摘要
利用脉冲梯度场技术，可采用自旋回波或梯度加波方法在单次或数次实验中获得高分辨的反映相位特性的特形脉冲激发轮廓。实验测量的关键在于准确确定回波汇集时间。由于脉冲梯度场的不完善，实验测量中任何回波时间确定的偏差将造成激发轮廓的线性相位误差。该文利用相位预补偿方法对实验测量的细节进行了讨论。
The high-resolution phase-sensitive excitation-profile of a shaped pulse can be measured with the pulsed-filed-gradient technique in one or several experiments by spinecho or gradient-echo sequence. The key to the implementation of this rapid measurement is the determination of the exact echo time (TE). However due to the imperfection of the field-gradient, the exact TE is difficult to determine experimentally. Any discrepancy between the ideal TE and an experimental TE will introduce the extra phase shift to the excitation profile. Experimental details are disussed in this article and a phase precompensation method is adopted to avoid the experimental error.
出处
《华东师范大学学报（自然科学版）》
CAS
CSCD
北大核心
1999年第1期47-50,共4页
Journal of East China Normal University(Natural Science)
基金
国家自然科学基金
国家教委博士点基金
关键词
特形脉冲
激发轮廓
脉冲梯度场
核磁共振
shaped pulse excitation profile pulsed field gradient auto-phase-correction
