Abstract
Ultralow-field (ULF) nuclear magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) are promising spectroscopy and imaging methods allowing for, e.g., the simultaneous detection of multiple nuclei or imaging in the vicinity of metals. To overcome the inherently low signal-to-noise ratio that usually hampers a wider application, we present an alternative approach to prepolarized ULF MRS employing hyperpolarization techniques like signal amplification by reversible exchange (SABRE) or Overhauser dynamic nuclear polarization (ODNP). Both techniques allow continuous hyperpolarization of 1H as well as other MR-active nuclei. For the implementation, a superconducting quantum interference device (SQUID)-based ULF MRS/MRI detection scheme was constructed. Due to the very low intrinsic noise level, SQUIDs are superior to conventional Faraday detection coils at ULFs. Additionally, the broadband characteristics of SQUIDs enable them to simultaneously detect the MR signal of different nuclei such as 13C, 19F, or 1H. Since SQUIDs detect the MR signal directly, they are an ideal tool for a quantitative investigation of hyperpolarization techniques such as SABRE or ODNP.
Highlights
High field magnetic resonance imaging (MRI) is one of the most powerful non-invasive imaging techniques used for medical diagnostics
To overcome the inherently low signal-to-noise ratio that usually hampers a wider application, we present an alternative approach to prepolarized ULF magnetic resonance spectroscopy (MRS) employing hyperpolarization techniques like signal amplification by reversible exchange (SABRE) or Overhauser dynamic nuclear polarization (ODNP)
We presented an ULF MRS and MRI system with an open geometry and an accessible sample volume for the combination with hyperpolarization techniques, such as SABRE and ODNP
Summary
High field magnetic resonance imaging (MRI) is one of the most powerful non-invasive imaging techniques used for medical diagnostics. The amplitude of the MR signal scales according to Curie’s law and increases with the B0 field strength This is the main reason why there is a trend toward even higher magnetic fields for MRI systems. Such devices produce hyperpolarized substances, which subsequently can be injected into a subject.30 Both techniques, SABRE and ODNP, can be performed ideally in the ULF regime B0 < 10 mT. In order to investigate the hyperpolarizability of newly developed substances and transfer catalysts at extremely low magnetic fields, the aim was to develop and construct a ULF-MRS/MRI system using a DC SQUID as a detector. In the subsequent section the “combination of ODNP hyperpolarization with ULF MRI” is demonstrated, followed by the conclusions, and an outlook on further possibilities of the instrument
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
