A 16-channel combined loop-dipole transceiver array for 7 Tesla body MRI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiofrequency (RF) Coil Technology
• High-Field MRI

Background:

• Developing advanced RF coil arrays is crucial for improving image quality in high-field MRI.
• Existing coil designs face limitations in transmit/receive efficiency and specific absorption rate (SAR) at 7.0T.
• Optimizing coil element design is key to overcoming these challenges.

Purpose of the Study:

• To develop a 16-channel transceive body imaging array at 7.0T.
• To enhance transmit, receive, and specific absorption rate (SAR) performance.
• To combine loop and dipole elements for improved near and far-field characteristics.

Main Methods:

• Designed and constructed a 16-channel loop-dipole (16LD) RF coil array.
• Quantitatively evaluated transmit and receive performance using simulations and experiments.
• Compared the 16LD array with 16-channel microstrip line (16ML) and 10-channel fractionated dipole antenna (10DA) arrays.
• Acquired anatomic and functional MRI of the prostate, kidneys, and heart.

Main Results:

• The 16LD array demonstrated over 14% improvement in SNR, peak B1+, and B1+ transmit/SAR efficiencies compared to 16ML and 10DA in simulations.
• Experimentally, the 16LD achieved over 20% higher SNR and B1+ transmit efficiency.
• Achieved up to 51.8% higher peak B1+ compared to the 10DA array.

Conclusions:

• Combining loop and dipole elements creates a high-channel-density body imaging array with reduced inter-element coupling.
• The 16LD array offers superior near and far-field performance compared to existing 7.0T body arrays.
• High-quality MRI of the prostate, kidneys, and heart was achieved using the 16LD array.