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A multisample 7 T dynamic nuclear polarization polarizer for preclinical hyperpolarized MR

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Cheng, Tian 
Gaunt, Adam P 
Marco‐Rius, Irene 
Chen, Albert P 

Abstract

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 4He 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 13C solutions. The 13C liquid‐state polarization of [1‐13C]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.

Description

Keywords

MRI, MRS, carbon-13, cryogen-free, cryostat, dynamic nuclear polarization, hyperpolarization, hyperpolarizer, Carbon Isotopes, Magnetic Resonance Imaging, Microwaves, Pyruvic Acid, Rheology, Temperature

Journal Title

NMR in Biomedicine

Conference Name

Journal ISSN

0952-3480
1099-1492

Volume Title

Publisher

Wiley

Rights

All rights reserved
Sponsorship
European Research Council (682574)
European Union's Horizon 2020 European Research Council (ERC Consolidator Grant). Grant Number: 682574