January 22, 2016 - It is revealed that the unique properties of ultrathin metasurface resonators can improve magnetic resonance imaging (MRI) dramatically, according to new research.1 A metasurface formed when an array of metallic wires is placed inside a scanner under the studied object and a substantial enhancement of the radio-frequency magnetic field is achieved by means of subwavelength manipulation with metasurface, also allowing improved image resolution.
ANU scientists are part of a group that has found a way to increase the resolution of MRI scanners, while at the same time making the procedure quicker and safer for the patient. The international group of researchers placed ultrathin metallic resonators under the patient inside an MRI machine and increased the efficiency and quality of the scanning process. "This research may evolve into a new and very practical device that enhances MRI imaging and scanning time," said Professor Yuri Kivshar, from the Australian National University (ANU). "It does not require any intervention into the hardware of the MRI scanner, but rather is an inexpensive add–on device that can be used with any existing MRI scanner," said Professor Kivshar, head of the Nonlinear Physics Centre in the ANU Research School of Physics and Engineering.
Source: Siemens Healthcare2
New high–field and ultra–high–field MRI scanners can heat the tissue of patients due to an increase of the radiofrequency energy absorption. The team found the resonators, artificial materials with nanoscale periodic structures, suppressed the electric field, which is responsible for tissue heating. In their publication in Advanced Materials, the team reported that the resonators, also known as metamaterials, were able to spatially redistribute the electromagnetic near fields and double the signal–to–noise ratio. The improvement will enable higher–resolution images to be obtained in the same time.
Reference:
1. Slobozhanyuk AP, Poddubny AN, Raaijmakers AJ, et al. Enhancement of Magnetic Resonance Imaging with Metasurfaces. Adv Mater. 2016 Jan 11. doi: 10.1002/adma.201504270. [Epub ahead of print]
2. Siemens. http://www.healthcare.siemens.com/magnetic-resonance-imaging/0-35-to-1-5t-mri-scanner/magnetom-aera/use
