抑制MRI运动伪影的双脉冲预饱和技术的实现  

Design and realization of double pulse spartial presaturation to restrain motion artifact in MRI

作　　者：胡丽丽[1] 杨文晖[1] 王慧贤[1] 王铮[1] 

机构地区：[1]中国科学院电工研究所生物电磁室,北京100080

出　　处：《生物医学工程与临床》2005年第4期198-200,共3页Biomedical Engineering and Clinical Medicine

摘　　要：目的设计双预饱和脉冲序列,要求被激发块边缘锐利、无交叉激发,并且要求其宽度、位置可调。方法在磁场强度为0.23T的全身开放式永磁磁共振成像仪上通过扫描水模进行研究,依据结果修改设计编写的脉冲序列直至达到期望的结果。结果双预饱和RF脉冲、SincGRF函数及扰相梯度的联合使用,成功地得到了边缘锐利、饱和均匀的预饱和带,减小了弛豫时间对数据采集的约束和限制。结论采用本文所述方法,可以有效实现预饱和扫描功能,获得边缘锐利的预饱和带。Objective To design a pulse sequence employing spartial presaturation that can create a rectangular section profile without cross-excitation of adjacent regions. And excited slabs can be defined with arbitrary thickness and position. Methods To repeatedly scan phantoms and modify designed pulse sequence in a 0.23T open magnetic resonance apparatus before getting perfect results. Results Using double RF pulses and dephasing gradients during spartial presaturation, not only successfully achieved presaturation regions that independent of imaging regions and get presaturation slabs of rectangular section profile but also reduced the restriction and dependence of the acquiring data on the relaxation time. Conclusion Application of this technology is able to achieve spartial presaturation and create a presaturation slab of rectangular section profile in MRI.

关 键 词：双脉冲 SincG 脉冲序列 磁共振成像 

分 类 号：R318.0[医药卫生—生物医学工程] TP399[医药卫生—基础医学]