Frequency-selective quadrupolar MRI contrast.

A method for the selective detection of quadrupolar nuclei located in anisotropic environments is presented. The image contrast can be tuned to the degree of anisotropy in the sample by using frequency-swept pulsed. These methods are particularly useful in the field of sodium-MRI, where sodium signals from locally-ordered environments provide diagnostic information. In solid-state MRI, these methods could be useful for probing structural defects within the sample. We demonstrate here one-dimensional images, in which the pixel contrast indicates the presence or absence of quadrupolar coupling within a certain frequency range.