论文部分内容阅读
目的 提出一种基于PRESS的用于磁共振扩散加权波谱的扩散敏感梯度磁场施加方案.方法 在PRESS序列中的2个π射频脉冲两侧各施加一对交错的扩散敏感梯度磁场.结果 本方案有效减小涡流,利用PRESS序列中2个π射频脉冲之间的时间,延长了扩散梯度磁场脉冲的持续时间.即使在扩散权重较大的情况下,Naa,Cr及Cho的峰仍十分清晰,信噪比满足进一步分析的需要.结论 利用这一方案可以在常规医用磁共振成像设备上实现扩散加权波谱(DWS).“,”Objective To propose a new diffusion sensitive gradient magnetic field implement scheme basing on point resolved spectroscopy( PRESS) for magnetic resonance diffusion weighted spectroscopy. Methods Two pairs of interleaving pulsed gradient magnetic fields were applied symmetrically around the two π RF pulse in PRESS sequence respectively. Results Through the proposed scheme, the induced eddy currents were minimized , the interval time between the two π RF pulses in PRESS sequence was utilized effectively and the duration time of diffusion sensitive gradient magnetic pulses was increased. Conclusion It is feasible to implement diffusion weighted spectroscopy(DWS) in conventional clinical MRI scanners with this scheme.