Degenerate mode birdcage volume coil for sensitivity-encoded imaging

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiofrequency Coil Design
• Parallel Imaging

Background:

• Accelerated MRI acquisition is crucial for reducing scan times and improving patient comfort.
• Parallel imaging techniques, such as SENSE, enable acceleration but can be limited by coil geometry and noise amplification.
• Birdcage coils are standard for brain imaging but often lack flexibility for advanced acceleration methods.

Purpose of the Study:

• To demonstrate a novel dual-mode degenerate birdcage coil designed for accelerated image encoding.
• To evaluate the coil's performance with SENSE reconstruction at various acceleration factors.
• To assess the impact of the coil's geometry on image noise using g-factor mapping.

Main Methods:

• A volume birdcage coil was degenerately tuned to resonate at both homogeneous and first gradient modes.
• Conventional and antisymmetric coupling structures were employed for simultaneous mode imaging.
• SENSE reconstruction was applied with acceleration factors of 1.3, 1.6, and 2-fold.
• In vivo brain imaging at 1.5 T was performed to validate accelerated and nonaccelerated scans.

Main Results:

• The dual-mode coil successfully enabled SENSE-type reconstruction with acceleration factors up to 2-fold.
• Spatially averaged g-factors were calculated, showing minimal noise increase (1.21 to 1.55) with acceleration.
• Accelerated and nonaccelerated anatomical brain images were acquired in vivo, demonstrating feasibility.

Conclusions:

• The demonstrated dual-mode degenerate birdcage coil effectively supports accelerated MRI acquisition using SENSE.
• This coil design has the potential to enhance SENSE-type reconstruction for applications requiring uniform whole-brain coverage.
• The system offers a promising approach for faster and more efficient brain MRI.