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

Ultra-high field magnetic resonance imaging (MRI) offers significant advantages in terms of signal-to-noise ratio and spatial resolution. In this study, we detail the development of a multi-channel home-built MRI console operating at 14 T. We propose a hybrid analog-digital framework that shifts high-frequency radio frequency transmission and reception issues to lower frequencies, utilizing software-defined radio technology to process these low-frequency signals. Digital pre-emphasis is used in gradient calculations to counteract the effects of eddy currents during gradient switching. Our console can transmit and receive at center frequencies up to 600 MHz. The pulse programmer module achieves a timing resolution of 20 ns, while the transmitter can independently generate waveforms with varying amplitude, frequency, phase, and envelope. The receiver's dual-stage gain control provides 63 dB of adjustable range, optimizing the magnetic resonance (MR) signal's dynamic range. After frequency conversion, the MR signals are digitized with 16-bit resolution and 100 MHz sampling rate. High-resolution water phantom images are acquired on the 14 T Bruker Ascend 600 nuclear magnetic resonance magnet, demonstrating its potential for clinical research and application.