Abstract: A dual-energy material identification method and system with under-sampling is disclosed. A CT image of the object is obtained by using the CT image reconstruction method, while the dual-energy projections are under-sampled to obtain a few samples. Photoelectric coefficient integral and Compton coefficient integral are computed from these dual-energy projection data. The CT image is segmented into regions with image processing technique, and the regions are labeled. The length by which a few dual-energy rays crosses each labeled region is computed, and an equation system is established with dual-energy preprocessing dual-effect decomposition reconstruction method to compute Photoelectric coefficient and Compton coefficient, and then atomic number and electron density of material in each region are computed. The material of the object can be identified with the atomic number.

Abstract: An x-ray imaging technology, performing an x-ray dark-field CT imaging of an examined object using an imaging system which comprises an x-ray source, two absorbing gratings G1 and G2, an x-ray detector, a controller and a data processing unit, comprising the steps of: emitting x-rays to the examined object; enabling one of the two absorbing gratings G1 and G2 to perform phase stepping motion within at least one period range thereof; where in each phase stepping step, the detector receives the x-ray and converts it into an electric signal; wherein through the phase stepping of at least one period, the x-ray intensity at each pixel point on the detector is represented as an intensity curve; calculating a second moment of scattering angle distribution for each pixel, based on a contrast of the intensity curve at each pixel point on the detector and an intensity curve without presence of the examined object; taking images of the object at various angles, then obtaining an image with scattering information of the

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether there are drugs concealed in the inspected liquid article based on the difference between the acquired physical attributes and reference physical attributes of the inspected liquid article. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: An X-ray imaging system comprising: an X-ray source, a source grating, a fixed grating module and an X-ray detector, which are successively positioned in the propagation direction of X-ray; an object to be detected is positioned between the source grating and the fixed gating module; said source grating can perform stepping movement in a direction perpendicular to the optical path and grating stripes; wherein the system further comprises a computer workstation for controlling said X-ray source, source grating and X-ray detector so as to perform the following processes: the source grating performs stepping movement in at least one period thereof; at each stepping step, the X-ray source emits X-ray to the object to be detected, and the detector receives the X-ray at the same time; wherein after at least one period of stepping and data acquisition, the light intensity of X-ray at each pixel point on the detector is represented as a light intensity curve; the light intensity curve at each pixel point on the detec

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether the inspected liquid article is dangerous based on the physical attributes. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: Disclosed is an image reconstruction method in a high-energy dual-energy CT system. The method comprises steps of scanning an objection with high-energy dual-energy rays to obtain high-energy dual-energy projection values, calculating projection values of base material coefficients corresponding to the dual-energy projection values on the basis of a pre-created lookup table or by analytically solving a set of equations, and obtaining an image of base material coefficient distribution based on the projection values of base material coefficients. The method provides a solution for reconstruction with high-energy dual energy CT technology and thus a more effective approach for substance identification and contraband inspection, thereby bringing a significant improvement on accuracy and efficiency in security inspection.

Abstract: A dual-energy material identification method and system with under-sampling is disclosed. A CT image of the object is obtained by using the CT image reconstruction method, while the dual-energy projections are under-sampled to obtain a few samples. Photoelectric coefficient integral and Compton coefficient integral are computed from these dual-energy projection data. The CT image is segmented into regions with image processing technique, and the regions are labeled. The length by which a few dual-energy rays crosses each labeled region is computed, and an equation system is established with dual-energy preprocessing dual-effect decomposition reconstruction method to compute Photoelectric coefficient and Compton coefficient, and then atomic number and electron density of material in each region are computed. The material of the object can be identified with the atomic number.

Abstract: The present invention discloses a method for performing CT imaging on a region of interest of an object under examination, comprising: acquiring the CT projection data of the region of interest; acquiring the CT projection data of region B; selecting a group of PI line segments covering the region of interest, and calculating the reconstruction image value for each PI line segment in the group; and combining the reconstruction image values in all the PI line segments to obtain the image of the region of interest. The present invention further discloses a CT imaging device using this method and a data processor therein. Since the 2D/3D slice image of the region of interest can be exactly reconstructed and obtained as long as the X-ray beam covers the region of interest and the region B, it is possible to use a small-sized detector to perform CT imaging on the region of interest at any position of a large-sized object, which reduces to a great extent the radiation dose of the X-ray during the CT scanning.

Abstract: Pseudo dual-energy material identification systems and methods with under-sampling are disclosed. The system comprises a ray generating device, a mechanic rotation control section, a data collecting subsystem comprising a first tier of detectors and a second tier of detectors, and a master control and data processing computer. The system utilizes a CT-imaging-based material identification method with under-sampled dual-energy projection data, in which only a few detectors at the second tier are used to perform dual-energy projection data sampling, and optimization is made on the procedure of solving an equation system.

Abstract: A method and apparatus for CT image reconstruction may include selecting, by a unit, projection data of the same height on a curve having a curvature approximate to that of the scanning circular orbit, implementing, by a unit, a weighting processing on the selected projection data, filtering, by a unit, the weighting processed projection data along a horizontal direction, implementing, by a unit, three-dimensional back projection on the filtered projection data along the direction of ray. The method and apparatus can effectively eliminate cone beam artifact under a large cone angle.

Abstract: A CT device and method based on motion compensation are proposed. The present invention obtains motion parameters of a target object by using a stereo-vision-based motion measurement system, and then implements motion compensation through the technology based on reconstructed image matrix transformation, thereby obtaining a clear 2D/3D CT image while eliminating motion artifacts. The present invention can effectively eliminate motion artifacts caused by the scanned object's own motions in the CT scanning, and can be easily embedded into the existing CT scanning equipments. The present invention can improve quality of the CT images, and is especially important for CT imaging of some special groups of people that can not control their own motions, such as Parkinson's patients, infants, living mouse and so on. It can also improve ultra-high-resolution imaging of human body.

Abstract: An x-ray imaging technology, performing an x-ray dark-field CT imaging of an examined object using an imaging system which comprises an x-ray source, two absorbing gratings G1 and G2, an x-ray detector, a controller and a data processing unit, comprising the steps of: emitting x-rays to the examined object; enabling one of the two absorbing gratings G1 and G2 to perform phase stepping motion within at least one period range thereof; where in each phase stepping step, the detector receives the x-ray and converts it into an electric signal; wherein through the phase stepping of at least one period, the x-ray intensity at each pixel point on the detector is represented as an intensity curve; calculating a second moment of scattering angle distribution for each pixel, based on a contrast of the intensity curve at each pixel point on the detector and an intensity curve without presence of the examined object; taking images of the object at various angles, then obtaining an image with scattering information of the

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether the inspected liquid article is dangerous based on the physical attributes. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: A method for phase contrast imaging comprises: illuminating an object by terahertz radiation such that the terahertz radiation interacts with the object; illuminating a diffraction grating by the terahertz radiation that has interacted with the object; translating the diffraction grating along the direction of the grating wave vector, to measure, for each of different grating positions, an intensity distribution of the terahertz radiation that has interacted with the object and with the grating in a diffraction field; and retrieving a phase contrast image of the object from the intensity distributions. An apparatus for phase contrast imaging is also provided.

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether the inspected liquid article is dangerous based on the physical attributes. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether there are drugs concealed in the inspected liquid article based on the difference between the acquired physical attributes and reference physical attributes of the inspected liquid article. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: 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.

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether there are drugs concealed in the inspected liquid article based on the difference between the acquired physical attributes and reference physical attributes of the inspected liquid article. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: In a linear track scanning imaging system and method, the imaging system may include: a ray generating unit having a plurality of ray sources that emit beams alternately, only one ray source at a time; an actuating arrangement causing an object under examination to move with respect to the linear track scanning imaging system along a linear track, leading the object to pass through a scanning area of the linear track scanning imaging system; a data collecting unit that collects projection data of the object for each ray source; an imaging unit that reconstructs an image of the object under examination based on the projection data collected for each ray source; and a display unit for displaying the reconstructed image.

Abstract: A method for phase contrast imaging comprises: illuminating an object by terahertz radiation such that the terahertz radiation interacts with the object; illuminating a diffraction grating by the terahertz radiation that has interacted with the object; translating the diffraction grating along the direction of the grating wave vector, to measure, for each of different grating positions, an intensity distribution of the terahertz radiation that has interacted with the object and with the grating in a diffraction field; and retrieving a phase contrast image of the object from the intensity distributions.