Magnetic resonance imaging (MRI) is a cornerstone of diagnostic medicine, offering unparalleled capabilities to visualize tissue structure and function. Advances in high-field scanners have expanded the scope of MRI beyond protons (¹H) to other nuclei such as sodium (²³Na) and deuterium (²H), opening new avenues to study metabolism alongside structural imaging. Our previous work demonstrated a link between glucose metabolism and intracellular sodium concentrations ([Na]) in breast cancer, highlighting the potential of multinuclear imaging for probing tumour energetics.
This project aims to develop high-field spectroscopic imaging techniques using ²³Na and ²H MRI for metabolic imaging in cancer, leveraging a Bruker 9.4 T preclinical scanner and a Siemens Terra.X 7 T clinical scanner at St Thomas’ Hospital. Prototype RF coils for ²H and ²³Na have been constructed, and preliminary images have been acquired on both platforms (Figure 1). The project will focus on advancing RF coil design, hardware engineering, pulse sequences, and MR physics to translate these promising approaches towards human studies.
Year 1:
Prototype coils will be optimized for sensitivity and re-engineered for seamless integration with the scanners. Imaging protocols for ²³Na and ²H will be validated in phantoms mimicking in vivo tissue concentrations and relaxation properties. The physics of quadrupolar nuclei (I > 1/2) will be explored, and MRI sequences—including FLASH, RARE, UTE, and various k-space sampling strategies (Cartesian vs centric)—will be optimized for in vivo imaging. Multiple quantum filtering and other quantum-mechanical properties will be exploited to generate novel contrast sensitive to anisotropic tissue architecture.
Year 2:
Preclinical MRI studies will be conducted in a human MDA-MB-231 breast cancer xenograft model using immunocompromised NOD/SCID/gamma mice. Glycolytic flux will be imaged using [6,6’-²H]glucose with ²H MRI, while intracellular sodium concentrations will be assessed with ²³Na MRI. Treatment response to Na⁺/K⁺-ATPase inhibition (ouabain) and sodium channel blockade (lidocaine) will be evaluated, linking ion transport and metabolism in vivo.
Years 3–4:
Clinical RF coils will be validated in healthy volunteers on the Siemens scanner. Transmit/receive characteristics and SAR profiles will be simulated and experimentally verified. A comprehensive MRI protocol combining anatomical imaging (T1- and T2-weighted) with metabolic imaging using ²³Na and ²H will be optimized, establishing a critical foundation for translation to cancer patients.
3-Month Rotation Project:
Optimization of ²H imaging protocols in phantoms mimicking in vivo tissue parameters on the 9.4 T scanner, to support subsequent preclinical and clinical studies.
