基于FPGA的磁共振成像仪梯度模块的设计

Design of MRI gradient module based on FPGA

针对磁共振成像仪小型化、数字化的发展需求,提出了一种基于FPGA的磁共振成像仪梯度模块设计方案。该方案以FPGA为系统控制核心,结合高精度的四通道DAC和高分辨率的数字电位计,实现了梯度脉冲波形的生成、转换、预加重处理等一系列的功能。与以往的方案相比,该方案不但有效的减轻了主处理器FPGA的工作负担,而且尽可能的提高了系统的数字化和集成化。通过软件仿真和联机调试,结果表明该方案工作稳定可靠,能够很好的满足小型化磁共振成像系统的需求。

Aiming at the needs of the digitalization and miniaturization of the MRI system, a design scheme of gradient module based on FPGA is proposed in this paper. This scheme uses FPGA as the system control center, combined with high accuracy quad DAC and high resolution digital potentiometer to achieve the gradient pulse waveform generation, conversion, pre-emphasisprocessing and so on.Compared with the previous schemes, this scheme not only effectively reduces the workload of the host processor FPGA, but also improves the digitalization and integration of the systemas much as possible. Through the software emulation and online debugging, results show that the scheme is stable and reliable, able to satisfy the needs of miniaturized magnetic resonance imaging system.