title: In situ detection of PHIP at 48 mT: demonstration using a centrally controlled polarizer.
abstract: Presented here is a centrally controlled, automated parahydrogen-based polarizer with in situ detection capability. A 20% polarization, corresponding to a 5,000,000-fold signal enhancement at 48 mT, is demonstrated on 2-hydroxyethyl-1-(13)C-propionate-d(2,3,3) using a double-tuned antenna and pulsed polarization transfer. In situ detection is a refinement of first-generation devices enabling fast calibration of rf pulses and B(0), quality assurance of hyperpolarized contrast agents, and stand-alone operation without the necessity of high-field MR spectrometers. These features are essential for biomedical applications of parahydrogen-based hyperpolarization and for clinical translation. We demonstrate the flexibility of the device by recording (13)C signal decay due to longitudinal relaxation of a hyperpolarized contrast agent at 48 mT corresponding to 2 MHz proton frequency. This appears to be the longest recorded T(1) (101 ± 7 s) for a (13)C hyperpolarized contrast agent in water.
authors.affiliation: Vanderbilt University Institute of Imaging Science, 1161 21st Avenue South, Nashville, Tennessee 37232, USA.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Waddell
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Coffey
authors.forename: Eduard Y
authors.initials: EY
authors.lastname: Chekmenev
mesh_terms: D002138:Calibration; D003287:Contrast Media / Q000737:chemistry; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D011422:Propionates / Q000737:chemistry; D011522:Protons; D011786:Quality Control; D014867:Water / Q000737:chemistry
chemical_list: C551061:2-hydroxyethylpropionate; D003287:Contrast Media; D011422:Propionates; D011522:Protons; D014867:Water; D006859:Hydrogen