A Bore-Integrated Patch Antenna Array for Whole-Body Excitation in Ultra-High-Field Magnetic Resonance Imaging

TL;DR

This paper presents a bore-integrated patch antenna array that significantly enhances transmit efficiency for whole-body ultra-high-field MRI by utilizing the MRI bore's RF shield, demonstrating superior performance over existing designs.

Contribution

The study introduces a novel bore-integrated patch antenna array that improves transmit efficiency and integrates into the MRI bore's RF shield, advancing UHF MRI technology.

Findings

3.9 times higher transmit efficiency compared to stripline array

Effective decoupling between antennas

Feasibility of integrating arrays into MRI RF shield

Abstract

Objective: To develop and evaluate a bore-integrated patch antenna array designed for whole-body excitation in ultra-high-field (UHF) magnetic resonance imaging (MRI) with improved transmit efficiency and address the limitations of existing RF coil designs. Methods: The proposed patch antenna array utilizes the MRI bore's RF shield as a functional component to enhance the RF magnetic field ($B_1^+$) distribution. Numerical simulations were conducted to compare the performance of the patch antenna array to bore-integrated stripline and local dipole arrays. A decoupling structure was implemented to minimize coupling between adjacent patch antennas. The performance of the patch array was evaluated experimentally. Results: The proposed patch array provides 3.9 times higher averaged transmit (Tx) efficiency in the CP mode and 3.0 times higher for the phase shimming regime versus the bore-integrated stripline array. Conclusion: Compared to the stripline array, the bore-integrated patch antenna array offers significant improvements in Tx efficiency for whole-body UHF MRI. Significance: The findings support the feasibility of integrating arrays into the RF shield of MRI scanners. This could broaden the clinical use of UHF body MRI technology.