A Magnetic Resonance Imaging Surface Coil Transceiver Employing a Metasurface for 1.5T Applications

IEEE Trans Med Imaging. 2020 Apr;39(4):1085-1093. doi: 10.1109/TMI.2019.2942194. Epub 2019 Sep 18.

Abstract

A capacitive impedance metasurface combined with a transceiver coil to improve the radio frequency magnetic field for 1.5T magnetic resonance imaging applications is presented. The novel transceiver provides localized enhancement in magnetic flux density when compared to a transceiver coil alone by incorporating an electrically small metasurface using an interdigital capacitance approach. Full field simulations employing the metasurface show a significant improvement in magnetic flux density inside a homogeneous dielectric phantom, which is also shown to perform well for a range of depths into the phantom. The concept was experimentally demonstrated through vector network analyzer measurements and images have been taken using a 1.5T MRI scanner. The results show there is a 216% improvement in transmission efficiency, a 133% improvement in receiver signal-to-noise-ratio (SNR), and a 415% improvement in transceiver SNR for a particular transmission power when compared against a surface coil positioned at the same distance from the phantom, where these improvements are the maximum observed during experiments.

MeSH terms

  • Algorithms
  • Equipment Design
  • Magnetic Resonance Imaging / instrumentation*
  • Magnetic Resonance Imaging / methods*
  • Phantoms, Imaging
  • Signal-To-Noise Ratio