High-density MRI coil arrays with integrated field monitoring systems for human connectome mapping

High-density MRI coil arrays with integrated field monitoring systems for human connectome mapping

Magnetic Resonance in Medicine | 94 (5) 2286-2303
Purpose To develop and test two high-density MRI coil arrays with integrated field monitoring systems for enhanced diffusion imaging with strong diffusion-sensitizing gradients. Methods Two multichannel head coils were constructed for first- and second-generation 3T Connectome MRI scanners, incorporating 64 and 72 receive channels, respectively. The array coils were evaluated using RF bench-level metrics, including quality factor, tuning, matching, and coupling measurements. Imaging performance was comprehensively assessed through metrics such as SNR, 𝐵+1 efficiency, and inter-channel noise correlations, and compared with and without field camera integration. Parallel imaging capability was evaluated using geometry (g)-factors. The field camera performance was characterized by quantifying phase errors and field probe FID lifetimes. In vivo DWI acquisitions with high 𝑏-values were performed to evaluate the system's ability to correct higher-order field perturbations. Results The developed arrays demonstrated up to 1.4-fold higher SNR and superior g-factor performance when compared to a commercially available 32-channel head coil. Integration of the field camera was achieved without compromising the performance of either system. In vivo imaging with concurrent field monitoring enabled accurate spatiotemporal field corrections, significantly reducing geometric distortions, blurring, and ghosting in high 𝑏-value DWI. Conclusion The integration of high-density MRI arrays with field monitoring systems facilitated the capture and correction of spatiotemporal field perturbations during strong gradient activity, substantially enhancing image quality and diffusion parameter mapping quality. These advancements provide a robust platform for exploring the structural intricacies of the human connectome.

Purpose

To develop and test two high-density MRI coil arrays with integrated field monitoring systems for enhanced diffusion imaging with strong diffusion-sensitizing gradients.

Methods

Two multichannel head coils were constructed for first- and second-generation 3T Connectome MRI scanners, incorporating 64 and 72 receive channels, respectively. The array coils were evaluated using RF bench-level metrics, including quality factor, tuning, matching, and coupling measurements. Imaging performance was comprehensively assessed through metrics such as SNR, 𝐵+1 efficiency, and inter-channel noise correlations, and compared with and without field camera integration. Parallel imaging capability was evaluated using geometry (g)-factors. The field camera performance was characterized by quantifying phase errors and field probe FID lifetimes. In vivo DWI acquisitions with high 𝑏-values were performed to evaluate the system's ability to correct higher-order field perturbations.

Results

The developed arrays demonstrated up to 1.4-fold higher SNR and superior g-factor performance when compared to a commercially available 32-channel head coil. Integration of the field camera was achieved without compromising the performance of either system. In vivo imaging with concurrent field monitoring enabled accurate spatiotemporal field corrections, significantly reducing geometric distortions, blurring, and ghosting in high 𝑏-value DWI.

Conclusion

The integration of high-density MRI arrays with field monitoring systems facilitated the capture and correction of spatiotemporal field perturbations during strong gradient activity, substantially enhancing image quality and diffusion parameter mapping quality. These advancements provide a robust platform for exploring the structural intricacies of the human connectome.

Research Team

Prof. Dr.
Boris Keil
Principal Investigator|Scientific Coordinator
Prof. Dr.
Susanne Knake
Principal Investigator|Dep. Scientific Coordinator
Mert Murat Kurt
PhD student
Mona Alem
PhD student
Dr. med.
Felix Zahnert
Staff

Publications

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    Purpose To develop and test an MRI coil assembly for imaging deep brain stimulation (DBS) at 3 T with a reduced level of local specific absorption rate of RF fields near the implant. Methods A mechanical rotatable linearly polarized birdcage transmitter outfitted with a 32-channel receive array was constructed. The coil performance and image quality were systematically evaluated using...
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  • Eddy current-induced artifact correction in high b-value ex vivo human brain diffusion MRI with dynamic field monitoring
    Purpose To investigate whether spatiotemporal magnetic field monitoring can correct pronounced eddy current-induced artifacts incurred by strong diffusion-sensitizing gradients up to 300 mT/m used in high b-value diffusion-weighted (DW) EPI. Methods A dynamic field camera equipped with 16 1H NMR field probes was first used to characterize field perturbations caused by residual eddy currents...
  • High-density MRI coil arrays with integrated field monitoring systems for human connectome mapping
    Purpose To develop and test two high-density MRI coil arrays with integrated field monitoring systems for enhanced diffusion imaging with strong diffusion-sensitizing gradients. Methods Two multichannel head coils were constructed for first- and second-generation 3T Connectome MRI scanners, incorporating 64 and 72 receive channels, respectively. The array coils were evaluated using RF...

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