基于数据采集卡和GPU的MRI信号接收设计

摘要

A receiver for magnetic resonance imaging (MRI) was developed based on data acquisition card and graphic processing unit (GPU). The data acquisition card is controlled by a triggering signal generated from the spectrometer, and samples the output from the pre-amplifier directly. Digital mixing, multi-stage filter decimation and image reconstruction are performed by GPU subsequently. GPU is specialized for high speed computation. When processing signals it can achieve a combination of filters flexibly based on the needs. In addition, double precision floating point format is used in the whole process to ensure a high computation precision. The feasibility of the receiver was demonstrated experimentally.%针对磁共振成像（Magnetic Resonance Imaging，MRI）的信号接收，提出一种基于高速数据采集卡和图形处理器（Graphic Processing Unit，GPU）的接收方法．采样每一行数据时，在谱仪输出触发脉冲的控制下，数据采集卡对前置放大器输出的信号进行直接采样．然后，使用 GPU 并行实现数字混频、多级滤波抽取和图像重建．GPU 具有很高的运算速度，信号处理过程中可以根据需要灵活地实现滤波器的组合．同时，数据全部采用双精度浮点类型，保证了很高的运算精度，提高了重建图像的信噪比．MRI 实验证明了该信号接收方法的可行性．