Patent application number | Description | Published |
20080310598 | Method for calibrating dual-energy CT system and method of image reconstruction - 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. | 12-18-2008 |
20090003516 | X-Ct Scan System - An X-CT scan system includes a base, an object rotary support, an X-ray generation device and a data acquisition system, wherein one side of the detector is leveled to or beyond the prolong line of the connecting line between the X-ray source of the X-ray generation device and the center of the object rotary support, the length of the beyond portion is less than the radius of the imaging field. The advantage of the invention is in that the invention can reconstruct the entire image of the object by means of X-ray projection data which only covers half of the area of the object. Compared with the traditional CT scan system, half of the detector size can be saved at most. The X-CT scan system is simplified and the projection data amount for scan and computation amount for image reconstruction are also reduced with the reconstructed image quality guaranteed. | 01-01-2009 |
20090092220 | METHOD AND DEVICE FOR INSPECTION OF LIQUID ARTICLES - 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. | 04-09-2009 |
20090110143 | INSPECTION SYSTEM, INSPECTION METHOD, CT APPARATUS AND DETECTION DEVICE - An inspection system is disclosed. The system comprises a CT apparatus. The CT apparatus includes a gantry, a radiation source connected with the gantry, a detection device connected with the gantry substantially opposite the radiation source, and a transfer device for transferring an object under inspection. The detection device comprises N rows of detectors arranged at predetermined intervals, where N is an integer greater than 1. With the inspection system according to the present invention, the CT apparatus can perform scanning imaging at a high rate to enable the CT apparatus and an scanning imaging device for obtaining a two-dimensional image of an object under inspection to simultaneously operate, thereby compensating each other's insufficiency. | 04-30-2009 |
20090262891 | LINEAR TRACK SCANNING IMAGING SYSTEM AND METHOD - 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. | 10-22-2009 |
20100040192 | IMAGE RECONSTRUCTION METHOD FOR HIGH-ENERGY, DUAL-ENERGY CT SYSTEM - 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. | 02-18-2010 |
20100284514 | METHOD AND DEVICE FOR INSPECTION OF LIQUID ARTICLES - 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. | 11-11-2010 |
20110024624 | PHASE CONTRAST IMAGING METHOD AND APPARATUS - 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 comprises: a terahertz radiation emitter for generating terahertz radiation, which illuminates an object to interact with the object; a diffraction grating, which is illuminated by the terahertz radiation that has interacted with the object; a terahertz radiation detector for measuring, 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 a data collecting and processing system for retrieving a phase contrast image of the object from the intensity distributions. | 02-03-2011 |
20110211671 | METHOD AND DEVICE FOR INSPECTION OF LIQUID ARTICLES - 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. | 09-01-2011 |
20110261922 | METHOD AND DEVICE FOR INSPECTION OF LIQUID ARTICLES - 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. | 10-27-2011 |
20110293064 | X-RAY DARK-FIELD IMAGING SYSTEM AND METHOD - 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 G | 12-01-2011 |
20120014579 | CT DEVICE AND METHOD BASED ON MOTION COMPENSATION - 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. | 01-19-2012 |
20120106832 | METHOD AND APPARATUS FOR CT IMAGE RECONSTRUCTION - 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. | 05-03-2012 |
20120134531 | Pseudo Dual-Energy Material Identification System And Method With Undersampling - 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. | 05-31-2012 |
20120140874 | Computer Tomography Imaging Device and Method - 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. | 06-07-2012 |
20120148133 | Dual-Energy Material Identification Method and Apparatus with Undersampling - 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. | 06-14-2012 |
20130094625 | X RAY SOURCE GRATING STEPPING IMAGING SYSTEM AND IMAGE METHOD - 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 detector is compared with a light intensity curve in the absence of the object to be detected, a pixel value of each pixel point is calculated from change in said light intensity curve; an image of the detected object is reconstructed according to the calculated pixel value. | 04-18-2013 |
20140093152 | METHODS AND DEVICES FOR LOCATING OBJECT IN CT IMAGING - The present disclosure provides methods and devices for locating a plurality of interested objects in CT imaging. Location of the interested objects in the three-dimensional space can be determined by using three projection images that are substantially perpendicular to each other. The method can rapidly locate interested objects in a CT image without pre-reconstruction of the CT image even if there are a plurality of interested objects in the field of view. The algorithm does not involve interactive steps. The method is rapid and effective, and thus applicable to industrial applications. | 04-03-2014 |
20140185741 | Multi-energy CT imaging system and Imaging Method - The present invention relates to a Computed Tomography (CT) imaging system, in particular to a multi-energy CT imaging system and imaging method. | 07-03-2014 |
20140211917 | APPARATUS AND METHOD FOR RAY SCANNING IMAGING - The present invention discloses apparatus and method for ray scanning imaging. The apparatus comprises a plurality of ray generators and a ray detection device. The plurality of ray generators are arranged uniformly along a circular arc and emit ray beams in sequence or simultaneously to an object to be inspected within a single scanning period. The ray detection device may be either in a multi-segmental semi-closed configuration composed of a plurality of linear arrays of ray detectors or in a circular arc configuration where a plurality of ray detection units arranged uniformly along a circular arc. During the inspection, the apparatus is advantageous in obtaining the complete ray projection values without rotation thereof, so as to effectively shorten the inspection time. | 07-31-2014 |
20140369458 | CT IMAGING METHODS AND SYSTEMS - Disclosed is a CT imaging method and system. The method includes: CT scanning an object with a dual-energy CT system to obtain a first complete set of projection data in a first scan mode, and to obtain a second incomplete set of projection data in a second scan mode; reconstructing a first attenuation coefficient image of the object from the first set of projection data, and extracting, from the first attenuation coefficient image, prior structure information of the object indicating edge intensity; and reconstructing a second attenuation coefficient image of the object from the second incomplete set of projection data using the extracted prior structure information as a constraint. With the method using the prior structure information of the imaged object as a constraint in reconstruction, it is possible to dramatically reduce an amount of data required for reconstruction, and achieve satisfactory effects even with ill-conditioned problems of limited-angle and inner reconstruction. | 12-18-2014 |
20150030225 | X-RAY DUAL-ENERGY CT RECONSTRUCTION METHOD - The present disclosure relates to a self-prior information based X-ray dual-energy CT reconstruction method, which can utilize information inherent in data to provide a prior model, thereby obtaining a reconstructed image with a high quality. The X-ray dual-energy CT reconstruction method according to the present disclosure comprises: (a) rating an energy spectrum and establishing a dual-energy lookup table; (b) collecting high-energy data p | 01-29-2015 |