ABSTRACT

This chapter discusses the relative sensitivity of some of the imaging techniques that have been used in Electron paramagnetic resonance (EPR) imaging. The resolution-sensitivity trade-off dominates the choice of experimental conditions for EPR imaging. The optimum experiment is performed by using that measuring technique which gives the maximum sensitivity for ideal conditions. EPR imaging is assumed to be based on a three-dimensional projection-reconstruction algorithm which gives the highest sensitivity. When Fourier-transform (FT)-EPR techniques achieve closer to theoretical sensitivity, FT-EPR with multiple gradients will be the method of choice for samples of appropriate spectral width and relaxation times. EPR imaging of an unknown sample requires the use of spectral-spatial imaging technique. Commonly, EPR imaging is applied to samples for which there is a lot of information available in advance of the experiment. Spectrally integrated imaging overcomes problems connected with spectral-concentration variance, which is observed mainly in the high-concentration range.