Publications [#328155] of Warren S. Warren

Journal Articles
  1. Shchepin, RV; Goodson, BM; Theis, T; Warren, WS; Chekmenev, EY, Toward Hyperpolarized 19 F Molecular Imaging via Reversible Exchange with Parahydrogen., Chemphyschem, vol. 18 no. 15 (August, 2017), pp. 1961-1965 [doi] .

    Fluorine-19 has high NMR detection sensitivity-similar to that of protons-owing to its large gyromagnetic ratio and high natural abundance (100 %). Unlike protons, however, fluorine-19 (19 F) has a negligible occurrence in biological objects, as well as a more sensitive chemical shift. As a result, in vivo 19 F NMR spectroscopy and MR imaging offer advantages of negligible background signal and sensitive reporting of the local molecular environment. Here we report on NMR hyperpolarization of 19 F nuclei using reversible exchange reactions with parahydrogen gas as the source of nuclear spin order. NMR signals of 3-fluoropyridine were enhanced by ≈100 fold, corresponding to 0.3 % 19 F nuclear spin polarization (at 9.4 T), using about 50 % parahydrogen. While future optimization efforts will likely significantly increase the hyperpolarization levels, we already demonstrate the utility of 19 F hyperpolarization for high-resolution hyperpolarized 19 F imaging and hyperpolarized 19 F pH sensing.