Method and apparatus for helical computed tomography scanning with
asymmetric detector system
    1.
    发明授权
    Method and apparatus for helical computed tomography scanning with asymmetric detector system 失效
    用不对称检测器系统进行螺旋计算机断层扫描的方法和装置

    公开(公告)号:US5828718A

    公开(公告)日:1998-10-27

    申请号:US829062

    申请日:1997-03-31

    IPC分类号: A61B6/03

    摘要: A system for and method of generating a reconstructed tomographic image is described using an asymmetric detector array during a helical scan. An improved helical weighting system applies a helical halfscan technique to data collected by a symmetric portion of an asymmetric detector system and applies a helical fullscan technique to data collected by an asymmetric portion of the asymmetric detector system. The preferred system comprises an equi-angle interpolator, a streak artifact suppression filter, and an isocenter interpolator that preserve the distinction between even and odd data points in parallel beam projection data.

    摘要翻译: 在螺旋扫描期间使用不对称检测器阵列描述了生成重建断层图像的系统和方法。 改进的螺旋加权系统将螺旋半扫描技术应用于由不对称检测器系统的对称部分收集的数据,并对不对称检测器系统的不对称部分收集的数据应用螺旋扫描技术。 优选的系统包括等角内插器,条纹伪影抑制滤波器和等距中心内插器,其保持平行光束投影数据中偶数和奇数数据点之间的区别。

    Computed tomography scanning apparatus and method using adaptive reconstruction window
    2.
    发明授权
    Computed tomography scanning apparatus and method using adaptive reconstruction window 失效
    计算机断层扫描装置和方法使用自适应重建窗口

    公开(公告)号:US06256404B1

    公开(公告)日:2001-07-03

    申请号:US08949127

    申请日:1997-10-10

    IPC分类号: G06K900

    CPC分类号: G01V5/005

    摘要: A method and apparatus for performing CT scans of baggage being carried or loaded onto commercial aircraft are described. The CT baggage scanner of the invention includes numerous features which provide the system with high baggage throughput on the order of seven hundred bags per hour as well as improved image quality and accurate target detection. In one aspect, the scanner includes an adaptive image reconstruction window which identifies data collected from the field of view that are not related to the baggage being scanned. These unrelated data are excluded from the image reconstruction process, resulting in greatly reduced reconstruction time and increased baggage throughput. The invention also includes the capability of performing calibration “air scans” with objects such as the system conveyor in the field of view. Data gathered during the calibration scan are applied to a threshold, and data exceeding the threshold are assumed to be from X-rays that are unobstructed by objects in the field of view and are therefore used to perform the air calibration. The baggage scanner can also analyze scan data to identify shapes of objects, particularly, objects formed in the shape of a sheet. This greatly improves the ability of the system to detect sheet explosives. The system also compensates for detector dark currents and provides dark current offsets which can be dependent upon detector temperature.

    摘要翻译: 描述了用于对携带或加载到商用飞机上的行李进行CT扫描的方法和装置。 本发明的CT行李扫描器包括许多特征,为系统提供每小时七百袋的高行李吞吐量,以及改进的图像质量和精确的目标检测。 在一个方面,扫描器包括自适应图像重建窗口,其识别从视场收集的与正在扫描的行李无关的数据。 这些不相关的数据从图像重建过程中排除,从而大大减少了重建时间和增加了行李吞吐量。 本发明还包括在视场中执行诸如系统输送机之类的物体的校准“空气扫描”的能力。 在校准扫描期间收集的数据被应用于阈值,并且超过阈值的数据被假设为来自视场中的物体不受阻挡的X射线,因此用于执行空气校准。 行李扫描器还可以分析扫描数据以识别物体的形状,特别是形成为片状形状的物体。 这大大提高了系统检测片状炸药的能力。 该系统还补偿检测器暗电流,并提供暗电流偏移,这取决于检测器温度。

    Apparatus and method for computed tomography scanning using halfscan
reconstruction with asymmetric detector system
    3.
    发明授权
    Apparatus and method for computed tomography scanning using halfscan reconstruction with asymmetric detector system 失效
    用不对称检测器系统进行半扫描重建的计算机断层扫描仪的设备和方法

    公开(公告)号:US5848117A

    公开(公告)日:1998-12-08

    申请号:US904516

    申请日:1997-08-01

    IPC分类号: A61B6/03

    摘要: A method and apparatus for halfscan reconstruction in a CT scanning system using an asymmetric detector system are described. In halfscan asymmetric (HSA) reconstruction, a halfscan reconstruction approach is used for data acquired by the symmetric portion of the array, and a fullscan reconstruction approach is used to reconstruct data acquired by the asymmetric portion of the array. When scanning oversized subjects which extend beyond the symmetric field of view of the array, a halfscan reconstruction approach is used which applies a zero weighting to data acquired by the asymmetric portion of the array and ramps data acquired by the asymmetric portion to zero.

    摘要翻译: 描述了使用不对称检测器系统的CT扫描系统中半扫描重建的方法和装置。 在半扫描不对称(HSA)重建中,半扫描重建方法用于由阵列的对称部分获取的数据,并且全扫描重建方法用于重建由阵列的不对称部分获取的数据。 当扫描超过阵列的对称视场的超大对象时,使用半扫描重建方法,其对由阵列的不对称部分获取的数据施加零加权,并将由非对称部分获取的数据斜坡化为零。

    Nutating slice CT image reconstruction apparatus and method
    4.
    发明授权
    Nutating slice CT image reconstruction apparatus and method 失效
    营养片CT图像重建装置及方法

    公开(公告)号:US5802134A

    公开(公告)日:1998-09-01

    申请号:US831558

    申请日:1997-04-09

    IPC分类号: A61B6/03 G01N23/04 G06T15/00

    摘要: A nutating slice CT image reconstruction apparatus and method generates a set of projection data using helical cone-beam scanning. The three-dimensional projection data is used to reconstruct a series of planar image slices. The slices are selected such that they define a tilt angle and a rotation angle with respect to the longitudinal axes of the object being scanned. Successive slices have equal tilt angles but changing rotation angles such that normal axes of successive slices define a nutation and precession about the longitudinal axis of the object. Projection data for the tilted slices are formed of selected one-dimensional fan-beam data. As such, the projection data can be applied to conventional two-dimensional reconstruction approaches to generate an image.

    摘要翻译: 章动切片CT图像重建装置和方法使用螺旋锥束扫描产生一组投影数据。 三维投影数据用于重建一系列平面图像切片。 切片被选择为使得它们相对于被扫描物体的纵向轴线限定倾斜角度和旋转角度。 连续切片具有相等的倾斜角度,但是改变旋转角度,使得连续切片的法线定义关于物体的纵向轴线的章动和进动。 倾斜切片的投影数据由选定的一维扇形光束数据形成。 因此,投影数据可以应用于常规的二维重建方法以产生图像。

    Computed tomography scanning apparatus and method with temperature
compensation for dark current offsets
    5.
    发明授权
    Computed tomography scanning apparatus and method with temperature compensation for dark current offsets 失效
    计算机断层摄影扫描仪和带有温度补偿的暗电流补偿方法

    公开(公告)号:US5970113A

    公开(公告)日:1999-10-19

    申请号:US948928

    申请日:1997-10-10

    IPC分类号: G01V5/00 G01N23/00

    CPC分类号: G01V5/005

    摘要: A method and apparatus for performing CT scans of baggage being carried or loaded onto commercial aircraft are described. The CT baggage scanner of the invention includes numerous features which provide the system with high baggage throughput on the order of seven hundred bags per hour as well as improved image quality and accurate target detection. In one aspect, the scanner includes an adaptive image reconstruction window which identifies data collected from the field of view that are not related to the baggage being scanned. These unrelated data are excluded from the image reconstruction process, resulting in greatly reduced reconstruction time and increased baggage throughput. The invention also includes the capability of performing calibration "air scans" with objects such as the system conveyor in the field of view. Data gathered during the calibration scan are applied to a threshold, and data exceeding the threshold are assumed to be from X-rays that are unobstructed by objects in the field of view and are therefore used to perform the air calibration. The baggage scanner can also analyze scan data to identify shapes of objects, particularly, objects formed in the shape of a sheet. This greatly improves the ability of the system to detect sheet explosives. The system also compensates for detector dark currents and provides dark current offsets which can be dependent upon detector temperature.

    摘要翻译: 描述了用于对携带或加载到商用飞机上的行李进行CT扫描的方法和装置。 本发明的CT行李扫描器包括许多特征,为系统提供每小时七百袋的高行李吞吐量,以及改进的图像质量和精确的目标检测。 在一个方面,扫描器包括自适应图像重建窗口,其识别从视场收集的与正在扫描的行李无关的数据。 这些不相关的数据从图像重建过程中排除,从而大大减少了重建时间和增加了行李吞吐量。 本发明还包括在视场中执行诸如系统输送机之类的物体的校准“空气扫描”的能力。 在校准扫描期间收集的数据被应用于阈值,并且超过阈值的数据被假设为来自视场中的物体不受阻挡的X射线,因此用于执行空气校准。 行李扫描器还可以分析扫描数据以识别物体的形状,特别是形成为片状形状的物体。 这大大提高了系统检测片状炸药的能力。 该系统还补偿检测器暗电流,并提供暗电流偏移,这取决于检测器温度。

    Parallel processing architecture for computed tomography scanning system
using non-parallel slices
    6.
    发明授权
    Parallel processing architecture for computed tomography scanning system using non-parallel slices 失效
    使用非平行切片的计算机断层摄影扫描系统的并行处理架构

    公开(公告)号:US5887047A

    公开(公告)日:1999-03-23

    申请号:US948697

    申请日:1997-10-10

    IPC分类号: A61B6/03 G01N23/04 G06T15/00

    摘要: A nutating slice CT image reconstruction apparatus and method generates a set of projection data using helical cone-beam scanning. The three-dimensional projection data is used to reconstruct a series of planar image slices. The slices are selected such that they define a tilt angle and a rotation angle with respect to the longitudinal axes of the object being scanned. Successive slices have equal tilt angles but changing rotation angles such that normal axes of successive slices define a nutation and precession about the longitudinal axis of the object. Projection data for the tilted slices are formed of selected one-dimensional fan-beam data. As such, the projection data can be applied to conventional two-dimensional reconstruction approaches to generate an image. The projection data can also be used to generate two-dimensional projection images at one or more stationary projection angles through an object being scanned. The nutation or tilt of image volume elements can be compensated for to provide a more accurate image and more accurate target assessment such as accurate total mass determination. A parallel processing architecture can be used to generate and process the nutated slices with improved efficiency.

    摘要翻译: 章动切片CT图像重建装置和方法使用螺旋锥束扫描产生一组投影数据。 三维投影数据用于重建一系列平面图像切片。 切片被选择为使得它们相对于被扫描物体的纵向轴线限定倾斜角度和旋转角度。 连续切片具有相等的倾斜角度,但是改变旋转角度,使得连续切片的法线定义关于物体的纵向轴线的章动和进动。 倾斜切片的投影数据由选定的一维扇形光束数据形成。 因此,投影数据可以应用于常规的二维重建方法以产生图像。 投影数据还可用于通过被扫描物体在一个或多个固定投影角度产生二维投影图像。 可以补偿图像体积元件的章动或倾斜,以提供更准确的图像和更准确的目标评估,例如准确的总质量确定。 可以使用并行处理架构来提高效率来生成和处理章程切片。

    Computed tomography scanning target detection using target surface
normals
    7.
    发明授权
    Computed tomography scanning target detection using target surface normals 失效
    计算机断层扫描目标检测使用目标表面法线

    公开(公告)号:US5901198A

    公开(公告)日:1999-05-04

    申请号:US948929

    申请日:1997-10-10

    IPC分类号: G01V5/00 G01N23/04

    CPC分类号: G01V5/005 Y10S378/901

    摘要: A method and apparatus for performing CT scans of baggage being carried or loaded onto commercial aircraft are described. The CT baggage scanner of the invention includes numerous features which provide the system with high baggage throughput on the order of seven hundred bags per hour as well as improved image quality and accurate target detection. In one aspect, the scanner includes an adaptive image reconstruction window which identifies data collected from the field of view that are not related to the baggage being scanned. These unrelated data are excluded from the image reconstruction process, resulting in greatly reduced reconstruction time and increased baggage throughput. The invention also includes the capability of performing calibration "air scans" with objects such as the system conveyor in the field of view. Data gathered during the calibration scan are applied to a threshold, and data exceeding the threshold are assumed to be from X-rays that are unobstructed by objects in the field of view and are therefore used to perform the air calibration. The baggage scanner can also analyze scan data to identify shapes of objects, particularly, objects formed in the shape of a sheet. This greatly improves the ability of the system to detect sheet explosives. The system also compensates for detector dark currents and provides dark current offsets which can be dependent upon detector temperature.

    摘要翻译: 描述了用于对携带或加载到商用飞机上的行李进行CT扫描的方法和装置。 本发明的CT行李扫描器包括许多特征,为系统提供每小时七百袋的高行李吞吐量,以及改进的图像质量和精确的目标检测。 在一个方面,扫描器包括自适应图像重建窗口,其识别从视场收集的与正在扫描的行李无关的数据。 这些不相关的数据从图像重建过程中排除,从而大大减少了重建时间和增加了行李吞吐量。 本发明还包括在视场中执行诸如系统输送机之类的物体的校准“空气扫描”的能力。 在校准扫描期间收集的数据被应用于阈值,并且超过阈值的数据被假设为来自视场中的物体不受阻挡的X射线,因此用于执行空气校准。 行李扫描器还可以分析扫描数据以识别物体的形状,特别是形成为片状形状的物体。 这大大提高了系统检测片状炸药的能力。 该系统还补偿检测器暗电流,并提供暗电流偏移,这取决于检测器温度。

    Multi-processor afterglow artifact correction filter for use with
computed tomography scanners
    8.
    发明授权
    Multi-processor afterglow artifact correction filter for use with computed tomography scanners 失效
    用于计算机断层扫描仪的多处理器余辉伪影校正滤镜

    公开(公告)号:US5644610A

    公开(公告)日:1997-07-01

    申请号:US690810

    申请日:1996-08-01

    IPC分类号: G06T11/00 A61B6/03

    CPC分类号: G06T11/005 Y10S378/901

    摘要: The disclosed CT scanner includes a tomography system for generating data during a scan. The tomography system includes a detector characterized by at least one afterglow amplitude and at least one afterglow time constant, and a sampling device for generating a plurality of samples x.sub.i for all i from zero to MAX minus one of the detector output signal. The scanner also includes a set of N sub-processors for processing the samples x.sub.i, each of the sub-processors being represented by a unique integer q selected from zero to N minus one and receiving only the samples X.sub.iN+q. Each sub-processor includes a device for generating a compensated signal according to a function of at least a portion of the received samples and parameters representative of the afterglow amplitude and the afterglow time constant.

    摘要翻译: 所公开的CT扫描仪包括用于在扫描期间产生数据的断层摄影系统。 该断层摄影系统包括一个检测器,其特征在于至少有一个余辉振幅和至少一个余辉时间常数,以及采样装置,用于产生从0到MAX减去检测器输出信号之一的所有i的多个采样xi。 扫描器还包括用于处理样本xi的一组N个子处理器,每个子处理器由从零到N减去一个并且仅接收样本XiN + q的独特整数q表示。 每个子处理器包括用于根据所接收的采样的至少一部分的功能和表示余辉振幅和余辉时间常数的参数产生补偿信号的装置。

    Air calibration scan for computed tomography scanner with obstructing
objects
    9.
    发明授权
    Air calibration scan for computed tomography scanner with obstructing objects 失效
    用于具有阻塞物体的计算机断层扫描仪的空气校准扫描

    公开(公告)号:US5949842A

    公开(公告)日:1999-09-07

    申请号:US948937

    申请日:1997-10-10

    IPC分类号: G01V5/00 G01N23/04

    CPC分类号: G01V5/005 Y10S378/901

    摘要: A method and apparatus for performing CT scans of baggage being carried or loaded onto commercial aircraft are described. The CT baggage scanner of the invention includes numerous features which provide the system with high baggage throughput on the order of seven hundred bags per hour as well as improved image quality and accurate target detection. In one aspect, the scanner includes an adaptive image reconstruction window which identifies data collected from the field of view that are not related to the baggage being scanned. These unrelated data are excluded from the image reconstruction process, resulting in greatly reduced reconstruction time and increased baggage throughput. The invention also includes the capability of performing calibration "air scans" with objects such as the system conveyor in the field of view. Data gathered during the calibration scan are applied to a threshold, and data exceeding the threshold are assumed to be from X-rays that are unobstructed by objects in the field of view and are therefore used to perform the air calibration. The baggage scanner can also analyze scan data to identify shapes of objects, particularly, objects formed in the shape of a sheet. This greatly improves the ability of the system to detect sheet explosives. The system also compensates for detector dark currents and provides dark current offsets which can be dependent upon detector temperature.

    摘要翻译: 描述了用于对携带或加载到商用飞机上的行李进行CT扫描的方法和装置。 本发明的CT行李扫描器包括许多特征,为系统提供每小时七百袋的高行李吞吐量,以及改进的图像质量和精确的目标检测。 在一个方面,扫描器包括自适应图像重建窗口,其识别从视场收集的与正在扫描的行李无关的数据。 这些不相关的数据从图像重建过程中排除,从而大大减少了重建时间和增加了行李吞吐量。 本发明还包括在视场中执行诸如系统输送机之类的物体的校准“空气扫描”的能力。 在校准扫描期间收集的数据被应用于阈值,并且超过阈值的数据被假设为来自视场中的物体不受阻挡的X射线,因此用于执行空气校准。 行李扫描器还可以分析扫描数据以识别物体的形状,特别是形成为片状形状的物体。 这大大提高了系统检测片状炸药的能力。 该系统还补偿检测器暗电流,并提供暗电流偏移,这取决于检测器温度。

    Computed tomography scanning target detection using non-parallel slices
    10.
    发明授权
    Computed tomography scanning target detection using non-parallel slices 失效
    使用非平行切片的计算机断层扫描目标检测

    公开(公告)号:US5909477A

    公开(公告)日:1999-06-01

    申请号:US948491

    申请日:1997-10-10

    IPC分类号: A61B6/03 G01N23/04 G06T15/00

    摘要: A nutating slice CT image reconstruction apparatus and method generates a set of projection data using helical cone-beam scanning. The three-dimensional projection data is used to reconstruct a series of planar image slices. The slices are selected such that they define a tilt angle and a rotation angle with respect to the longitudinal axes of the object being scanned. Successive slices have equal tilt angles but changing rotation angles such that normal axes of successive slices define a nutation and precession about the longitudinal axis of the object. Projection data for the tilted slices are formed of selected one-dimensional fan-beam data. As such, the projection data can be applied to conventional two-dimensional reconstruction approaches to generate an image. The projection data can also be used to generate two-dimensional projection images at one or more stationary projection angles through an object being scanned. The nutation or tilt of image volume elements can be compensated for to provide a more accurate image and more accurate target assessment such as accurate total mass determination. A parallel processing architecture can be used to generate and process the nutated slices with improved efficiency.

    摘要翻译: 章动切片CT图像重建装置和方法使用螺旋锥束扫描产生一组投影数据。 三维投影数据用于重建一系列平面图像切片。 切片被选择为使得它们相对于被扫描物体的纵向轴线限定倾斜角度和旋转角度。 连续切片具有相等的倾斜角度,但是改变旋转角度,使得连续切片的法线定义关于物体的纵向轴线的章动和进动。 倾斜切片的投影数据由选定的一维扇形光束数据形成。 因此,投影数据可以应用于常规的二维重建方法以产生图像。 投影数据还可用于通过被扫描物体在一个或多个固定投影角度产生二维投影图像。 可以补偿图像体积元件的章动或倾斜,以提供更准确的图像和更准确的目标评估,例如准确的总质量确定。 可以使用并行处理架构来提高效率来生成和处理章程切片。