Magnetic field modeling with a set of individual localized coils.
Magnetic field modeling with a set of individual localized coils.
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DOI：
10.1016/j.jmr.2010.03.008
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发表时间：
2010-06
期刊：
影响因子：
--
通讯作者：
de Graaf RA
中科院分区：
文献类型：
--
作者：
Juchem C;Nixon TW;McIntyre S;Rothman DL;de Graaf RA
一组通用的，圆形的个别线圈被证明是能够产生高度复杂的磁场分布在一个灵活的方式。可以在三维以及切片体积中以允许成像应用的幅度生成纵向取向的线性场梯度。多线圈方法允许通过相同设置同时生成线性MRI编码场和复杂匀场，从而降低系统复杂性。在其上优化磁场的敏感体积的选择始终保持时间和空间可变。将场合成限制到实验相关的较小体积（例如单个切片）直接转化为提高的效率，即更高的磁场幅度和/或减小的线圈电流。对于像动脉自旋标记、信号破坏和扩散加权这样的应用，不需要梯度场的完美线性，并且对精度的降低的要求也可以容易地转化为提高的效率。第一个实验实现了小鼠头部MRI与24个线圈，安装在一个圆柱形的表面上。产生20 kHz/cm（47 mT/m）的倾斜线性场梯度，最大电流为1.4 A，可对小鼠头部进行径向成像。通过合成更复杂的高阶球谐磁场分布X2-Y2、Z2和Z2 X，证明了用于产生任意磁场形状的新方法的潜力。新的多线圈方法提供了将传统成像和匀场线圈集成到单个多线圈系统中的框架，其中磁场的形状，强度，精度和空间覆盖范围可以针对手头的应用进行专门优化。
A set of generic, circular individual coils is shown to be capable of generating highly complex magnetic field distributions in a flexible fashion. Arbitrarily oriented linear field gradients can be generated in three-dimensional as well as sliced volumes at amplitudes that allow imaging applications. The multi-coil approach permits the simultaneous generation of linear MRI encoding fields and complex shim fields by the same setup, thereby reducing system complexity. The choice of the sensitive volume over which the magnetic fields are optimized remains temporally and spatially variable at all times. The restriction of the field synthesis to experimentally relevant, smaller volumes such as single slices directly translates into improved efficiency, i.e. higher magnetic field amplitudes and/or reduced coil currents. For applications like arterial spin labeling, signal spoiling and diffusion weighting, perfect linearity of the gradient fields is not required and reduced demands on accuracy can also be readily translated into improved efficiency. The first experimental realization was achieved for mouse head MRI with 24 coils that were mounted on the surface of a cylindrical former. Oblique linear field gradients of 20 kHz/cm (47 mT/m) were generated with a maximum current of 1.4 A which allowed radial imaging of a mouse head. The potential of the new approach for generating arbitrary magnetic field shapes is demonstrated by synthesizing the more complex, higher order spherical harmonic magnetic field distributions X2-Y2, Z2 and Z2X. The new multi-coil approach provides the framework for the integration of conventional imaging and shim coils into a single multi-coil system in which shape, strength, accuracy and spatial coverage of the magnetic field can be specifically optimized for the application at hand.
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影响因子：
3.3
作者：
JEZZARD, P;BALABAN, RS
通讯作者：
BALABAN, RS
人类前额叶皮层与一组局部电气线圈的磁场均匀化。
影响因子：
3.3
作者：
Juchem, Christoph;Nixon, Terence W.;McIntyre, Scott;Rothman, Douglas L.;de Graaf, Robin A.
通讯作者：
de Graaf, Robin A.
影响因子：
3.3
作者：
Hsu, JJ;Glover, GH
通讯作者：
Glover, GH
影响因子：
2.1
作者：
Schill, RA
通讯作者：
Schill, RA
影响因子：
64.8
作者：
LAUTERBUR, PC
通讯作者：
LAUTERBUR, PC