Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for extracting information of a cardiac cycle from projection data is presented. The method provides for acquiring one or more sets of computed tomography (CT) projection data. Further, the method includes analyzing the one or sets of CT projection data to obtain a center of cardiac mass. Also, the method provides for estimating raw motion data representative of the motion of the center of cardiac mass from the one or more sets of CT projection data. In addition, the method includes processing the center of mass through time to extract a motion signal from the raw projection data. Also, the method provides for extracting the periodicity information from the motion signal.

Abstract: 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.

Abstract: A method for reconstructing cone-beam projection data is provided. The method comprises scanning an object in helical mode, wherein the scanning comprises obtaining cone-beam projection data. The method further comprises processing the cone-beam projection data along a plurality of data filtering curves. The processing includes processing the cone-beam projection data along a portion of the data filtering curves that extends outside of a physical detector area to a virtual detector area. Then, the method comprises using the processed cone-beam projection data in the generation of a reconstructed image of the object.

Abstract: A method for reconstructing an image of an object, the image comprising a plurality of image elements, is disclosed. The method includes accessing image data associated with the plurality of image elements, applying a first algorithm to the plurality of image elements, selecting a spatially non-homogenous set of the plurality of image elements, and applying an iterative algorithm to the set of image elements to reduce an amount of time necessary for reconstructing the image, or to improve an image quality at a fixed computation time, or both.

Abstract: A method for reconstructing image data acquired by a computed tomography system is provided. The method comprises selecting a portion of image data to be reconstructed and determining a corresponding portion of projection data. An adaptive filter is computed and applied to the portion of projection data to generate a portion of adaptively-filtered projection data. The adaptive filter is computed based upon desired quality properties of the portion of image data. Finally, the portion of image data is reconstructed based upon the portion of adaptively-filtered projection data. The step of selecting, computing and reconstructing is repeated for every pixel or group of pixels comprising the image data.

Abstract: A method for acquiring an image data set comprising energy integrating (EI) and energy discriminating (ED) data measurements is provided. The method comprises obtaining EI measurement data and ED measurement data during an acquisition cycle. The method then comprises combining the EI measurement data and the ED measurement data before, during or after reconstruction. Finally the method comprises performing reconstruction on the original or combined datasets to obtain one or more of an EI image and one or more ED component images.

Abstract: Various configurations for scatter reduction and control are provided for CT imaging. These configurations include an imaging system having a stationary detector extending generally around a portion of an imaging volume and a distributed X-ray source placed proximal to the stationary detector for radiating an X-ray beam toward the stationary detector. A scatter control system is further provided that is configured to adaptively operate in cooperation with the stationary detector and the distributed X-ray source to focally align collimator septa contained therein to the X-ray beam at a given focal point and to provide X-ray beam scatter control.

Abstract: Configurations for stationary imaging systems are provided. The configurations may include combinations of various types of distributed sources of X-ray radiation, which generally include addressable emitter elements which may be triggered for emission in desired sequences and combinations. The sources may be ring-like, partial ring-like, or line-like (typically along a Z-axis), and so forth. Combinations of these are envisaged. Corresponding detectors may also be full ring detectors or partial ring detectors associated with the sources to provide sufficient coverage of imaging volumes and to provide the desired mathematical completeness of the collected data.

Abstract: A method for Computed Tomography (CT) imaging is provided. The method comprises rotating a gantry at a substantially slow rotation speed about a volume of interest. The gantry comprises a combination of X-ray source points. The X-ray source points comprise one or more discrete emission points and an arc of discrete or continuous X-ray source points. The method then comprises obtaining projection data from the combination of X-ray source points and performing a suitable reconstruction based on the projection data obtained from the combination of X-ray source points, to generate one or more reconstructed images.

Abstract: Methods for three-dimensional projecting and backprojecting rays with respect to voxels/detector bins to attenuate/eliminate high-frequency artifacts, are disclosed. A distance-driven technique wherein the transitions of the voxels and the detector bins are respectively projected onto a predetermined plane. This projection allows a determination of the contribution of each of the voxels/bins for each of the bins/voxels with lower computation time and improved artifact free images.

Abstract: A technique is provided for CT reconstruction for use in CT metrology. The boundary based CT reconstruction method includes the steps of initializing a boundary of an object to obtain a boundary estimate, defining a forward model based on the boundary estimate, linearizing the forward model to obtain a system matrix and implementing an iterative image reconstruction process using the system matrix to update the boundary estimate.

Abstract: A radiological imaging system includes one or more radiation sources substantially surrounding a desired portion of an imaging volume and configured to emanate a radiation beam from a plurality of individual source positions around the imaging volume, and one or more detectors configured to receive the transmitted radiation beam. At least one of the radiation source and the detector are displaceable to allow an unimpeded path for the radiation beam and to receive the transmitted radiation beam more completely.

Abstract: The present invention provides a method for determining a geometry of a scanning volumetric computed tomographic (CT) system having a rotation axis, a rotational plane, an x-ray source and a detector. The method includes scanning a phantom having a series of spatially separated discrete markers with the scanning volumetric computed tomographic system, wherein the markers are configured on a supporting structure of the phantom so as to permit separate identification of each marker in a collection of projection images. The method further includes locating images of the markers in each projection, using the located marker images to assign marker locations to tracks, and using the assigned tracks, determining a relative alignment between the detector, the source, and the rotation axis of the scanning volumetric computed tomographic system.

Abstract: A technique is provided for CT reconstruction for use in CT metrology. The boundary based CT reconstruction method includes the steps of initializing a boundary of an object to obtain a boundary estimate, defining a forward model based on the boundary estimate, linearizing the forward model to obtain a system matrix and implementing an iterative image reconstruction process using the system matrix to update the boundary estimate.

Abstract: Geometries and configurations are provided for CT systems in which rotational loading is reduced, permitting higher speeds and lighter structures to be implemented in the systems. In certain embodiments a distributed and addressable rotating radiation source is provided with a rotating detector. In other embodiments a distributed and addressable stationary radiation source is provided with a rotating detector. In yet other embodiments a distributed and addressable radiation source is provided that rotates with respect to a stationary detector. The sources may be ring-like, arcuate and/or lines extending at least in the Z-direction. Sources may include a large number of distributed emitters arranged in lines, arcs and one- or two-dimensional arrays.

Abstract: A method for imaging an object that includes utilizing a computed tomography imaging apparatus having a distributed x-ray source to acquire samples of projection data of an object in angular and temporal space utilizing a predetermined sampling lattice. Acquired projection data is filtered utilizing a two-dimensional linear filter to produce filtered data, and the filtered data is then backprojected to obtain a reconstructed image of the object.

Abstract: Methods for projecting and backprojecting rays with respect to pixels/detector bins to attenuate/eliminate high-frequency artifacts, are disclosed. The first two methods are adaptations of pixel-driven and ray-driven linear interpolation techniques respectively. In these techniques, the window or shadow of each pixel/bin is dynamically adjusted and projected onto the detector bin/pixel to eliminate gaps between the shadows. This allows the effect of each pixel on a given detector bin (or vice versa) to be appropriately weighted. A third is a distance-driven technique wherein the transitions of the pixels and the detector bins are respectively projected onto a common axis. This allows a determination of the contribution of each of the pixels/bins for each of the bins/pixels with lower computation time and improved artifact free images.