公开(公告)号：US07724866B2

公开(公告)日：2010-05-25

申请号：US11769370

申请日：2007-06-27

申请人： Ram Naidu ,  Basak Ulker Karbeyaz ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  David Schafer ,  Carl R. Crawford

发明人： Ram Naidu ,  Basak Ulker Karbeyaz ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  David Schafer ,  Carl R. Crawford

IPC分类号： A61B6/03

CPC分类号： G01V5/005 ,  A61B6/027 ,  G01T1/2985

摘要： A method of and a system for variable pitch CT scanning for baggage screening and variable pitch image reconstruction are disclosed. The method comprises decelerating conveyor belt speed when additional time is needed to render a decision on a complex bag; accelerating conveyor belt speed to its normal speed when decisions are reached on undecided bags; generating cone-beam projection data at variable scanning pitch corresponding to variable conveyor belt speed; computing a tilt angle and a distance offset for each tilted slice using the pitch values at which the cone-beam projection data is acquired for that tilted slice; generating fan-beam projection data for each tilted slice using the tilted angle and the distance offset; generating correction projection data to compensate for the error between the source trajectory and the tilted reconstruction plane; generating the corrected fan-beam projection data by adding the correction projection data to the fan-beam projection data; reconstructing tilted slices using the corrected fan-beam projection data; and interpolating the reconstructed tilted slices into axial slices.

摘要翻译： 公开了用于行李筛选和可变间距图像重构的可变间距CT扫描的方法和系统。 该方法包括在需要额外的时间来对复杂袋子做出决定时减速输送带速度; 加速输送带速度达到正常速度，在未定的袋子上达成决定; 产生对应于可变输送带速度的可变扫描间距的锥形束投影数据; 使用对于该倾斜切片获取锥形束投影数据的间距值来计算每个倾斜切片的倾斜角和距离偏移; 使用倾斜角度和距离偏移量为每个倾斜切片生成扇形投影数据; 产生校正投影数据以补偿源轨迹和倾斜重建平面之间的误差; 通过将校正投影数据添加到扇形投影数据来生成校正的扇形投影数据; 使用校正的扇形束投影数据重建倾斜的切片; 并将重构的倾斜切片内插到轴向切片中。

公开(公告)号：US07474786B2

公开(公告)日：2009-01-06

申请号：US11198360

申请日：2005-08-04

申请人： Ram Naidu ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  Carl R. Crawford

发明人： Ram Naidu ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  Carl R. Crawford

IPC分类号： G06K9/00

CPC分类号： G01V5/0008

摘要： A method of and a system for identifying objects using histogram segment features from multi-energy CT images are provided. The multi-energy CT images include a CT image, which approximates density measurements of scanned objects, and a Z image, which approximates effective atomic number measurements of scanned objects. The method comprises: computing a density histogram for each potential threat object; smoothing the density histogram using a low-pass filter; identifying peaks in the smoothed density histogram; assigning a segment to each peak; computing histogram segment features for each segment; classifying each potential threat object into a threat or a non-threat using computed features.

摘要翻译： 提供了一种用于使用来自多能CT图像的直方图段特征来识别对象的方法和系统。 多能CT图像包括近似于扫描对象的密度测量的CT图像和近似有效的扫描对象原子数测量的Z图像。 该方法包括：计算每个潜在威胁对象的密度直方图; 使用低通滤波器平滑密度直方图; 识别平滑密度直方图中的峰值; 为每个峰分配一个段; 计算每个段的直方图段特征; 使用计算特征将每个潜在的威胁对象分类为威胁或非威胁。

公开(公告)号：US06721387B1

公开(公告)日：2004-04-13

申请号：US10171116

申请日：2002-06-13

申请人： Ram Naidu ,  Ibrahim Bechwati ,  Seemee S. Karimi ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Ram Naidu ,  Ibrahim Bechwati ,  Seemee S. Karimi ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： A61B603

CPC分类号： G06T11/005 ,  A61B6/032 ,  A61B6/4488 ,  A61B6/5258

摘要： A method of reducing metal artifacts in a computed tomography (CT) system includes: A. generating a preliminary image from input projection data collected by the CT system; B. identifying metal objects in the preliminary image; C. generating secondary projections from the input projection data by removing projections of objects having characteristics that may cause the objects to be altered in a final artifact-corrected image. D. extracting the projections of metal objects identified in step B from the secondary projection data generated in step C. E. generating corrected projections by removing the projections of the metal objects extracted in Step D from the input projection data. F. generating a final image by reconstructing the corrected projections generated in step E and inserting the metal objects identified in Step B into the final image.

摘要翻译： 计算机断层摄影（CT）系统中减少金属伪像的方法包括：A。 由CT系统收集的输入投影数据产生初步图像; B。 识别初步图像中的金属物体; C。 通过去除具有可能导致在最终伪像校正图像中改变对象的特征的对象的投影来从输入投影数据产生二次投影。 从步骤CE中生成的二次投影数据中提取在步骤B中识别的金属物体的投影，通过从输入的投影数据去除在步骤D中提取的金属物体的投影来产生校正的投影。 通过重建步骤E中生成的校正投影并将步骤B中识别的金属物体插入到最终图像中来产生最终图像。

公开(公告)号：US06471400B1

公开(公告)日：2002-10-29

申请号：US10016570

申请日：2001-10-26

申请人： Sergey Simanovsky ,  Carl R. Crawford

发明人： Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： G01D1800

CPC分类号： A61B6/032 ,  A61B6/5252

摘要： Monitor detectors can be obstructed by the patient and/or the table, leading to image artifacts in a CT scanner. An algorithm for adaptive monitor correction is therefore provided, in which the algorithm replaces obstructed monitor readings with a value consistent with unobstructed monitor readings for the scan.

摘要翻译： 监视器检测器可能被患者和/或桌子阻碍，导致CT扫描仪中的图像伪影。 因此，提供了一种用于自适应监视器校正的算法，其中该算法用阻挡的监视器读数替换与扫描不受阻碍的监视器读数一致的值。

公开(公告)号：US07224763B2

公开(公告)日：2007-05-29

申请号：US10899775

申请日：2004-07-27

申请人： Ram Naidu ,  Zhengrong Ying ,  Chitra Subramanian ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Ram Naidu ,  Zhengrong Ying ,  Chitra Subramanian ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： G01N23/00

CPC分类号： G01N23/046 ,  G01N2223/419 ,  G01T1/185

摘要： A method of and a system for spectral correction in multi-energy computed tomography are provided to correct reconstructed images, including high-energy CT images and Z (effective atomic number) images, for spectral variations, which include time variations on a scanner due to HVPS drift and scanner to scanner variations due to the beamline component differences. The method uses a copper filter mounted on the detector array for tracking the spectral changes. The method comprises: generating copper ratios; computing working air tables; calculating scales and offsets; and correcting high-energy CT images and Z images using calculated scales and offsets. The method further includes an off-line calibration procedure to generate necessary parameters for the online correction.

摘要翻译： 提供了一种用于多能量计算机断层摄影中的光谱校正的方法和系统，用于校正重建图像，包括高能CT图像和Z（有效原子序数）图像，用于光谱变化，包括扫描仪上的时间变化，由于 HVPS漂移和扫描仪由于束线分量差异而导致扫描仪变化。 该方法使用安装在检测器阵列上的铜过滤器来跟踪光谱变化。 该方法包括：产生铜比; 计算工作台面; 计算比例和偏移量; 并使用计算的比例和偏移校正高能CT图像和Z图像。 该方法还包括离线校准程序以产生用于在线校正的必要参数。

公开(公告)号：US07136450B2

公开(公告)日：2006-11-14

申请号：US10853942

申请日：2004-05-26

申请人： Zhengrong Ying ,  Ram Naidu ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Zhengrong Ying ,  Ram Naidu ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： A61B6/00

CPC分类号： G06T11/005 ,  A61B6/032 ,  A61B6/5282 ,  G01N23/046 ,  G01N2223/419 ,  G06T2211/408

摘要： Method of and system for adaptive scatter correction in the absence of scatter detectors in multi-energy computed tomography are provided, wherein input projection data acquired using at least two x-ray spectra for scanned objects may include a set of low energy projections and a set of high energy projections; wherein a low-pass filter of variable size is provided; the method comprises estimating the size of the low-pass filter; computing amounts of scatter; and correcting both sets of projections for scatter. The estimation of low-pass filter size comprises thresholding high energy projections into binary projections; filtering the binary projections; finding the maximum of the filtered binary projections; calculating the low-pass filter size from the found maximum. The computation of amounts of scatter comprises exponentiating input projections; low-pass filtering the exponentiated projections with the estimated filter size; computing the amounts of scatter from the filtered projections.

摘要翻译： 提供了在多能计算机断层摄影中不存​​在散射检测器的自适应散射校正的方法和系统，其中使用至少两个用于扫描对象的X射线光谱获得的输入投影数据可以包括一组低能量投影和一组 的高能量预测; 其中提供可变尺寸的低通滤波器; 该方法包括估计低通滤波器的尺寸; 计算散射量; 并且校正两组用于散射的投影。 低通滤波器尺寸的估计包括将高能量投影阈值化为二进制投影; 过滤二进制投影; 找出滤波后的二进制投影的最大值; 从找到的最大值计算低通滤波器尺寸。 散射量的计算包括指数输入投影; 用估计的滤波器大小对指数投影进行低通滤波; 从过滤的投影计算散射量。

公开(公告)号：US07692650B2

公开(公告)日：2010-04-06

申请号：US11142216

申请日：2005-06-01

申请人： Zhengrong Ying ,  Matthew Hirsch ,  Purvin Desai ,  Kyle Guilbert ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Zhengrong Ying ,  Matthew Hirsch ,  Purvin Desai ,  Kyle Guilbert ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： G06T17/00

CPC分类号： A61B6/482 ,  A61B6/03 ,  G01V5/0041 ,  G01V5/005 ,  G06T11/008

摘要： A method of and a system for displaying volumetric multi-energy CT images are disclosed, wherein a CT image, a Z image, and a label image from an automatic explosive detection are provided, are disclosed. The method comprises generating an index image through a nonlinear transformation of the CT image, the Z image, and the label image, rotating and coloring the index image as desired, and rendering and displaying the rotated and colored image.

摘要翻译： 公开了一种用于显示体积多能CT图像的方法和系统，其中提供了CT图像，Z图像和来自自动爆炸检测的标签图像。 该方法包括通过CT图像，Z图像和标签图像的非线性变换生成索引图像，根据需要旋转和着色索引图像，以及渲染和显示旋转和着色图像。

公开(公告)号：US20090003515A1

公开(公告)日：2009-01-01

申请号：US11769370

申请日：2007-06-27

申请人： Ram Naidu ,  Basak Ulker Karbeyaz ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  David Schafer ,  Carl R. Crawford

发明人： Ram Naidu ,  Basak Ulker Karbeyaz ,  Zhengrong Ying ,  Sergey Simanovsky ,  Matthew Hirsch ,  David Schafer ,  Carl R. Crawford

IPC分类号： G01N23/00

CPC分类号： G01V5/005 ,  A61B6/027 ,  G01T1/2985

摘要： A method of and a system for variable pitch CT scanning for baggage screening and variable pitch image reconstruction are disclosed. The method comprises decelerating conveyor belt speed when additional time is needed to render a decision on a complex bag; accelerating conveyor belt speed to its normal speed when decisions are reached on undecided bags; generating cone-beam projection data at variable scanning pitch corresponding to variable conveyor belt speed; computing a tilt angle and a distance offset for each tilted slice using the pitch values at which the cone-beam projection data is acquired for that tilted slice; generating fan-beam projection data for each tilted slice using the tilted angle and the distance offset; generating correction projection data to compensate for the error between the source trajectory and the tilted reconstruction plane; generating the corrected fan-beam projection data by adding the correction projection data to the fan-beam projection data; reconstructing tilted slices using the corrected fan-beam projection data; and interpolating the reconstructed tilted slices into axial slices.

摘要翻译： 公开了用于行李筛选和可变间距图像重构的可变间距CT扫描的方法和系统。 该方法包括在需要额外的时间来对复杂袋子做出决定时减速输送带速度; 加速输送带速度达到正常速度，在未定的袋子上达成决定; 产生对应于可变输送带速度的可变扫描间距的锥形束投影数据; 使用对于该倾斜切片获取锥形束投影数据的间距值来计算每个倾斜切片的倾斜角和距离偏移; 使用倾斜角度和距离偏移量为每个倾斜切片生成扇形投影数据; 产生校正投影数据以补偿源轨迹和倾斜重建平面之间的误差; 通过将校正投影数据添加到扇形投影数据来生成校正的扇形投影数据; 使用校正的扇形束投影数据重建倾斜的切片; 并将重构的倾斜切片内插到轴向切片中。

公开(公告)号：US07277577B2

公开(公告)日：2007-10-02

申请号：US10831909

申请日：2004-04-26

申请人： Zhengrong Ying ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Zhengrong Ying ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： G06K9/00

CPC分类号： G06K9/00201 ,  G06K9/00771 ,  G06K9/48 ,  G06K2209/09

摘要： A method of and system for detecting threat objects represented in 3D CT data uses knowledge of one or more predefined shapes of the threat objects. An object represented by CT data for a region is identified. A two-dimensional projection of the object along a principal axis of the object is generated. A contour of the object boundary in the projection image is computed. A shape histogram is computed from the extracted contour. A difference measure between the extracted shape histogram and a set of pre-computed threat shape histograms is computed. A declaration of a threat object is made if the difference measure is less than a pre-defined threshold.

摘要翻译： 用于检测在3D CT数据中表示的威胁对象的方法和系统使用威胁对象的一个​​或多个预定义形状的知识。 识别由区域的CT数据表示的对象。 产生物体沿物体主轴的二维投影。 计算投影图像中物体边界的轮廓。 从提取的轮廓计算形状直方图。 计算提取的形状直方图和一组预先计算的威胁形状直方图之间的差异度量。 如果差异度量小于预定义的阈值，则作出威胁对象的声明。

公开(公告)号：US06813374B1

公开(公告)日：2004-11-02

申请号：US09842075

申请日：2001-04-25

申请人： Seemeen S. Karimi ,  David Rozas ,  Sergey Simanovsky ,  Ibrahim Bechwati ,  Carl R. Crawford

发明人： Seemeen S. Karimi ,  David Rozas ,  Sergey Simanovsky ,  Ibrahim Bechwati ,  Carl R. Crawford

IPC分类号： G06K900

CPC分类号： G06K9/00771 ,  A61B6/482 ,  A61B6/583 ,  G01V5/0008 ,  G06K2209/09

摘要： A method of and apparatus for assessing the image quality of a CT scanner is described in which assessment can be made manually or automatically. No special image quality mode of CT scanner operation is necessary, and no precise alignment of the phantom is necessary. In general, performance of the scanner comprises: using the scanner (a) to scan a phantom in one or more of its normal modes of operation while translating said phantom along the scanner axis of rotation and (b) to produce scanned data of the phantom, and assessing the performance of the scanner from the scanned data. In accordance with another aspect, the assessment is performed by (a) using the scanner to scan a phantom in one or more of its normal modes of operation; (b) reconstructing a three-dimensional volume CT image for a region containing at least a portion of the phantom; (c) calculating properties of the CT image; and (d) using the calculated properties of the CT image to assess CT scanner performance.

摘要翻译： 描述了用于评估CT扫描仪的图像质量的方法和装置，其中可以手动或自动地进行评估。 不需要CT扫描仪操作的特殊图像质量模式，并且不需要精确对准幻像。 通常，扫描仪的性能包括：使用扫描仪（a）在其一般或多种操作模式中扫描幻影，同时沿着扫描仪旋转轴旋转所述幻影，并且（b）产生幻影的扫描数据 并从扫描数据评估扫描仪的性能。 根据另一方面，评估通过以下步骤来执行：（a）使用扫描仪扫描其一种或多种正常操作模式中的体模; （b）为包含至少一部分体模的区域重建三维体积CT图像; （c）计算CT图像的性质; 和（d）使用CT图像的计算性能来评估CT扫描仪性能。