磁共振成像信号的数字化接收系统设计  

The Design of a Digital Receiver System for MRI Scanners

作　　者：李睿[1,2] 肖亮[1,2] 王为民[1,2] 

机构地区：[1]北京大学信息科学技术学院,北京100871 [2]万东医疗装备股份有限公司,北京100016

出　　处：《波谱学杂志》2009年第3期359-368,共10页Chinese Journal of Magnetic Resonance

基　　金：北京市重大攻关资助项目(D0205002040221)

摘　　要：磁共振成像信号的采集是磁共振成像系统当中最重要的环节之一,设计性能良好的信号接收系统直接关系到成像质量的好坏.本文根据磁共振信号强度弱、频率高、带宽窄的特性对接收系统进行了统一设计.详细地对可控增益放大、高速A/D、数字解调以及抽样滤波器等几个部分进行了讨论,给出一整套设计方案,尤其对多级抽样滤波器,根据磁共振成像的性能需求和滤波器的不同特性给出了抽样系数分配和滤波器设计的一般方法.根据该方案设计出的磁共振信号接收系统有较高的信噪比,已经应用在临床医疗诊断当中.The receiver system is an integrating part in the magnetic resonance imaging （MRI） scanner, and the performance of which affects the iuality directly. In this paper, the design of a digital receiver system was presenich took into account the intrinsic properties of the MRI signals including weak ate, high frequency and narrow bandwidth. The role and the design of each part oceiver system, such as controlled amplifier, high speed A/D, digital demodulatolecimating filter, were discussed in detail. A special sample rate distribution andesign method were developed for the multi-stage decimating filter. The receivert designed was used on diagnostic MRI systems, and showed good performance irof signal noise ratio.

关 键 词：磁共振成像(MRI) 数字化接收系统 可控增益放大器 高速A/D 数字解调 抽样滤波器 

分 类 号：R445.2[医药卫生—影像医学与核医学]