磁共振成像谱仪B_0信号的高精度发生与测试

High Accuracy Generation and Test of B_0 Signals on Magnetic Resonance Imaging Spectrometer

设计了一种基于现场可编程门阵列(FPGA)的磁共振成像(MRI)谱仪B_0信号的高精度发生方法,并对产生的B_0信号经高速采集卡采集之后进行测试和验证.FPGA从外部读取波形数据和参数,分别存储在双端口随机存取存储器(RAM)和参数寄存器中,根据预补偿算法实现B_0信号的发生,并通过对时间参数和幅度参数的控制,产生不同的B_0信号,时间分辨率为1μs.对谱仪的B_0输出进行采集,再进行最小二乘拟合,以验证B_0信号发生的准确性.经实验证实,该设计可以产生正确、可控的高精度B_0信号.

A field programmable gate array （FPGA）-based method is proposed to generate B0 signals, with high accuracy,on magnetic resonance imaging （MRI） spectrometers. The FPGA reads the waveform data and external parameters, andstores them in the dual-port random access memory （RAM） and parameter registers, respectively. The B0 signals are thengenerated using the pre-emphasis algorithm, and different time or amplitude parameters give different B0 signals. The B0signals are collected by high speed acquisition card, and the least squares fitting algorithm is used to test the accuracy of theB0 signals generated. The performance of this method was validated by experiments.