Integrated RF/shim coil array for parallel reception and localized B0 shimming in the human brain

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biomedical Engineering
• Neuroimaging

Background:

• Susceptibility-induced B0 inhomogeneities cause significant image distortions in human brain MRI.
• Conventional B0 shimming methods, like spherical harmonic shimming, have limitations in addressing localized B0 field variations.

Purpose of the Study:

• To develop and evaluate a novel integrated radiofrequency and shim (RF/shim) coil array for simultaneous parallel reception and localized B0 shimming in the human brain.
• To enhance signal-to-noise ratio (SNR) and shimming efficiency within the same coil system.

Main Methods:

• A 32-channel receive-only head coil array was modified to allow both RF currents for reception and direct currents for B0 shimming in individual elements.
• In vivo performance was assessed in the frontal brain region, targeting susceptibility-induced B0 inhomogeneities.
• B0 maps and echo-planar images were acquired to evaluate the effectiveness of localized shimming.

Main Results:

• The integrated RF/shim coil array maintained coil quality factor and SNR.
• Localized B0 shimming significantly reduced B0 inhomogeneities and image distortions in the frontal brain.
• B0 root-mean-square error in the anterior brain was reduced by 60.3% compared to second-order spherical harmonic shimming.

Conclusions:

• The integrated RF/shim coil array effectively performs parallel reception and localized B0 shimming in the human brain.
• This technology offers superior shimming performance compared to conventional methods without occupying additional space or compromising SNR.
• The developed coil array represents a significant advancement for high-resolution brain imaging.