A 64-channel transmitter for investigating parallel transmit MRI.

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Radiofrequency (RF) Engineering
• Medical Physics

Background:

• Multiple channel RF transmitters are crucial for advanced MRI techniques like transmit SENSE and B(1) shimming.
• High cost and limited availability of current multi-channel transmitters restrict their widespread adoption in research.

Purpose of the Study:

• To develop and validate a cost-effective, easily replicable 64-channel RF transmit system for MRI research.
• To enable broader access to advanced MRI capabilities through an affordable hardware solution.

Main Methods:

• Designed a modular 64-channel RF transmit system using vector modulators, 100W MOSFET amplifiers, and digital potentiometers.
• Implemented amplitude and phase control for B(1) shimming and dynamic modulation capabilities for transmit SENSE.
• Tested the system with bench and imaging data to demonstrate performance.

Main Results:

• The developed system provides 64 channels with 100W peak output, featuring modularity for scalability.
• Demonstrated precise amplitude and phase control essential for B(1) shimming.
• Confirmed the system's capability for dynamic modulation required for transmit SENSE applications.

Conclusions:

• The inexpensive, modular 64-channel RF transmit system significantly lowers the barrier to entry for advanced MRI research.
• This development facilitates wider implementation of techniques like B(1) shimming and transmit SENSE.
• The system's design is suitable for duplication by researchers with RF hardware experience.