Development of Novel RF Coils for Hyperpolarized Magnetic Resonance Imaging

Many human diseases are associated with changes in the way the body turns the fuels we eat (e.g. sugars and fats) into the energy needed for growth, movement and repair, processes we collectively call 'metabolism'. As such, assessment of metabolism provides a vital way to understand the mechanisms of disease, as well as providing a means to assess the response to different drugs and medicines. However, the tools that we have to study metabolism in vivo are limited and new methods are required.

Our recent work has focussed on the development of a novel in vivo approach for the measurement of metabolism, called Hyperpolarized Magnetic Resonance Imaging (HP-MRI). This is an approach that allows >10,000-fold increases in the sensitivity of magnetic resonance imaging (MRI) to detect and monitor the uptake and utilisation of fuels in vivo. HP-MRI requires the generation of 13C-labelled tracers in a hyperpolarizer system which operates at very low temperatures (~1K) and high magnetic fields (>3T). Following a rapid dissolution step, the hyperpolarized tracer can be injected and its in vivo uptake and utilisation followed non-invasively using magnetic resonance imaging. The metabolic probes produced are not radioactive (as 13C is a stable isotope) and are made from naturally occurring, physiological compounds making them safe and suitable for repeat injections to monitor changes in metabolism as a disease progresses or following treatment.

To read out the signals that are emitted by the hyperpolarized probes requires specific radiofrequency (RF) coils which need to be optimised for the organ of interest (e.g. heart, liver, kidney) to maximise the signal that can be recorded and to ensure good image quality. In partnership with PulseTeq Ltd, a UK based RF coil design company, this project aims to develop novel RF coils specifically for HP-MRI to allow rapid clinical translation of this emerging medical imaging technology.

Standard MRI scanners, and therefore RF coil designs, are focussed on detecting the signal from the 1H nuclei within the water molecules inside the body. To make RF coils suitable for HP-MRI, they need to be specifically tuned to the frequencies emitted by 13C nuclei. This project will aim to develop such RF coils, optimising them for the sensitive detection of signals from different organs of the human body.