36 results about "X Ray Computerized Tomography" patented technology

The invention provides a computerized tomography (CT) image metal artifact correction method, a computerized tomography (CT) image metal artifact correction device and a computerized tomography (CT) apparatus. The computerized tomography (CT) image metal artifact correction method comprises the following steps that: a metal projection range caused by an interference object is determined according to an original image corresponding to original projection data; diagnosis object projection data after the removal of the interference object are obtained based on metal projection data in the metal projection range, and after that, the original projection data are corrected and a model image is constructed based on the diagnosis object projection data; and secondary correction is performed on the original projection data according to the projection data of the model image, and reconstruction is performed based on corrected target projection data and according to clinically-used scanning and image construction conditions so as to obtain a metal artifact-free target image, and therefore, the purpose of metal artifact correction can be achieved. According to the computerized tomography (CT) image metal artifact correction method of the invention, the original projection data are adopted as a correction object, and therefore, the spatial resolution and low-contrast ability of a processed image can be ensured; and the original projection data completely contain all information of the interference object, and therefore, the introduction of a new artifact can be avoided.

An X-ray computed tomographic apparatus includes a gantry 100 including an X-ray tube 101 which generates X-rays and an X-ray detector 103 which detects X-rays transmitted through a subject to be examined, a reconstruction device 114 which generates tomogram data on the basis of an output from the X-ray detector, a breath detector 203 which detects a respiration waveform representing a temporal change in respiration index value associated with the subject, a regular respiration waveform generating unit 207 which generates a respiration waveform with a regular respiration cycle which originates from the detected respiration waveform, and a gantry mount display 201 which displays the generated regular respiration waveform.

The embodiment of the invention provides a rock performance evaluating device. The device comprises a pressure chamber and a CT (computed tomography) device, wherein the pressure chamber is a sealed cavity body, is positioned in the scanning range of an X-ray computerized tomography CT device, and is used for providing preset testing temperature and preset testing pressure for a rock core test specimen, wherein the preset testing temperature is higher than a first threshold, and the preset testing pressure is higher than a second threshold; the CT device is used for scanning the rock core test specimen to acquire image information of the internal structure of the rock core test specimen at different time, and analyzing according to the image information so as to obtain a strain curve of the rock core test specimen. The embodiment of the invention prevents the situation that the rock strain is measured by a sensor at high temperature, thereby measuring the rock strain simply and accurately at high temperature.

The invention provides a method for performing non-destructive detection on evolution of the three-dimensional carbonation depth of a cement-based material through X-ray computerized tomography and relates to a novel detection method for the carbonation depth of a cement-based material. The main principle is that: an image is reconstructed by acquiring ray attenuation information of a rotary object based on an X-ray source; a carbonized region and a non-carbonized region of the cement-based material are distinguished according to difference of gray value; and the defects in the traditional pHmethod of phenolphthalein alcohol solution are overcome. Under the condition of not damaging a test piece, the evolution process of the three-dimensional carbonation depth of the cement-based material along with the time is detected. By the method, flaw space distribution in the carbonation process, the flaw volume, the flaw closing area, the evolution law of porosity and hole dimensional distribution and the topological properties, such as connectivity, sinuosity and the like, of the hole can be achieved.

The invention relates to a method and system for eliminating geometrical artifacts in a CT (Computerized Tomography) image. The method comprises the following steps of: performing CT scanning on a die body to obtain the projection coordinate of the mass center of the die body on a CT detector; defining geometrical parameters according to the projection coordinate of the mass center of the die body on the CT detector, and substituting the geometrical parameters in a reconstruction formula, wherein the geometrical parameters include: a distance h of a projection point of the turntable rotating center on the detector and a center of the detector, an included angle alpha between an ideal position of a straight line where the detector id and an actual position, and a distance SDD between the projection point of the turntable rotating center on the detector and an X ray source focus; performing CT scanning on an object to be imaged to obtain fan-beam projection parameters of the object to be imaged; and processing the fan-beam projection parameters of the object to be processed by the reconstruction formula to obtain CT image data of the object to be imaged and further obtain a CT image with the CT image data of the object to be imaged serving as a gray level. According to the technical scheme, the method and the system can be used for accurately obtaining the CT image without the geometrical artifacts.

Disclosed is a method for performing X-ray Computed Tomography scanning, the method including acquiring a plurality of images of an object, obtaining an initial image from the plurality of images, calculating NonLocal weight of the initial image, utilizing a current image estimation and registered prior image, performing a successive over-relaxation optimization to yield a new image estimation with an intensity of the new image estimation equal or greater than zero, performing a cycle update, generating an image of the object utilizing the new image estimation obtained from the optimization, and outputting a resultant image.

The invention relates to a three-dimensional digital imaging method of the large view field cone-beam X-ray tilting scanning of a biased detector, belonging to the technical field of X-ray computerized tomography (CT). In the three-dimensional digital imaging method, the area array detector is placed to be biased, and an X-ray source is used for generating cone-beam X-rays which irradiate a member imaging area with a certain angle in a penetrating and tilting way relative to the length and width surface of a member; in the scanning process, the X-ray source and the area array detector are static, the member rotates in an angle of 360 degrees in an equal angle and step length way surrounding a rotating shaft, and the area array detector acquires an X-ray signal modulated by the member under each rotation angle. A three-dimensional computerized tomography image of a scanning area can be reestablished and obtained by a data truncation smoothing preprocessing method and a filtering back projection reestablishing arithmetic according to data obtained by the area array detector under the scanning angle of 360 degrees. Compared with the traditional tilting scanning method, the three-dimensional digital imaging method can double the tilting scanning imaging view field without changing the system hardware and the scanning speed and has high reestablishment quality, simple process and high efficiency.

In an X-ray computerized tomography scanner, a correction phantom embedding an X-ray absorbing object is put on or around a non-vertical rotary axis between an X-ray source and a two-dimensional X-ray detector, and two dimensional imaging data of the phantom is acquired. Then a locus of the X-ray absorbing material is determined in the two-dimensional imaging data, and based on the locus an ideal locus is obtained in the direction of the rotary axis. Next, a difference between the calculated position of the ideal locus and a measured position is determined in the direction of the rotary axis. The difference is used to correct deviation in the direction of the rotary axis.

The invention discloses a nondestructive testing method of a three-dimensional shape and stress characteristics of internal defects of a metal welding seam. According to the nondestructive testing method, with combination of an X-ray computed tomography scanning technology and a finite element analysis technology, the three-dimensional shape and the stress characteristics of the internal hole defects of the dissimilar metal welding seam can be tested under the condition without destroying a test piece. The method can also be used for obtaining space distribution, the hole size, the porosity, a pore-size distribution evolution law and the hole topological performance such as information including connectivity and tortuous degree of the internal hole defects of the dissimilar metal welding seam. The nondestructive testing method comprises the following steps: preparing a sample, scanning the test sample piece to acquire a scanned picture, recording a corresponding metal welding parameter, processing acquired scanned picture information, rebuilding a three-dimensional model, and testing and verifying the three-dimensional model by carrying out model mechanical analysis.

The invention discloses an X-ray computerized tomography system, which is used for partially scanning an object to be detected. The system comprises a middle angle computing module, a rebuilding angle computing module and a scanner, wherein the middle angle computing module is used for computing a middle angle according to the size of the vision field cross section and the central coordinate of the object to be detected, and transmitting the middle angle to the rebuilding angle computing module; the rebuilding angle computing module is used for adding the middle angle to 180 degrees to obtain a rebuilding angle, and transmitting the rebuilding angle to the scanner; and the scanner is used for scanning a part of the object to be detected according to the rebuilding angle. The invention further discloses an X-ray computerized tomography method. Due to the adoption of the system and the method, the scanning time can be shortened, the time resolution can be increased, and the radiation dosage received by a patient can be reduced.

The invention belongs to the technical field of X ray computerized tomography (CT), and particularly relates to a wide visual field cone-beam X ray oblique scanning three-dimension digital imaging method based on an algebraic reconstruction algorithm. The method comprises the following steps: acquiring two-dimension projection data of a scanned component in detector biasing wide visual field cone-beam X ray oblique scanning way; and rebuilding an image by the algebraic reconstruction algorithm to obtain a three-dimension computerized tomography image in a scanning area. Compared with the widevisual field cone-beam X ray oblique scanning three-dimension digital imaging method based on a filter back projection algorithm, the method can effectively inhibit structure aliasing between layers and obviously improve the quality of the rebuilt picture in the condition that the system hardware, the scanning view field and the scanning speed are not changed.

The invention discloses an automatically radiation-proof FMT-and-CT dual-mode imaging system. The automatically radiation-proof FMT-and-CT dual-mode imaging system comprises a signal collecting module, a controller module, a data transmission module, a power module and an automatically radiation-proof module, wherein the signal collecting module is used for collecting fluorescence excitation imaging data and X-ray computerized tomography data of an imaging sample, the controller module is used for controlling operation, parameter setting, data processing and data storage of other modules, the data transmission module is used for transmitting internal data of the system, the power module is used for providing electricity for the whole system, and the automatically radiation-proof module is used for protecting a CCD camera and reducing damage caused by X-rays to the CCD camera. The automatically radiation-proof FMT-and-CT dual-mode imaging system can achieve dual-mode rapid imaging of FMT and CT, and due to the fact that the automatically radiation-proof module is designed, when an X-ray power source is turned on, the CCD camera is effectively protected, and damage to an internal sensitization chip can be reduced.

The invention discloses an X-ray computerized tomography system and an X-ray computerized tomography method. The system comprises an X-ray tube, a collimator, a detector, a computing assembly and an adjusting assembly, and is used for shooting a plurality of circular sections of an object to be detected in the scanning direction, wherein the detector comprises a plurality of detector channels; the X-ray tube, the collimator and the detector rotate synchronously around the object to be detected; the collimator is a collimator with an adjustable opening; the computing assembly is used for computing the opening width of the collimator needed for irradiating each circular section respectively, and transmitting the opening width to the adjusting assembly; and the adjusting assembly is used for adjusting the opening of the collimator according to the opening width. The invention further discloses the X-ray computerized tomography method. Due to the adoption of the system and the method, extra exposure of the surrounding area of the objected to be detected can be reduced, and the X-ray dosage received by a patient can be reduced.

The invention relates to a method for determining and analyzing a pore structure of saline-alkali soil, and belongs to the field of soil structure determination and analysis method. The invention aimsto provide the method for determining the pore structure of the saline-alkali soil with no disturbance and no destruction and an application thereof, so as to solve the problem in the prior art thatsoil with macropore property cannot be measured under a condition without destroying soil. The method for determining and analyzing the pore structure of the saline-alkali soil includes the followingsteps: sample collection: selecting to-be-measured soil, knocking a sampling container into soil in a vertical direction, and collecting an original soil column; sample scanning: putting the originalsoil column into an X-ray computerized tomography scanner, and scanning; and image processing: inputting the scanned image of the cross section of the original soil column into a computer, and carrying out batch treatment on the image by the computer, to obtain the number and area of pores of the cross section of the original soil column. The spatial distribution of the macropore structure in thesoil column is more rapid, accurate and intuitive to determine and calculate.

The invention provides a positron tomoscan method and a reconstruction method, and relates to the technical field of X-ray computed tomoscan imaging. The scanning method comprises the steps: a PET device is positioned to a predetermined axial region of interest; the axial region of interest is moved forward by 1/4 of the axial detector crystal width; the PET device starts to statically acquire data, and the continuous acquisition time is half of the preset single-bed scanning duration; the region of interest is moved backwards by half of the axial detector crystal width; and a static data acquisition task of remaining single-bed scanning time is completed. The reconstruction method comprises the step of combining two times of the scanning data on a coincidence event or on a sinogram. According to the scanning method, the positioning length of an original axial scanning region of interest is not changed; by controlling the small deviation of the scanning bed, two times of sub-scanning are carried out in the region of interest, the single scanning time is half of the original scanning time, and more fined spatial distribution information in the axial direction can be obtained, so that the axial imaging resolution rate of the PET system is improved.

The invention discloses an X-ray low-dose computerized tomography (CT) image reconstruction method based on weighting alpha divergence constraint. The method comprises the steps of utilizing a CT imaging device to acquire low-dose CT projection data and an imaging system parameter; adopting alpha divergence measure as distance measure between original projection data with noise and projection data to be recovered, calculating the weight factor of the alpha divergence measure according to the acquired system parameter, and constructing a projection data recovering model based on the alpha divergence constraint; carrying out an objective function solution on the constructed projection data recovering model and establishing an iterative algorithm format; for the acquired low-dose CT projection data, carrying out an iteration solution on the projection data recovering model by means of the established iterative algorithm format; and carrying out image reconstruction on recovered projection data. The X-ray low-dose CT image reconstruction method based on the weighting alpha divergence constraint plays important roles in both noise suppression and edge preservation.

Systems and methods for integrating a three-dimensional X-ray computed tomography system with an independent sound wave system to determine mechanical properties of tissue using signals from the sound wave system. Methods are disclosed that generate a numerical simulation and take the transmitted wave signals as the optimization objective to estimate modulus distribution of the tissue. Further, the mechanical properties of the tissue are reconstructed based on an inverse algorithm.

In a method and an evaluation device for determining the position of a structure located in an object to be investigated by means of X-ray computer tomography, a cutting data record, which images the object in a cutting plane, is determined from a volume data record of the object. The cutting data record is binarized to form a binary data record, in which the structure voxels imaging the structure and the surface voxels imaging an object surface are determined. To determine the position, a distance data record is produced in such a way that a distance value, which characterizes the smallest distance of the respective distance voxel from the surface voxels, is assigned to each distance voxel of the distance data record. The distance voxels corresponding to the structure voxels are then determined and the associated distance values evaluated.

The present invention relates to a surface-modified tantalum oxide nanoparticle, a method for preparation thereof, a contrast agent (medium) for X-ray computed tomography, and a highly dielectric (high-K) film using the same. In particular, the present invention is directed to a surface-modified tantalum oxide nanoparticle, a method for preparing surface-modified tantalum oxide nanoparticles, comprising: (i) adding an aqueous phase to an organic solvent which contains a surfactant, to prepare a water-in-oil microemulsion; (ii) introducing a tantalum precursor to said microemulsion; (iii) adding a surface-modifier having an organic silane group or phosphine group to a solution obtained at the step (ii); (iv) removing said organic solvent from a product obtained at the step (iii); and (v) separating surface-modified tantalum oxide nanoparticles from a mixture obtained at the step (iv), a contrast agent for X-ray computed tomography, and a highly dielectric (thin) film using the same.