The Design of a Digital Receiver System for MRI Scanners
磁共振成像信号的数字化接收系统设计

The receiver system is an integrating part in the magnetic resonance imaging (MRI) scanner, and the performance of which affects the image quality directly. In this paper, the design of a digital receiver system was presented, which took into account the intrinsic properties of the MRI signals including weak amplitude, high frequency and narrow bandwidth. The role and the design of each part of the receiver system, such as controlled amplifier, high speed A/D, digital demodulator and decimating filter, were discussed in detail. A special sample rate distribution and filter design method were developed for the multi-stage decimating filter. The receiver system designed was used on diagnostic MRI systems, and showed good performance in terms of signal noise ratio.