磁共振成像数字谱仪的射频发射/接收通道相位相干性的研究

Phase Coherence between RF Transmitter and Receiver in Digital MRI Spectrometer

讨论了一种在核磁共振成像数字谱仪中保证射频发射机与接收机之间射频信号相位相干的方法,该方法在成像脉冲序列执行过程中,同步切换发射机与接收机的频率,并在脉冲序列最后,将发射和接收频率恢复到脉冲序列最初的频率值,从而实现发射与接收的信号相干,其优点是无需加入额外的"回绕延时",从而使得脉冲序列的编写得到简化,并且该方法不依赖于磁共振谱仪发射机和接收机硬件部分的具体结构,是适用于数字化谱仪的一种普遍的方法.

Phase coherence between RF transmitter and receiver in digital MRI spectrometer was studied. In order to keep phase coherence between the transmitter and the receiver, we implemented a method in which the frequencies of the transmitter and the receiver were switched simultaneously during pulse sequence execution, and reset to their original values, respectively, at the end of sequence. The experimental results showed that this method is suitable for digital spectrometer and independent on the structure of transmitter and receiver.