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11.发明授权Apparatus and methods for magnetic resonance (MR) imaging of cavities using fluids polarized at low temperatures 失效使用在低温下极化的流体对空腔进行磁共振（MR）成像的装置和方法
公开(公告)号：US5617859A
公开(公告)日：1997-04-08
申请号：US537574
申请日：1995-10-02
IPC分类号： A61B5/055
CPC分类号： A61B5/055
摘要： A magnetic resonance (MR) active invasive device system employs a small, high-field polarizing magnet, and a large magnetic resonance (MR) imaging magnet for the purpose of generating MR images of selected body cavities. A subject is positioned in a large low-field MR imaging magnet. A substance, intended to be used as a contrast agent is first cooled, and then passed through the small high-field polarizing magnet where it becomes highly polarized. The substance is then heated to physiologic temperatures, vaporized, and introduced into the subject through a transfer conduit as a vapor. Radiofrequency (RF) pulses and magnetic field gradients are then applied to the patient as in conventional MR imaging. Since the vapor is highly polarized, it can be imaged even though it has a much lower density than the surrounding tissue.
摘要翻译： 磁共振（MR）有源侵入性装置系统采用小型高场极化磁体和大型磁共振（MR）成像磁体，用于产生选定体腔的MR图像。 受试者位于大型低场MR成像磁体中。 首先将要用作造影剂的物质冷却，然后通过小型高场极化磁体，在其中高度极化。 然后将物质加热至生理温度，蒸发，并通过作为蒸气的转移导管引入受试者。 然后将射频（RF）脉冲和磁场梯度应用于患者，如在常规MR成像中。 由于蒸气是高度极化的，所以即使其具有比周围组织低得多的密度，也可以成像。
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12.发明授权Tracking system to monitor the position of a device using multiplexed magnetic resonance detection 失效跟踪系统监视使用复用磁共振检测的设备的位置
公开(公告)号：US5353795A
公开(公告)日：1994-10-11
申请号：US989283
申请日：1992-12-10
IPC分类号： A61B5/06 , G01R33/28 , G01R33/561 , G01R33/563 , A61B5/055
CPC分类号： G01R33/285 , A61B5/06 , 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 applied magnetic gradients to determine the position of the device in several dimensions. Sensitivity of the measured position to resonance offset conditions such as transmitter frequency misadjustment, chemical shift and the like is minimized by repeating the process a plurality of times with selected amplitudes and polarities for the applied magnetic field gradient. Linear combinations of the data acquired responsive to the different applied magnetic field gradients are computed to determine the position of the device in three orthogonal 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。 响应于所施加的磁梯度检测信号以确定装置在几个维度中的位置。 通过用所施加的磁场梯度的选定幅度和极性重复该过程多次来最小化测量位置对谐振偏移条件（例如发射机频率误调整，化学位移等）的灵敏度。 计算响应于不同施加的磁场梯度采集的数据的线性组合，以确定装置在三个正交尺寸中的位置。 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：US5265610A
公开(公告)日：1993-11-30
申请号：US753566
申请日：1991-09-03
CPC分类号： A61B6/463 , A61B5/06 , A61B6/12 , H05G1/26 , A61B2034/2051
摘要： During an X-ray fluoroscopy procedure, the position and orientation of an invasive device, such as a catheter, are measured with radiofrequency fields. The invasive device has a transient 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. Multiple views of the instantaneous position of the invasive device are displayed by superposition of graphic symbols on multiple static X-ray images obtained at multiple view angles. Each view angle is displayed upon a different display means. 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射线透视程序期间，用射频场来测量诸如导管的侵入性装置的位置和取向。 侵入性装置具有靠近其端部附接的瞬态线圈，并且由低功率RF源驱动以产生偶极电磁场，该偶极电磁场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。 通过在多个视角获得的多个静态X射线图像上叠加图形符号来显示侵入性设备的瞬时位置的多个视图。 每个视角都显示在不同的显示装置上。 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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14.发明授权Apparatus and methods for magnetic resonance (MR) angiography using fluids polarized at low temperatures 失效使用在低温下极化的流体进行磁共振（MR）血管造影术的装置和方法
公开(公告)号：US5626137A
公开(公告)日：1997-05-06
申请号：US537572
申请日：1995-10-02
IPC分类号： A61B5/055
CPC分类号： A61B5/055
摘要： A magnetic resonance (MR) active invasive device system employs a small, high-field polarizing magnet, and a large, possibly low-field magnetic resonance (MR) imaging magnet for the purpose of generating MR angiograms of selected blood vessels. A subject is positioned in a large MR imaging magnet. A catheter is inserted into the patient at or near the root of a vessel tree to be imaged. A fluid, intended to be used as a contrast agent is first cooled and frozen, and then passed through the small high-field polarizing magnet where it becomes highly polarized. The frozen fluid is then heated and melted to physiologic temperatures and introduced into the subject through the catheter. Radiofrequency (RF) pulses and magnetic field gradients are then applied to the patient as in conventional MR imaging. Since the fluid has a larger longitudinal magnetization than tissue which has not passed through the polarizing magnet, the fluid produces a much larger MR response signal than other tissue, resulting in vessel tree images with excellent contrast.
摘要翻译： 磁共振（MR）主动侵入性装置系统采用小型，高场极化磁体和大型可能的低场磁共振（MR）成像磁体，用于产生选定血管的MR血管造影。 受试者位于大型MR成像磁体中。 在要成像的血管树的根部处或附近将导管插入患者体内。 首先将要用作造影剂的流体冷却并冷冻，然后通过小型高场极化磁体，在其中高度极化。 然后将冷冻的流体加热并熔化成生理温度并通过导管引入受试者。 然后将射频（RF）脉冲和磁场梯度应用于患者，如在常规MR成像中。 由于流体具有比没有通过偏振磁体的组织更大的纵向磁化强度，所以流体产生比其他组织大得多的MR响应信号，导致具有优异对比度的容器树图像。
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公开(公告)号：US5577502A
公开(公告)日：1996-11-26
申请号：US415409
申请日：1995-04-03
CPC分类号： A61B5/721 , A61B34/20 , A61B5/06 , A61B5/1135 , A61B8/0833 , A61B8/5276 , A61B2017/00694 , A61B5/7289
摘要： A tracking system monitors the position of a device within a subject and superimposes a graphic symbol on a diagnostic image of the subject. Registration of the tracked location with the diagnostic image is maintained in the presence of subject motion by monitoring subject motion and adjusting the display to compensate for subject motion. Motion monitoring can be performed with ultrasonic, optical or mechanical methods. The display can be adjusted by modifying the displayed location of the device or it can be adjusted by translating, rotating or distorting the diagnostic image.
摘要翻译： 跟踪系统监视对象内的设备的位置并将图形符号叠加在被摄体的诊断图像上。 通过监视对象运动并调整显示以补偿被摄体运动，通过诊断图像对被跟踪位置的注册保持在受试者运动的存在下。 运动监测可以用超声波，光学或机械方法进行。 可以通过修改显示的设备位置来调整显示，也可以通过翻译，旋转或扭曲诊断图像进行调整。
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公开(公告)号：US5479925A
公开(公告)日：1996-01-02
申请号：US264283
申请日：1994-06-23
IPC分类号： A61B5/055 , A61B6/00 , G01R33/28 , G01R33/48 , G01R33/561 , G01R33/563 , G06T1/00 , H01F7/20
CPC分类号： A61B6/504 , A61B6/481 , G01R33/285 , G01R33/563 , G01R33/281 , G01R33/445 , G01R33/56308
摘要： A magnetic resonance (MR) active invasive device system employs a small, high-field polarizing magnet, and a large low-field magnetic resonance (MR) imaging magnet for the purpose of generating MR angiograms of selected blood vessels. A subject is positioned in a large low-field MR imaging magnet. A catheter in inserted into the patient at or near the root of a vessel tree desired to be imaged. A fluid, intended to be used as a contrast agent is first passed through the small high-field polarizing magnet, causing a great deal of net longitudinal magnetization to be produced in the fluid. The fluid is then introduced into the subject through the catheter. Radiofrequency (RF) pulses and magnetic field gradients are then applied to the patient as in conventional MR imaging. Since the fluid has a larger longitudinal magnetization, before the MR imaging sequence, the fluid produces a much larger MR response signal than other tissue resulting in the vessel tree being imaged with excellent contrast.
摘要翻译： 磁共振（MR）主动侵入性装置系统采用小型，高场极化磁体和大型低场磁共振（MR）成像磁体，用于产生选定血管的MR血管造影。 受试者位于大型低场MR成像磁体中。 插入患者的导管，该导管需要被成像的血管树根部或附近。 旨在用作造影剂的流体首先通过小型高场极化磁体，导致在流体中产生大量的净纵向磁化强度。 然后通过导管将流体引入受试者。 然后将射频（RF）脉冲和磁场梯度应用于患者，如在常规MR成像中。 由于流体具有较大的纵向磁化强度，在MR成像序列之前，流体产生比其它组织大得多的MR响应信号，导致血管树被成像，具有出色的对比度。
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公开(公告)号：US5445150A
公开(公告)日：1995-08-29
申请号：US10720
申请日：1993-01-29
CPC分类号： G01V3/12 , A61B5/06 , A61B2560/0214 , A61B5/07
摘要： An invasive imaging system employs a self-contained RF transmitter attached to an invasive device which allows tracking of the invasive device within a subject without physical connections to a tracking/display system and without the use of ionizing rays. An imaging system obtains a medical diagnostic image of the subject. The self-contained RF transmitter is comprised of a power generator, a power conversion means such as an oscillator which converts the generated power to a radiofrequency (RF) signal, and a broadcasting means such as a tuned transmit coil for radiating the RF signal. The radiated RF signal is received by receive coils of a tracking/display means which calculates the location of the RF transmitter. The tracking/display means displays the medical diagnostic image on a monitor and superimposes a symbol on the image at a position corresponding to the calculated location of the RF transmitter. Prior to operation, the power generator may be energized inductively, photo-voltaically, or by direct contact with either an external power supply. The power generator may also be a charged battery sealed inside the RF transmitter. The RF transmitter may be implanted to track the motion of internal tissues.
摘要翻译： 侵入式成像系统采用连接到侵入性装置的独立的RF发射器，其允许跟踪受试者内的侵入性装置，而无需与跟踪/显示系统的物理连接，而不使用电离射线。 成像系统获得被检体的医学诊断图像。 独立的射频发射机包括功率发生器，诸如将所产生的功率转换为射频（RF）信号的振荡器的功率转换装置，以及用于辐射RF信号的诸如调谐发射线圈的广播装置。 辐射的RF信号由计算RF发射机的位置的跟踪/显示装置的接收线圈接收。 跟踪/显示装置在监视器上显示医疗诊断图像，并且在与RF计算机的位置相对应的位置处将图像叠加在图像上。 在操作之前，发电机可以感应地，光电地或通过与外部电源直接接触而被激励。 发电机也可以是密封在RF发射器内的充电电池。 可以植入RF发射器以跟踪内部组织的运动。
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18.发明授权Tracking system to monitor the position and orientation of a device using magnetic resonance detection of a sample contained within the device 失效跟踪系统用于使用包含在该装置内的样本的磁共振检测来监测装置的位置和方位
公开(公告)号：US5271400A
公开(公告)日：1993-12-21
申请号：US861662
申请日：1992-04-01
IPC分类号： A61B5/055 , A61B5/06 , A61B5/07 , G01R33/28 , G01R33/561 , G01R33/563
CPC分类号： G01R33/563 , A61B5/055 , A61B5/06 , G01R33/285 , G01R33/5617
摘要： A tracking system employs magnetic resonance signals to monitor the position and orientation of a device, such as a catheter, within a subject. The device has an MR active sample and a receiver coil which is sensitive to magnetic resonance signals generated by the MR active sample. 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 device's position in several dimensions. The position of the device as determined by the tracking system is superimposed upon independently acquired medical diagnostic images. One or more devices can be simultaneously tracked.
摘要翻译： 跟踪系统采用磁共振信号来监测被检体内的装置（例如导管）的位置和方位。 该器件具有对MR活性样品产生的磁共振信号敏感的MR活性样品和接收器线圈。 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。 可以同时跟踪一个或多个设备。
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19.发明授权Magnetic resonance (MR) angiography using a toroidal polarizing magnet and a low-field imaging magnet 失效使用环形偏振磁体和低场成像磁体进行磁共振（MR）血管造影
公开(公告)号：US5609153A
公开(公告)日：1997-03-11
申请号：US534998
申请日：1995-09-27
IPC分类号： A61B5/055 , A61B6/00 , G01R33/28 , G01R33/48 , G01R33/561 , G01R33/563
CPC分类号： G01R33/563 , A61B5/055 , G01R33/285 , G01R33/445 , G01R33/56308
摘要： A magnetic resonance (MR) active invasive device system employs a small, high-field polarizing magnet having a toroidal geometry, and a large low-field magnetic resonance (MR) imaging magnet for the purpose of generating MR angiograms of selected blood vessels. A subject is positioned in a large low-field MR imaging magnet. A catheter is inserted into the patient at or near the root of a vessel tree to be imaged. A fluid, intended to be used as a contrast agent is first passed through the small high-field polarizing magnet, causing a great deal of net longitudinal magnetization to be produced in the fluid. The fluid is then introduced into the subject through the catheter. Radiofrequency (RF) pulses and magnetic field gradients are then applied to the patient as in conventional MR imaging. Since the fluid has a larger longitudinal magnetization, before the MR imaging sequence, the fluid produces a much larger MR response signal than other tissue, resulting in the vessel tree being imaged with excellent contrast.
摘要翻译： 磁共振（MR）有源侵入性装置系统采用具有环形几何形状的小型高场极化磁体和大型低场磁共振（MR）成像磁体，用于产生选定血管的MR血管造影。 受试者位于大型低场MR成像磁体中。 在要成像的血管树的根部处或附近将导管插入患者体内。 旨在用作造影剂的流体首先通过小型高场极化磁体，导致在流体中产生大量的净纵向磁化强度。 然后通过导管将流体引入受试者。 然后将射频（RF）脉冲和磁场梯度应用于患者，如在常规MR成像中。 由于流体具有较大的纵向磁化强度，在MR成像序列之前，流体产生比其他组织大得多的MR响应信号，导致血管树被成像，具有优异的对比度。
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20.发明授权Method for the prevention of registration artifacts due to motion in magnetic resonance images 失效用于防止由于磁共振图像中的运动引起的对准伪影的方法
公开(公告)号：US5541512A
公开(公告)日：1996-07-30
申请号：US313957
申请日：1994-09-28
IPC分类号： G01R33/567 , G01V3/00 , G01V3/14
CPC分类号： G01R33/56509
摘要： A magnetic resonance system employs a sequence of radio frequency pulses and magnetic field gradients to generate a flow-compensated image of a selected portion of a sample. Flow-compensation is performed with an oscillating readout gradient waveform which is comprised of two components. The first component is a constant amplitude gradient waveform whose amplitude is determined by the desired field-of-view and the bandwidth of the imaging system. The second component is an oscillating waveform whose amplitude, frequency and phase are chosen to obtain the desired degree of flow-compensation. The frequency of the oscillating waveform is typically chosen to match the sampling frequency of the imaging system. In effect, each acquired data point is preceded by the application of a bi-polar magnetic field gradient pulse which causes a phase shift in the acquired signal which is proportional to nuclear spin velocity. The amplitude is typically chosen to cause an incremental phase shift which when repeatedly added to the acquired MR response signal at the sampling rate causes a frequency modulation. This frequency modulation, in turn, induces a spatial displacement of signal intensity in the readout dimension which corresponds to the displacement of spin magnetization during the interval between the phase-encoding and frequency-encoding.
摘要翻译： 磁共振系统采用一系列射频脉冲和磁场梯度来产生样本的所选部分的流量补偿图像。 使用由两个部件组成的振荡读出梯度波形执行流量补偿。 第一分量是恒幅幅度梯度波形，其幅度由所需的视场和成像系统的带宽决定。 第二个组件是振幅波形，其振幅，频率和相位被选择以获得所需的流量补偿程度。 通常选择振荡波形的频率以匹配成像系统的采样频率。 实际上，每个获取的数据点之前是施加双极磁场梯度脉冲，其引起所获取的信号中与核旋转速度成比例的相移。 通常选择幅度以引起增量相移，当以采样率重复地添加到所获取的MR响应信号时，会产生频率调制。 这种频率调制又引起了在相位编码和频率编码之间的间隔期间对应于自旋磁化的位移的读出维度中的信号强度的空间位移。
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