title: Molecular MRI in the Earth's Magnetic Field Using Continuous Hyperpolarization of a Biomolecule in Water.
abstract: In this work, we illustrate a method to continuously hyperpolarize a biomolecule, nicotinamide, in water using parahydrogen and signal amplification by reversible exchange (SABRE). Building on the preparation procedure described recently by Truong et al. [ J. Phys. Chem. B , 2014 , 118 , 13882 - 13889 ], aqueous solutions of nicotinamide and an Ir-IMes catalyst were prepared for low-field NMR and MRI. The (1)H-polarization was continuously renewed and monitored by NMR experiments at 5.9 mT for more than 1000 s. The polarization achieved corresponds to that induced by a 46 T magnet (P = 1.6 × 10(-4)) or an enhancement of 10(4). The polarization persisted, although reduced, if cell culture medium (DPBS with Ca(2+) and Mg(2+)) or human cells (HL-60) were added, but was no longer observable after the addition of human blood. Using a portable MRI unit, fast (1)H-MRI was enabled by cycling the magnetic field between 5 mT and the Earth's field for hyperpolarization and imaging, respectively. A model describing the underlying spin physics was developed that revealed a polarization pattern depending on both contact time and magnetic field. Furthermore, the model predicts an opposite phase of the dihydrogen and substrate signal after one exchange, which is likely to result in the cancelation of some signal at low field.
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Rovedo
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Knecht
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Bäumlisberger
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Anna Lena
authors.initials: AL
authors.lastname: Cremer
authors.affiliation: Centre for Hyperpolarization in Magnetic Resonance, University of York , York, YO10 5DD, U.K.
authors.forename: Simon B
authors.initials: SB
authors.lastname: Duckett
authors.affiliation: School of Science and the Environment, Manchester Metropolitan University , Chester Street, Manchester, M1 5GD, U.K.
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Mewis
authors.affiliation: Centre for Hyperpolarization in Magnetic Resonance, University of York , York, YO10 5DD, U.K.
authors.forename: Gary G R
authors.initials: GG
authors.lastname: Green
authors.affiliation: Centre for Hyperpolarization in Magnetic Resonance, University of York , York, YO10 5DD, U.K.
authors.forename: Michael
authors.initials: M
authors.lastname: Burns
authors.affiliation: Centre for Hyperpolarization in Magnetic Resonance, University of York , York, YO10 5DD, U.K.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rayner
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Leibfritz
authors.affiliation: Institute of Microstructure Technology, Karlsruhe Institute of Technology , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Jan G
authors.initials: JG
authors.lastname: Korvink
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Institute for Clinical Chemistry, University Medical Center , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Pütz
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: von Elverfeldt
authors.affiliation: Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg , Breisacher Strasse 60 a, 79106 Freiburg, Germany.|German Consortium for Cancer Research (DKTK) Partner Site Freiburg , 69120 Heidelberg, Germany.
authors.forename: Jan-Bernd
authors.initials: JB
authors.lastname: Hövener
mesh_terms: D001773:Blood Cells / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry; D017666:Deuterium Oxide / Q000737:chemistry; D018922:HL-60 Cells; D006801:Humans; D006859:Hydrogen / Q000737:chemistry; D007495:Iridium / Q000737:chemistry; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D009536:Niacinamide / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D014867:Water / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D014867:Water; D009536:Niacinamide; D007495:Iridium; D006859:Hydrogen; D017666:Deuterium Oxide