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公开(公告)号：US06411677B1
公开(公告)日：2002-06-25
申请号：US09950261
申请日：2001-09-10
IPC分类号： G21K102
CPC分类号： A61B6/583 , A61B6/4021 , G01N23/046 , G01N2223/419 , G01N2223/612
摘要： The present invention is, in one embodiment, a method for determining tracking control parameters for positioning an x-ray beam of a computed tomography imaging system having a movable collimator positionable in steps and a detector array including a plurality of rows of detector elements. The method includes steps of obtaining detector samples at a series of collimator step positions while determining a position of a focal spot of the x-ray beam; determining a beam position for each detector element at each collimator step utilizing the determined focal spot positions, a nominal focal spot length, and geometric parameters of the x-ray beam, collimator, and detector array; and determining a calibration parameter utilizing information so obtained. For example, in determining a target beam position at which to maintain the x-ray beam, a detector element differential error is determined according to ratios of successive collimator step positions; and a target beam position is selected for an isocenter element in accordance with the determined element differential errors.
摘要翻译： 本发明在一个实施例中是一种用于确定跟踪控制参数的方法，所述跟踪控制参数用于定位具有可定位的可移动准直仪的计算机断层摄影成像系统的X射线束和包括多行检测器元件的检测器阵列。 该方法包括以下步骤：在确定X射线束的焦斑的位置的同时在一系列准直器步骤位置获得检测器样本; 使用所确定的焦点位置，标称焦点长度以及x射线束，准直仪和检测器阵列的几何参数来确定每个准直器步骤处的每个检测器元件的光束位置; 以及使用如此获得的信息来确定校准参数。 例如，在确定维持X射线束的目标光束位置时，根据连续的准直仪台阶位置的比例来确定检测器元件差分误差; 并且根据确定的元件微分误差为等角点元件选择目标光束位置。
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公开(公告)号：US06385279B1
公开(公告)日：2002-05-07
申请号：US09384169
申请日：1999-08-27
IPC分类号： A61B600
CPC分类号： A61B6/583 , A61B6/032 , A61B6/4085
摘要： In one embodiment, the present invention is a method for positioning an x-ray beam on a multi-slice detector array of an imaging system in which the detector array has rows of detector elements and is configured to detect x-rays in slices along a z-axis. The method includes steps of comparing data signals representative of x-ray intensity received from different rows of detector elements and positioning the x-ray beam in accordance with a result of the comparison.
摘要翻译： 在一个实施例中，本发明是一种用于将X射线束定位在成像系统的多切片检测器阵列上的方法，其中检测器阵列具有行的检测器元件，并且被配置为沿着检测器元件的切片检测x射线 z轴。 该方法包括比较表示从不同行的检测器元件接收的x射线强度的数据信号和根据比较结果来定位x射线束的步骤。
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公开(公告)号：US06307918B1
公开(公告)日：2001-10-23
申请号：US09140112
申请日：1998-08-25
申请人： Thomas L. Toth , Carmine F. Vara , Willi W. Hampel
发明人： Thomas L. Toth , Carmine F. Vara , Willi W. Hampel
IPC分类号： G21K300
CPC分类号： A61B6/032 , A61B6/4035 , G21K1/10
摘要： The present invention, in one form, is an imaging system which, in one embodiment, utilizes a filter assembly including a plurality of filter portions for altering the intensity and quality of an x-ray beam. Specifically, in one embodiment, by positioning the filter assembly so that the x-ray beam is filtered by the first portion of the filter assembly, the x-ray beam is altered to perform a body portion scan. By positioning the filter assembly to the second portion, the x-ray beam is altered to perform a head portion scan.
摘要翻译： 本发明在一种形式中是一种成像系统，其在一个实施例中利用包括多个滤光器部分的滤光器组件来改变X射线束的强度和质量。 具体地说，在一个实施例中，通过将过滤器组件定位成使得X射线束被过滤器组件的第一部分过滤，改变x射线束以执行身体部位扫描。 通过将过滤器组件定位到第二部分，改变X射线束以执行头部扫描。
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公开(公告)号：US6056437A
公开(公告)日：2000-05-02
申请号：US139995
申请日：1998-08-25
申请人： Thomas L. Toth
发明人： Thomas L. Toth
CPC分类号： G01T1/2985 , G01T1/1648
摘要： The present invention, in one form, is a system which, in one embodiment, determines an x-ray beam z-axis profile and properly positions a detector array. Specifically, in one embodiment, signals intensities from the detector array are used to determine the optimal position of the detector array. In addition, the signal intensities are utilized to adjust an aperture of a pre-patient collimator. By adjusting the collimator aperture an x-ray beam umbra is aligned with the edges of the detector array. As a result, an optimal x-ray beam is radiated toward the detector array.
摘要翻译： 本发明在一种形式中是在一个实施例中确定x射线束z轴轮廓并适当地定位探测器阵列的系统。 具体地，在一个实施例中，来自检测器阵列的信号强度用于确定检测器阵列的最佳位置。 此外，信号强度被用于调整患者前准直仪的孔径。 通过调整准直器孔径，X射线束与检测器阵列的边缘对准。 结果，最佳X射线束朝向检测器阵列辐射。
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公开(公告)号：US5625662A
公开(公告)日：1997-04-29
申请号：US560672
申请日：1995-11-20
申请人： Thomas L. Toth , Mark K. Limkeman
发明人： Thomas L. Toth , Mark K. Limkeman
摘要： The present invention, in one form, is an x-ray CT system that modulates x-ray tube current as a function of gantry angle and reconstruction algorithm weighting coefficients. View indexes are stored in a table, and during scanning, values are periodically read from this table to determine weighting coefficients. An algorithm is applied to the weighting coefficients to generate an x-ray tube modulating factor. This modulating factor is then applied to the x-ray tube current to generate modulated x-ray tube current.
摘要翻译： 本发明以一种形式是一种x射线CT系统，其将X射线管电流作为机架角度和重建算法加权系数的函数进行调制。 视图索引存储在表中，并且在扫描期间，从该表周期性地读取值以确定加权系数。 将一个算法应用于加权系数以产生X射线管调制因子。 然后将该调节因子施加到X射线管电流以产生调制的X射线管电流。
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公开(公告)号：US5090037A
公开(公告)日：1992-02-18
申请号：US615514
申请日：1990-11-19
申请人： Thomas L. Toth , Kevin F. King , Carl R. Crawford
发明人： Thomas L. Toth , Kevin F. King , Carl R. Crawford
摘要： A CT apparatus reduces errors in projection data acquired in helical scanning. The imaged object moves concurrently along a translation axis and the x-ray beam is periodically translated with the imaged object so as to subtend a single predetermined volume element during the acquisition of one projection set of data for a first slice. The x-ray beam then returns to its starting position and tracks a second predetermined volume element within a next slice. The x-ray beam may be translated by moving the focal point or a collimator or a combination of both.
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公开(公告)号：US4991189A
公开(公告)日：1991-02-05
申请号：US509598
申请日：1990-04-16
CPC分类号： A61B6/06 , A61B6/4021 , G21K1/02
摘要： A computed tomography system corrects image errors resulting from misalignment of the fan beam as a result of placement of the x-ray tube, thermal drift of the x-ray tube anode of mechanical stresses of the gantry or x-ray tube. Misalignment is determined alternately by means of a z-axis offset detector which detects movement of the exposure area of the CT fan beam or a predictive model that calculates thermal drift of mechanical deflection of the focal spot of the x-ray tube based on previous use. The system includes a collimator with a controllable z-axis position which may be controlled to reduce z-axis offset of the fan beam exposure area or to make the fan beam more parallel with the imaging plane of the CT system.
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