Ex vivo continuous Overhauser nuclear dynamic polarization in a SQUID-based ultralow field magnetic resonance imaging system

Abstract

Overhauser Dynamic Nuclear Polarization (ODNP) is a method to achieve continuous hyperpolarization in MR measurements. Here, the polarization of free radicals is transferred to 1H using High Frequency (HF) pulses at the electron Larmor frequency. At UltraLow Fields (ULF) the frequency of the HF pulse lies in the range of several 100 MHz and is able to penetrate large sample volumes, making continuous in vivo ODNP measurements possible. Since conventional Faraday coils are not sensitive enough at ULF, a Superconducting QUantum Interference Device (SQUID) based detector is employed. First ex vivo images using ODNP enhanced MR have been acquired successfully