Patent application number | Description | Published |
20080304726 | METHODS AND SYSTEMS FOR IMPROVING SPATIAL AND TEMPORAL RESOLUTION OF COMPUTED IMAGES OF MOVING OBJECTS - A method of improving a resolution of an image using image reconstruction is provided. The method includes acquiring scan data of an object and forward projecting a current image estimate of the scan data to generate calculated projection data. The method also includes applying a data-fit term and a regularization term to the scan data and the calculated projection data and modifying at least one of the data fit term and the regularization term to accommodate spatio-temporal information to form a reconstructed image from the scan data and the calculated projection data. | 12-11-2008 |
20090161816 | METHOD AND SYSTEM FOR X-RAY IMAGING - A technique is provided for imaging a field of view using an X-ray source comprising two or more emission points. The two or more emission points may be independently operated. Independent operation of the two or more emission points in performed in accordance with a list of commands that specifies the operation of the emission points. The list of commands, in one embodiment, is stored in a sequence buffer. In other embodiments, the list of commands is generated for a given usage, without being stored in a sequence buffer. | 06-25-2009 |
20100054561 | SYSTEM AND METHOD FOR IMAGE RECONSTRUCTION - A tomographic imaging apparatus is provided for generating images. The tomographic apparatus includes a computer programmed to access a data sinogram representative of the image, reconstruct the image, divide the image into a plurality of sub-regions, define a region of interest including at least one sub-region, reprojecting a region of interest or a complement of the region of interest to generate a region of interest sinogram or a sinogram representative of the complement of the region of interest and reconstructing a resultant sinogram using iterative methods to generate an image. | 03-04-2010 |
20110097007 | Iterative Reconstruction - An improved iterative reconstruction method to reconstruct a first image includes generating an imaging beam, receiving said imaging beam on a detector array, generating projection data based on said imaging beams received by said detector array, providing said projection data to an image reconstructor, enlarging one of a plurality of voxels and a plurality of detectors of the provided projection data, reconstructing portions of the first image with the plurality of enlarged voxels or detectors, and iteratively reconstructing the portions of the first image to create a reconstructed image. | 04-28-2011 |
20110142314 | SYSTEM AND METHOD OF INCREASING TEMPORAL RESOLUTION OF AN X-RAY IMAGE - A system, method, and apparatus includes a computed tomography (CT) system having a rotatable gantry, an x-ray source, a generator, a detector having pixels and positioned to receive x-rays, and a computer. The computer is programmed to acquire CT data representative of an object, determine a first subset of the CT data, determine a second subset of the CT data, and determine a difference between the first and second subsets of the CT data to identify a motion region in the object. The computer is also programmed to update image data reconstructed from a first portion of the first subset of the CT data and corresponding to the region and reconstruct an image based on the updated image data and non-updated image data. The non-updated image data is reconstructed from a second portion the first subset of the CT data. | 06-16-2011 |
20110150308 | SYSTEM AND METHOD OF ITERATIVE IMAGE RECONSTRUCTION FOR COMPUTED TOMOGRAPHY - A system and method include acquisition of a set of image data corresponding to a time period of data acquisition, the set of image data corresponding to a plurality of voxels, wherein each of the plurality of voxels corresponds to a distinct acquisition time within the time period of data acquisition. The system and method further include the modeling of the plurality of voxels as a function of time based on a plurality of kinetic parameters associated therewith and reconstruction of an image from the set of image data based on the modeled plurality of voxels. | 06-23-2011 |
20110211667 | DE-POPULATED DETECTOR FOR COMPUTED TOMOGRAPHY AND METHOD OF MAKING SAME - A system, method, and apparatus includes a computed tomography (CT) detector array having a central region with a plurality of central region detecting cells configured to acquire CT data of a first number of slices during a scan, a first wing along a first side of the central region, and a second wing along a second side of the central region opposite the first side. The first wing includes a plurality of first wing detecting cells configured to acquire CT data of a second number of slices during the scan. The second wing includes a plurality of second wing detecting cells configured to acquire CT data of a third number of slices during the scan. The second and third number of slices are less than the first number of slices. The first wing detecting cells are of a different type than the central region detecting cells. | 09-01-2011 |
20110243413 | METHOD AND SYSTEM FOR IMAGE DATA ACQUISITION - A technique for acquiring desired image data in an imaging system comprising at least one radiation source and a detector is described. Initially, preliminary image data corresponding to an object may be acquired. Further, at least one parameter associated with the radiation source and corresponding to a particular view angle of the radiation source may be determined based on the preliminary image data and a priori information. Similarly, at least one parameter associated with the detector and corresponding to the particular view angle may be determined based on a priori information and the preliminary image data. Efficient operating modes of the radiation source and the detector corresponding to the particular view angle may be selected based on the determined parameters to achieve a desired system performance. Subsequently, the final image data may be acquired using the selected operating modes of the radiation source and the detector. | 10-06-2011 |
20120014502 | ASYMMETRIC DE-POPULATED DETECTOR FOR COMPUTED TOMOGRAPHY AND METHOD OF MAKING SAME - A computed tomography (CT) detector array includes a central region substantially symmetric about a central axis thereof and includes a first plurality of x-ray detector cells configured to acquire CT data from a first number of detector rows during a scan, wherein the central axis is in a channel direction of the CT detector array and transverse to a slice direction of the CT detector array. A first wing is coupled to a first side of the central region, and a second wing is coupled to a second side of the central region opposite the first side. The first and second wings include respective second and third pluralities of x-ray detector cells and are each configured to acquire CT data from a number of detector rows that is less than the first number of detector rows. The CT detector array is asymmetric about the central axis of the central region. | 01-19-2012 |
20120039440 | SYSTEM AND METHOD OF OPTIMIZING A REPRESENTATION OF DUAL ENERGY SPECTRAL CT IMAGES - An imaging system includes an x-ray source, a detector, a data acquisition system (DAS) operably connected to the detector, and a computer operably connected to the DAS. The computer is programmed to obtain CT scan data with two or more incident energy spectra, decompose the obtained CT scan data into projection CT data of a first basis material and a second basis material, generate a first basis material image and a second basis material image using the decomposed projection CT data, generate a first monochromatic image from the first basis material image and the second basis material image at a first energy that is selected based on an amount of correlated noise at the first energy, noise-reduce the first monochromatic image to generate a noise-reduced first monochromatic image, and generate a final monochromatic image based at least on the noise-reduced first monochromatic image. | 02-16-2012 |
20120069953 | SYSTEM AND METHOD OF NOTCH FILTRATION FOR DUAL ENERGY CT - An imaging system includes an x-ray source that emits a beam of x-rays toward an object to be imaged, a detector that receives the x-rays attenuated by the object, a spectral notch filter positioned between the x-ray source and the object, a data acquisition system (DAS) operably connected to the detector, and a computer operably connected to the DAS and programmed to acquire a first image dataset at a first kVp, acquire a second image dataset at a second kVp that is greater than the first kVp, and generate an image of the object using the first image dataset and the second image dataset. | 03-22-2012 |
20120106816 | SYSTEM AND METHOD FOR MATERIAL DECOMPOSITION OPTIMIZATION IN IMAGE DOMAIN - A system and method for material decomposition optimization in the image domain include a non-transitory computer readable medium has stored thereon a sequence of instructions which, when executed by a computer, causes the computer to access a reconstructed basis material image. For a first voxel of the reconstructed basis material image, the instructions also cause the computer to optimize a concentration of a pair of materials (a,b) in the first voxel exclusively in the image domain and based on a first probability based on random perturbations and a second probability based on random perturbations. The optimization is further based on a third probability based on known materials and a fourth probability based on concentrations of the pair of materials in a pair of voxels neighboring the first voxel. | 05-03-2012 |
20120314928 | SYSTEM AND METHOD OF INCREASING TEMPORAL RESOLUTION OF AN X-RAY IMAGE - A system, method, and apparatus includes a computed tomography (CT) system having a rotatable gantry, an x-ray source, a generator, a detector having pixels and positioned to receive x-rays, and a computer. The computer is programmed to acquire CT data representative of an object, determine a first subset of the CT data, determine a second subset of the CT data, and determine a difference between the first and second subsets of the CT data to identify a motion region in the object. The computer is also programmed to update image data reconstructed from a first portion of the first subset of the CT data and corresponding to the region and reconstruct an image based on the updated image data and non-updated image data. The non-updated image data is reconstructed from a second portion the first subset of the CT data. | 12-13-2012 |
20130003912 | SYSTEM AND METHOD OF ACQUIRING COMPUTED TOMOGRAPHY DATA USING A MULTI-ENERGY X-RAY SOURCE - The subject matter disclosed herein relates to X-ray imaging systems, and more specifically, to multi-energy computed tomography (CT) X-ray imaging systems. In an embodiment, a multi-energy computed tomography (CT) imaging system includes an X-ray source that emits X-rays upon the application of a low stable bias, a high stable bias, and transitional biases between the low stable bias and the high stable bias. The imaging system also includes an X-ray detector configured to produce an electrical signal corresponding to the intensity of the X-rays emitted by the X-ray source that reach the X-ray detector. The imaging system also includes data processing circuitry configured to acquire a first set of data corresponding to the electrical signal produced by the X-ray detector only when the low stable bias or the high stable bias is applied to the X-ray source. The imaging system also includes a processor configured to process the first set of acquired data and construct one or more multi-energy CT images. | 01-03-2013 |
20130003914 | METHOD AND SYSTEM FOR REDUCED DOSE X-RAY IMAGING - Approaches for acquiring CT image data corresponding to a full scan, but at a reduced dose are disclosed. In one implementation, X-ray tube current modulation is employed to reduce the effective dose. In other implementations, acquisition of sparse views, z-collimation, and two-rotation acquisition protocols may be employed to achieve a reduced dose relative to a full-scan acquisition protocol. | 01-03-2013 |
20130083986 | METHOD AND SYSTEM FOR RECONSTRUCTION OF TOMOGRAPHIC IMAGES - Approaches are described for processing half-scan or full-scan cone beam image data using one or more half-ramp filtering operations. In one embodiment, the half-ramp filtering operations allow extraction and use of missing frequency data so as to generate a reconstructed image that is relatively complete in terms of frequency data and which has suitable temporal resolution. In addition, in certain embodiments, the reconstructed image may have uniform frequency weighting. | 04-04-2013 |
20130108007 | METHODS AND SYSTEMS FOR CT SINOGRAM EXTRAPOLATION | 05-02-2013 |
20130343672 | METHOD AND APPARATUS FOR ITERATIVE RECONSTRUCTION - A method is provided for reconstructing an image of an object that includes image elements. The method includes accessing measurement data associated with the image elements, introducing an auxiliary variable to transform an original problem of reconstructing the image to a constrained optimization problem, and solving the constrained optimization problem using a method of multipliers to create a sequence of sub-problems and solve the sequence of sub-problems. Solving the sequence of sub-problems includes reconstructing the image by optimizing a first objective function. The first objective function is optimized by iteratively solving a nested sequence of approximate optimization problems. An inner loop iteratively optimizes a second objective function approximating the first objective function. An outer loop utilizes the solution of the second objective function to optimize the first objective function. | 12-26-2013 |
20130343673 | METHOD AND APPARATUS FOR ITERATIVE RECONSTRUCTION - A method is provided for iteratively reconstructing an image of an object. The method includes accessing measurement data associated with the image, and using a simultaneous algorithm to reconstruct the image. Using the simultaneous algorithm to reconstruct the image includes determining a scaling factor that is voxel-dependent, and applying the voxel-dependent scaling factor to a gradient of an objective function to reconstruct the image. | 12-26-2013 |
20140105356 | X-RAY DOSE ESTIMATION TECHNIQUE - Embodiments of the disclosure relate to projection-based dose estimation for X-ray systems, such as X-ray imaging systems. For example, in one embodiment, an X-ray system is capable of estimating an X-ray dose based on an intensity profile of the detected X-rays that have passed through a scanned object and an estimated mass of the object. In one embodiment, the intensity profile may be compared to a baseline scan to acquire an estimate of energy interaction with the object. | 04-17-2014 |
20140133622 | MULTI-SECTOR COMPUTED TOMOGRAPHY IMAGE ACQUISITION - An approach is disclosed for acquiring multi-sector computed tomography scan data. The approach includes activating an X-ray source during heartbeats of a patient to acquire projection data over a limited angular range for each heartbeat. The projection data acquired over the different is combined. An image having good temporal resolution is reconstructed using the combined projection data. | 05-15-2014 |
20140140599 | ORDERED SUBSETS WITH MOMENTUM FOR X-RAY CT IMAGE RECONSTRUCTION - Methods, systems, and non-transitory computer readable media for image reconstruction are presented. Measured data corresponding to a subject is received. A preliminary image update in a particular iteration is determined based on one or more image variables computed using at least a subset of the measured data in the particular iteration. Additionally, at least one momentum term is determined based on the one or more image variables computed in the particular iteration and/or one or more further image variables computed in one or more iterations preceding the particular iteration. Further, a subsequent image update is determined using the preliminary image update and the momentum term. The preliminary image update and/or the subsequent image update are iteratively computed for a plurality of iterations until one or more termination criteria are satisfied. | 05-22-2014 |
20140161340 | ITERATIVE RECONSTRUCTION - An improved iterative reconstruction method to reconstruct a first image includes generating an imaging beam, receiving said imaging beam on a detector array, generating projection data based on said imaging beams received by said detector array, providing said projection data to an image reconstructor, enlarging one of a plurality of voxels and a plurality of detectors of the provided projection data, reconstructing portions of the first image with the plurality of enlarged voxels or detectors, and iteratively reconstructing the portions of the first image to create a reconstructed image. | 06-12-2014 |
20140177794 | SYSTEM AND METHOD FOR FOCAL SPOT DEFLECTION - An X-ray tube and methods for imaging are disclosed. The X-ray tube includes an emitter configured to generate an electron beam. Further, the X-ray tube includes a target configured to generate X-rays in response to the electron beam, where a target surface includes at least a first region having a first elevation and a second region having a second elevation different from the first elevation. The X-ray tube also includes a detector configured to generate projection data based on the X-rays and a computing device coupled to the emitter, the detector and/or the target. The computing device is configured to deflect a focal spot on the target surface by controlling target rotation such that the electron beam impinges alternatively on the first and second regions. The computing device processes the projection data corresponding to the deflected focal spot positions and reconstructs images of a subject using the processed projection data. | 06-26-2014 |
20140185751 | X-RAY DOSE ESTIMATION TECHNIQUE - Embodiments of the disclosure relate to projection-based volumetric dose estimation for X-ray systems, such as X-ray imaging systems. For example, in one embodiment, an X-ray system is capable of estimating an X-ray dose based on an energy interaction of the X-rays with respective portions of an object. In another embodiment, the X-ray dose estimate may be provided on a per voxel, per region, and/or per organ basis. | 07-03-2014 |
20140205171 | METHOD AND SYSTEM FOR CORRECTING ARTIFACTS IN IMAGE RECONSTRUCTION - Methods and systems are provided for correcting artifacts in iterative reconstruction processes. In certain embodiments, weighting schemes may be applied such that less than all of the available scan or projection data is utilized in the iterative reconstruction. In this manner, inconsistencies in the data undergoing reconstruction may be reduced. | 07-24-2014 |
20140369580 | ACCELERATED ITERATIVE RECONSTRUCTION - A framework for an iterative reconstruction algorithm is described which combines two or more of an ordered subset method, a preconditioner method, and a nested loop method. In one type of implementation a nested loop (NL) structure is employed where the inner loop sub-problems are solved using ordered subset (OS) methods. The inner loop may be solved using OS and a preconditioner method. In other implementations, the inner loop problems are created by augmented Lagrangian methods and then solved using OS method. | 12-18-2014 |
20140369581 | ITERATIVE RECONSTRUCTION IN IMAGE FORMATION - The use of the channelized preconditioners in iterative reconstruction is disclosed. In certain embodiments, different channels correspond to different frequency sub-bands and the output of the different channels can be combined to update an image estimate used in the iterative reconstruction process. While individual channels may be relatively simple, the combined channels can represent complex spatial variant operations. The use of channelized preconditioners allows empirical adjustment of individual channels. | 12-18-2014 |