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公开(公告)号：US5465719A
公开(公告)日：1995-11-14
申请号：US98775
申请日：1993-07-29
CPC分类号： G01R33/385 , G01R33/3802 , G01R33/3854
摘要： A bobbin for holding a gradient magnetic field coil, having a changeable size and sectional shape (a separable bobbin) is constituted by assembling coil supporters (a bobbin divided into a plurality of segments). The separable bobbin has coil supporters of an upper part a bottom part and a set of side surface parts and at least two supporting rods made of a nonmagnetic substance are fitted to the side surface parts of the coil supporters. Holes permitting the insertion of the supporting rods are bored in the upper and bottom parts of the coil supporters. The length d1 between both side surface parts can be made variable by adjusting the insertion length of the supporting rod into the upper and bottom parts. Accordingly, the distance between a patient and a gradient magnetic field can be reduced, and an intended gradient magnetic field intensity can be generated by a smaller current producing the gradient magnetic field than in the prior art. Setting of the patient to an MRI imaging apparatus becomes also easier, and there can be obtained a gradient magnetic field coil capable of being easily fitted and removed to and from the MRI imaging apparatus.
摘要翻译： 用于保持具有可变尺寸和截面形状（分离线圈架）的梯度磁场线圈的线轴由线圈支架（分为多个段的线轴）组装而成。 可分离筒管具有上部的线圈支撑件，底部部分和一组侧面部分，并且至少两个由非磁性物质制成的支撑杆装配到线圈支撑件的侧表面部分。 允许插入支撑杆的孔在线圈支撑件的上部和底部中钻孔。 通过将支撑杆的插入长度调节到上部和底部，两个侧面部分之间的长度d1可以变化。 因此，可以减少患者与梯度磁场之间的距离，并且通过产生梯度磁场的较小电流可以产生预期的梯度磁场强度，而不是现有技术。 将患者设置到MRI成像设备变得更容易，并且可以获得能够容易地装配和去除MRI成像设备的梯度磁场线圈。
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公开(公告)号：US5539311A
公开(公告)日：1996-07-23
申请号：US160807
申请日：1993-12-03
IPC分类号： G01R33/561 , G01V3/00
CPC分类号： G01R33/56554
摘要： In magnetic resonance imaging, a first echo train is obtained by applying a readout gradient magnetic field to a region of interest to be imaged and periodically inverting the polarity of the readout gradient magnetic field, without applying an encoding gradient magnetic field to the region of interest. A periodic change of phase shift of the first echo train is detected from the first echo train. Information indicating phase shifts of all of the echoes in the first echo train is obtained using the periodic change of phase shift. A second echo train is obtained by applying a readout gradient magnetic field and an encoding magnetic field to the region of interest and periodically inverting the polarity of the readout gradient magnetic field. Phases of echoes in the second echo train are corrected using the information indicating phase shifts of all of the echoes in the first echo train.
摘要翻译： 在磁共振成像中，通过将读出梯度磁场施加到要成像的感兴趣区域并周期性地反转读出梯度磁场的极性，而不对感兴趣的区域施加编码梯度磁场，获得第一回波串 。 从第一回波列检测第一回波串的相移的周期性变化。 使用相移的周期性变化来获得指示第一回波列中的所有回波的相移的信息。 通过将读出梯度磁场和编码磁场施加到感兴趣的区域并周期性地反转读出梯度磁场的极性来获得第二回波串。 使用指示第一回波列中的所有回波的相移的信息来校正第二回波列中的回波相位。
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公开(公告)号：US5394872A
公开(公告)日：1995-03-07
申请号：US44778
申请日：1993-04-12
IPC分类号： A61B5/055 , G01R33/48 , G01R33/561 , G01R33/563 , G01R33/20
CPC分类号： G01R33/563 , G01R33/5618 , G01R33/56333
摘要： In a magnetic resonance imagining method, using an effect that a fluid flows out of a plane where it is selectively excited between the time of applying a 90.degree. radio frequency pulse and the time of applying of a 180.degree. radio frequency pulse, two, images are separately constructed from multiple echo signals which are sampled before applying the 180.degree. radio frequency pulse and multiple echo signals which are sampled after applying the 180.degree. radio frequency pulse. An image of the fluid flow and an image of a static part are separated from each other based on a difference between the two constructed images.
摘要翻译： 在磁共振想象方法中，使用流体从施加90°射频脉冲的时间和施加180°射频脉冲的时间之间选择性激发的平面流出的效果，两个图像 分别由在应用180°射频脉冲之前被采样的多个回波信号和在施加180°射频脉冲之后被采样的多个回波信号构成。 基于两个构造的图像之间的差异，流体流动的图像和静态部分的图像彼此分离。
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公开(公告)号：US5754047A
公开(公告)日：1998-05-19
申请号：US778251
申请日：1997-01-08
IPC分类号： G01R33/3875 , G01R33/54 , G01V3/00
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。 这种检查方法也可以应用于其他切片的测量在相关切片的测量间隔中实现的情况。
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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：US08614574B2
公开(公告)日：2013-12-24
申请号：US12993905
申请日：2009-05-22
CPC分类号： A61B5/055 , A61B5/7285 , A61B5/7289 , A61B5/7292 , G01R33/288 , G01R33/543 , G01R33/5614 , G01R33/56325 , G01R33/5635
摘要： A magnetic resonance imaging apparatus is provided, which is capable of reducing SAR while maintaining S/N ratio and image contrast in a GrE-type pulse sequence, regardless of whether a synchronous imaging is performed or not.The present invention controls a flip angle as to each measurement set 409 that is obtained by division according to the size of phase encoding and a body motion cycle of a subject in the GrE-type pulse sequence. In a set 501 which measures echoes with phase encoding having a minimum absolute value, the flip angle is maximized as to the RF pulse having a minimum phase encoding amount and at least one RF pulse irradiated immediately before. As for the other RF pulses, the flip angle varies within a range less than the maximum, irrespective of the non-imaging mode, the imaging mode, or the size of phase encoding.
摘要翻译： 提供一种磁共振成像装置，其能够在保持GrE型脉冲序列中的S / N比和图像对比度的同时减小SAR，而不管是否执行同步成像。 本发明通过根据GrE型脉冲序列中的对象的相位编码的大小和体动周期进行分割而获得的每个测量组409来控制翻转角。 在测量具有最小绝对值的相位编码回波的组501中，对于具有最小相位编码量的RF脉冲和紧接着照射的至少一个RF脉冲，翻转角度最大化。 对于其他RF脉冲，翻转角度在小于最大值的范围内变化，而与非成像模式，成像模式或相位编码的大小无关。
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公开(公告)号：US20110133735A1
公开(公告)日：2011-06-09
申请号：US12993905
申请日：2009-05-22
IPC分类号： G01R33/44
CPC分类号： A61B5/055 , A61B5/7285 , A61B5/7289 , A61B5/7292 , G01R33/288 , G01R33/543 , G01R33/5614 , G01R33/56325 , G01R33/5635
摘要： A magnetic resonance imaging apparatus is provided, which is capable of reducing SAR while maintaining S/N ratio and image contrast in a GrE-type pulse sequence, regardless of whether a synchronous imaging is performed or not.The present invention controls a flip angle as to each measurement set 409 that is obtained by division according to the size of phase encoding and a body motion cycle of a subject in the GrE-type pulse sequence. In a set 501 which measures echoes with phase encoding having a minimum absolute value, the flip angle is maximized as to the RF pulse having a minimum phase encoding amount and at least one RF pulse irradiated immediately before. As for the other RF pulses, the flip angle varies within a range less than the maximum, irrespective of the non-imaging mode, the imaging mode, or the size of phase encoding.
摘要翻译： 提供一种磁共振成像装置，其能够在保持GrE型脉冲序列中的S / N比和图像对比度的同时减小SAR，而不管是否执行同步成像。 本发明通过根据GrE型脉冲序列中的对象的相位编码的大小和体动周期进行分割而获得的每个测量组409来控制翻转角。 在测量具有最小绝对值的相位编码回波的组501中，对于具有最小相位编码量的RF脉冲和紧接着照射的至少一个RF脉冲，翻转角度最大化。 对于其他RF脉冲，翻转角度在小于最大值的范围内变化，而与非成像模式，成像模式或相位编码的大小无关。
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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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9.发明授权System of generating a magnetic field and MRI system using the system of generating a magnetic field 失效使用产生磁场的系统产生磁场和MRI系统的系统公开(公告)号：US07358726B2
公开(公告)日：2008-04-15
申请号：US10242442
申请日：2002-09-13
IPC分类号： G01V3/00
CPC分类号： G01R33/3806 , A61B5/055
摘要： An MRI system using an open type magnet, wherein two coils different in radius for generating gradient magnetic fields in a vertical direction are arranged in the open type magnet for generating a static magnetic field in the vertical direction. Currents are caused to flow through the two coils in directions opposite to each other to improve the degree of uniformity of the magnetic field in the vertical direction, thereby reducing the degradation thereof by equal to or smaller than 2 figures compared with the degree of uniformity of the static magnetic field generated by the existing MRI system. The positional information about a read-out direction is given through the dynamic control for the RF magnetic field to give the positional information about other two axes directions based on the gradient magnetic field having strength much larger than that of nonuniformity of the magnetic field.
摘要翻译： 使用开放型磁体的MRI系统，其中在垂直方向上产生梯度磁场的半径不同的两个线圈被布置在用于在垂直方向上产生静态磁场的开放型磁体中。 引起电流流过彼此相反方向的两个线圈，以提高垂直方向上磁场的均匀度，从而与其均匀度相比降低等于或小于2个数字 由现有MRI系统产生的静磁场。 通过对RF磁场的动态控制，给出关于读出方向的位置信息，基于具有比磁场不均匀性强的强度的梯度磁场给出关于其他两个轴方向的位置信息。
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公开(公告)号：US5453692A
公开(公告)日：1995-09-26
申请号：US98816
申请日：1993-07-29
CPC分类号： G01R33/3415 , G01R33/34046 , G01R33/365
摘要： An RF probe for an MRI device including a plurality of hollow cylindrical resonators arranged in series such that the respective axes of the resonators align substantially in a z-axis direction of a three dimensional orthogonal coordinate system, radio frequency power signal supply/reception pickup coils to/from the respective resonators; and loop coils situated riding on two adjacent resonators in x- and y-axis directions, and an electromagnetic shield which surrounds the hollow cylindrical resonators, pickup coils and loop coils and grounded with respect to radio frequency.
摘要翻译： 一种用于MRI装置的RF探针，其包括串联布置的多个中空圆柱形谐振器，使得谐振器的各个轴线基本上在三维正交坐标系的z轴方向上对准，射频功率信号供应/接收拾取线圈 来自相应的谐振器; 以及围绕x和y轴方向的两个相邻谐振器上的环形线圈，以及围绕中空圆柱形谐振器，拾取线圈和环形线圈并相对于射频接地的电磁屏蔽。
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