-
公开(公告)号：US4995394A
公开(公告)日：1991-02-26
申请号：US392315
申请日：1989-08-11
IPC分类号： A61B5/055 , G01R33/48 , G01R33/561 , G01R33/563 , G01R33/567
CPC分类号： G01R33/5676 , G01R33/4836 , G01R33/446 , G01R33/4824 , G01R33/5617 , G01R33/56308
摘要： A substantially continuous image, recording motion of a portion of a sample, is provided by first NMR exciting, through use of a rotating-gradient (.rho.) pulse signal, a relatively narrow cylindrical region, typically with diameter less than 1 inch, of magnetization intersecting the sample to be imaged and then acquiring the NMR response signal thus excited, in the presence of a readout gradient oriented along the length of the cylindrical excitation beam and establishing position thereon. A Fourier transformation of the acquired data allows display of a real-time record of the profile of the sample along the axis of the cylindrical probe beam. The cylinder-beam axis can be oriented in an arbitrary direction by proper mixing of the excitation and readout gradient fields; use of three orthogonal gradients in a Cartesian coordinate system is presently preferred. Spatial offsetting of the cylindrical beam, from the center of the static magnetic field of the NMR imaging system, to any specific location within the system's imaging volume, can be obtained by frequency modulation of the .rho. pulse RF waveform.
-
公开(公告)号：US5584293A
公开(公告)日：1996-12-17
申请号：US515786
申请日：1995-08-16
CPC分类号： G01R33/54
摘要： Imaging parameters, such as the location, orientation and field of view of an imaging plane are selected. These parameters are provided to a pulse sequencer of a magnetic resonance (MR) scanner which modifies an MR pulse sequence to acquire an image at the selected imaging plane. The pulse sequencer controls an RF transmitter and gradient amplifiers to cause an MR image of the subject at an imaging plane to be acquired. The MR image is displayed on a display device. An interface device receives and reduces the MR image to an image icon and saves the image icon along with the corresponding imaging parameters. The image icons are displayed on the periphery of the screen around an MR image. An operator may then view and select one of the image icons, employing the pointing device. This causes the imaging parameters corresponding to the selected image icon to be sent to the pulse sequencer thereby causing an MR image to be acquired with these imaging parameters.
摘要翻译： 选择成像参数，例如成像平面的位置，方位和视场。 这些参数被提供给磁共振（MR）扫描器的脉冲序列器，其修改MR脉冲序列以获取所选成像平面上的图像。 脉冲序列发生器控制RF发射器和梯度放大器，以获得成像平面上的对象的MR图像。 MR图像显示在显示设备上。 接口装置将MR图像接收并减少到图像图标，并将图像图标与相应的成像参数一起保存。 图像图标显示在MR图像周围的屏幕周围。 然后，操作者可以使用指示设备来查看和选择一个图像图标。 这使得与所选择的图像图标相对应的成像参数被发送到脉冲序列器，从而使得利用这些成像参数获取MR图像。
-
公开(公告)号：US5327884A
公开(公告)日：1994-07-12
申请号：US162921
申请日：1993-12-08
IPC分类号： G01R33/20 , A61B5/055 , A61B18/00 , A61B18/20 , A61B18/24 , A61B19/00 , A61N7/00 , A61N7/02 , G01R33/48 , G01R33/561
CPC分类号： A61N7/02 , A61B18/24 , G01R33/4804 , G01R33/561 , A61B2090/374 , G01R33/56308
摘要： Surgery is performed with a pulsed heat-producing device that selectively heats a region in a specific tissue within a patient destroying the tissue. The pulsed heat-producing device may be a coherent optical source that is guided by laser fiber to the tissue to be destroyed. In another embodiment, the pulsed heat-producing device is a focussed ultrasound transducer which concentrates ultrasonic energy at a focal point within the specific tissue. A magnetic resonance imaging system employing a real-time temperature-sensitive pulse sequence monitors the heated region of the tissue to provide temperature profiles allowing an operator to alter the position and size of the heated region.
-
公开(公告)号：US5258711A
公开(公告)日：1993-11-02
申请号：US871154
申请日：1992-04-20
申请人： Christopher J. Hardy
发明人： Christopher J. Hardy
CPC分类号： G01R33/4833
摘要： A method for reducing distortion in magnetic resonance (MR) images of a subject employs distortion compensating MR pulses in a conventional MR imaging sequence. The distortion compensating pulses are determined by first creating a conventional MR image of a slice of a subject having inherent distortions; constructing a target slice which is distorted in a manner opposite the direction of distortions in the slice image; taking a multi-dimensional Fourier transformation of the target slice to obtain a k-space region; choosing a continuous trajectory which efficiently traverses the k-space region; applying principles of multidimensional selective-excitation design to create simultaneous RF pulses and magnetic field gradient waveforms from the trajectory; and simultaneously applying the RF pulses and gradient waveforms in place of a traditional slice-select pulse in conventional MR imaging sequences to obtain images having reduced distortion as compared with conventional images.
摘要翻译： 用于减少受试者的磁共振（MR）图像中的失真的方法使用常规MR成像序列中的失真补偿MR脉冲。 通过首先创建具有固有失真的对象的切片的常规MR图像来确定失真补偿脉冲; 构造以与切片图像中的失真方向相反的方式失真的目标切片; 对目标切片进行多维傅里叶变换以获得k空间区域; 选择有效穿过k空间区域的连续轨迹; 应用多维选择激励设计的原理，从轨迹创建同时的RF脉冲和磁场梯度波形; 并且在常规MR成像序列中同时施加RF脉冲和梯度波形来代替传统的切片选择脉冲，以获得与常规图像相比具有减小的失真的图像。
-
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。
-
16.发明授权Quantitative measurement of blood flow using cylindrically localized Fourier velocity encoding 失效使用圆柱体局部化的速度编码对血液流量的定量测量
公开(公告)号：US5133357A
公开(公告)日：1992-07-28
申请号：US651872
申请日：1991-02-07
CPC分类号： A61B5/7257 , A61B5/0263 , G01R33/563 , A61B5/7285 , G01R33/446
摘要： A method of imaging and quantitatively measuring blood velocity distribution within a selected vessel employs Nuclear Magnetic Resonance cylindrical excitation of the sample to be imaged, followed by Fourier velocity encoding excitation along a second axis for selectively encoding molecules based upon their flow velocities, then sensing the re-radiated signal data acquired in the presence of a readout gradient to provide resolution along the cylindrical axis, and reconstructing a velocity profile. Spatial localization is accomplished with an excitation pulse having a cylindrical rather than slab geometry. This method can be combined with cardiac synchronization to measure flow dynamics or it can be applied without synchronization to measure steady flow. The geometry of the measurement is flexible in that the directions of flow sensitivity and geometric resolution are independent.
-
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.
-
18.发明授权
公开(公告)号：US5548216A
公开(公告)日：1996-08-20
申请号：US558298
申请日：1995-11-15
CPC分类号： G01R33/4835
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 modulating the phase of each RF excitation pulse in concert with the amplitude of the phase-encoding gradient pulse to cause the image data from each excitation plane to be displaced by a unique amount in the phase-encoding direction.
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。 通过与相位编码梯度脉冲的振幅一致地调制每个RF激励脉冲的相位来防止来自获取的图像中的每个激发的图像平面的图像数据的重叠，从而使来自每个激励平面的图像数据移位 通过相位编码方向的独特量。
-
公开(公告)号：US5514962A
公开(公告)日：1996-05-07
申请号：US203079
申请日：1994-02-28
CPC分类号： G01R33/54 , G01R33/543 , G01R33/546
摘要： Three-dimensional (3D) image data is acquired from a subject with a medical imaging device and stored. The stored 3D image data is processed by a model workstation to segment the model into discrete structures and produce a segmented computer graphic model. An operator interacts with the model workstation to cause it to display desired structures of the the segmented model in a desired view and orientation. The operator also selects a position and orientation of a cutting plane passing through the segmented model. Once selected, the position and orientation information is provided to a pulse sequencer of a magnetic resonance (MR) imaging system. The pulse sequencer controls an RF transmitter and gradient amplifiers to cause an MR image of the subject at an imaging plane, corresponding to the cutting plane of the model workstation, to be acquired. This allows fast, accurate image plane selection, which may be selected by an operator who is simultaneously performing a medical procedure on the subject, aid in the procedure.
摘要翻译： 利用医学成像装置从受检者获取三维（3D）图像数据并存储。 存储的3D图像数据由模型工作站处理以将模型分割成离散结构并产生分段计算机图形模型。 操作者与模型工作站进行交互，使其以期望的视图和方向显示分段模型的所需结构。 操作员还选择通过分段模型的切割平面的位置和方向。 一旦选择，位置和取向信息被提供给磁共振（MR）成像系统的脉冲序列器。 脉冲序列发生器控制RF发射器和梯度放大器，以便在对应于模型工作站的切割平面的成像平面处引起被摄体的MR图像。 这允许快速，准确的图像平面选择，其可以由同时对主体执行医疗程序的操作者选择，辅助该过程。
-
公开(公告)号：US5512826A
公开(公告)日：1996-04-30
申请号：US458601
申请日：1995-06-02
CPC分类号： G01R33/54 , G01R33/543 , G01R33/546
摘要： An MR image of a subject is displayed on a display device. Scan-control icons are displayed over this image. An operator interacts with an interface device to select imaging plane parameters during imaging. This is performed by selecting one of the icons with a pointing device, and dragging. Interface device then provides a display which indicates the motion of the imaging plane as well as the extent of the motion. Once selected, the location and orientation information transformed to global coordinates and is provided to a pulse sequencer of a magnetic resonance (MR) imaging system. The pulse sequencer controls an RF transmitter and gradient amplifiers to cause an MR image of the subject at an imaging plane to be acquired. This allows fast, accurate imaging plane selection, which may be selected by an operator who is searching for structures within the subject, or who is simultaneously performing a medical procedure on the subject.
摘要翻译： 主体的MR图像显示在显示装置上。 扫描控制图标显示在此图像上。 操作者与接口设备进行交互以在成像期间选择成像平面参数。 这是通过使用指点设备选择一个图标并拖动来执行的。 然后，接口装置提供指示成像平面的运动以及运动程度的显示器。 一旦被选择，将位置和方位信息变换为全局坐标并提供给磁共振（MR）成像系统的脉冲序列器。 脉冲序列发生器控制RF发射器和梯度放大器，以获得成像平面上的对象的MR图像。 这允许快速，精确的成像平面选择，其可以由正在搜索对象内的结构的操作者选择，或者同时对该对象执行医疗程序。
-
-
-
-
-
-
-
-
-
搜索结果
24 条记录 (耗时 0.025 秒)
