在低场MRI系统中用数字接收机测量梯度波形的方法

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

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.

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 am- plitude 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.