首页>
外国专利>
Magnetic resonance tomography apparatus and method employing a true FISP sequence with improved off-resonant behavior of two spin ensembles
Magnetic resonance tomography apparatus and method employing a true FISP sequence with improved off-resonant behavior of two spin ensembles
展开▼
机译:使用具有两个自旋集合的改进的非共振行为的真实FISP序列的磁共振层析成像设备和方法
展开▼
页面导航
摘要
著录项
相似文献
摘要
In a magnetic resonance tomography apparatus employing a FISP pulse sequence, the pulse sequence is repeated with a repetition time TR with different phase-coding gradient directions and with an alternating operational sign of the flip angle α. The gradient pulse trains are thereby completely balanced. A phase increment ΔΦ=β is generated in addition to the alternating operational sign of the flip angle α between successive excitation pulses, so that the steady state signals for a first and a second spin ensemble optionally have either identical or reversed signal polarities. A first dataset on the basis of identical signal polarities and a second dataset on the basis of reversed signal polarities are obtained by means of the free selection of the mutual signal polarities. A pure image of the first and the second spin ensembles is thus obtained by the addition and/or subtraction of the first and second datasets.
展开▼
机译:在采用FISP脉冲序列的磁共振断层摄影设备中,以具有不同相位编码梯度方向并且具有交替的翻转角α的重复时间T R Sub>来重复脉冲序列。梯度脉冲串由此完全平衡。除了相继激励脉冲之间的翻转角α的交替操作符号之外,还产生相位增量ΔΦ=β,使得第一和第二自旋系综的稳态信号可选地具有相同或相反的信号极性。通过相互选择信号极性来获得基于相同信号极性的第一数据集和基于相反信号极性的第二数据集。因此,通过对第一和第二数据集进行加法和/或减法来获得第一和第二自旋合奏的纯图像。
展开▼