磁共振成像谱仪梯度波形分析

梯度是磁共振成像（MRI）的关键环节.通过采集谱仪梯度波形信号并进行分析，提取出各通道波形的特征点，从而有助于快速准确地判断谱仪梯度硬件电路或脉冲序列编写是否存在问题.采用虚拟仪器LabVIEW软件控制高速采集卡DAQ-2005设计实现多路采集系统，对谱仪的梯度输出进行采集.通过对波形数据进行直方图统计、滤波、差分计算等分析，提取出波形的特征点，这些特征点包含时间与幅度信息.使用实验室自主研发的谱仪进行了多次实验，对该方法进行验证，证明了该方法的有效性，也为谱仪研制和脉冲序列开发提供了一种辅助测试方法.

Analysis of Gradient Waveform in Magnetic Resonance Imaging

The accuracy of gradient pulse waveform affects image quality significantly in magnetic resonance imaging (MRI). Recording and analyzing the waveform of gradient pulse helps to make rapid and accurate diagnosis of spectrometer gradient hardware and/or pulse sequence. Using the virtual instrument software LabVIEW to control the high speed data acquisition card DAQ-2005, a multi-channel acquisition scheme was designed to collect the gradient outputs from a custom-made spectrometer. The collected waveforms were post-processed (i.e., histogram statistical analysis, data filtering and difference calculation) to obtain feature points containing time and amplitude information. Experiments were carried out to validate the method, which is an auxiliary test method for the development of spectrometer and pulses sequence.