中文摘要：

针对扰相梯度在基于梯度回波（GRE）的二维相位对比磁共振成像（2DPC-MRI）序列中的作用进行理论分析和实验研究.使用基于流动质子的2DPC-MRI仿真对扰相梯度的作用进行分析;在流动模体和志愿者实验中使用的扰相梯度分别为0π、2π、4π、6π、8π和10π,对成像结果进行测量,得到对应的流量.实验结果表明：当2DPCMRI序列中的的扰相梯度为0π和2π时,流动模体测量结果与设定值之间存在较大的误差,志愿者实验中扰相梯度为0π和2π的实验组与其他实验组的测量结果相比误差明显;当2DPC-MRI序列中的扰相梯度大于等于4π时,各实验组之间的测量误差小于5%.从保证成像质量和减少成像时间两方面考虑,相位对比磁共振序列中最优的扰相梯度为4π.

英文摘要：

Effect of gradient spoiling in gradient recalled echo （GRE） based two-dimensional phase contrast magnetic resonance imaging （2D PC-MRI） sequence was studied by theoretical analysis and experimental research. 2D PC-MRI simulation was applied to analyze the effect of gradient spoiling on flowing protons. Gradient spoilings of 0π,2π,4π,6π,8π and 10π were employed for flow phantom and volunteer experiment, and the relative flow rates through calculation of imaging results were obtained. Results showed that there was obvious error between the measured flow and setting values when the gradient spoilings of 0n and 2n were applied in the flow phantom experiment. There were significant errors comparing the group with gradient spoilings of 0n and 2n to other groups＇ results in the volunteer experiment. When the gradient spoiling was equal or greater than 4n, the measuring errors between the experiment groups were less than 5 %. However, due to the fact that the greater use of gradient spoiling requires more time for imaging, 4n was the optimal gradient spoiling in 2D PC-MRI sequence when considering the image quality and the imaging time.