B1+ compensation in 3T cardiac Imaging using short 2DRF pulses
B1+ compensation in 3T cardiac Imaging using short 2DRF pulses
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DOI：
10.1002/mrm.21443
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Nayak, Krishna S.
中科院分区：
文献类型：
--
作者：
Sung, Kyunghyun;Nayak, Krishna S.
这项研究的目的是确定定制的2DRF脉冲是否可以用来补偿3T时发射的射频场的面内变化。激励脉冲曲线被设计为近似测量的RF发射变化的倒数，其中左心室的变化近似为单向变化。使用了利用三个子脉冲的简单的2DRF脉冲设计，使得轮廓可以快速且容易地适应不同的感兴趣区域。结果来自体模和活体心脏成像。与传统的切片选择激发相比，3T时心脏研究中左心室的平均翻转角变化(用标准差除以平均翻转角)减少了0.001，平均减少了41%。
The purpose of this study was to determine if tailored 2DRF pulses could be used to compensate for in-plane variations of the transmitted RF field at 3T. Excitation pulse profiles were designed to approximate the reciprocal of the measured RF transmit variation where the variation over the left ventricle was approximated as unidirectional. A simple 2DRF pulse design utilizing three subpulses was used, such that profiles could be quickly and easily adapted to different regions of interest. Results are presented from phantom and in vivo cardiac imaging. Compared with conventional slice-selective excitation, the average flip angle variation over the left ventricle (measured as the standard deviation divided by the mean flip angle) was reduced with P < 0.001 and the average reduction was 41% in cardiac studies at 3T.