Multi-flux-transformer MRI detection with an atomic magnetometer.

Area of Science:

• Medical Imaging
• Biophysics
• Quantum Sensing

Background:

• Atomic magnetometers (AM) enable ultra-low field (ULF) Magnetic Resonance Imaging (MRI).
• Flux-transformers (FT) are crucial for decoupling MRI fields and gradients from sensitive AMs.
• Current AM-based ULF MRI systems face limitations in field of view (FOV) due to coil size and sensitivity trade-offs.

Purpose of the Study:

• To enhance the field of view (FOV) in atomic magnetometer (AM) based ultra-low field (ULF) MRI.
• To demonstrate a multi-channel acquisition strategy using a single AM and acquisition channel.
• To enable broader applications of non-cryogenic ULF MRI.

Main Methods:

• Utilized three flux-transformer (FT) input coils to achieve a twofold increase in FOV.
• Implemented a frequency-encoding gradient along the detection array span.
• Acquired three independent MRI signals using a single atomic magnetometer and acquisition channel.

Main Results:

• Demonstrated a twofold increase in the field of view (FOV) compared to previous AM-based ULF MRI setups.
• Successfully acquired three independent MRI signals with a single atomic magnetometer and acquisition channel.
• Validated the feasibility of multi-channel acquisition for enhanced FOV in ULF MRI.

Conclusions:

• The proposed multi-coil FT approach significantly expands FOV in AM-based ULF MRI.
• This method allows for efficient multi-signal acquisition with a single AM, reducing system complexity.
• The technique is critical for advancing non-cryogenic ULF MRI for various anatomical imaging applications.