Rotating Permanent Magnets for NMR and MRI of heterogeneous systems

The goal of this project is to establish the foundations for the next generation diagnostic magnetic resonance for in-vivo studies of biochemical processes. Magnetic resonance, unlike other techniques, probes in a non-invasive manner the local structure and dynamics of chemical and biological function. Many systems (e.g. organisms) are however heterogeneous and, currently, studies by high-resolution NMR spectroscopy necessitate fast sample rotation (thousands of revolutions per second) at the so-called “magic angle” with the magnetic field. Practical, scientific and ethical issues are raised when we extrapolate this technique to small animals or even to living cell cultures. We aim to push the technology of magnetic resonance to the next level by introducing rotating magnetic fields around static samples. Rotating magnets capable of offering ultra high-resolution NMR and MRI will be built and used to acquire metabolic signatures from living organisms at cellular and macroscopic level of observation.

This research was initiated with the R-EVOLUTION-M-R project (for Rotating Evolution Magnetic Resonance), generously funded in 2008 by the European Research Council (Starting Grant). The initial aim of our project was to design and built uniform permanent magnets producing a strong magnetic field, tilted with respect to the clear bore of the magnet. An innovative design of such titled permanent magnets has been demonstrated in [1]. This designed was first realized in small scale prototypes that allowed us to demonstrate magic angle field spinning on static samples of liquid crystals. Since, the first preclinical spinning MRI magnet is shown on the figure above. The project has reached the point were rapidly rotating uniform magnets and associated MR instrumentation are operational. We are currently recording high-resolution 1H NMR spectra under rapid magnet (1.0 Tesla) rotation. Progress is undeway !

References:

[1] Sakellariou, D.; Hugon, C.; Guiga, A.; Aubert, G.; Cazaux, S. & Hardy, P. Permanent magnet assembly producing a strong tilted homogeneous magnetic field: Towards magic angle field spinning NMR and MRI. Magn. Reson. Chem., 2010, 48, 903-908