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    Method for statistically reconstructing images from a plurality of transmission measurements having energy diversity and image reconstructor apparatus utilizing the method
    1.
    发明授权
    Method for statistically reconstructing images from a plurality of transmission measurements having energy diversity and image reconstructor apparatus utilizing the method 有权
    用于从具有能量分集的多个传输测量统计重构图像的方法和利用该方法的图像重建装置

    公开(公告)号：US06754298B2

    公开(公告)日：2004-06-22

    申请号：US10368534

    申请日：2003-02-18

    申请人： Jeffrey A. Fessler

    发明人： Jeffrey A. Fessler

    IPC分类号： A61B603

    CPC分类号： A61B6/482 ,  A61B6/032 ,  A61B6/4035 ,  A61B6/405 ,  A61B6/4241 ,  G06T5/002 ,  G06T11/006 ,  G06T2207/10081 ,  G06T2211/408 ,  G06T2211/424

    摘要： A method for statistically reconstructing images from a plurality of transmission measurements having energy diversity and image reconstructor apparatus utilizing the method are provided. A statistical (maximum-likelihood) method for dual-energy X-ray CT accommodates a wide variety of potential system configurations and measurement noise models. Regularized methods (such as penalized-likelihood or Bayesian estimations) are straightforward extensions. One version of the algorithm monotonically decreases the negative log-likelihood cost function each iteration. An ordered-subsets variation of the algorithm provides a fast and practical version. The method and apparatus provide material characterization and quantitatively accurate CT values in a variety of applications. The method and apparatus provide improved noise/dose properties.

    摘要翻译： 提供了一种用于利用该方法从具有能量分集的多个传输测量和图像重建装置统计重构图像的方法。 双能X射线CT的统计（最大似然）方法可适应各种潜在的系统配置和测量噪声模型。 正则化方法（如惩罚似然或贝叶斯估计）是简单的扩展。 该算法的一个版本单调减少每次迭代的负对数似然成本函数。 该算法的有序子集变化提供了一个快速和实用的版本。 该方法和装置在各种应用中提供材料表征和定量精确的CT值。 该方法和装置提供改善的噪声/剂量特性。

    METHOD AND APPARATUS FOR ITERATIVE RECONSTRUCTION
    3.
    发明申请
    METHOD AND APPARATUS FOR ITERATIVE RECONSTRUCTION 有权
    用于迭代重建的方法和装置

    公开(公告)号：US20130343672A1

    公开(公告)日：2013-12-26

    申请号：US13531082

    申请日：2012-06-22

    申请人： ZHOU YU ,  Bruno Kristiaan Bernard De Man ,  Jean-Baptiste Thibault ,  Debashish Pal ,  Lin Fu ,  Charles A. Bouman ,  Ken Sauer ,  Sathish Ramani ,  Jeffrey A. Fessler ,  Somesh Srivastava

    发明人： ZHOU YU ,  Bruno Kristiaan Bernard De Man ,  Jean-Baptiste Thibault ,  Debashish Pal ,  Lin Fu ,  Charles A. Bouman ,  Ken Sauer ,  Sathish Ramani ,  Jeffrey A. Fessler ,  Somesh Srivastava

    IPC分类号： G06T11/00

    CPC分类号： G06T11/003 ,  G06T11/006 ,  G06T2211/424

    摘要： A method is provided for reconstructing an image of an object that includes image elements. The method includes accessing measurement data associated with the image elements, introducing an auxiliary variable to transform an original problem of reconstructing the image to a constrained optimization problem, and solving the constrained optimization problem using a method of multipliers to create a sequence of sub-problems and solve the sequence of sub-problems. Solving the sequence of sub-problems includes reconstructing the image by optimizing a first objective function. The first objective function is optimized by iteratively solving a nested sequence of approximate optimization problems. An inner loop iteratively optimizes a second objective function approximating the first objective function. An outer loop utilizes the solution of the second objective function to optimize the first objective function.

    摘要翻译： 提供了一种用于重构包括图像元素的对象的图像的方法。 该方法包括访问与图像元素相关联的测量数据，引入辅助变量以将原始图像重建问题转换为约束优化问题，以及使用乘法器的方法来解决约束优化问题以创建子问题序列 并解决子问题的顺序。 解决子问题的顺序包括通过优化第一目标函数重建图像。 通过迭代求解近似优化问题的嵌套序列，优化了第一个目标函数。 内循环迭代地优化接近于第一目标函数的第二目标函数。 外环利用第二目标函数的解来优化第一目标函数。

    THREE-DIMENSIONAL FORWARD AND BACK PROJECTION METHODS
    4.
    发明申请
    THREE-DIMENSIONAL FORWARD AND BACK PROJECTION METHODS 有权
    三维前向和后向投影方法

    公开(公告)号：US20120051626A1

    公开(公告)日：2012-03-01

    申请号：US13219997

    申请日：2011-08-29

    申请人： Yong Long ,  Jeffrey A. Fessler ,  James M. Balter

    发明人： Yong Long ,  Jeffrey A. Fessler ,  James M. Balter

    IPC分类号： G06K9/00

    CPC分类号： G06T11/006 ,  G06T15/08 ,  G06T2211/424

    摘要： Methods provided for forward and back-projection, which are referred to as separable footprint (SF) projectors: exemplified by the SF-TR and SF-TT projectors. These methods approximate the voxel footprint functions as 2D separable functions. Because of the separability of these footprint functions, calculating their integrals over a detector cell is greatly simplified and can be implemented efficiently. In some embodiments, the SF-TR projector uses trapezoid functions in the transaxial direction and rectangular functions in the axial direction. In some embodiments, the SF-TT projector uses trapezoid functions in both the axial and transaxial directions. Simulations and experiments showed that both SF projector methods are more accurate than conventional distance-driven (DD) projectors. Moreover, the SF-TT projector is more accurate than the SF-TR projector for rays associated with large cone angles. In some embodiments, the SF-TR projector has similar computation speed with the DD projector and the SF-TT projector is about two times slower.

    摘要翻译： 提供用于正向和反向投影的方法，被称为可分离足迹（SF）投影仪：由SF-TR和SF-TT投影机示例。 这些方法将体素足迹功能近似为2D可分离函数。 由于这些足迹功能的可分离性，大大简化了在检测器单元上计算它们的积分，并且可以有效地实现。 在一些实施例中，SF-TR投影仪在轴向方向上使用梯形函数并且在轴向方向上使用矩形函数。 在一些实施例中，SF-TT投影仪在轴向和横轴方向都使用梯形函数。 模拟和实验表明，两种SF投影仪的方法比传统的距离驱动（DD）投影机更为准确。 此外，与大锥角相关的射线，SF-TT投影机比SF-TR投影机更准确。 在一些实施例中，SF-TR投影仪具有与DD投影仪相似的计算速度，并且SF-TT投影机的速度约为慢两倍。

    Method for statistically reconstructing a polyenergetic X-ray computed tomography image and image reconstructor apparatus utilizing the method
    6.
    发明授权
    Method for statistically reconstructing a polyenergetic X-ray computed tomography image and image reconstructor apparatus utilizing the method 有权
    用于统计重建多能X射线计算机断层摄影图像的方法和利用该方法的图像重建装置

    公开(公告)号：US06507633B1

    公开(公告)日：2003-01-14

    申请号：US09784740

    申请日：2001-02-15

    申请人： Idris A. Elbakri ,  Jeffrey A. Fessler

    发明人： Idris A. Elbakri ,  Jeffrey A. Fessler

    IPC分类号： A61B603

    CPC分类号： G06T11/006 ,  A61B6/027 ,  G06T2211/408 ,  G06T2211/424

    摘要： A method for statistically reconstructing an X-ray computed tomography image produced by a single X-ray CT scan having a polyenergetic source spectrum and an image reconstructor which utilize a convergent statistical algorithm which explicitly accounts for the polyenergetic source spectrum are provided. First and second related statistical iterative methods for CT reconstruction based on a Poisson statistical model are described. Both methods are accelerated by the use of ordered subsets, which replace sums over the angular index of a sinogram with a series of sums over angular subsets of the sinogram. The first method is generalized to model the more realistic case of polyenergetic computed tomography (CT). The second method eliminates beam hardening artifacts seen when filtered back projection (FBP) is used without post-processing correction. The methods are superior to FBP reconstruction in terms of noise reduction. The method and image reconstructor of the invention are effective in producing corrected images that do not suffer from beam hardening effects.

    摘要翻译： 提供了一种用于统计重建由具有多能源光谱的单次X射线CT扫描产生的X射线计算机断层摄影图像和利用明确考虑多能源光谱的收敛统计算法的图像重建器的方法。 描述了基于泊松统计模型的CT重建的第一和第二相关统计迭代方法。 通过使用有序子集来加速两种方法，这些子集在正弦图的角度子集上用一系列和来代替正弦图的角度索引的和。 第一种方法被推广到对多能计算机断层扫描（CT）更现实的情况进行建模。 第二种方法消除了当使用滤波反投影（FBP）而不进行后处理校正时看到的束固化伪影。 该方法在减少噪声方面优于FBP重建。 本发明的方法和图像重建器有效地产生不遭受光束硬化效应的校正图像。

    Three-dimensional forward and back projection methods
    7.
    发明授权
    Three-dimensional forward and back projection methods 有权
    三维前后投影方法

    公开(公告)号：US08913805B2

    公开(公告)日：2014-12-16

    申请号：US13219997

    申请日：2011-08-29

    申请人： Yong Long ,  Jeffrey A. Fessler ,  James M. Balter

    发明人： Yong Long ,  Jeffrey A. Fessler ,  James M. Balter

    IPC分类号： G06K9/00 ,  G06K9/40 ,  G06T11/00 ,  G06T15/08

    CPC分类号： G06T11/006 ,  G06T15/08 ,  G06T2211/424

    摘要： Methods provided for forward and back-projection, which are referred to as separable footprint (SF) projectors: exemplified by the SF-TR and SF-TT projectors. These methods approximate the voxel footprint functions as 2D separable functions. Because of the separability of these footprint functions, calculating their integrals over a detector cell is greatly simplified and can be implemented efficiently. In some embodiments, the SF-TR projector uses trapezoid functions in the transaxial direction and rectangular functions in the axial direction. In some embodiments, the SF-TT projector uses trapezoid functions in both the axial and transaxial directions. Simulations and experiments showed that both SF projector methods are more accurate than conventional distance-driven (DD) projectors. Moreover, the SF-TT projector is more accurate than the SF-TR projector for rays associated with large cone angles. In some embodiments, the SF-TR projector has similar computation speed with the DD projector and the SF-TT projector is about two times slower.

    摘要翻译： 提供用于正向和反向投影的方法，被称为可分离足迹（SF）投影仪：由SF-TR和SF-TT投影机示例。 这些方法将体素足迹功能近似为2D可分离函数。 由于这些足迹功能的可分离性，大大简化了在检测器单元上计算它们的积分，并且可以有效地实现。 在一些实施例中，SF-TR投影仪在轴向方向上使用梯形函数并且在轴向方向上使用矩形函数。 在一些实施例中，SF-TT投影仪在轴向和横轴方向都使用梯形函数。 模拟和实验表明，两种SF投影仪的方法比传统的距离驱动（DD）投影机更为准确。 此外，与大锥角相关的射线，SF-TT投影机比SF-TR投影机更准确。 在一些实施例中，SF-TR投影仪具有与DD投影仪相似的计算速度，并且SF-TT投影机的速度约为慢两倍。

    Method and apparatus for iterative reconstruction
    8.
    发明授权
    Method and apparatus for iterative reconstruction 有权
    迭代重建的方法和装置

    公开(公告)号：US08885975B2

    公开(公告)日：2014-11-11

    申请号：US13531082

    申请日：2012-06-22

    申请人： Zhou Yu ,  Bruno Kristiaan Bernard De Man ,  Jean-Baptiste Thibault ,  Debashish Pal ,  Lin Fu ,  Charles A. Bouman ,  Ken Sauer ,  Sathish Ramani ,  Jeffrey A. Fessler ,  Somesh Srivastava

    发明人： Zhou Yu ,  Bruno Kristiaan Bernard De Man ,  Jean-Baptiste Thibault ,  Debashish Pal ,  Lin Fu ,  Charles A. Bouman ,  Ken Sauer ,  Sathish Ramani ,  Jeffrey A. Fessler ,  Somesh Srivastava

    IPC分类号： G06K9/36 ,  G06K9/00 ,  G06T11/00

    CPC分类号： G06T11/003 ,  G06T11/006 ,  G06T2211/424

    摘要： A method is provided for reconstructing an image of an object that includes image elements. The method includes accessing measurement data associated with the image elements, introducing an auxiliary variable to transform an original problem of reconstructing the image to a constrained optimization problem, and solving the constrained optimization problem using a method of multipliers to create a sequence of sub-problems and solve the sequence of sub-problems. Solving the sequence of sub-problems includes reconstructing the image by optimizing a first objective function. The first objective function is optimized by iteratively solving a nested sequence of approximate optimization problems. An inner loop iteratively optimizes a second objective function approximating the first objective function. An outer loop utilizes the solution of the second objective function to optimize the first objective function.

    摘要翻译： 提供了一种用于重构包括图像元素的对象的图像的方法。 该方法包括访问与图像元素相关联的测量数据，引入辅助变量以将原始图像重建问题转换为约束优化问题，以及使用乘法器的方法来解决约束优化问题以创建子问题序列 并解决子问题的顺序。 解决子问题的顺序包括通过优化第一目标函数重建图像。 通过迭代求解近似优化问题的嵌套序列，优化了第一个目标函数。 内循环迭代地优化接近于第一目标函数的第二目标函数。 外环利用第二目标函数的解来优化第一目标函数。