An 80-channel receive array for 10.5T neuroimaging: Key considerations for SNR optimization

Area of Science:

• Medical Imaging
• Radiofrequency Engineering

Background:

• Ultrahigh field strengths (e.g., 10.5T) offer superior Signal-to-Noise Ratio (SNR) and parallel imaging capabilities for brain MRI.
• Parasitic losses in RF coil components can degrade achieved SNR, deviating from the theoretical ultimate intrinsic SNR (uiSNR).

Purpose of the Study:

• To systematically assess parasitic losses in RF coil components at ultrahigh fields.
• To develop engineering solutions to mitigate these losses and maximize SNR.
• To achieve a higher fraction of the uiSNR limit for improved MRI performance.

Main Methods:

• Developed a 16-channel loop-folded dipole transceiver array and an 80-channel receive-only loop array for 10.5T brain imaging.
• Optimized receive array design considering coil dimensions, loop configuration, and circuit strategies to minimize parasitic losses.
• Quantitatively assessed SNR and parallel imaging performance against uiSNR and existing arrays at 7T and 10.5T.
• Safety validated the complete 80-channel receive array for human use.

Main Results:

• The 80-channel array with larger, overlapped loops and optimized circuitry significantly improved SNR.
• The array performance approached the uiSNR limit across a substantial portion of the head.
• Parallel imaging capabilities were maintained or enhanced compared to non-overlapped layouts.

Conclusions:

• High-channel-count loop receive arrays can approach the uiSNR limit at ultrahigh fields (>10T).
• Meticulous design optimization, including parasitic loss minimization, is critical for achieving optimal performance in this regime.
• This work provides engineering insights for advancing ultrahigh-field MRI technology.