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公开(公告)号：US5602480A
公开(公告)日：1997-02-11
申请号：US422234
申请日：1995-04-14
IPC分类号： G01R33/3875 , G01R33/54 , G01R33/20
CPC分类号： G01R33/3875 , G01R33/4835
摘要： An inspection method by means of an inspection apparatus using nuclear magnetic resonance and having magnetic field generating apparatus for generating a static magnetic field, gradient magnetic fields and an RF magnetic field; magnetic field generating apparatus by means of additional shim coils, which vary homogeneity of the static magnetic field by varying current flowing therethrough; signal detecting apparatus for detecting nuclear magnetic resonance signals from an object to be inspected; an apparatus for processing signals detected by the signal detecting apparatus; and control apparatus for controlling currents flowing through the shim coils, which method using nuclear magnetic resonance comprises a step of storing shim currents corresponding to each of a plurality of slices, capable of improving homogeneity of the static magnetic field for each of the plurality of slices, and a step of switching over the shim currents to those corresponding to a relevant slice to be measured prior to measurements of nuclear magnetic resonance signals from the slice. This inspection method can be applied also to a case where measurements of other slices are effected in intervals of measurements of the relevant slice.
摘要翻译： 使用核磁共振的检查装置的检查方法，具有用于产生静磁场的磁场产生装置，梯度磁场和RF磁场; 通过附加的垫片线圈产生磁场产生装置，其通过改变流过其中的电流来改变静态磁场的均匀性; 信号检测装置，用于检测来自被检体的核磁共振信号; 用于处理由信号检测装置检测的信号的装置; 以及用于控制流过所述垫片线圈的电流的控制装置，所述使用核磁共振的方法包括存储对应于多个片中的每一个的片状电流的步骤，能够提高所述多个片中的每一个的静态磁场的均匀性 以及在来自切片的核磁共振信号的测量之前，将垫片电流切换到与要测量的相关切片相对应的片电流的步骤。 该检查方法也可以应用于在相关切片的测量的间隔中实现其他切片的测量的情况。
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公开(公告)号：US5600245A
公开(公告)日：1997-02-04
申请号：US319724
申请日：1994-10-07
IPC分类号： G01R33/385 , G01R33/565 , G01V3/00
CPC分类号： G01R33/385 , G01R33/56518
摘要： An inspection apparatus using magnetic resonance includes magnetic field generators for generating a static magnetic field, a gradient magnetic field and a radio frequency magnetic field, respectively, a signal detector for detecting magnetic resonance signals from an inspected object, a computer for executing arithmetic operations for detection signals from the signal detector and an output device of the result of the arithmetic operations by the computer. The gradient magnetic field generator includes first and second gradient coils, the first gradient coil is a coil fixed to a magnet for generating a static magnetic field, the second gradient coil is a movable coil, and the magnetic field generated by the second gradient coil at a conducting portion of the magnet is offset by the magnetic field generated by the first gradient coil. According to this construction, an eddy current that occurs with the time change of the gradient magnetic field can be reduced.
摘要翻译： 使用磁共振的检查装置包括分别产生静磁场，梯度磁场和射频磁场的磁场发生器，用于检测来自被检查物体的磁共振信号的信号检测器，用于执行用于 来自信号检测器的检测信号和计算机的算术运算结果的输出装置。 梯度磁场发生器包括第一和第二梯度线圈，第一梯度线圈是固定到磁体上以产生静态磁场的线圈，第二梯度线圈是可动线圈，并且由第二梯度线圈产生的磁场在 磁体的导电部分由第一梯度线圈产生的磁场偏移。 根据该结构，可以减少随着梯度磁场的时间变化而发生的涡电流。
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公开(公告)号：US5510714A
公开(公告)日：1996-04-23
申请号：US926517
申请日：1992-08-10
CPC分类号： G01R33/34046 , G01R33/3642 , G01R33/3657 , G01R33/3678
摘要： In a bird cage resonator, the axial length of rungs is changed between orthogonal elements. By doing this, the real view fields of orthogonal ports A and B in the sagittal direction are changed and the sensitivity difference between both view fields is reduced. For an object with an elliptical section to be inspected such as the human body, a remarkable difference in detection sensitivity between each orthogonal ports is eliminated and the receiving sensitivity of MRI apparatus employing the QD method is improved.
摘要翻译： 在鸟笼式谐振器中，梯级的轴向长度在正交元件之间变化。 通过这样做，矢状方向上的正交端口A和B的真实视场被改变，并且两个视场之间的灵敏度差减小。 对于具有诸如人体等待检查的椭圆形截面的物体，消除了每个正交端口之间的检测灵敏度的显着差异，并且提高了采用QD方法的MRI装置的接收灵敏度。
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公开(公告)号：US5477145A
公开(公告)日：1995-12-19
申请号：US177393
申请日：1994-01-05
CPC分类号： G01R33/3642 , G01R33/34046 , G01R33/3657
摘要： In an RF probe comprising a resonator and a pickup coil, the pickup coil is an 8-shaped coil, and a center portion of this pickup coil is constituted in such a manner that crossing coils become parallel to each other at the portion. The center portion where the coils of the pickup coil are parallel to each other is so disposed as to extend along, and in the vicinity of, a part of a conductor loop of the resonator.
摘要翻译： 在包括谐振器和拾取线圈的RF探针中，拾取线圈是8形线圈，并且该拾取线圈的中心部分以这样的方式构成，使得交叉线圈在该部分处彼此平行。 拾波器线圈的线圈彼此平行的中心部分被布置成沿着谐振器的导体环的一部分延伸并且在谐振器的导体环的一部分附近。
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75.发明授权
公开(公告)号：US5371465A
公开(公告)日：1994-12-06
申请号：US850589
申请日：1992-03-13
申请人： Yukari Onodera , Etsuji Yamamoto , Ryuichi Suzuki
发明人： Yukari Onodera , Etsuji Yamamoto , Ryuichi Suzuki
IPC分类号： G01R33/24 , G01R33/3875 , G01R33/565 , G01R33/20
CPC分类号： G01R33/3875 , G01R33/24 , G01R33/56563
摘要： In an inspection apparatus using nuclear magnetic resonance (NMR), a spatial distribution of homogeneity of a static magnetic field can be quickly measured even when a heterogeneous object is inspected, by measuring simultaneously phase data and a transverse relaxation time at the same spatial position of the heterogeneous object, removing the difference of a phase term due to a chemical shift by anticipating components at that position and obtaining only the phase data resulting from static magnetic field inhomogeneity. A plurality of low-pass filters are provided to a shim power supply unit for driving a shim coil for generating additional static magnetic fields to correct static magnetic field homogeneity so that a low-pass filter having a small time constant is used at the time of adjustment of static magnetic field homogeneity so as quickly adjust static magnetic field homogeneity, and a low-pass filter having a large time constant is used at the time of the actual measurement of the object in order to prevent degradation of S/N of signals.
摘要翻译： 在使用核磁共振（NMR）的检查装置中，即使在异质物体被检查时也可以快速地测量静态磁场的均匀性的空间分布，通过同时测量相位数据和相同空间位置处的横向弛豫时间 异质物体，通过预测该位置处的分量来消除由于化学位移引起的相位项的差异，并且仅获得由静态磁场不均匀性产生的相位数据。 多个低通滤波器被提供给垫片电源单元，用于驱动垫片线圈以产生额外的静态磁场，以校正静态磁场均匀性，使得在使用具有小时间常数的低通滤波器时 调整静磁场均匀性，以便快速调整静磁场均匀性，并且在物体的实际测量时使用具有大时间常数的低通滤波器，以防止信号的S / N的劣化。
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