波谱学杂志 ›› 2007, Vol. 24 ›› Issue (3): 329-334.

• 研究论文 • 上一篇    下一篇

在低场MRI系统中用数字接收机测量梯度波形的方法

王鹤;任洁静;宁瑞鹏;李鲠颖   

  1. 上海市功能磁共振成像重点实验室,华东师范大学 物理系,上海 200062
  • 收稿日期:2006-11-30 修回日期:2007-01-29 出版日期:2007-09-05 发布日期:2009-12-05
  • 通讯作者: 李鲠颖

Measuring Gradient Waveform on Low-Field MRI Systems with a Digital Receiver

WANG He;REN Jie-jing;NING Rui-peng;LI Geng-ying   

  1. Shanghai Key Laboratory of Functional Magnetic Resonance Imaging, Department of Physics, East China Normal University, Shanghai 200062
  • Received:2006-11-30 Revised:2007-01-29 Online:2007-09-05 Published:2009-12-05
  • Contact: Li-Geng-ying

摘要: 提出了一种用数字接收机来测量低场系统中梯度波形的方法,详细介绍了该数字接收机接收音频信号的原理,并且对接收机的音频接收性能进行了测试. 最后利用该接收机测得的梯度波形,设置了系统的预加重参数,有效地减小了梯度线圈引起的涡流.

关键词: 磁共振成像, 涡流, 梯度波形测量, 数字接收机

Abstract: A method was proposed to measure the gradient waveform on low-field MRI systems with a digital receiver. The principles underlying such a method were discussed in detail. A variable gain amplifier was used in the digital receiver to modulate the amplitude of RF signal according to the audio-frequency (AF) signal. The performance of the digital receiver was tested and evaluated. It was shown that fitting the gradient waveforms measured with the digital receiver could result in correct pre-emphasis parameters, as demonstrated by evidently reduced eddy currents.

Key words: MRI, eddy current, gradient waveform measurement, digital receiver