This is said to represent a significant advance in MRI sensitivity as modern MRI techniques commonly used in medical imaging yield spatial resolutions on the millimetre length scale, with the highest-resolution experimental instruments giving spatial resolution of a few micrometers.
‘This is a very promising experimental result,’ said U. of I. physicist Raffi Budakian, who led the research. ‘Our approach brings MRI one step closer in its eventual progress toward atomic-scale imaging.’
MRI is used widely in clinical practice to distinguish pathologic tissue from normal tissue. It is non-invasive and harmless to the patient, using strong magnetic fields and non-ionising electromagnetic fields in the radio frequency range, unlike CT scans and traditional X-rays, which use more harmful ionising radiation.
MRI uses static and time-dependent magnetic fields to detect the collective response of large ensembles of nuclear spins from molecules localised within millimetre-scale volumes in the body. Increasing the detection resolution from the millimetre to nanometre range would be a significant technological advance.
According to a statement, the new technique introduces two unique components to overcome obstacles to applying classic pulsed magnetic resonance techniques in nanoscale systems. First, a novel protocol for spin manipulation applies periodic radio-frequency magnetic field pulses to encode temporal correlations in the statistical polarisation of nuclear spins in the sample. Second, a nanoscale metal constriction focuses current, generating intense magnetic field-pulses.
In their proof-of-principal demonstration, the team used an ultrasensitive magnetic resonance sensor based on a silicon nanowire oscillator to reconstruct a two-dimensional projection image of the proton density in a polystyrene sample at nanoscale spatial resolution.
‘We expect this new technique to become a paradigm for nanoscale magnetic-resonance imaging and spectroscopy into the future,’ said Budakian. ‘It is compatible with and can be incorporated into existing conventional MRI technologies.’
The team’s paper, Nanoscale Fourier-Transform Magnetic Resonance Imaging, is published in Physical Review X.
Massive new Coventry campus targets 60GWh battery output
Where will all the raw materials come from for the manufacturing process? How will they be transported to the factory and what is going to be done with the various scrap and residues?