公开(公告)号：US20120087481A1

公开(公告)日：2012-04-12

申请号：US13376715

申请日：2009-06-12

申请人： Andrew Litvin ,  Julia Pavlovich ,  Aleksander Roshi ,  Sergey Simanovsky ,  Ram Naidu

发明人： Andrew Litvin ,  Julia Pavlovich ,  Aleksander Roshi ,  Sergey Simanovsky ,  Ram Naidu

IPC分类号： G01D18/00

CPC分类号： A61B6/405 ,  A61B6/032 ,  A61B6/4007 ,  A61B6/4035 ,  A61B6/482 ,  A61B6/583 ,  G06T11/005 ,  G06T2211/408

摘要： The techniques described herein provide for correcting projection data that comprises contamination due to source switching in a multi energy scanner. The correction is a multi-neighbor correction. That is, it uses data from at least two other views of an object (e.g., generally a previous view and a subsequent view) to correct a current view of the object. The multi-neighbor correction may use one or more correction factors to determine how much data from the other two views to use to correct the current view. The correction factor(s) are determined based upon a calibration that utilizes image space data and/or projection space data of a phantom. In this way, the correction factor(s) account for source leakage that occurs in multi energy scanners.

摘要翻译： 本文描述的技术提供用于校正投影数据，其包括由于多能量扫描器中的源切换引起的污染。 校正是多邻居校正。 也就是说，它使用来自对象的至少两个其他视图的数据（例如，通常为先前视图和后续视图）来校正对象的当前视图。 多邻居校正可以使用一个或多个校正因子来确定来自用于校正当前视图的另外两个视图的数据量。 基于利用幻影的图像空间数据和/或投影空间数据的校准来确定校正因子。 以这种方式，校正因子考虑到在多能量扫描仪中发生的源泄漏。

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：US20070014471A1

公开(公告)日：2007-01-18

申请号：US11183378

申请日：2005-07-18

申请人： Sergey Simanovsky ,  Zhengrong Ying ,  Carl Crawford

发明人： Sergey Simanovsky ,  Zhengrong Ying ,  Carl Crawford

IPC分类号： G06K9/00 ,  G06K9/46

CPC分类号： G06K9/00771 ,  G01T1/2985 ,  G01V5/0041 ,  G01V5/005 ,  G06K9/6219

摘要： A method of and a system for splitting a compound object using multi-energy CT data including a density and an atomic number measurements are provided. The method comprises: compound object detection; computing a two-dimensional DZ distribution of a compound object; identifying clusters within the DZ distribution; assigning a component label to each object voxel based on the DZ distribution clusters; and post-processing the set of voxels identified as belonging to each component.

摘要翻译： 提供了使用包括密度和原子序数测量的多能量CT数据来分割复合对象的方法和系统。 该方法包括：复合物体检测; 计算复合对象的二维DZ分布; 识别DZ分布中的簇; 基于DZ分布集群为每个对象体素分配一个组件标签; 并且后处理被识别为属于每个组件的一组体素。

公开(公告)号：US20060023844A1

公开(公告)日：2006-02-02

申请号：US10899775

申请日：2004-07-27

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

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

IPC分类号： H05G1/00

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：US20050259781A1

公开(公告)日：2005-11-24

申请号：US10850910

申请日：2004-05-21

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

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

IPC分类号： A61B6/00 ,  G01N23/00 ,  G01N23/04

CPC分类号： G01N23/046 ,  G01N2223/419

摘要： A method of and a system for computing Z (effective atomic number) images from projection data are provided, wherein the projections are acquired using at least two x-ray spectra for a set of scanned objects, including a set of low energy projections and a set of high energy projections; the method comprises decomposing the low energy projections and high energy projections into photoelectric projections, reconstructing the photoelectric projections into photoelectric images, reconstructing one of the two sets of projections into CT images, and computing Z images from the CT images and the photoelectric images with parameters obtained from a calibration procedure.

摘要翻译： 提供了一种用于从投影数据计算Z（有效原子序号）图像的方法和系统，其中使用用于一组扫描对象的至少两个X射线光谱来获取投影，包括一组低能量投影和 一套高能量投影; 该方法包括将低能量投影和高能量投影分解为光电投影，将光电投影重建为光电图像，将两组投影中的一个重建为CT图像，并从CT图像和光电图像中计算Z图像 从校准程序获得。

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：US06345113B1

公开(公告)日：2002-02-05

申请号：US09228379

申请日：1999-01-12

申请人： Carl R. Crawford ,  Ibrahim M. Bechwati ,  Sergey Simanovsky ,  Muzzafer Hiraoglu

发明人： Carl R. Crawford ,  Ibrahim M. Bechwati ,  Sergey Simanovsky ,  Muzzafer Hiraoglu

IPC分类号： G06K900

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

摘要： An apparatus and method for identifying and classifying objects represented in CT data for a region using the shape of the objects are disclosed. An object represented by CT data for a region is identified. Next, a two-dimensional projection of the object along a principal axis of the object is generated. The principal axis can be identified by computing eigenvectors of a covariance matrix of spatial locations of voxels in the CT data that are associated with the object. The smallest eigenvector can be selected as the principal axis of the object along which the two-dimensional projection is generated. The identification of the object can be used in the classification of the object such as by altering one or more discrimination parameters.

摘要翻译： 公开了一种用于使用对象的形状来识别和分类在用于区域的CT数据中表示的对象的装置和方法。 识别由区域的CT数据表示的对象。 接下来，生成物体沿物体的主轴的二维投影。 可以通过计算与对象相关联的CT数据中的体素的空间位置的协方差矩阵的特征向量来识别主轴。 可以选择最小的特征向量作为生成二维投影的物体的主轴。 对象的识别可以用于对象的分类，例如通过改变一个或多个辨别参数。

公开(公告)号：US6111974A

公开(公告)日：2000-08-29

申请号：US22189

申请日：1998-02-11

申请人： Muzaffer Hiraoglu ,  Ibrahim M. Bechwati ,  Sergey Simanovsky ,  Carl R. Crawford

发明人： Muzaffer Hiraoglu ,  Ibrahim M. Bechwati ,  Sergey Simanovsky ,  Carl R. Crawford

IPC分类号： A61B6/00 ,  G01T1/166 ,  G01V5/00 ,  G06K9/00 ,  G06K9/56 ,  G06T5/00

CPC分类号： G06T7/0081 ,  G01V5/005 ,  G06K9/00771 ,  G06T7/0091 ,  G06K2209/09 ,  G06T2200/04 ,  G06T2207/10081 ,  G06T2207/30112

摘要： A method and apparatus for detecting objects in computed tomography (CT) data, including sheet-shaped objects such as sheet explosives can be detected by analyzing a neighborhood of voxels surrounding a test voxel. If the density of the test voxel is sufficiently different from the mean density of the neighboring voxels, then it is concluded that the test voxel is associated with a sheet object. A connectivity process can be applied to voxels to combine them into objects after sheets are detected to prevent sheets from being inadvertently removed from the data by erosion.

摘要翻译： 可以通过分析围绕测试体素的体素的邻域来检测计算机断层摄影（CT）数据中包括片状物体（例如片状炸药）的物体的方法和装置。 如果测试体素的密度与相邻体元的平均密度有很大的不同，则可以得出结论，测试体素与片材物体相关联。 可以将连接过程应用于体素，以便在检测到页面之后将其组合到对象中，以防止纸张被侵蚀从而无意中从数据中移除。