波谱学杂志 ›› 2011, Vol. 28 ›› Issue (2): 198-206.

• 磁共振谱仪研制技术进展专栏 • 上一篇    下一篇

磁共振信号并行高速接收系统设计

严政1,2,赵武贻1,2,王慧贤1, 胡丽丽1, 杨文晖1*   

  1. 1.中国科学院 电工研究所,北京 100190; 2.中国科学院 研究生院,北京 100049
  • 收稿日期:2010-09-16 修回日期:2010-10-14 出版日期:2011-06-05 发布日期:2011-06-05
  • 基金资助:

    国家自然科学基金资助项目(50707033,50807050).

Design of a Parallel High-Speed Receiving System

 YAN Zheng1,2, ZHAO Wu-Yi1,2, WANG Hui-Xian1, HU Li-Li1, YANG Wen-Hui1*   

  1. 1. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2. Graduate School of the Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-09-16 Revised:2010-10-14 Online:2011-06-05 Published:2011-06-05
  • Supported by:

    国家自然科学基金资助项目(50707033,50807050).

摘要:

针对低场磁共振成像系统,该文设计了一种紧凑灵活的信号接收方案,实现对多通道磁共振信号的高速采样与直接数字解调. 系统采用高速模数转换器(A/D)对磁共振信号直接采样;以单片数字下变频器(DDC)——AD6636, 完成4路采样信号的数字解调;以数字信号处理器(DSP)作为控制器,实现对AD6636的配置以及I/Q数据的读取. 信号采样频率可达100 MSPS,适用于1 T以下的系统. 实验证明该设计具有结构紧凑,采样速率高,配置方便快速,滤波器设计丰富灵活等特点,为磁共振成像谱仪的研制提供了一种高性能的信号接收方案.

关键词: 磁共振成像(MRI), 多通道, 数字下变频, AD6636

Abstract:

In this paper, a compact and flexible signal receiving system mainly designed for low-field MRI systems is presented, which is capable of sampling multi-channel magnetic resonance signals simultaneously at a high speed and demodulating them directly. A digital down conversion chip (AD6636) was used to demodulate and decimate the signals from the four channels in a quadrature way. Digital signal processing (DSP) methods were used to complete the configuration of AD6636 and read out the I/Q data either from all channels at once, or just from one channel of interest. The sampling speed of the system could reach 100 million samples per second, giving high signal-to-noise. The system can be applied in MRI system with magnetic field strength up to 1 T. The performance of the signal receiving system was demonstrated by experimental results.

Key words: magnetic resonance imaging, multi-channel, digital down conversion, AD6636

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