磁共振现代射频脉冲理论在非均匀场成像中的应用

The application of modern radio-frequency excitation theory in nonhomogeneous field magnetic resonance imaging

在磁共振非均匀场成像中 ,传统的射频脉冲导致回波信号的衰减 .为了减小和消除这种磁共振信号的衰减 ,在讨论了经典理论的基础上根据非线性动力学中的逆散射理论和Shinnar LeRoux方法导出了用于非均匀场成像的射频脉冲设计方法 .模拟结果表明 ,采用逆散射理论和Shinnar

In the problem of nonhomogeneous field magnetic resonance imaging (MRI) echo peaks decay quickly due to traditional design of radio frequency (RF) pulse. In this article, using inverse scattering transform (IST) of the nonlinear dynamics and Shinnar-Le Roux selective excitation pulse design algorithm (SLR Algorithm) we have designed the RF pulse for the nonhomogeneous field MRI. Simulation has been made to test the signal loss induced by the excitation of different types of RF pulses. Simulation results show that the RF pulse sequence optimized by IST and SLR algorithm can improve the signal to noise ratio of MRI considerably