Boudries, Dahmane, Philippe Massot, Elodie Parzy, Seda Seren, Philippe Mellet, Jean-Michel Franconi, Sylvain Miraux, et al. “A System for in Vivo On-Demand Ultra-Low Field Overhauser-Enhanced 3D-Magnetic Resonance Imaging.” Journal of Magnetic Resonance 348 (March 1, 2023): 107383.
https://doi.org/10.1016/j.jmr.2023.107383.
Development of very-low field MRI is an active area of research. It aims at reducing operating costs and improve portability. However, the signal-to-noise issue becomes prominent at ultra-low field (<1 mT), especially for molecular imaging purposes that addresses specific biochemical events. In the context of preclinical molecular MRI of abnormal proteolysis the paper describes a MRI system able to produce Overhauser-enhanced MR images in living rats through in situ Dynamic Nuclear Polarization at 206 µT using stable and non-toxic nitroxides. In parallel conventional images are generated at 206 µT following pre-polarization at 20 mT. Results show that nitroxides are visualized in 3D within a few minutes in the lungs, kidneys and bladder post-administration. This system will be used for molecular imaging of inflammation using protease-specific nitroxide probes.