74. A non-synthetic approach to extending the lifetime of hyperpolarized molecules using D2O solvation

Andrew Cho, Roozbeh Eskandari, Vesselin Z. Miloushev, Kayvan R. Keshari, Journal of Magnetic Resonance, (2018) DOI: 10.1016/10.1016/j.jmr.2018.08.001

Although dissolution dynamic nuclear polarization is a robust technique to significantly increase magnetic resonance signal, the short T1 relaxation time of most 13C-nuclei limits the timescale of hyperpolarized experiments. To address this issue, we have characterized a non-synthetic approach to extend the hyperpolarized lifetime of 13C-nuclei in close proximity to solvent-exchangeable protons. Protons exhibit stronger dipolar relaxation than deuterium, so dissolving these compounds in D2O to exchange labile protons with solvating deuterons results in longer-lived hyperpolarization of the 13C-nucleus 2-bonds away. 13C T1 and T2 times were longer in D2O versus H2O for all molecules in this study. This phenomenon can be utilized to improve hyperpolarized signal-to-noise ratio as a function of longer T1, and enhanced spectral and imaging resolution via longer T2.