公开(公告)号：US5396528A

公开(公告)日：1995-03-07

申请号：US723361

申请日：1991-06-28

申请人： Hui Hu ,  Carl R. Crawford ,  Armin H. Pfoh ,  Jiang Hsieh

发明人： Hui Hu ,  Carl R. Crawford ,  Armin H. Pfoh ,  Jiang Hsieh

IPC分类号： A61B6/03 ,  G01N23/04 ,  G01N23/083

CPC分类号： A61B6/032 ,  A61B6/4085 ,  Y10S378/901

摘要： A CT apparatus employing a cone beam of x-rays reduces image artifacts by employing full as opposed to half scans of less than 360.degree.. The present invention recognizes that rays of a cone beam that cross the imaging plane are not redundant with opposing rays in the scan, as is the case with the rays within the imaging plane. In a second embodiment, half scans of less than 360.degree. are obtained using in-plane and cross-plane rays of the cone beam and the data from the in-plane rays is used to estimate the missing data from that collected with the cross-plane rays.

摘要翻译： 使用X射线锥形束的CT装置通过采用与小于360度的半扫描相反的方式来减少图像伪影。 本发明认识到，如同成像平面内的射线的情况一样，穿过成像平面的锥形束的射线在扫描中与相对的射线不是冗余的。 在第二实施例中，使用锥形束的平面内和平面光线获得小于360°的半扫描，并且使用来自平面内射线的数据来估计从交叉点收集的数据中丢失的数据， 飞机射线

公开(公告)号：US07801348B2

公开(公告)日：2010-09-21

申请号：US11183471

申请日：2005-07-18

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

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

IPC分类号： G06K9/00

CPC分类号： G06K9/00771 ,  G01V5/0041 ,  G01V5/005

摘要： A method of and a system for identifying objects using local distribution 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 local distribution features are first and second order statistics of the local distributions of the density and atomic number measurements of different portions of a segmented object. The local distributions are the magnitude images of the first order derivative of the CT image and the Z image. Each segmented object is also divided into different portions to provide geometrical information for discrimination. The method comprises preprocessing the CT and Z images, segmenting images into objects, computing local distributions of the CT and Z images, computing local distribution histograms, computing local distribution features from the said local distribution histograms, classifying objects based on the local distribution features.

摘要翻译： 提供了一种使用多能CT图像的局部分布特征识别物体的方法和系统。 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。 局部分布特征是分段对象的不同部分的密度和原子序数测量的局部分布的一阶和二阶统计。 局部分布是CT图像和Z图像的一阶导数的幅度图像。 每个分段对象也被分成不同的部分以提供用于辨别的几何信息。 该方法包括预处理CT和Z图像，将图像分割成对象，计算CT和Z图像的局部分布，计算局部分布直方图，从所述局部分布直方图计算局部分布特征，根据局部分布特征对对象进行分类。

公开(公告)号：US07415147B2

公开(公告)日：2008-08-19

申请号：US10860984

申请日：2004-06-04

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： G06K9/00

CPC分类号： G06T5/005 ,  G06T5/20 ,  G06T2200/04 ,  G06T2207/10081 ,  G06T2207/30112

摘要： A method of and a system for destreaking the photoelectric image in multi-energy computed tomography are provided, wherein the photoelectric projections are generated from the projection data acquired using at least two x-ray spectra for scanned objects; wherein a neighboring scheme is provided; the method comprises computing the statistics including mean and standard deviation using the neighboring scheme; calculating an upper limit and a lower limit from the computed statistics; detecting outliers in the photoelectric projections using the upper and lower limits; and replacing values of outliers using the upper or lower limit.

摘要翻译： 提供了一种用于在多能计算机断层摄影中破坏光电图像的方法和系统，其中光电投影是从使用扫描对象的至少两个X射线光谱获取的投影数据产生的; 其中提供相邻方案; 该方法包括使用相邻方案计算包括平均值和标准偏差的统计量; 从计算的统计量计算上限和下限; 利用上下限检测光电投影中的异常值; 并使用上限或下限替换异常值的值。

公开(公告)号：US20080193002A1

公开(公告)日：2008-08-14

申请号：US11704482

申请日：2007-02-09

申请人： Zhengrong Ying ,  Kyle Guilbert ,  Carl R. Crawford

发明人： Zhengrong Ying ,  Kyle Guilbert ,  Carl R. Crawford

IPC分类号： G06K9/00

CPC分类号： G01V5/0008

摘要： A method of and a system for automatic object display of volumetric CT data for fast on-screen threat resolution are disclosed, wherein the CT data includes a CT image in a single energy CT scanner, or a CT image and a Z image in a multi-energy CT scanner, and a label image defining each object as a plurality of voxels of the volumetric CT data. The method comprises generating volumetric CT image data corresponding to a scanned bag; performing automatic threat detection to generate a label image; processing the volumetric CT data and the label image to obtain visualization parameters for each object; automatically generating display images for each object using corresponding visualization parameters; and displaying the generated display images for on-screen threat resolution.

摘要翻译： 公开了用于自动对象显示用于快速屏幕上威胁分辨率的体积CT数据的方法和系统，其中CT数据包括单能CT扫描仪中的CT图像，或多CT扫描仪中的CT图像和Z图像 - 能量CT扫描器和将每个对象定义为体积CT数据的多个体素的标签图像。 该方法包括产生对应于扫描袋的体积CT图像数据; 执行自动威胁检测以生成标签图像; 处理体积CT数据和标签图像以获得每个对象的可视化参数; 使用相应的可视化参数自动生成每个对象的显示图像; 并显示生成的显示图像以进行屏幕上的威胁解决。

公开(公告)号：US07197172B1

公开(公告)日：2007-03-27

申请号：US10611572

申请日：2003-07-01

申请人： Ram Naidu ,  Ibrahim Bechwati ,  Carl R. Crawford

发明人： Ram Naidu ,  Ibrahim Bechwati ,  Carl R. Crawford

IPC分类号： G06K9/00 ,  G01N23/04

CPC分类号： G01N23/04 ,  G01N23/227

摘要： A method of decomposition of projection data is provided, wherein such projection data includes input projection data acquired using at least two x-ray spectra for a scanned object, including low energy projection data (PL) and high energy projection data (PH); the method comprises solving the projections PL and PH to determine a photoelectric line integral (Ap) component of attenuation and a Compton line integral (Ac) component of attenuation of the scanned object using a multi-step fitting procedure and constructing a Compton image Ic and a photoelectric image Ip from the Compton line integral and photoelectric line integral.

摘要翻译： 提供了投影数据的分解方法，其中这种投影数据包括使用扫描对象的至少两个X射线光谱获取的输入投影数据，包括低能量投影数据（P L L L L）和高 能量投影数据（P＆lt; H＆gt;）; 该方法包括求解投影P L L和P H H以确定衰减的光电线路积分（A> P）分量和康普顿线积分 使用多步骤拟合程序对扫描对象的衰减的分量进行分析，并且构建康普顿图像I C和光电图像I＆lt; P＆lt; SUB>从康普顿线积分和光电线路积分。

公开(公告)号：US07136451B2

公开(公告)日：2006-11-14

申请号：US10958713

申请日：2004-10-05

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

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

IPC分类号： A61B6/03 ,  H05G1/32

CPC分类号： G01V5/0008 ,  H05G1/10

摘要： A method of and a system for stabilizing High Voltage Power Supply (HVPS) DC and AC voltages in multi-energy X-ray computed tomography scanners are provided. The method comprises generating filter ratios, computing DC and AC voltages, and feeding back the computed DC and AC voltages to the commanded voltages. The filtered ratios including an air ratio and a copper ratio are modeled as nonlinear functions of the DC and AC voltages. Computing DC and AC voltages include computing an m-ratio and an n-ratio. The parameters of the nonlinear model comprise an exponent parameter and a set of polynomial coefficients. The parameters are determined by a calibration procedure, which performs scanning at different combination of DC and AC voltages. The optimal parameters are obtained through a nonlinear least square minimization, which is solved through a brute force search over the exponent parameter and a closed form solution of the polynomial coefficients. Feeding back the computed DC and AC voltages include comparing the computed voltages with commanded voltages, integrating the difference between the computed voltages and commanded voltages, and adding the integrated voltage differences to the commanded voltages.

摘要翻译： 提供了一种用于在多能X射线计算机断层扫描仪中稳定高压电源（HVPS）直流和交流电压的方法和系统。 该方法包括产生滤波比，计算直流和交流电压，以及将计算的直流和交流电压反馈到指令电压。 包括空气比和铜比的滤波比被建模为DC和AC电压的非线性函数。 计算直流和交流电压包括计算m比和n比。 非线性模型的参数包括指数参数和一组多项式系数。 这些参数由校准程序确定，校准程序以不同的直流和交流电压组合进行扫描。 通过非线性最小二乘法最小化获得最优参数，通过对指数参数的强力搜索和多项式系数的闭合形式解决求解。 反馈计算的直流和交流电压包括将计算出的电压与指令电压进行比较，积分计算电压和指令电压之间的差，并将积分电压差加到指令电压上。

公开(公告)号：US06256404B1

公开(公告)日：2001-07-03

申请号：US08949127

申请日：1997-10-10

申请人： Bernard M. Gordon ,  Eric M. Bailey ,  David A. Schafer ,  Christopher C. Ruth ,  Carl R. Crawford

发明人： Bernard M. Gordon ,  Eric M. Bailey ,  David A. Schafer ,  Christopher C. Ruth ,  Carl R. Crawford

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。

公开(公告)号：US5525906A

公开(公告)日：1996-06-11

申请号：US273577

申请日：1994-07-11

申请人： Carl R. Crawford ,  Matthew G. Eash ,  Steven P. Souza ,  Norbert J. Pelc ,  Dennis G. DallaPiazza ,  Daniel S. Small ,  Robert S. Stormont

发明人： Carl R. Crawford ,  Matthew G. Eash ,  Steven P. Souza ,  Norbert J. Pelc ,  Dennis G. DallaPiazza ,  Daniel S. Small ,  Robert S. Stormont

IPC分类号： G01R33/32 ,  A61B5/055 ,  G01R33/36 ,  G01R33/56 ,  G01R33/28

CPC分类号： G01R33/3621 ,  G01R33/5608

摘要： An MRI system includes a noise filter which receives each acquired NMR signal during a scan and detects short-duration noise pulses by sensing the signal level in a band of frequencies outside the imaging bandwidth. A blanking circuit suppresses the NMR signal during the time interval each noise pulse is detected to remove the noise pulse prior to image reconstruction.

摘要翻译： MRI系统包括噪声滤波器，其在扫描期间接收每个获取的NMR信号，并且通过感测成像带宽以外的频带中的信号电平来检测短持续时间的噪声脉冲。 消隐电路在时间间隔期间抑制NMR信号，每个噪声脉冲被检测以去除图像重建之前的噪声脉冲。

公开(公告)号：US5438602A

公开(公告)日：1995-08-01

申请号：US172660

申请日：1993-12-23

申请人： Carl R. Crawford ,  Cameron J. Ritchie

发明人： Carl R. Crawford ,  Cameron J. Ritchie

IPC分类号： A61B6/03 ,  G01N23/04 ,  G06T11/00 ,  G01N23/083

CPC分类号： A61B6/032 ,  G01N23/046 ,  G06T11/005 ,  G01N2223/419 ,  Y10S378/901

摘要： In an x-ray computed tomography system which acquire x-ray attenuation data using a fan beam of radiation, corrections for beam hardening are made by reprojecting the CT image data. The reprojection computations are reduced by rotating and warping the CT image data, and then performing a parallel reprojection along columns of data.

摘要翻译： 在使用扇形辐射束获取X射线衰减数据的X射线计算机断层摄影系统中，通过重新喷射CT图像数据来进行束硬化的校正。 通过旋转和扭曲CT图像数据，然后沿着数据列执行并行重投影，减少了重新投影计算。

公开(公告)号：US5216601A

公开(公告)日：1993-06-01

申请号：US440530

申请日：1989-11-22

申请人： Carl R. Crawford ,  Kevin F. King

发明人： Carl R. Crawford ,  Kevin F. King

IPC分类号： A61B6/03 ,  G06T11/00

CPC分类号： G06T11/005 ,  A61B6/027

摘要： A method of reducing image artifacts in images acquired with fan beam, helical scanning, tomographic imaging systems rebins the fan beam data into parallel beam projection sets. Data is spliced from first areas of the parallel beam projection data to second areas to create a set of 2.pi. radians of complete projection data. The 2.pi. of projection data is divided into half scans which are interpolated and extrapolated to produce a new projection set at the slice plane with reduced helical offset error. A feathering function is used to blend the discontinuities in the interpolation and extrapolation weights to prevent streak image artifacts.