Comparative Analysis of RF Coils for Low-Field Portable MRI

Abstract

The emerging Permanent Magnet Array (PMA) based portable MRI scanners is promising technology to enable a mobile and low cost version of this imaging modality. The Radio-Frequency (RF) coils in low-field MRI systems require high band-width and low Q-factor in contrast to the conventional RF coils due to highly inhomogeneous static B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> field generated by the PMA. To develop highly efficient RF coils for low-field portable MRI, it is important to study the comparative performance of conventional RF coils in low-field and mid-field MRI to gain insights on the critical parameters. In this paper, we study and analyze a number of widely used RF coils in MRI engineering at both mid-field (1.5 T, 64 MHz) and low-field (0.117 T, 5 MHz) through numerical simulations. The parameters under investigations include the B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> -field distribution, Full Width at Half Maximum (FWHM) bandwidth, Q-factor and field homogeneity.