Irene Marco-Rius1, 2, Michael C. D. Tayler3, Mikko I. Kettunen1, 2, Eva M. Serrao1, 2, Timothy J. Larkin1, 2, Tiago B. Rodrigues2, Kerstin N. Timm1, 2, Giuseppe Pileio3, Malcolm H. Levitt3, Kevin M. Brindle1, 2
1Biochemistry, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Cancer Research UK, Cambridge, Cambridgeshire, United Kingdom; 3Chemistry, University of Southampton, Southampton, Hampshire, United Kingdom
Hyperpolarized NMR is a promising technique for non-invasive imaging of tissue metabolism in vivo. However, the range of reactions that can be investigated is limited by the fast T1-dependent decay of the nuclear spin order. In metabolites with coupled nuclear spin-1/2 pairs, polarization may be maintained for a longer time by exploiting the non-magnetic singlet (spin-0) state of the pair. We show here that the 13C singlet lifetime of [1,2-13C2]pyruvate is longer than T1 in human blood and in a mouse in vivo at low field, albeit shorter than its T1 in high magnetic field.