A Near-Field Coupling Array Enables Parallel Imaging and SNR Gain in MRI

Area of Science:

• Medical Imaging
• Metamaterials and Metasurfaces
• Radiofrequency Engineering

Background:

• Wireless radiofrequency (RF) coils using metasurfaces can streamline clinical magnetic resonance imaging (MRI) by removing cable constraints and simplifying coil design.
• Clinical adoption of wireless RF coils hinges on their ability to support parallel imaging, which enhances efficiency but often compromises signal-to-noise ratio (SNR).
• Existing wireless RF coils with metamaterials frequently lack parallel imaging support and exhibit suboptimal SNR.

Purpose of the Study:

• To propose a novel wireless RF coil architecture, the near-field coupling array (NFCA).
• To establish a theoretical framework for applying metasurface arrays in MRI RF coil design.
• To demonstrate the NFCA's capability for both high SNR performance and effective parallel imaging.

Main Methods:

• Development of a new wireless RF coil architecture termed the near-field coupling array (NFCA).
• Formulation of a general theoretical framework for metasurface array application in RF coil design.
• Derivation and validation of the SNR expression for the NFCA architecture through case studies.

Main Results:

• The NFCA architecture demonstrates excellent SNR performance and robust parallel imaging capabilities.
• A 66% improvement in SNR was achieved compared to conventional wired RF coils.
• The NFCA's average acceleration factor reached over 94% of that of commercial coils.

Conclusions:

• The proposed NFCA represents a significant advancement in wireless RF coil technology for MRI.
• The NFCA effectively addresses the trade-off between SNR and parallel imaging performance.
• This technology holds promise for enhancing clinical MRI workflows through improved efficiency and image quality.