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

Mirsad Mahmutovic; Manisha Shrestha; Gabriel Ramos-Llordén; Dongsuk Sung; Luke J Edwards; Ying Chu; Paul I Dubovan; Alina Müller; Sam-Luca J D Hansen; Anpreet Ghotra; Kerrin J Pine; Roland Müller; Nikolaus Weiskopf; Lawrence L Wald; Choukri Mekkaoui; Harald E Möller; Susie Y Huang; Boris Keil

doi:10.1002/mrm.30606

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

Magn Reson Med. 2025 Jun 18. doi: 10.1002/mrm.30606. Online ahead of print.

Authors

Mirsad Mahmutovic¹, Manisha Shrestha¹, Gabriel Ramos-Llordén², Dongsuk Sung², Luke J Edwards³, Ying Chu³, Paul I Dubovan², Alina Müller¹, Sam-Luca J D Hansen¹, Anpreet Ghotra¹, Kerrin J Pine³, Roland Müller⁴, Nikolaus Weiskopf^{3

5

6}, Lawrence L Wald^{2

7}, Choukri Mekkaoui², Harald E Möller^{4

5}, Susie Y Huang^{2

7}, Boris Keil^{1

8

9}

Affiliations

¹ Institute of Medical Physics and Radiation Protection, TH-Mittelhessen University of Applied Sciences, Giessen, Hesse, Germany.
² Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
³ Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Saxony, Germany.
⁴ Nuclear Magnetic Resonance Methods and Development Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Saxony, Germany.
⁵ Felix Bloch Institute for Solid State Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Saxony, Germany.
⁶ Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, UK.
⁷ Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
⁸ Department of Diagnostic and Interventional Radiology, University Hospital Marburg, Philipps University of Marburg, Marburg, Hesse, Germany.
⁹ LOEWE Research Cluster for Advanced Medical Physics in Imaging and Therapy (ADMIT), TH-Mittelhessen University of Applied Sciences, Giessen, Hesse, Germany.

PMID: 40534115
DOI: 10.1002/mrm.30606

Abstract

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.

Keywords: MRI radiofrequency coil; diffusion MRI; field monitoring; human connectome project; phased array coil.

Abstract

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