62 results about "Computed tomography colography" patented technology

The present invention relates to the field of x-ray imaging. More particularly, embodiments of the invention relate to methods, systems, and apparatus for imaging, which can be used in a wide range of applications, including medical imaging, security screening, and industrial non-destructive testing to name a few. Specifically provided as embodiments of the invention are systems for x-ray imaging comprising: a) a first collimator-and-detector assembly having a first operable configuration to provide at least one first dataset comprising primary x-ray signals as a majority component of its data capable of being presented as a first image of an object subjected to x-ray imaging; b) a second collimator-and-detector assembly having a second operable configuration or wherein the first collimator-and-detector assembly is adjustable to a second configuration to provide at least one second dataset comprising primary and dark-field x-ray signals as a majority component of its data capable of being presented as a second image of the object; and c) a computer operably coupled with the collimator-and-detector assemblies comprising a computer readable medium embedded with processing means for combining the first dataset and the second dataset to extract the dark-field x-ray signals and produce a target image having higher contrast quality than the images based on the first or second dataset alone. Such systems can be configured to comprise at least two collimator-and-detector assemblies or configurations differing with respect to collimator height, collimator aperture, imaging geometry, or distance between an object subjected to the imaging and the collimator-and-detector assembly.

This invention is directed to a collimator and collimation techniques. Specifically, the invention is directed to a collimator and method for collimation wherein the collimator combines the resolution and sensitivity properties of pinhole Single Photon Emission Computed Tomography (SPECT) imaging with the 2D complete-sampling properties of fan-beam collimators.

A deliverable four dimensional (4D) intensity modulated radiation therapy (IMRT) planning method is disclosed, for delivery using a linear accelerator with a dynamic multi-leaf collimator (DMLC). A 4D computed tomography (CT) scan is used for segmenting tumor anatomy on a reference phase of periodic motion of the tumor. Deformable registration of the 4D CT data is used to generate corresponding anatomical structures on other phases. Preferably, the collimator for each beam position is aligned using the gross tumor volume (GTV) centroid motion corresponding to the periodic motion of the tumor, as determined from the two dimensional (2D) projection of a given beam position. A deliverable IMRT plan is created on the 4D CT image set in which the MLC leaf positions and beam on / off status can vary as a function of respiratory phase by solving a four dimensional optimization problem. The mechanical constraints of the MLC leaves are included in the optimization.

A method of utilizing bolus propagation and control for contrast enhancement comprises measuring with an imaging device a position of a bolus moving along a path in a biological structure. The method further comprises predicting a future position of the bolus using a simplified target model and comparing the predicted future position of the bolus with the measured position of the bolus. A control action is determined to eliminate a discrepancy, if any, between the predicted position of the bolus and the measured position of the bolus and the relative position of the imaging device and the biological structure is adaptively adjusted according to the control action to chase the motion of the bolus.

A deliverable four dimensional (4D) intensity modulated radiation therapy (IMRT) planning method is disclosed, for delivery using a linear accelerator with a dynamic multi-leaf collimator (DMLC). A 4D computed tomography (CT) scan is used for segmenting tumor anatomy on a reference phase of periodic motion of the tumor. Deformable registration of the 4D CT data is used to generate corresponding anatomical structures on other phases. Preferably, the collimator for each beam position is aligned using the gross tumor volume (GTV) centroid motion corresponding to the periodic motion of the tumor, as determined from the two dimensional (2D) projection of a given beam position. A deliverable IMRT plan is created on the 4D CT image set in which the MLC leaf positions and beam on / off status can vary as a function of respiratory phase by solving a four dimensional optimization problem. The mechanical constraints of the MLC leaves are included in the optimization.

A 3D metal artifacts correction technique corrects the streaking artifacts generated by titanium implants or other similar objects. A cone-beam computed tomography system is utilized to provide 3D images. A priori information (such as the shape information and the CT value) of high density sub-objects is acquired and used for later artifacts correction. An optimization process with iterations is applied to minimize the error and result in accurate reconstruction images of the object.

Nondestructive evaluation (NDE) of objects can elucidate impacts of various process parameters and qualification of the object. Computed tomography (CT) enables rapid NDE and characterization of objects. However, CT presents challenges because of artifacts produced by standard reconstruction algorithms. Beam-hardening artifacts especially complicate and adversely impact the process of detecting defects. By leveraging computer-aided design (CAD) models, CT simulations, and a deep-neutral network high-quality CT reconstructions that are affected by noise and beam-hardening can be simulated and used to improve reconstructions. The systems and methods of the present disclosure can significantly improve the reconstruction quality, thereby enabling better detection of defects compared with the state of the art.

The invention discloses a computed tomography data correcting method. The method includes the steps that a reference object is scanned, and first detector response corresponding to the first focal position is obtained; the target object is scanned, and second detector response corresponding to the second focal position is obtained; a correction table is inquired, third detector response corresponding to the first focal position and fourth detector response corresponding to the second focal position are determined, and the correction table comprises the corresponding relation between differentfocal positions and detection response; based on the third detector response and the fourth detector response, the first detector response is corrected; imaging data corresponding to the target objectis obtained based on the first detector response and the second detector response obtained after correction. By correcting computed tomography data, image artifacts caused by focal position offset are reduced or eliminated, and imaging quality is improved.

In CT (computed tomography) images, streak artifacts caused by the presence of metal implants and inhomogeneous estimation of tissue density are reduced or eliminated. The algorithm has two basic steps: 1) illumination correction and 2) adaptive 3D filtering. The algorithm starts by estimating the direction of the streak and the degree of inhomogeneous densities by gray scale morphology dilatation. Then, it proceeds to estimate the correct densities based on the estimations and to reduce the streak by an adaptive 3D filtering whose parameters depend on the streak direction and the local image contrast.

A method of and a system for identifying objects using histogram segment 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 method comprises: computing a density histogram for each potential threat object; smoothing the density histogram using a low-pass filter; identifying peaks in the smoothed density histogram; assigning a segment to each peak; computing histogram segment features for each segment; classifying each potential threat object into a threat or a non-threat using computed features.

The invention belongs to a method for quickly detecting the water content of bamboo on the basis of an X-ray CT (computed tomography) technology. The method comprises steps as follows: standard specimens for detecting the water content of to-be-detected bamboo are selected as required; the manufactured specimens are put into dryers containing different saturated salt solutions, the mass of the specimens in different water content gradient states and the mass of the totally dry specimens are weighed according to Testing Methods for Physical and Mechanical Properties of Bamboos GB / T 15780-1995 when the water content of the specimens is stable and does not change, the specimens in different water content states are subjected to CT scanning in the axial direction of moso bamboo by means of the X-ray CT technology, appropriate scanning parameters are selected according to different bamboo species, the number of scanned layers is determined according to the thickness of the scanned layer and the interval between the adjacent layers, a fitting equation is established according to a fitting curve, and the water content of the to-be-detected sample is calculated. The method is environment-friendly and efficient, can be used for detecting the water content of the bamboo conveniently, quickly and intactly and has the advantages of accuracy, environment-friendliness, low cost and simplicity and convenience in operation.

A method for imaging unknown objects in a computed tomography (CT) system, comprising determining ray gain for a known object is provided. A CT reconstruction is performed with the known object to obtain reconstructed values. Ideal values are obtained for pixels of the known object. An error related to a difference between the reconstructed values and the ideal values is generated. A ray gain is estimated that reduces the error.

A method and apparatus are disclosed for high-sensitivity Single-Photon Emission Computed Tomography (SPECT), and Positron Emission Tomography (PET). The apparatus includes a two-dimensional (2D) gamma detector array that moves to different positions in a three-dimensional (3D) volume space near an emission source and records a data vector g. In particular, the 3D volume space in which emission data g is measured extends substantially along a radial direction r pointing away from the emission source and each photon detector element in the 2D gamma detector array is provided with a very large collimator aperture. Data g is related to the 3D spatial density distribution f of the emission source, noise vector n, and a system matrix H of the SPECT / PET apparatus through the linear system of equations g=Hf+n. This equation is solved for f by a method that reduces the effect of noise.

The present application discloses an x-ray detector for use in a computed tomography (CT) imaging system. The x-ray detector assembly comprises an array of detector cells coupled between detector rails. The present invention provides a self regulating heating element having a body that, when current is passed therethrough, radiates heat until a specific reference temperature is reached, at which point the resistance of the PTC heater increases, thus reducing the current through the PTC heater, and, as a result, the radiative heating of the PTC heater.

An exemplary system, method, and computer-accessible medium for generating computed tomography (“CT”) image(s) of a subject(s) can be provided which can include receiving low dose CT imaging information for the subject(s), where the low dose CT imaging information can be based on a radiation dose of less than about 50 mAs, receiving a priori CT image data, and generating the CT image(s) based on the low dose CT imaging information and the a priori CT image data. A further CT images(s) can be generated based on the CT image(s) and the a priori CT image data. The a priori CT image data can include a set of Markov Random Field (MRF) coefficients derived from high dose or full dose CT image data.

Disclosed is a method of testing the effectiveness of perforations and well treatments to enhance production, wherein tomographic image data is collected while fluid flow tests are conducted on a formation sample and thereafter three dimensional images are created and analyzed.

A method and apparatus for automated reconstruction of a 3D computed tomography (CT) volume from a small number of X-ray images is disclosed. A sparse 3D volume is generated from a small number of x-ray images using a tomographic reconstruction algorithm. A final reconstructed 3D CT volume is generated from the sparse 3D volume using a trained deep neural network. A 3D segmentation mask can also be generated from the sparse 3D volume using the trained deep neural network.

A method for artifact correction in computed tomography, the method including: (1) acquiring a plurality of data sets associated with at least one low X-ray energy, and at least one high X-ray energy; (2) generating a plurality of preliminary images from the plurality of data sets; (3) identifying sources of an artifact source image; (4) forward projecting the artifact source image to produce artifact source data; (5) selecting and combining the plurality of data sets acquired in order to produce a new subset of data associated with the artifact, whereby to produce artifact reduced data; (6) generating a repaired data set to keep data sets associated with the low X-ray energy in artifact-free data and to introduce data sets associated with the high X-ray energy in regions impacted by an artifact; and (7) generating a final reduced artifact image from the repaired data set.

Systems and methods for obtaining scattering images during computed tomography (CT) imaging are provided. Two gratings or grating layers can be disposed between the object to be imaged and the detector, and the gratings or grating layers can be arranged such that primary X-rays are blocked while scattered X-rays that are deflected as they pass through the object to be imaged reach the detector to generate the scattering image.

The invention provides a PET time resolution measuring, calculating and reconstructing system and method, and belongs to the technical field of X-ray computed tomography imaging. The method comprise PET original coincidence data acquisition, radiation source space distribution acquisition, coincidence event accumulation, LOR line tracking accumulation, feature width calculation, iterative updatingand reconstruction. According to the method, spatial intensity calculation is carried out on the reconstructed image while counting statistics is carried out, and the accurate time resolution on eachLOR is accurately calculated through the similarity between the spatial intensity and the spatial intensity. According to the invention, for any gamma light source, the time resolution of the crystalcan be accurately tested; and when the time resolution difference of a PET detector is very large, accurate imaging can also be realized. Compared with a traditional method, the method not only can calculate the resolution to obtain each crystal, but also has no requirement for the form of the radiation source, and can perform real-time measurement.

There is provided a radiographic three-dimensional phantom for inter alia mimicking specific anatomical parts in a computerized tomography scan. Methods are provided for a variety of purposes including detecting a difference between a measured optical deformation of a radiographic three-dimensional phantom pair and a theoretical deformation of the radiographic three-dimensional phantom pair. These three-dimensional phantom can be divided into a plurality of portions, and non-radiopaque markers can be added to the portions. The portions of the three-dimensional phantom can be re-assembled, and images of the three-dimensional phantom can be generated and compared.

The present invention is directed to a system and method for dual-energy (DE) or multiple-energy (spectral) cone-beam computed tomography (CBCT) using a configuration of multiple x-ray sources and a single detector. The x-ray sources are operated to produce x-ray spectra of different energies (peak kilovoltage (kVp) and / or filtration). Volumetric 3D image reconstruction and dual or triple energy 3D image decomposition can be executed using data from the CBCT scan. The invention allows for a variety of selections in energy and filtration associated with each source and the order of pulsing for each source (“firing pattern”). The motivation for distributing the sources along the z direction in CBCT includes extension of the longitudinal field of view and reduction of cone-beam artifacts.

Described are anatomically specified conformation computed tomography (ASC-CT) systems, which are fully tomographic x-ray imaging systems configured to conform to the contour of the anatomy of interest and perform a near scatter-free image acquisition, thereby providing an enhanced contrast resolution in the reconstructed CT image volume. The apparatus comprises independently controlled, yet synchronized, x-ray generation and detection assemblies configured to perform a tomographic image acquisition. The method of image acquisition entails adjusting the layout of the x-ray panels within the detector assembly based on the shape of the anatomy, followed by capturing a collimated, narrow x-ray beam composed of primary photons while sweeping a circular trajectory around the anatomy placed in the field of view, resulting in a conforming sinogram of the anatomy.