A multi-channel MRI console for ultra-high field up to 14 T

Area of Science:

• Medical Imaging
• Biophysics
• Electrical Engineering

Background:

• Ultra-high field (UHF) magnetic resonance imaging (MRI) provides superior signal-to-noise ratio (SNR) and spatial resolution.
• Developing advanced hardware is crucial for leveraging the benefits of UHF MRI.

Purpose of the Study:

• To develop and characterize a multi-channel, home-built MRI console operating at 14 Tesla (T).
• To implement a hybrid analog-digital framework for efficient radio frequency (RF) signal processing.
• To demonstrate the console's capability for high-resolution imaging.

Main Methods:

• A hybrid analog-digital framework was employed, shifting RF transmission and reception to lower frequencies using software-defined radio (SDR).
• Digital pre-emphasis was utilized for gradient calculations to mitigate eddy current effects.
• The console features a pulse programmer with 20 ns resolution and a transmitter with independent waveform generation.
• The receiver incorporates dual-stage gain control (63 dB range), and signals are digitized at 16-bit resolution and 100 MHz sampling rate.

Main Results:

• The developed MRI console operates at 14 T with transmit and receive capabilities up to 600 MHz.
• High-resolution water phantom images were successfully acquired using the console on a 14 T Bruker Ascend 600 magnet.
• The system demonstrates precise timing control and optimized dynamic range for MR signals.

Conclusions:

• The novel multi-channel 14 T MRI console, based on a hybrid analog-digital SDR framework, is a viable tool for advanced imaging.
• This development facilitates enhanced signal processing and precise control for UHF MRI.
• The system shows significant potential for future clinical research and applications requiring high-resolution MRI.