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21.发明授权
公开(公告)号：US5017871A
公开(公告)日：1991-05-21
申请号：US407180
申请日：1989-09-14
IPC分类号： G01R33/20 , A61B5/055 , G01R33/385
CPC分类号： G01R33/3852
摘要： A gradient current speed-up circuit, for use in a higher-speed NMR imaging system with a gradient power amplifier and an associated gradient, coil, has a high-voltage power supply which is selectively connected to the associated gradient coil, typical via a plurality of semiconductor switching elements, to supply a pulse of a very high voltage when fast coil rise and fall times are needed. The gradient coil is connected between selected ones of semiconductors devices which are turned on and off in selected patterns, to cause the direction of coil current flow to be determined.
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22.发明授权
公开(公告)号：US4825162A
公开(公告)日：1989-04-25
申请号：US130046
申请日：1987-12-07
IPC分类号： G01R33/3415 , G01R33/20
CPC分类号： G01R33/3415
摘要： A method for simultaneously receiving a different NMR response signal from each of a plurality of closely-spaced surface coils, first provides an array of a plurality of the surface coils, each positioned so as to have substantially no interaction with all adjacent surface coils. A different NMR response signal is received from an associated portion of the sample enclosed within an imaging volume defined by the array. Each different NMR response signal is used to construct a different one of a like plurality of NMR images of the sample, with the plurality of different images then being combined, on a point-by-point basis, to produce a single composite NMR image of a total sample portion from which NMR response signal contribution was received by any of the array of surface coils. Interactions between non-adjacent surface coils are minimized by coupling each onto an associated preamplifier.
摘要翻译： 同时从多个紧密间隔的表面线圈中的每一个接收不同的NMR响应信号的方法首先提供多个表面线圈的阵列，每个表面线圈定位成与所有相邻的表面线圈基本上没有相互作用。 从包含在由阵列定义的成像体积内的样品的相关部分接收不同的NMR响应信号。 每个不同的NMR响应信号用于构建样品的相同多个NMR图像中的不同的一个，然后在逐点的基础上组合多个不同的图像，以产生单个的NMR图像 通过表面线圈阵列中的任何阵列接收到NMR响应信号贡献的总样本部分。 通过将每个相邻的前置放大器相耦合，使非相邻表面线圈之间的相互作用最小化。
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公开(公告)号：US4646024A
公开(公告)日：1987-02-24
申请号：US548174
申请日：1983-11-02
CPC分类号： H01F7/20 , H01F41/045 , Y10S505/844
摘要： In the production of nuclear magnetic resonance images, it is necessary to provide various magnetic fields with specified orientations and configurations in particular relationships with respect to a cylindrical coil form on which the RF and gradient coils are generally disposed. In particular, it is necessary to produce so-called transverse gradient fields which are oriented transversely with respect to the cylindrical form. It is necessary to produce a component parallel to the axis of the cylinder, but which component varies linearly in intensity in the direction transverse to the axis. That is to say, it is desirable to produce a magnetic field component within the cylinder such that surfaces on which this component is constant are parallel and are generally oriented parallel to the axis of the cylinder. Furthermore, for the purpose of providing proper spatial definition and resolution, it is necessary that this transverse field exhibit a highly linear variation in intensity inside the cylinder. In a nuclear magnetic resonance imaging system, two such coil sets are required and are oriented at right angles to one another so as to generate x-axis and y-axis positioning information. The present invention describes coil winding patterns which are capable of producing such transverse gradient magnetic fields with an exceedingly high degree of linearity.
摘要翻译： 在生产核磁共振图像时，有必要提供具有指定取向和配置的各种磁场，这些磁场与通常设置有RF和梯度线圈的圆柱形线圈形式有关。 特别地，有必要产生相对于圆柱形横向定向的所谓的横向梯度场。 需要产生平行于圆柱体轴线的分量，但哪个分量在横向于轴线的方向上强度线性变化。 也就是说，期望在圆柱体内产生磁场分量，使得该部件恒定的表面是平行的，并且大致定向为平行于圆柱体的轴线。 此外，为了提供适当的空间定义和分辨率，有必要使该横向场在气缸内呈现高度线性的强度变化。 在核磁共振成像系统中，需要两个这样的线圈组，并且彼此成直角定向，以便产生x轴和y轴定位信息。 本发明描述了能够产生具有非常高的线性度的这种横向梯度磁场的线圈绕组图案。
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24.发明授权Low-noise RF preamplifier (especially for nuclear magnetic resonance system) 失效低噪声射频前置放大器（特别适用于核磁共振系统）
公开(公告)号：US4631495A
公开(公告)日：1986-12-23
申请号：US730522
申请日：1985-05-06
摘要： A low-noise radio-frequency preamplifier, especially suited for use in the reception channel of a nuclear magnetic resonance spectrometer and the like, utilizes a low-noise input stage having a plurality of bipolar junction transistors effectively connected in radio-frequency parallel, but with each of the plurality of parallel bipolar transistors isolated from one another for direct current flow through at least one electrode thereof.
摘要翻译： 特别适用于核磁共振光谱仪等的接收通道的低噪声射频前置放大器利用具有多个双极结型晶体管的低噪声输入级，该多个双极结型晶体管以射频平行方式有效连接，但是 所述多个并联双极晶体管中的每一个彼此隔离以直流流过其至少一个电极。
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公开(公告)号：US4506222A
公开(公告)日：1985-03-19
申请号：US320953
申请日：1981-11-09
申请人： William A. Edelstein , James M. S. Hutchison , Glyn Johnson , Thomas W. T. Redpath , John R. Mallard
发明人： William A. Edelstein , James M. S. Hutchison , Glyn Johnson , Thomas W. T. Redpath , John R. Mallard
CPC分类号： G01R33/482 , G01R33/5615 , G01R33/5616
摘要： To produce image information from an object it is subjected to a continuous static magnetic field along a Z axis and to sets of sequences of orthogonal gradients G.sub.x, G.sub.y and G.sub.z to the magnetic field. Spins in a selected plane (the X-Z plane) are excited by selective rf pulses and an associated G.sub.y gradient and the selected spins are subjected to all three gradients of which the G.sub.z gradient provides twist or warp to each column of spins extending along the Z axis to phase-encode the columns. The spin-echo signals are read out in the presence of a G.sub.x gradient. In each set of sequences a different value of Z gradient is employed. The Fourier transformed spin-echo signals obtained from each sequence, when arranged in order of increasing G.sub.z gradient and subjected to a second Fourier transform represent the distribution of spin density in the Z direction, thus giving a two-dimensional image of the selected X-Z plane.
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公开(公告)号：US07215122B2
公开(公告)日：2007-05-08
申请号：US10957822
申请日：2004-10-04
申请人： Qun Zhao , G. Randy Duensing , Hu Cheng , William A. Edelstein
发明人： Qun Zhao , G. Randy Duensing , Hu Cheng , William A. Edelstein
IPC分类号： G01V3/00
CPC分类号： G01R33/32 , G01R33/4806 , G01R33/58
摘要： The subject invention relates to a method and apparatus for producing stimulated MRI data. In an embodiment, a remote-controlled “smart phantom” can produce simulated data. The simulated data can be acquired from a MRI system. The subject device can generate control signals and send the generated control signals to secondary coils/probes placed in the subject smart phantom. The control signals determine the current flow in the secondary coils/probes, which act as local spin magnetization amplifiers and thus produce regions of variable contrast to noise ratio. The control signals can be generated with various parameters, such as BOLD models, different levels of contrast-to-noise ratio (CNR), signal intensities, and physiological signals. Comparisons can be made with the widely-used simulated data by computers. Validation of the subject smart phantom can be performed with both theoretical analysis and data of human subjects.
摘要翻译： 本发明涉及一种用于产生模拟MRI数据的方法和装置。 在一个实施例中，远程控制的“智能幻影”可以产生模拟数据。 可以从MRI系统获取模拟数据。 主体装置可以产生控制信号，并将产生的控制信号发送到放置在主体智能幻影中的次级线圈/探头。 控制信号确定次级线圈/探头中的电流，其作为局部自旋磁化放大器，从而产生可变对比度噪声比的区域。 控制信号可以用诸如BOLD模型，不同等级的对比噪声比（CNR），信号强度和生理信号等各种参数产生。 可以用计算机广泛使用的模拟数据进行比较。 可以通过理论分析和人类受试者的数据进行主体智能幻影的验证。
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公开(公告)号：US06498947B2
公开(公告)日：2002-12-24
申请号：US09791307
申请日：2001-02-23
IPC分类号： A61B505
CPC分类号： G01R33/422
摘要： A technique is disclosed for shielding rf magnetic fields in MRI systems. An rf shield is embedded in a gradient coil structure including X-, Y- and Z-axis coils. The rf shield is positioned between an inner gradient coil which is inherently decoupled from the rf field, and the remaining coils which require rf shielding. The inner gradient coil may be a Z-axis coil wound as a solenoid, the field of which is generally orthogonal with respect to the rf magnetic field. The rf shield is thereby placed at an enhanced distance from the rf coil, providing greater efficiency and permitting energy levels to be reduced to obtain the desired rf magnetic field strength.
摘要翻译： 公开了一种用于屏蔽MRI系统中的rf磁场的技术。 rf屏蔽嵌入包括X，Y和Z轴线圈的梯度线圈结构中。 rf屏蔽位于固有地与rf场分离的内部梯度线圈和需要rf屏蔽的剩余线圈之间。 内部梯度线圈可以是卷绕成螺线管的Z轴线圈，其磁场大致与rf磁场正交。 因此，rf屏蔽件被放置在距离rf线圈增强的距离处，提供更高的效率并且允许减小能量水平以获得期望的rf磁场强度。
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公开(公告)号：US5484985A
公开(公告)日：1996-01-16
申请号：US291260
申请日：1994-08-16
申请人： William A. Edelstein , Icko T. Iben , Otward M. Mueller , Egidijus E. Uzgiris , Peter B. Roemer
发明人： William A. Edelstein , Icko T. Iben , Otward M. Mueller , Egidijus E. Uzgiris , Peter B. Roemer
CPC分类号： B09C1/06 , E21B36/04 , E21B43/003 , H05B6/62 , B09C2101/00
摘要： An in-situ method of extracting contaminants from a soil volume comprises applying a radiofrequency (RF) excitation signal to heat the soil with an array of electrodes. The electrodes are inserted into the contaminated volume or inserted into a matrix of holes drilled into the volume. A first row of electrodes is electrically coupled to a shield of a coaxial cable, with a second row electrically coupled to the central conductor of the coaxial cable. RF energy is applied to pairs of electrode rows through the coaxial cable and a matching network is installed in front of the electrode-row pair to maximize power flow into the electrode-row pair. This results in very evenly distributed voltages which results in even heating. A balanced-to-unbalanced transformer (balun) is installed at the input to the matching network to prevent the deposition of RF energy outside the target volume and creation of voltages that could be hazardous to personnel. The electrodes are perforated and connected to collection tubes which collect volatilized contaminant vapors and pass the vapors to a vapor treatment unit for neutralization.
摘要翻译： 从土壤体积中提取污染物的原位方法包括施加射频（RF）激发信号以用电极阵列加热土壤。 电极被插入到污染的体积中或插入钻孔体积中的孔的矩阵中。 第一排电极电耦合到同轴电缆的屏蔽，第二行电耦合到同轴电缆的中心导体。 RF能量通过同轴电缆施加到电极对对，并且匹配网络安装在电极列对的前面，以最大限度地增加流入电极列对的功率。 这导致非常均匀的分布电压，这导致均匀的加热。 平衡不平衡变压器（平衡 - 不平衡转换器）安装在匹配网络的输入端，以防止射频能量沉积在目标体积之外，并产生可能对人员造成危害的电压。 电极被穿孔并连接到收集挥发性污染物蒸汽并将蒸气传递到蒸气处理单元进行中和的收集管中。
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29.发明授权Double-sided RF shield for RF coil contained within gradient coils of NMR imaging device 失效用于RF线圈的双面RF屏蔽包含在NMR成像装置的梯度线圈内
公开(公告)号：US4879515A
公开(公告)日：1989-11-07
申请号：US288344
申请日：1988-12-22
IPC分类号： G01R33/422
CPC分类号： G01R33/422
摘要： A double-sided RF shield, for use between a set of gradient coils and an RF coil, is a hollow member formed of a conductor-dielectric-conductor laminate. Each conductor is a sheet divided into first and second opposed half-cylinders, each having a plurality of conductive streamline loop portions with a series of nonconductive cut lines formed therebetween, with each of the cut lines being parallel to the RF current. Each of the loops is separated into a "C"-shaped conductive portion along at least one "radial" line cut in each half-cylinder. The cut lines are substantially opposite to one another on opposite surfaces of the half-cylinders, to form a loop with a pair of series capacitances of maximized value, which shield the RF current, yet pass gradient magnetic fields in all three mutually orthogonal directions of a Cartesian coordinate system.
摘要翻译： 在一组梯度线圈和RF线圈之间使用的双面RF屏蔽是由导体 - 电介质导体层叠体形成的中空构件。 每个导体是分成第一和第二相对的半圆柱体的片，每个具有多个导电流线环部分，其间形成有一系列非导电切割线，每条切割线平行于RF电流。 沿着每个半圆筒中切割的至少一个“径向”线将每个环分成“C”形导电部分。 切割线在半圆柱的相对表面上基本上彼此相反，以形成具有最大值的一对串联电容的环路，其屏蔽RF电流，但在所有三个相互正交的方向上通过梯度磁场 笛卡尔坐标系。
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公开(公告)号：US4602214A
公开(公告)日：1986-07-22
申请号：US702126
申请日：1985-02-15
申请人： William A. Edelstein , James M. S. Hutchison , Glyn Johnson , Thomas W. T. Redpath , John R. Mallard
发明人： William A. Edelstein , James M. S. Hutchison , Glyn Johnson , Thomas W. T. Redpath , John R. Mallard
CPC分类号： G01R33/482 , G01R33/5615 , G01R33/5616
摘要： To produce image information from an object it is subjected to a continuous static magnetic field along a Z axis to sets of sequences of orthogonal gradients G.sub.x, G.sub.y and G.sub.z to the magnetic field. Spins in a selected plane (the X-Z plane) are excited by selective rf pulses and an associated G.sub.y gradient and the selected spins are subjected to all three gradients of which the G.sub.z gradient provides twist or warp to each column of spins extending along the Z axis to phase-encode the columns. The spin-echo signals are read out in the presence of a G.sub.x gradient. In each set of sequences a different value of Z gradient is employed. The Fourier transformed spin-echo signals obtained from each sequence, when arranged in order of increasing G.sub.z gradient and subjected to a second Fourier transform represent the distribution of spin density in the Z direction, thus giving a two-dimensional image of the selected X-Z plane.
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