK ) and E . K . Zavoiskij ( USSR ) in 1946.
12.
Recently, MRI has been demonstrated also at ultra-low fields, i . e ., in the microtesla-to-millitesla range, where sufficient signal quality is made possible by prepolarization ( on the order of 10-100 mT ) and by measuring the Larmor precession fields at about 100 microtesla with highly sensitive superconducting quantum interference devices ( SQUID s ).
