公开(公告)号：US07881424B2

公开(公告)日：2011-02-01

申请号：US12075463

申请日：2008-03-11

申请人： Li Zhang ,  Zhiqiang Chen ,  Gnowei Zhang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Zhiqiang Chen ,  Gnowei Zhang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G01N23/00

CPC分类号： G01T7/005 ,  G01T1/1648

摘要： A method for calibrating a dual-energy CT system and an image reconstruction method are disclosed to calculate images of atomic number and density of a scanned object as well as its attenuation coefficient images at any energy level. The present invention removes the effect from a cupping artifact due to X-ray beam hardening. The method for calibrating a dual-energy CT system is provided comprising steps of selecting at least two different materials, detecting penetrative rays from dual-energy rays penetrating said at least two different materials under different combinations of thickness to acquire projection values, and creating a lookup table in a form of correspondence between said different combinations of thickness and said projection values. The image reconstruction method is provided comprising steps of scanning an object with dual-energy rays to acquire dual-energy projection values, calculating projection values of base material coefficients corresponding to said dual-energy projection values based on a pre-created lookup table, and reconstructing an image of base material coefficient distribution based on said projection values of base material coefficients. In this way, images of atomic number and density of an object as well as its attenuation coefficient images can be calculated from the images of the distribution of base material coefficients. Compared with the prior art technique, the method proposed in the present invention has advantages of simple calibration procedure, high calculation precision and invulnerability to X-ray beam hardening.

摘要翻译： 公开了用于校准双能量CT系统和图像重建方法的方法，以计算被扫描物体的原子序数和密度以及其在任何能级的衰减系数图像的图像。 本发明消除了由于X射线束硬化引起的拔罐伪影的影响。 提供了一种用于校准双能量CT系统的方法，包括以下步骤：选择至少两种不同的材料，从不同厚度的组合穿透所述至少两种不同材料的双能量射线检测穿透射线，以获得投影值， 以所述不同的厚度组合和所述投影值之间的对应形式的查找表。 提供了图像重建方法，包括以下步骤：用双能量射线扫描物体以获取双能量投影值，基于预先创建的查找表计算与所述双能量投影值相对应的基材系数的投影值，以及 基于所述基材系数的投影值重构基材系数分布的图像。 以这种方式，可以从基材系数分布的图像中计算出物体的原子数和密度以及衰减系数图像的图像。 与现有技术相比，本发明提出的方法具有校准过程简单，计算精度高，X射线束硬化无效的优点。

公开(公告)号：US07672427B2

公开(公告)日：2010-03-02

申请号：US11545255

申请日：2006-10-10

申请人： Zhiqiang Chen ,  Li Zhang ,  Hewei Gao ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Zhiqiang Chen ,  Li Zhang ,  Hewei Gao ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G01N23/04

CPC分类号： G01N23/04 ,  A61B6/027

摘要： It is disclosed an imaging system comprising: radiation generating means including at least one radiation source for generating radiations; data acquiring means including an detector matrix faced the radiation source for obtaining projection data by receiving radiations penetrated through an object to be inspected; transporting means for making the object to be inspected between the radiation source and the detector matrix linearly moving relative to the radiation source and the detector matrix; and controlling and image processing means for controlling the radiation generating means, the data acquiring means and the transporting means, and for reconstructing an image of the object to be inspected from the projection data. The imaging system according to the present invention achieves a real stereoscopic radiography by using straight-line trajectory scan and reconstructing a tomographic or stereoscopic image through a straight-line filtered back-projection algorithm. The present imaging system has advantages of fast examination speed, no rotation, and out of large cone-angle problem in a circular-orbit cone-beam CT.

摘要翻译： 公开了一种成像系统，包括：辐射发生装置，其包括用于产生辐射的至少一个辐射源; 数据获取装置，包括面向辐射源的检测器矩阵，用于通过接收穿过待检查对象的辐射来获得投影数据; 用于使所述物体在所述辐射源和所述检测器矩阵之间相对于所述辐射源和所述检测器矩阵线性移动的传送装置; 以及控制和图像处理装置，用于控制辐射发生装置，数据获取装置和传送装置，并用于从投影数据重建待检查对象的图像。 根据本发明的成像系统通过使用直线轨迹扫描并通过直线过滤的反投影算法重建断层摄影或立体图像来实现真正的立体放射照相。 本发明的成像系统在圆锥轨道锥形CT中具有检测速度快，无旋转和大锥角问题的优点。

公开(公告)号：US20070116175A1

公开(公告)日：2007-05-24

申请号：US11546717

申请日：2006-10-12

申请人： Li Zhang ,  Hewei Gao ,  Zhiqiang Chen ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Hewei Gao ,  Zhiqiang Chen ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： H05G1/60 ,  A61B6/00 ,  G01N23/00 ,  G21K1/12

CPC分类号： G01N23/046 ,  A61B6/032 ,  G01N2223/3303 ,  G01N2223/419 ,  G06T11/006 ,  G06T2211/421

摘要： It is disclosed a system and a method for reconstructing an image by using a straight-line trajectory scan to avoid image spatial resolution reduction due to interpolations in angular direction and detector direction during data rebinning. This system comprises: a projection data conversion section for converting projection data from straight-line trajectory scan into projection data under quasi-parallel-beam scan; a filtration section for obtaining filtered projection data by convoluting the projection data under quasi-parallel-beam scan with a predetermined convolutional kernel; and a back-projection section for reconstructing an image by back-projecting the filtered projection data with a weighting factor. By using the inventive system and method, the spatial resolution in the reconstructed image is improved, and the influence of data truncation on the reconstructed image is reduced. The present invention applies the filtration and back-projection mode, and thus has general advantages of the filtration and back projection, such as simplicity and efficiency. And it is easy to be parallelized and accelerated.

摘要翻译： 公开了一种通过使用直线轨迹扫描来重建图像的系统和方法，以避免在数据重组期间由于在角度方向和检测器方向上的内插而导致的图像空间分辨率降低。 该系统包括：投影数据转换部分，用于将投影数据从直线轨迹扫描转换成准并行束扫描的投影数据; 过滤部分，用于通过用预定的卷积核在准平行束扫描下卷积投影数据来获得经滤波的投影数据; 以及背投影部分，用于通过用加权因子反投影过滤的投影数据来重建图像。 通过使用本发明的系统和方法，改善了重建图像中的空间分辨率，减少了数据截断对重建图像的影响。 本发明应用过滤和反投影模式，因此具有过滤和反投影的一般优点，例如简单性和效率。 并行并行加速很容易。

公开(公告)号：US20080310598A1

公开(公告)日：2008-12-18

申请号：US12075463

申请日：2008-03-11

申请人： Li Zhang ,  Zhiqiang Chen ,  Guowei Zhang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Zhiqiang Chen ,  Guowei Zhang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G01D18/00 ,  G06K9/00

CPC分类号： G01T7/005 ,  G01T1/1648

摘要： A method for calibrating a dual-energy CT system and an image reconstruction method are disclosed to calculate images of atomic number and density of a scanned object as well as its attenuation coefficient images at any energy level. The present invention removes the effect from a cupping artifact due to X-ray beam hardening. The method for calibrating a dual-energy CT system is provided comprising steps of selecting at least two different materials, detecting penetrative rays from dual-energy rays penetrating said at least two different materials under different combinations of thickness to acquire projection values, and creating a lookup table in a form of correspondence between said different combinations of thickness and said projection values. The image reconstruction method is provided comprising steps of scanning an object with dual-energy rays to acquire dual-energy projection values, calculating projection values of base material coefficients corresponding to said dual-energy projection values based on a pre-created lookup table, and reconstructing an image of base material coefficient distribution based on said projection values of base material coefficients. In this way, images of atomic number and density of an object as well as its attenuation coefficient images can be calculated from the images of the distribution of base material coefficients. Compared with the prior art technique, the method proposed in the present invention has advantages of simple calibration procedure, high calculation precision and invulnerability to X-ray beam hardening.

摘要翻译： 公开了用于校准双能量CT系统和图像重建方法的方法，以计算被扫描物体的原子序数和密度以及其在任何能级的衰减系数图像的图像。 本发明消除了由于X射线束硬化引起的拔罐伪影的影响。 提供了一种用于校准双能量CT系统的方法，包括以下步骤：选择至少两种不同的材料，从不同厚度的组合穿透所述至少两种不同材料的双能量射线检测穿透射线，以获得投影值， 以所述不同的厚度组合和所述投影值之间的对应形式的查找表。 提供了图像重建方法，包括以下步骤：用双能量射线扫描物体以获取双能量投影值，基于预先创建的查找表计算与所述双能量投影值相对应的基材系数的投影值，以及 基于所述基材系数的投影值重构基材系数分布的图像。 以这种方式，可以从基材系数分布的图像中计算出物体的原子数和密度以及衰减系数图像的图像。 与现有技术相比，本发明提出的方法具有校准过程简单，计算精度高，X射线束硬化无效的优点。

公开(公告)号：US07424089B2

公开(公告)日：2008-09-09

申请号：US11546717

申请日：2006-10-12

申请人： Li Zhang ,  Hewei Gao ,  Zhiqiang Chen ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Hewei Gao ,  Zhiqiang Chen ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： H05G1/60

CPC分类号： G01N23/046 ,  A61B6/032 ,  G01N2223/3303 ,  G01N2223/419 ,  G06T11/006 ,  G06T2211/421

摘要： It is disclosed a system and a method for reconstructing an image by using a straight-line trajectory scan to avoid image spatial resolution reduction due to interpolations in angular direction and detector direction during data rebinning. This system comprises: a projection data conversion section for converting projection data from straight-line trajectory scan into projection data under quasi-parallel-beam scan; a filtration section for obtaining filtered projection data by convoluting the projection data under quasi-parallel-beam scan with a predetermined convolutional kernel; and a back-projection section for reconstructing an image by back-projecting the filtered projection data with a weighting factor. By using the inventive system and method, the spatial resolution in the reconstructed image is improved, and the influence of data truncation on the reconstructed image is reduced. The present invention applies the filtration and back-projection mode, and thus has general advantages of the filtration and back projection, such as simplicity and efficiency. And it is easy to be parallelized and accelerated.

摘要翻译： 公开了一种通过使用直线轨迹扫描来重建图像的系统和方法，以避免在数据重组期间由于在角度方向和检测器方向上的内插而导致的图像空间分辨率降低。 该系统包括：投影数据转换部分，用于将投影数据从直线轨迹扫描转换成准并行束扫描的投影数据; 过滤部分，用于通过用预定的卷积核在准平行束扫描下卷积投影数据来获得经滤波的投影数据; 以及背投影部分，用于通过用加权因子反投影过滤的投影数据来重建图像。 通过使用本发明的系统和方法，改善了重建图像中的空间分辨率，减少了数据截断对重建图像的影响。 本发明应用过滤和反投影模式，因此具有过滤和反投影的一般优点，例如简单性和效率。 并行并行加速很容易。

公开(公告)号：US20070116177A1

公开(公告)日：2007-05-24

申请号：US11545255

申请日：2006-10-10

申请人： Zhiqiang Chen ,  Li Zhang ,  Hewei Gao ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

发明人： Zhiqiang Chen ,  Li Zhang ,  Hewei Gao ,  Kejun Kang ,  Jianping Cheng ,  Yuanjing Li ,  Yinong Liu ,  Yuxiang Xing ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G01N23/04

CPC分类号： G01N23/04 ,  A61B6/027

摘要： It is disclosed an imaging system comprising: radiation generating means including at least one radiation source for generating radiations; data acquiring means including an detector matrix faced the radiation source for obtaining projection data by receiving radiations penetrated through an object to be inspected; transporting means for making the object to be inspected between the radiation source and the detector matrix linearly moving relative to the radiation source and the detector matrix; and controlling and image processing means for controlling the radiation generating means, the data acquiring means and the transporting means, and for reconstructing an image of the object to be inspected from the projection data. The imaging system according to the present invention achieves a real stereoscopic radiography by using straight-line trajectory scan and reconstructing a tomographic or stereoscopic image through a straight-line filtered back-projection algorithm. The present imaging system has advantages of fast examination speed, no rotation, and out of large cone-angle problem in a circular-orbit cone-beam CT.

摘要翻译： 公开了一种成像系统，包括：辐射发生装置，其包括用于产生辐射的至少一个辐射源; 数据获取装置，包括面向辐射源的检测器矩阵，用于通过接收穿过待检查对象的辐射来获得投影数据; 用于使所述物体在所述辐射源和所述检测器矩阵之间相对于所述辐射源和所述检测器矩阵线性移动的传送装置; 以及控制和图像处理装置，用于控制辐射发生装置，数据获取装置和传送装置，并用于从投影数据重建待检查对象的图像。 根据本发明的成像系统通过使用直线轨迹扫描并通过直线过滤的反投影算法重建断层摄影或立体图像来实现真正的立体放射照相。 本发明的成像系统在圆锥轨道锥形CT中具有检测速度快，无旋转和大锥角问题的优点。

公开(公告)号：US20060291742A1

公开(公告)日：2006-12-28

申请号：US11472193

申请日：2006-06-21

申请人： Li Zhang ,  Zhiqiang Chen ,  Yuxiang Xing ,  Yuanjing Li ,  Yinong Liu ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Zhiqiang Chen ,  Yuxiang Xing ,  Yuanjing Li ,  Yinong Liu ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G06K9/40 ,  G06K9/00

CPC分类号： G06T5/40 ,  G06T5/009 ,  G06T2207/10116 ,  G06T2207/30004

摘要： A method of image information enhancement in radiography relates to image information processing techniques in radiography. The method comprising steps of: normalizing an acquired image A(x,y) to form a normalized image B(x,y); filtering the normalized image B(x,y) by a low-pass filter to obtain an filtered image C(x,y); calculating a relative standard deviation for each pixel in the image A(x,y), three times the relative standard deviation being an edge threshold for each pixel; thresholding a difference image obtained by subtracting the filtered image C(x,y) from the normalized image B(x,y) by using the edge threshold for each pixel to form a threshold-processed image D(x,y); enhancing a contrast of the threshold-processed image D(x,y) by using a non-linear function to form a contrast-enhanced image E(x,y); determining a enhancement coefficient a(x,y); obtaining a edge-enhanced image F(x,y) by multiplying the enhancement coefficient a(x,y), the contrast-enhanced image E(x,y) and the filtered image C(x,y); and generating a resulting image by multiplying a sum of the edge-enhanced image F(x,y) and the filtered image C(x,y) with the maximum value Amax As compared with the prior arts, the inventive method has a fast processing speed for image information enhancement and a simple algorithm, images clearly, eliminates noises in the images, and satisfies the requirements of relatively more enhancement to the contrast of the dark regions in the scanned images.

摘要翻译： 射线照相术中图像信息增强的方法涉及放射照相术中的图像信息处理技术。 该方法包括以下步骤：归一化所获取的图像A（x，y）以形成归一化图像B（x，y）; 通过低通滤波器对归一化图像B（x，y）进行滤波，得到滤波图像C（x，y）; 计算图像A（x，y）中每个像素的相对标准偏差，相对标准偏差的三倍是每个像素的边缘阈值; 通过使用每个像素的边缘阈值来从归一化图像B（x，y）中减去滤波图像C（x，y）获得的差分图像，以形成阈值处理图像D（x，y）; 通过使用非线性函数来增强阈值处理图像D（x，y）的对比度，以形成对比度增强图像E（x，y）; 确定增强系数a（x，y）; 通过将增强系数a（x，y），对比度增强图像E（x，y）和滤波图像C（x，y）相乘来获得边缘增强图像F（x，y） 并且通过将边缘增强图像F（x，y）和滤波图像C（x，y）的和乘以最大值A最大值来产生所得到的图像。与现有技术相比， 本发明的方法具有图像信息增强的快速处理速度和简单的算法，图像清晰，消除了图像中的噪声，并且满足了对扫描图像中的暗区域的对比度相对更加增强的要求。

公开(公告)号：US07962283B2

公开(公告)日：2011-06-14

申请号：US11644137

申请日：2006-12-22

申请人： Li Zhang ,  Zhiqiang Chen ,  Lijun Wang ,  Zhiming Wang ,  Ziran Zhao ,  Yuxiang Xing ,  Yongshun Xiao ,  Yuanjing Li ,  Yinong Liu

发明人： Li Zhang ,  Zhiqiang Chen ,  Lijun Wang ,  Zhiming Wang ,  Ziran Zhao ,  Yuxiang Xing ,  Yongshun Xiao ,  Yuanjing Li ,  Yinong Liu

IPC分类号： G01C21/30 ,  G01C21/32

CPC分类号： G05D1/0246 ,  G05D2201/0216

摘要： The present invention relates to the deviation-correction system for positioning of moving objects, and discloses a deviation-correction system for positioning of moving objects and the motion-tracking method thereof. The system includes a control system for receiving motion parameters required for deviation-correction, and sending commands to an actuator to control a moving object based on the motion parameters, the deviation-correction system for positioning of moving objects further comprising: a reference object which is set as a specified motion trail for the moving object; an image capturing system for acquiring successive digital image data upon the moving object moves; a motion tracking system for performing a motion tracking algorithm based on the digital image data transmitted by the image capturing system to judge whether the current motion state needs to be corrected and then transmitting the motion parameters required for deviation-correction to the control system.

摘要翻译： 本发明涉及用于移动物体的定位的偏差校正系统，并且公开了用于移动物体的定位的偏差校正系统及其运动跟踪方法。 该系统包括用于接收偏差校正所需的运动参数的控制系统，以及基于运动参数向致动器发送命令以控制运动物体的运动对象的偏移校正系统，还包括：参考对象， 被设置为移动物体的指定运动轨迹; 用于在移动物体移动时获取连续的数字图像数据的图像捕获系统; 运动跟踪系统，用于基于由图像捕获系统发送的数字图像数据执行运动跟踪算法，以判断当前运动状态是否需要被校正，然后向控制系统发送偏差校正所需的运动参数。

公开(公告)号：US07689055B2

公开(公告)日：2010-03-30

申请号：US11472193

申请日：2006-06-21

申请人： Li Zhang ,  Zhiqiang Chen ,  Yuxiang Xing ,  Yuanjing Li ,  Yinong Liu ,  Ziran Zhao ,  Yongshun Xiao

发明人： Li Zhang ,  Zhiqiang Chen ,  Yuxiang Xing ,  Yuanjing Li ,  Yinong Liu ,  Ziran Zhao ,  Yongshun Xiao

IPC分类号： G06K9/40

CPC分类号： G06T5/40 ,  G06T5/009 ,  G06T2207/10116 ,  G06T2207/30004

摘要： A method of image information enhancement in radiography relates to image information processing techniques in radiography. The method comprising steps of: normalizing an acquired image A(x,y) to form a normalized image B(x,y); filtering the normalized image B(x,y) by a low-pass filter to obtain an filtered image C(x,y); calculating a relative standard deviation for each pixel in the image A(x,y), three times the relative standard deviation being an edge threshold for each pixel; thresholding a difference image obtained by subtracting the filtered image C(x,y) from the normalized image B(x,y) by using the edge threshold for each pixel to form a threshold-processed image D(x,y); enhancing a contrast of the threshold-processed image D(x,y) by using a non-linear function to form a contrast-enhanced image E(x,y); determining a enhancement coefficient a(x,y); obtaining a edge-enhanced image F(x,y) by multiplying the enhancement coefficient a(x,y), the contrast-enhanced image E(x,y) and the filtered image C(x,y); and generating a resulting image by multiplying a sum of the edge-enhanced image F(x,y) and the filtered image C(x,y) with the maximum value Amax As compared with the prior arts, the inventive method has a fast processing speed for image information enhancement and a simple algorithm, images clearly, eliminates noises in the images, and satisfies the requirements of relatively more enhancement to the contrast of the dark regions in the scanned images.

摘要翻译： 射线照相术中图像信息增强的方法涉及放射照相术中的图像信息处理技术。 该方法包括以下步骤：归一化所获取的图像A（x，y）以形成归一化图像B（x，y）; 通过低通滤波器对归一化图像B（x，y）进行滤波，得到滤波图像C（x，y）; 计算图像A（x，y）中每个像素的相对标准偏差，相对标准偏差的三倍是每个像素的边缘阈值; 通过使用每个像素的边缘阈值来从归一化图像B（x，y）中减去滤波图像C（x，y）获得的差分图像，以形成阈值处理图像D（x，y）; 通过使用非线性函数来增强阈值处理图像D（x，y）的对比度，以形成对比度增强图像E（x，y）; 确定增强系数a（x，y）; 通过将增强系数a（x，y），对比度增强图像E（x，y）和滤波图像C（x，y）相乘来获得边缘增强图像F（x，y） 并且通过将边缘增强图像F（x，y）和滤波图像C（x，y）的和与最大值Amax As相乘来生成结果图像，与现有技术相比，本发明的方法具有快速处理 图像信息增强的速度和简单的算法，图像清晰，消除了图像中的噪声，并且满足了相对更加增强扫描图像中的暗区域的对比度的要求。

公开(公告)号：US07570737B2

公开(公告)日：2009-08-04

申请号：US11801279

申请日：2007-05-08

申请人： Kejun Kang ,  Li Zhang ,  Zhiqiang Chen ,  Haifeng Hu ,  Yuanjing Li ,  Yinong Liu ,  Guowei Zhang ,  Ziran Zhao ,  Yuxiang Xing ,  Yongshun Xiao

发明人： Kejun Kang ,  Li Zhang ,  Zhiqiang Chen ,  Haifeng Hu ,  Yuanjing Li ,  Yinong Liu ,  Guowei Zhang ,  Ziran Zhao ,  Yuxiang Xing ,  Yongshun Xiao

IPC分类号： G01N23/04

CPC分类号： G01N23/046 ,  A61B6/027 ,  G01N2223/419 ,  G06T7/0008 ,  G06T7/97 ,  G06T2207/10081 ,  G06T2207/20016 ,  G06T2207/30112 ,  Y10S378/901

摘要： A cargo security inspection method and system based on spiral scanning, the method including: spirally scanning an inspected object at a first precision to obtain the transmission projection data; judging whether there is a suspect area in the inspected area; scanning at least one slice of the suspect area at a second precision wherein the second precision is greater than the first precision; reconstructing a tomographic image of the at least one slice; and using the reconstructed tomographic image to judge whether there is any dangerous article in the suspect area.

摘要翻译： 一种基于螺旋扫描的货物安全检查方法和系统，所述方法包括：以第一精度螺旋扫描检查对象以获得传输投影数据; 判断被检区域是否有可疑区域; 以第二精度扫描所述可疑区域的至少一个切片，其中所述第二精度大于所述第一精度; 重建所述至少一个切片的断层图像; 并使用重建的断层图像来判断可疑区域中是否存在任何危险物品。