Premium
A multisample 7 T dynamic nuclear polarization polarizer for preclinical hyperpolarized MR
Author(s) -
Cheng Tian,
Gaunt Adam P.,
MarcoRius Irene,
Gehrung Marcel,
Chen Albert P.,
Klink Jacques J.,
Comment Arnaud
Publication year - 2020
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.4264
Subject(s) - polarizer , spins , hyperpolarization (physics) , polarization (electrochemistry) , nuclear magnetic resonance , cryostat , liquid helium , physics , materials science , atomic physics , optics , chemistry , helium , nuclear magnetic resonance spectroscopy , condensed matter physics , superconductivity , birefringence
Dynamic nuclear polarization (DNP) provides the opportunity to boost liquid state magnetic resonance (MR) signals from selected nuclear spins by several orders of magnitude. A cryostat running at a temperature of ~ 1 K and a superconducting magnet set to between 3 and 10 T are required to efficiently hyperpolarize nuclear spins. Several DNP polarizers have been implemented for the purpose of hyperpolarized MR and recent systems have been designed to avoid the need for user input of liquid cryogens. We herein present a zero boil‐off DNP polarizer that operates at 1.35 ± 0.01 K and 7 T, and which can polarize two samples in parallel. The samples are cooled by a static helium bath thermally connected to a 1 K closed‐cycle 4 He refrigerator. Using a modified version of the commercial fluid path developed for the SPINlab polarizer, we demonstrate that, within a 12‐minute interval, the system can produce two separate hyperpolarized 13 C solutions. The 13 C liquid‐state polarization of [1‐ 13 C]pyruvate measured 26 seconds after dissolution was 36%, which can be extrapolated to a 55% solid state polarization. The system is well adapted for in vitro and in vivo preclinical hyperpolarized MR experiments and it can be modified to polarize up to four samples in parallel.