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公开(公告)号：US4812760A
公开(公告)日：1989-03-14
申请号：US78427
申请日：1987-07-27
CPC分类号： G01R33/446
摘要： A single rotating NMR .pi. pulse provides simultaneous spatially-selective inversion or spin-echo refocussing of nuclear pins in two orthogonal dimensions. The two-dimensional spatially-selective pulse utilizes a single RF pulse, with either a square of an amplitude-modulated or a frequency-modulated envelope, and applied in the presence of an amplitude-modulated magnetic field gradient which reorients through the desired dimensions in which selection is desired while the RF pulse is present. These rotating, or ".rho.", pulses are useful for reduction of aliasing signal artifacts is restricted field-of-view high-resolution NMR imaging and, when combined with one-dimensional-localized chemical shift spectroscpoy techniques (such as those employing surface detection coils) is especially useful for the production of three-dimensionally localized NMR spectra. Substantial suppression of undesirable residual excited signals, arising from outside the desired two-dimensional spatially selected region, can be obtained by simulated annealing optimization of both the RF and magnetic field gradient amplitude portions of the .rho. pulse and/or by use of surface coil detection. The location of the selected volume is varied by frequency modulation of the RF signal pulse, or by variation of the ratio of currents in the halves of the magnetic field gradient coils.
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公开(公告)号：US5365927A
公开(公告)日：1994-11-22
申请号：US146345
申请日：1993-11-02
申请人： Peter B. Roemer , Samuel M. Blumenfeld , Kirby G. Vosburgh , Harvey E. Cline , William D. Barber , William E. Lorensen , Richard L. St. Peters , John F. Schenck , Charles L. Dumoulin , Robert D. Darrow , Christopher J. Hardy
发明人： Peter B. Roemer , Samuel M. Blumenfeld , Kirby G. Vosburgh , Harvey E. Cline , William D. Barber , William E. Lorensen , Richard L. St. Peters , John F. Schenck , Charles L. Dumoulin , Robert D. Darrow , Christopher J. Hardy
IPC分类号： G01R33/48 , A61B5/055 , G01R33/28 , G01R33/38 , G01R33/385 , G01R33/54 , G01R33/563
CPC分类号： G01R33/385 , G01R33/3806 , G01R33/285 , G01R33/4804 , G01R33/543 , G01R33/563
摘要： A magnetic resonance (MR) imaging system for use in a medical procedure employs an open main magnet allowing access to a portion of a patient within an imaging volume, for producing a main magnetic field over the imaging volume; a set of open gradient coils which provide magnetic fields gradients over the imaging volume without restricting access to the imaging volume; a radiofrequency coil set for transmitting RF energy into the imaging volume to nutate nuclear spins within the imaging volume and receive an MR response signal from the nuclear spins; and a pointing device for indicating the position and orientation of a plane in which an image is to be acquired; an image control means for operating power supplies for the gradient coils and the RF coils to acquire an MR signal from the desired imaging plane; and a computation unit for constructing an image of the desired imaging plane. The MR imaging system is intended to operate to provide images to a physician during medical procedures to guide the physician in his procedures.
摘要翻译： 用于医疗过程的磁共振（MR）成像系统采用打开的主磁体，其允许进入成像体积内的患者的一部分，用于在成像体积上产生主磁场; 一组开放的梯度线圈，其在成像体积上提供磁场梯度，而不限制对成像体积的访问; 射频线圈组，用于将RF能量传输到成像体积中，以在成像体积内盘旋核自旋，并从核自旋接收MR响应信号; 以及指示装置，用于指示要获取图像的平面的位置和方位; 图像控制装置，用于操作梯度线圈和RF线圈的电源，以从期望的成像平面获取MR信号; 以及用于构造所需成像平面的图像的计算单元。 MR成像系统旨在在医疗程序期间向医生提供图像以在他的程序中指导医师。
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公开(公告)号：US5027071A
公开(公告)日：1991-06-25
申请号：US489124
申请日：1990-03-05
IPC分类号： A61B5/055 , G01R33/32 , G01R33/36 , G01R33/385 , G01R33/387 , G01R33/54 , G01R33/565 , G06T1/00
CPC分类号： G01R33/385 , G01R33/56518 , G01R33/3607 , G01R33/3852
摘要： A method of reducing slice profile degradation due to gradient signal amplitude ripple, has steps of: sensing the gradient signal ripple amplitude; normalizing the sensed ripple signal amplitude responsive to the gradient amplitude commanded; and modulating the RF signal amplitude with the adjusted-amplitude ripple signal, to cause the RF and gradient magnetic fields to have an effective vector pointing substantially in the same direction, during the slice-selection interval, as would the effective field vector formed with a gradient field devoid of ripple. Apparatus for reducing the slice profile degradation modulates the RF signal with the ripple envelope obtained from the output of the gradient signal amplifier, by a signal controlled by the gradient amplifier input.
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公开(公告)号：US5192909A
公开(公告)日：1993-03-09
申请号：US637910
申请日：1991-01-07
CPC分类号： G01R33/446
摘要： An NMR system performs in vivo localized NMR spectroscopy. A two-dimensional selective RF excitation pulse is used to localize to a cylindrical region of interest, and either phase encoding or slice selective inversion is used to localize to a disk in the cylindrical region of interest. The two-dimensional selective RF excitation is performed in a series of pulse sequences rather than a single pulse sequence, and the resulting series of acquired NMR signals are summed together to substantially cancel signal conributions from outside the cylindrical region of interest.
摘要翻译： NMR体系进行体内局部NMR光谱。 使用二维选择性RF激励脉冲来定位到感兴趣的圆柱形区域，并且使用相位编码或切片选择性反转来定位到感兴趣的圆柱形区域中的盘。 二维选择性RF激励以一系列脉冲序列而不是单个脉冲序列执行，并且所得到的一系列获取的NMR信号被相加在一起以基本上消除来自感兴趣的圆柱体区域的信号。
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公开(公告)号：US4973908A
公开(公告)日：1990-11-27
申请号：US370518
申请日：1989-06-23
IPC分类号： G01R33/36 , A61B5/055 , G01R33/32 , G01R33/34 , G01R33/341
CPC分类号： G01R33/341
摘要： An NMR antenna probe has at least one substantially circular surface coil arranged in a plane and a surface coil having substantially a Figure-8 shape, substantially coplanar with the at least one circular surface coil. The Figure-8 coil has a cross-over portion which is located substantially coaxial with the axis of the at least one circular surface coil. The coil corresponding to the least-NMR-sensitive nucleus is circular, while the non-circular coil corresponds to the most-NMR-sensitive nucleus. The circular coil is positioned on the side of the NMR probe closest to the subject to be studied.
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公开(公告)号：US5201311A
公开(公告)日：1993-04-13
申请号：US927780
申请日：1992-08-10
IPC分类号： G01R33/483 , G01R33/485
CPC分类号： G01R33/485 , G01R33/483
摘要： A method for providing information about the rate of a selected chemical reaction in each of at least one selected volume elements (voxels) in a sample includes the steps of: exciting a reaction-rate-dependent chemical-shift spectrum, by a selected stimulus (such as one of saturation-transfer and inversion-transfer RF signal pulses) to label the NMR signal of a first reaction constituent; spatially localizing the NMR response signal, provided by the excited resonance, to a selected voxel within the sample; and acquiring and processing the NMR response data from the localized voxel. The excitation, localization and data acquisition subsequences are repeated to generate data substantially proportional, or equal, to the reaction rate constants in the selected voxels, and in planes and/or volumes thereof.
摘要翻译： 提供关于样品中至少一个选定的体积元素（体素）中的每一个中选择的化学反应的速率的信息的方法包括以下步骤：通过所选择的刺激（激发反应速率依赖的化学位移谱） 例如饱和转移和反转传输RF信号脉冲之一）来标记第一反应成分的NMR信号; 将由激发谐振提供的NMR响应信号空间定位到样品内的选定体素; 并从局部体素获取和处理NMR响应数据。 重复激发，定位和数据采集子序列以产生与所选择的体素中的反应速率常数以及其平面和/或体积基本成比例或相等的数据。
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公开(公告)号：US4695799A
公开(公告)日：1987-09-22
申请号：US746146
申请日：1985-06-18
CPC分类号： G01R33/446 , G01R33/3607
摘要： A method for the complete inversion of magnetization by adiabatic fast passage during an NMR experiment on a sample having a selected nuclear specie with a Larmor frequency .omega..sub.0. A radio-frequency magnetic field is generated with an amplitude B.sub.1 and an instantaneous frequency .omega.(t) which is non-linearly swept, as a function of time, from a minimum frequency .omega..sub.1 substantially at a maximum offset frequency .DELTA..omega. below the Larmor frequency .omega..sub.0, through the Larmor frequency, to a maximum frequency .omega..sub.h substantially at the maximum offset frequency .DELTA..sub..omega. above the Larmor frequency. The non-linearly swept, monotonic RF signal is applied to the sample-being-investigated for a sweep time interval sufficient to invert the magnetization of the selected nuclear specie. The preferred sweep is a tangential function:.omega.(t)=.omega..sub.0 .+-..gamma.B.sub.1 tan (arcsin (.omega..sub.s t)), (A)or.omega.(t)=.omega..sub.0 .+-..gamma.B.sub.1 tan (.omega..sub.s t)where .omega..sub.s =.alpha..gamma.B.sub.1, .gamma. is the gyromagnetic ratio of the selected nuclear specie and 0
摘要翻译： 在具有Larmor频率ω0的选定核子样品的NMR实验中通过绝热快速通过完全反转磁化的方法。产生具有振幅B1和瞬时频率ω（t）的射频磁场 ），其通过拉莫尔频率从基本上在低于拉莫尔频率ω0的最大偏移频率DELTAω的基本上最大频率ω1的最小频率ω1作为时间的非线性扫描到最大频率ωh 偏移频率DELTA omega高于拉莫尔频率。 将非线性扫描的单调RF信号施加到被研究的样品的扫描时间间隔，以足以反转所选择的核物种的磁化。 优选的扫描是切向函数：ω（t）=ω0 +/-γB1 tan（arcsin（ω）），（A）或ω（t）=ω0 +/-γB1 tan（ω） 其中ω=α伽马B1，γ是所选核物种的回磁比，0≤α= 1。
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公开(公告)号：US20080100294A1
公开(公告)日：2008-05-01
申请号：US11554951
申请日：2006-10-31
IPC分类号： G01V3/00
CPC分类号： G01R33/3415 , G01R33/34007 , G01R33/34084
摘要： An RF coil assembly includes a plurality of coil supports rotatably interconnected to each other. Each coil support is configured to rotate with respect to at least one adjoining coil support. A plurality of RF coils is connected to each coil support.
摘要翻译： RF线圈组件包括可互相互连的多个线圈支架。 每个线圈支撑件构造成相对于至少一个相邻的线圈支撑件旋转。 多个RF线圈连接到每个线圈支架。
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9.发明授权Method and apparatus for automated tracking of non-linear vessel movement using MR imaging 有权使用MR成像自动跟踪非线性血管运动的方法和装置公开(公告)号：US07209777B2
公开(公告)日：2007-04-24
申请号：US09728071
申请日：2000-11-30
IPC分类号： A61B5/05
CPC分类号： G01R33/56509 , A61B5/0037 , A61B5/055 , A61B5/7285 , G01R33/56 , G01R33/5673
摘要： A system and method is disclosed for tracking a moving object using magnetic resonance imaging. The technique includes acquiring a scout image scan having a number of image frames and extracting non-linear motion parameters from the number of image frames of the scout image scan. The technique includes prospectively shifting slice location using the non-linear motion parameters between slice locations while acquiring a series of MR images. The system and method are particularly useful in tracking coronary artery movement during the cardiac cycle to acquire the non-linear components of coronary artery movement during a diastolic portion of the R—R interval.
摘要翻译： 公开了一种使用磁共振成像跟踪运动物体的系统和方法。 该技术包括获取具有多个图像帧的侦察图像扫描，并从侦察图像扫描的图像帧的数量中提取非线性运动参数。 该技术包括使用切片位置之间的非线性运动参数前进移位切片位置，同时获取一系列MR图像。 该系统和方法在心脏周期期间跟踪冠状动脉运动特别有用，以在R-R间期的舒张期期间获得冠状动脉运动的非线性分量。
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10.发明授权
公开(公告)号：US5578924A
公开(公告)日：1996-11-26
申请号：US558296
申请日：1995-11-15
CPC分类号： G01R33/4835 , G01R33/4833
摘要： A multi-planar imaging method employs magnetic resonance to detect image data from multiple planes within a subject. Data from each plane are detected in response to the same readout gradient and are simultaneously detected. The image planes can be arbitrarily oriented with respect to each other and with respect to the readout and phase-encoding image formation magnetic field gradient pulses if desired. Overlap of image data from each of the excited image planes in the acquired image is prevented by employing a thick refocusing slab oriented orthogonal to the readout and phase-encoding directions, or by choosing planes which intersect outside the subject's anatomy.
摘要翻译： 多平面成像方法采用磁共振来检测受试者内的多个平面的图像数据。 根据相同的读出梯度检测来自每个平面的数据，并同时检测。 如果需要，图像平面可以相对于彼此和相对于读出和相位编码图像形成磁场梯度脉冲任意取向。 通过采用与读出和相位编码方向正交取向的厚度重聚焦板，或通过选择与被摄体的解剖结构外部相交的平面来防止获取的图像中的每个激发的图像平面上的图像数据的重叠。
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