1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
Selective detection of sodium signal from nuclei in ordered environments that exhibit non-zero residual quadrupole interactions is possible with a double-quantum magic-angle (DQ-MA) sequence. We show that DQ-MA signal from sodium is only detected in xanthan gum (ordered macromolecular environment) and not in either saline or 4% agar gel (disordered). We then demonstrate the first DQ-MA images of human brain acquired in 18 minutes at 4.7T in 3 healthy volunteers. This selective sodium measurement may provide novel insight into alterations of the microscopic ordered tissue microstructure of the brain.