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公开(公告)号：US06426623B1
公开(公告)日：2002-07-30
申请号：US09964155
申请日：2001-09-26
申请人： Matthew A. Bernstein
发明人： Matthew A. Bernstein
IPC分类号： G01V300
CPC分类号： G01R33/3614 , G01R33/288 , G01R33/583
摘要： An MRI system performs a pulse sequence to acquire image data from a subject. The RF power applied to the subject is monitored and the acquisition is altered if any one of three trip levels is exceeded. Each trip level is different and is associated with a different time interval over which applied RF power is measured.
摘要翻译： MRI系统执行脉冲序列以从对象获取图像数据。 如果超过三个行程级别中的任何一个，则监控施加到被摄体的RF功率，并且更改采集。 每个跳闸电平不同，并且与测量施加的RF功率的不同时间间隔相关联。
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公开(公告)号：US06339626B1
公开(公告)日：2002-01-15
申请号：US09039436
申请日：1998-03-16
IPC分类号： H04L700
CPC分类号： G01R33/56
摘要： An MRI system acquires NMR signals and digitizes them at a fixed sample rate. A lower, prescribed sample rate is obtained by fractionally decimating the sampled NMR signals. Fractional decimation is achieved by a combination of zeropadding the sampled NMR signal in the frequency domain and decimating the sampled NMR signal in the time domain.
摘要翻译： MRI系统获取NMR信号并以固定的采样率数字化。 通过对采样的NMR信号进行分数抽取，获得较低的规定采样率。 通过在频域中加样采样的NMR信号并在时域中抽取采样的NMR信号来组合分数抽取。
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公开(公告)号：US06249694B1
公开(公告)日：2001-06-19
申请号：US09118411
申请日：1998-07-17
IPC分类号： A61B5055
CPC分类号： G01R33/5635 , G01R33/5601 , G01R33/56572
摘要： A method of peripheral MR angiography is provided for imaging an artery or other vessel, wherein the vessel is of such length that MR data must be acquired at each of a plurality of scan stations spaced along the vessel. In accordance with the method, a contrast agent is intravenously injected, in order to provide a bolus which successively flows to each of the scan stations. After acquiring an initial subset of the MR data associated with a given scan station, the bolus is tracked to determine whether it has arrived at the next-following scan station. If so, at least some of the MR data associated with the next scan station are then acquired. However, if it is found that the bolus has not yet arrived at the next scan station, acquisition of further data at the given scan station is continued.
摘要翻译： 提供了一种用于对动脉或其他血管进行成像的外周MR血管造影术的方法，其中所述血管具有这样的长度，使得必须在沿着血管间隔开的多个扫描站中的每一个处获取MR数据。 根据该方法，静脉内注射造影剂，以提供连续流向每个扫描站的推注。 在获取与给定扫描站相关联的MR数据的初始子集之后，跟踪该推注以确定其是否到达下一个扫描站。 如果是，则随后获取与下一个扫描站相关联的至少一些MR数据。 然而，如果发现大剂量尚未到达下一个扫描站，则继续在给定扫描站获取进一步的数据。
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34.依法登记的发明公开(公告)号：USH1968H1
公开(公告)日：2001-06-05
申请号：US08475719
申请日：1995-06-07
申请人： Matthew A. Bernstein
发明人： Matthew A. Bernstein
IPC分类号： A61B5055
摘要： A method and apparatus is provided for generating an MR image of a structural portion of a subject, the portion lying within a hypothetical imaging volume. A specified level of hyperpolarized magnetization is provided within the imaging volume, and a series of MR pulse sequences are applied to the imaging volume to generate respective corresponding MR data signals, each pulse sequence comprising a number of magnetic field gradient pulses and an excitation pulse, and having an associated flip angle determined by the excitation pulse. The associated flip angles of successive pulse sequences are progressively increased to maintain the signal strength of the corresponding MR data signals at a substantially constant level. Acquired MR data signals are cumulatively processed to provide an image of the structural portion.
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公开(公告)号：US6026318A
公开(公告)日：2000-02-15
申请号：US984362
申请日：1997-12-03
CPC分类号： G01G19/445
摘要： A method is provided for measuring the weight of a medical imaging scanner patient. The scanner has a bore portion for receiving and housing the patient during a scan. Initially, a reclining apparatus associated with the scanner is provided, on which the patient can recline during the scan. A hydraulic lift mechanism is then used to position the reclining apparatus and the patient at bore level. The pressure within the hydraulic lift mechanism can then be measured as a function of downward force exerted by the reclining apparatus and the patient surface. Alternatively, the automatic measuring of patient mass, associated with the movement of the reclining apparatus and patient into the bore, can be determined by calculating instantaneous acceleration of the reclining apparatus and patient as the reclining apparatus and patient are slid into the bore.
摘要翻译： 提供了一种用于测量医学成像扫描仪患者的重量的方法。 扫描器具有用于在扫描期间接收和容纳患者的孔部分。 最初，提供与扫描仪相关联的倾斜装置，患者在扫描期间可以倾斜。 然后使用液压提升机构来将倾斜装置和患者定位在钻孔水平。 液压提升机构中的压力随后可以作为由斜倚装置和患者表面施加的向下的力的函数来测量。 或者，与倾斜装置和患者移动到膛孔中的移动相关联的患者质量的自动测量可以通过在斜倚装置和患者滑入孔中计算斜倚装置和患者的瞬时加速度来确定。
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公开(公告)号：US5783942A
公开(公告)日：1998-07-21
申请号：US782027
申请日：1996-12-30
IPC分类号： G01R33/563 , G01R33/565 , G01R33/20
CPC分类号： G01R33/56308 , G01R33/56545
摘要： A phase unwrapping method is provided comprising a post-processing MR operation for an array of phase-related MR data elements. The method includes the steps of defining a Region of Interest, of comparing each data element with the first and second data elements which are adjacent thereto in the array, in order to generate respectively corresponding first and second gradient values. A subset of the data elements is constructed, wherein a data element is assigned to the subset only if its corresponding first and second gradient values are less than a selected threshold value VENC/2. The data element subset is employed to generate a fitted phase function having a value at the position of each data element in the array, and the value of the fitted function thereof, for a given data element, is subtracted from the measured value thereof. A first unwrap correcting value is subtracted from the given data element if the difference is greater than a first specified level, and a second unwrap correcting value is added thereto if the difference is less than a second specified level. A measure of the number of wrapped pixels is monitored. The phase unwrap procedure can be iterated until the number of unwrapped pixels is zero, or does not decrease with further iterating.
摘要翻译： 提供了一种相位展开方法，包括用于相位相关MR数据元素阵列的后处理MR操作。 该方法包括以下步骤：定义感兴趣区域，将每个数据元素与阵列中与其相邻的第一和第二数据元素进行比较，以分别产生对应的第一和第二梯度值。 构造数据元素的子集，其中仅当其对应的第一和第二梯度值小于所选择的阈值VENC / 2时，才将数据元素分配给子集。 使用数据元素子集来产生在阵列中的每个数据元素的位置处具有值的拟合相位函数，并且从其测量值中减去给定数据元素的拟合函数的值。 如果差大于第一指定电平，则从给定数据元素中减去第一解开校正值，如果差小于第二指定电平，则将第二解开校正值加到其上。 监测包装像素数量的度量。 可以迭代相位解包过程，直到展开像素的数量为零，或者不进一步迭代减少。
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公开(公告)号：US5510713A
公开(公告)日：1996-04-23
申请号：US497132
申请日：1995-06-30
申请人： Matthew A. Bernstein
发明人： Matthew A. Bernstein
IPC分类号： G01R33/483 , G01R33/485 , G01R33/20
CPC分类号： G01R33/4838 , G01R33/5607
摘要： A system is provided for MR imaging wherein a volume within an imaging subject positioned with respect to the system contains both water molecules and fat tissue proximate to one another. The water molecules and fat tissue are selectively saturated by first determining whether application of a first RF excitation pulse of a first RF frequency to the volume, in association with a gradient magnetic field having a selected polarity with respect to an axis, would saturate fat tissue in a band lying closer to or farther from a selected location than a band of saturated water molecules. The first frequency comprises the sum of a center frequency and a first offset frequency having a magnitude and polarity determined by the gradient magnetic field. In the event the saturated fat band associated with the first frequency would lie farther from the specified location, a second RF pulse of a second RF frequency is instead applied to the volume to saturate fat tissue within a band lying closer to the specified location, the second RF frequency comprising the sum of the center frequency and a second offset frequency having a magnitude equal to the magnitude of the first offset frequency and a polarity opposite to the polarity thereof. The polarity of the selection gradient of the second RF pulse is similarly negated compared to the polarity of the selection gradient of the first pulse.
摘要翻译： 提供了一种用于MR成像的系统，其中相对于系统定位的成像对象内的体积包含彼此靠近的水分子和脂肪组织。 水分子和脂肪组织通过首先确定将第一RF频率的第一RF激发脉冲施加到体积上是否与相对于轴线具有选定极性的梯度磁场相关联将使饱和脂肪组织饱和 在比一个饱和水分子带更靠近或远离所选择的位置的带中。 第一频率包括具有由梯度磁场确定的幅度和极性的中心频率和第一偏移频率之和。 在与第一频率相关联的饱和脂肪带将远离指定位置的情况下，将第二RF频率的第二RF脉冲施加到体积以使位于更靠近指定位置的频带内的脂肪组织饱和， 第二RF频率包括具有等于第一偏移频率的幅度的幅度和与其极性相反的极性的中心频率和第二偏移频率之和。 与第一脉冲的选择梯度的极性相比，第二RF脉冲的选择梯度的极性也是相似的。
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公开(公告)号：US5281916A
公开(公告)日：1994-01-25
申请号：US921532
申请日：1992-07-29
IPC分类号： G01R33/563 , G01R33/20
CPC分类号： G01R33/56308 , G01R33/56316
摘要： An NMR angiogram is produced from two data sets acquired using a fast pulse sequence. One data set is acquired with a readout gradient having a first moment of zero at each refocusing pulse and a first value at each acquired echo signal. A second data set is acquired with a readout gradient having a first moment of zero at each refocusing pulse and a second value at each acquired echo signal. Signals from stationary tissues are suppressed with a dephasing gradient pulse in the slice select direction applied after each refocusing pulse, and a corresponding rewinder gradient pulse is applied after each acquired echo signal.
摘要翻译： 使用快速脉冲序列获得的两个数据集产生NMR血管造影图。 在每个重聚焦脉冲处以一个第一时刻为零的读出梯度获取一个数据集，并且在每个获取的回波信号处获取一个第一值。 在每个再聚焦脉冲处以第一时刻为零的读出梯度获取第二数据集，并且在每个获取的回波信号处获取第二数据集。 在每个重聚焦脉冲之后，在切片选择方向上用去相位梯度脉冲抑制来自静止组织的信号，并且在每个获取的回波信号之后施加相应的倒卷梯度脉冲。
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39.发明授权
公开(公告)号：US5226418A
公开(公告)日：1993-07-13
申请号：US738765
申请日：1991-08-01
IPC分类号： F28D7/08 , A61B5/055 , F28D9/00 , G01P5/00 , G01P13/00 , G01R33/28 , G01R33/563 , G01R33/565
CPC分类号： F28D9/0037 , G01R33/563 , G01R33/565 , G01R33/56563
摘要： An NMR system produces an angiogram using the complex-difference method. Artifacts caused by system phase errors are reduced by calculating a corrected phase angle using the acquired NMR data sets and using the corrected phase angle in calculating the complex difference in the corresponding elements of the image domain NMR data sets.
摘要翻译： NMR系统使用复差法产生血管造影。 通过使用所获取的NMR数据集计算校正的相位角并且在计算图像域NMR数据集的相应元素中的复差时使用校正的相位角来减少由系统相位误差引起的伪像。
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