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61.发明授权Tracking system and pulse sequences to monitor the position of a device using magnetic resonance 失效跟踪系统和脉冲序列来监控使用磁共振的设备的位置
公开(公告)号：US5307808A
公开(公告)日：1994-05-03
申请号：US861718
申请日：1992-04-01
IPC分类号： A61B5/055 , A61B5/06 , G01R33/28 , G01R33/32 , G01R33/561 , G01R33/563
CPC分类号： G01R33/285 , G01R33/563 , G01R33/5617
摘要： A tracking system employs magnetic resonance signals to monitor the position of a device such as a catheter within a subject. The device has a receiver coil which is sensitive to magnetic resonance signals generated in the subject. These signals are detected in the presence of magnetic field gradients and thus have frequencies which are substantially proportional to the location of the coil along the direction of the applied gradient. Signals are detected responsive to sequentially applied mutually orthogonal magnetic gradients to determine the position of the device in several dimensions. The position of the device as determined by the tracking system is superimposed upon independently acquired medical diagnostic images.
摘要翻译： 跟踪系统采用磁共振信号来监测被检体内诸如导管之类的装置的位置。 该装置具有对受试者中产生的磁共振信号敏感的接收器线圈。 在存在磁场梯度的情况下检测这些信号，因此具有与沿施加的梯度方向的线圈位置基本成比例的频率。 响应于顺序施加的相互正交的磁梯度来检测信号，以确定器件在几个维度中的位置。 由跟踪系统确定的设备的位置叠加在独立获取的医学诊断图像上。
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公开(公告)号：US5251635A
公开(公告)日：1993-10-12
申请号：US753564
申请日：1991-09-03
CPC分类号： H04N13/0221 , A61B5/06 , A61B6/487 , H04N13/0253 , H04N13/0296 , H04N13/0434
摘要： During an X-ray procedure, the position and orientation of an invasive device, such as a catheter are measured with radio frequency fields and displayed stereoscopically. Instantaneous three-dimensional positions of the invasive device are displayed by superposition of a graphic symbol on static X-ray images obtained at two different view angles. The X-ray images are obtained only when deemed necessary by the operator to minimize X-ray dose. A single X-ray source and detector may be implemented since it is not necessary to obtain the X-ray images simultaneously.
摘要翻译： 在X射线过程中，诸如导管的侵入性装置的位置和取向用射频场测量并立体显示。 通过将图形符号叠加在以两个不同视角获得的静态X射线图像上来显示侵入性装置的瞬时三维位置。 仅当操作者认为必要时才能获得X射线图像以最小化X射线剂量。 可以实现单个X射线源和检测器，因为不需要同时获得X射线图像。
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63.发明授权Projection methods for producing two-dimensional images from three-dimensional data 失效用于从三维数据生成二维图像的投影方法
公开(公告)号：US5233299A
公开(公告)日：1993-08-03
申请号：US674476
申请日：1991-03-25
CPC分类号： G01R33/563 , G01R33/56
摘要： A method of collecting three-dimensional magnetic resonance (MR) fluid flow images from a volume of a subject and constructing a high contrast low noise two-dimensional image therefrom is accomplished by statistical calculation of voxel values along projection lines cast through a three-dimensional data volume obtained from three-dimensional MR angiography techniques, and converting the data to projection images by summing the weighted differences from the projection average of data for each voxel along a projection ray. The data are then normalized and repeated for all projection rays to obtain a set of projection values which are displayed on a two-dimensional display device.
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64.发明授权Method and apparatus for volumetric projection rendering using reverse ray casting 失效使用反射射线投射的体积投影渲染的方法和装置
公开(公告)号：US5226113A
公开(公告)日：1993-07-06
申请号：US844983
申请日：1992-02-28
IPC分类号： G06T17/00
CPC分类号： G06T17/00
摘要： A method for providing a volumetrically-rendered projection image using reverse ray casting, uses the steps of: acquiring, from an object volume of interest, a set of data sampled from each volume element (voxel) therein responsive to a selected characteristic of that object volume; storing the data for each object voxel in a corresponding data volume element; scanning sequentially through each data voxel within the data volume corresponding to the object volume of interest; projecting each scanned data voxel to an image plane, at a solid angle determined from the solid angle at which the object volume is viewed; storing a value for each image plane pixel, responsive to a selected criteria, from the values of all projected data voxel values impingent upon that image plane pixel; and then scaling the dimensions of each image plane pixel responsive to the dimensions of the corresponding object volume shape, and the involved projection solid angle, to correct for anisotropy.
摘要翻译： 使用反射射线投射提供体积绘制的投影图像的方法使用以下步骤：从感兴趣的对象体积中获取从每个体元素（体素）采样的一组数据，其中响应于该对象的所选特征 卷; 将每个对象体素的数据存储在对应的数据量元素中; 依次扫描与感兴趣的物体体积相对应的数据体内的每个数据体素; 将每个扫描的数据体素以从观察对象体积的立体角度确定的立体角投影到图像平面; 响应于所选择的标准，从撞击该图像平面像素的所有投影数据体素值的值存储每个图像平面像素的值; 然后响应于相应的对象体积形状的尺寸和所涉及的投影立体角来缩放每个图像平面像素的尺寸，以校正各向异性。
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65.发明授权Tracking system to follow the position and orientation of a device with radiofrequency field gradients 失效跟踪系统遵循具有射频场梯度的设备的位置和方向
公开(公告)号：US5211165A
公开(公告)日：1993-05-18
申请号：US753565
申请日：1991-09-03
CPC分类号： A61B5/06 , A61B6/12 , G01V3/104 , A61B2034/2051
摘要： A tracking system in which radiofrequency signals emitted by an invasive device such as a catheter are detected and used to measure the position and orientation of the invasive device within a subject. Detection of the radiofrequency signals is accomplished with coils having sensitivity profiles which vary approximately linearly with position. The invasive device has a transmit coil attached near its end and is driven by a low power RF source to produce a dipole electromagnetic field that can be detected by an array of receive coils distributed around a region of interest of the subject. The position and orientation of the device as determined by the tracking system are superimposed upon independently acquired Medical Diagnostic images, thereby minimizing the diagnostic exposure times. One or more invasive devices can be simultaneously tracked.
摘要翻译： 检测由诸如导管的侵入性装置发射的射频信号并用于测量受试者内的侵入性装置的位置和取向的跟踪系统。 射频信号的检测是用具有随位置近似线性变化的灵敏度分布的线圈来实现的。 侵入性装置具有靠近其端部附接的发射线圈，并且由低功率RF源驱动以产生可以通过分布在受试者的感兴趣区域周围的接收线圈阵列来检测的偶极电磁场。 由跟踪系统确定的设备的位置和方向叠加在独立获取的医学诊断图像上，从而最小化诊断曝光时间。 可以同时跟踪一个或多个入侵设备。
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66.发明授权
公开(公告)号：US5022398A
公开(公告)日：1991-06-11
申请号：US497288
申请日：1990-03-22
申请人： Charles L. Dumoulin
发明人： Charles L. Dumoulin
IPC分类号： G01R33/563
CPC分类号： G01R33/563
摘要： Several sequences of radio-frequency and magnetic field gradients are presented for obtaining from a sample multiple response echo signals from which to obtain a plurality of independent angiograms, which can be combined or separately analyzed to provide more information than an individual angiogram, but in substantially the same amount of time as a single angiogram. For example, a series of angiograms, each with a different projection axis, can be obtained in the time required to obtain a single angiogram using a single echo method. If the view angle of each echo is the same, then the acquired angiograms can be added to enhance the signal-to-noise ratio. Another pulse sequence simultaneously obtains two or more angiograms, each sensitive to one of two orthogonal flow components of the overall blood flow; the angiograms are then added to give an angiogram which is sensitive to total flow in all directions. Multiple velocity ranges are accommodated in a fourth sequence form.
摘要翻译： 呈现射频和磁场梯度的几个序列用于从样本多响应回波信号获得多个独立血管造影图，其可以被组合或单独分析以提供比单个血管造影更多的信息，但是基本上 与单次血管造影相同的时间量。 例如，可以在使用单回波方法获得单个血管造影所需的时间内获得每一个具有不同投影轴的血管造影图。 如果每个回波的视角相同，则可以添加获取的血管造影以提高信噪比。 另一个脉冲序列同时获得两个或更多个血管造影图，每个血管造影检查对于整个血流的两个正交流分量之一敏感; 然后加入血管造影以产生对所有方向的总流量敏感的血管造影。 多个速度范围以第四顺序形式被容纳。
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公开(公告)号：US4796635A
公开(公告)日：1989-01-10
申请号：US13592
申请日：1987-02-11
申请人： Charles L. Dumoulin
发明人： Charles L. Dumoulin
IPC分类号： A61B5/055 , G01R33/48 , G01R33/563 , A61B5/05
CPC分类号： G01R33/563
摘要： Several sequences of radio-frequency and magnetic field gradients are presented for obtaining from a sample multiple response echo signals from which to obtain a plurality of independent angiograms, which can be combined or separately analyzed to provide more information than an individual angiogram, but in substantially the same amount of time as a single angiogram. For example, a series of angiograms, each with a different projection axis, can be obtained in the time required to obtain a single angiogram using a single echo method. If the view angle of each echo is the same, then the acquired angiograms can be added to enhance the signal-to-noise ratio. Anothe pulse sequence simultaneously obtains two or more angiograms, each sensitive to one of two orthogonal flow components of the overall blood flow, the angiograms are then added to give an angiogram which is sensitive to total flow in all directions. Multiple velocity ranges are accommodated in a fourth sequence form.
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68.发明授权Apparatus for shifting the phase of transmitter and receiver analog baseband signals in an NMR system 失效用于在NMR系统中移位发射机和接收机模拟基带信号的相位的装置
公开(公告)号：US4736328A
公开(公告)日：1988-04-05
申请号：US779338
申请日：1985-09-23
CPC分类号： G01R33/3607
摘要： Apparatus for shifting the phase of a phase-quadrature signal pair, in at least one of the transmitter and receiver of an NMR system, uses a circuit for shifting the phase of each of the pair of signals by a substantially similar amount responsive to a control signal, and a microcontroller for programmably establishing the control signal data to provide a desired phase shift. Typically, the control signal is of digital data nature and the phase shifter operates to shift signal phase through an angle equal to a selected multiple N of a basic angle. The basic angle is selected such that a plurality of equal angle increments are established by the resolving properties of the data signal. A plurality of phase shifters can be controlled by a single microcontroller.
摘要翻译： 用于在NMR系统的发射机和接收机中的至少一个中移相相位正交信号对的相位的装置使用一个电路，用于使一对信号中的每一个的相位相应于对应于控制的基本类似的量 信号和微控制器，用于可编程地建立控制信号数据以提供期望的相移。 通常，控制信号具有数字数据性质，并且移相器操作以使信号相位移动等于基本角度的选定多个N的角度。 选择基本角度，使得通过数据信号的分辨率特性建立多个相等的角度增量。 多个移相器可以由单个微控制器控制。
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公开(公告)号：US4714081A
公开(公告)日：1987-12-22
申请号：US835683
申请日：1986-03-03
IPC分类号： A61B10/00 , A61B5/055 , G01R33/48 , G01R33/563 , A61B5/05
CPC分类号： G01R33/563
摘要： Magnetic field gradient and radio-frequency (RF) pulse signal sequences permitting moving nuclear spins to be selectively detected and then displayed as projected angiographic data in a nuclear magnetic resonance (NMR) image, without the use of contrast agents. The method allows the intensity of an image pixel to be determined by the macroscopic detected spin velocity and can provide essentially complete suppression of non-moving spins. Resulting images have high signal-intensity dynamic range for detected vessels. The selected detection of moving flows is not dependent upon pulsatile flow so that venous and arterial structures are equally as well visualized in high-resolution NMR angiographic images.
摘要翻译： 磁场梯度和射频（RF）脉冲信号序列允许选择性地检测移动的核自旋，然后在核磁共振（NMR）图像中显示为投影的血管造影数据，而不使用造影剂。 该方法允许通过宏观检测的旋转速度确定图像像素的强度，并且可以基本上完全抑制非移动自旋。 所得图像对于检测到的血管具有高信号强度动态范围。 选择的移动流动检测不依赖于脉动流动，因此静脉和动脉结构在高分辨率NMR血管造影图像中同样可视化。
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