Proposal for a permanent magnet system with a constant gradient mechanically adjustable in direction and strength
Proposal for a permanent magnet system with a constant gradient mechanically adjustable in direction and strength
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DOI：
10.1002/cmr.b.21320
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发表时间：
2016-02-01
影响因子：
0.9
通讯作者：
Bluemler, Peter
中科院分区：
文献类型：
--
作者：
Bluemler, Peter
提出了一种永磁系统的设计，该系统产生空间均匀的恒定磁场梯度，从而为无需梯度线圈和放大器的MRI创造了条件。这是通过将弱哈尔巴赫四极子叠加在强哈尔巴赫偶极子上实现的。四极杆或整个磁铁组件的旋转可用于通过过滤后的反向投影生成二维图像。此外，两个四极杆的相互旋转可用于缩放所产生的梯度。如果两个梯度具有相同的强度，甚至可以使梯度消失。通过分析和有限元模拟验证了这一概念。然而，工作原型的演示仍在等待中。(c) 2016 Wiley Periodicals, Inc.；机械工程B辑（机械工程），46 (1):41-48,2016
A design for a permanent magnet system is proposed that generates spatially homogeneous, constant magnetic field gradients, thus creating conditions suitable for MRI without gradient coils and amplifiers. This is achieved by superimposing a weak Halbach quadrupole on a strong Halbach dipole. Rotation of either the quadrupole or the entire magnet assembly can be used to generate two-dimensional images via filtered backprojection. Additionally, the mutual rotation of two quadrupoles can be used to scale the resulting gradient. If both gradients have identical strength the gradient can even be made to vanish. The concept is demonstrated by analytical considerations and FEM simulations. However, a demonstration on a working prototype is still pending. (c) 2016 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 46B: 41-48, 2016