NMR = Nuclear Magnetic Resonance is the resonance that occurs when a nucleus
(usually hydrogen, but any nucleus that has non-zero spin will work) is placed in a
magnetic field and is 'swept' by a radio frequency that causes the nuclei to
This causes the radio frequency to be absorbed, which is what is measured.
MRI = Magnetic Resonance Imaging is a more complex application of NMR in which the
geometric source of the resonances are detected and deconvoluted by Fourier
ESR = Electron Spin Resonance is also a resonance phenomenon, except in this case
it is the spin of an unpaired electron that is in resonance, rather than a nuclear
Answered by: Vince Calder, Ph.D., Physical Chemist, retired
'A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving…'