Designing parallel transmit head coil arrays based on radiofrequency pulse performance

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Electromagnetic Engineering

Background:

• Parallel transmit (pTx) technology enhances MRI performance.
• Designing efficient pTx head arrays requires integrating pulse design with electromagnetic properties.

Purpose of the Study:

• To propose a novel approach for designing pTx head arrays.
• To integrate radiofrequency pulse design with electromagnetic modeling of array coil elements.

Main Methods:

• Developed an algorithm for optimal coil element selection and pruning in pTx array design.
• Extended array-compressed parallel transmit pulse design to include coil element optimization.
• Simulated performance using dynamic multislice shimming and reduced field-of-view excitation on human head models at 7T.

Main Results:

• Achieved 15% lower mean excitation errors and 20% lower standard deviations.
• Reduced mean global averaged specific absorption rate by 20% and standard deviation by 50%.
• Demonstrated improved performance in simulations for shimming and targeted excitation.

Conclusions:

• The proposed optimal coil element selection algorithm enhances pTx head array design.
• Achieved higher transmit excitation accuracy and lower radiofrequency heating.
• The new pTx arrays exhibit more robust performance across subjects compared to previous designs.