In conclusion, we have demonstrated a novel type of hyperpolarized 1 H imaging experiment, in which nuclear hyperpolarization is locked in a long-lived singlet state until liberation by a chemical/biological process. We used paraenriched hydrogen gas to hyperpolarize the proton singlet state in the biomolecule fumarate, and the signals were released by enzymatic conversion to malate. In our experiments, up to 20% proton spin polarization was observed on malate. The released signals are antiphase when observed directly after applying an rf pulse which complicates imaging, and so we employed two pulse sequences, OPE-45 and OPE-s90, for converting the antiphase spin order into in-phase magnetization. By adding pulsed field gradients for coherence filtering, we show that background signals from the protons in the water solvent can be effectively suppressed. We have demonstrated the method by acquiring images of hyperpolarized fumarate-to-malate metabolism over the course of a minute using OPE-s90, with effective suppression of the water background signals. The relatively short proton singlet lifetime in water (8 s) will likely limit this specific molecular system to studying samples with high metabolic flux. We expect this imaging method to be extended to alternative PHIP systems , or other nuclear spin species, e.g. N or C singlet pairs , which are known to be long-lived in aqueous solution.