Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Algorithms are disclosed that recombine acquired data so as to generate a substantially uniform and complete set of frequency data where frequency data might otherwise be incomplete. This process, or its equivalent, may be accomplished in a computationally efficient manner using filtering steps in one or both of the reconstruction space and/or the post-processing space.

Abstract: Approaches are described for generating an initial reconstruction of CT data acquired using a wide-cone system. The initial reconstruction may be processed (such as via a non-linear operation) to correct frequency omissions and/or errors in the reconstruction. Corrected frequency information may then be added to the reconstruction to improve the reconstructed image.

Abstract: A system and method for CT sinogram extrapolation are provided. The method comprises receiving a CT projection for extrapolation. The method also comprises selecting a target patch comprising at least one pixel of a row to be extrapolated. The method further comprises generating a correlation profile between the target patch and one or more source patches, wherein the source patches comprise measured pixels in the CT projection in one or more rows adjacent to the target patch. The projection data is generated for at least one pixel of the target patch based on the correlation profile and the measured pixels of at least one of the source patches.

Abstract: 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.

Abstract: Algorithms are disclosed that recombine acquired data so as to generate a substantially uniform and complete set of frequency data where frequency data might otherwise be incomplete. This process, or its equivalent, may be accomplished in a computationally efficient manner using filtering steps in one or both of the reconstruction space and/or the post-processing space.

Abstract: Approaches are described for generating an initial reconstruction of CT data acquired using a wide-cone system. The initial reconstruction may be processed (such as via a non-linear operation) to correct frequency omissions and/or errors in the reconstruction. Corrected frequency information may then be added to the reconstruction to improve the reconstructed image.

Abstract: A method of performing a computed tomographic image reconstruction is provided. The method provides for performing a short scan of an imaging object to acquire a short scan data, performing a plurality of image reconstructions based on the short scan data wherein the plurality of image reconstructions result in a corresponding plurality of image volumes wherein the image reconstructions use different view weighting functions, filtering the plurality of image volumes such that when the volumes are added together, the frequency domain data is substantially uniformly weighted. Further, the method provides for combining the plurality of image volumes together to produce a final image volume.

Abstract: A method for analytically reconstructing a multi-axial computed tomography (CT) dataset, acquired using one or more longitudinally-offset x-ray beams emitted from multiple x-ray sources is provided. The method comprises acquiring one or more CT axial projection datasets, wherein the CT axial projection datasets are acquired using less than a full scan of data. The method further comprises reconstructing the CT axial projection datasets to generate a reconstructed image volume. The reconstruction comprises back projecting one or more voxels comprising the multi-axial CT dataset, along one or more projection views, based upon a cone-angle weight determined for the voxels, wherein the cone-angle weight for the voxels is determined along a longitudinal direction.

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: Systems and methods are provided for acquiring and reconstructing projection data that is mathematically complete or sufficient using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a distributed source is provided as arcuate segments offset in the X-Y plane and along the Z-axis.

Abstract: Disclosed are embodiments of methods for reconstructing x-ray projection data (e.g., one or more sinograms) acquired using a multi-source, inverse-geometry computed tomography (“IGCT”) scanner. One embodiment of a first method processes an IGCT sinogram by rebinning first in “z” and then in “xy,” with feathering applied during the “xy” rebinning. This produces an equivalent of a multi-axial 3rd generation sinogram, which may be further processed using a parallel derivative and/or Hilbert transform. A TOM-window (with feathering) technique and a combines backprojection technique may also be applied to produce a reconstructed volume. An embodiment of a second method processes an IGCT sinogram using a parallel derivative and/or redundancy weighting. The second method may also use signum weighting, TOM-windowing (with feathering), backprojection, and a Hilbert Inversion to produce another reconstructed volume.

Abstract: A method of performing a computed tomographic image reconstruction is provided. The method provides for performing a short scan of an imaging object to acquire a short scan data, performing a plurality of image reconstructions based on the short scan data wherein the plurality of image reconstructions result in a corresponding plurality of image volumes wherein the image reconstructions use different view weighting functions, filtering the plurality of image volumes such that when the volumes are added together, the frequency domain data is substantially uniformly weighted. Further, the method provides for combining the plurality of image volumes together to produce a final image volume.

Abstract: Systems and methods are provided for acquiring and reconstructing projection data using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a non-sequential activation of X-ray source locations on an annular source is employed to acquire projection data. In another embodiment, a distributed source is tilted relative to an axis of the scanner to acquire the projection data. In a further embodiment, a plurality of X-ray source locations on an annular source are activated such that the aggregated signals correspond to two or more sets of spatially interleaved helical scan data.

Abstract: Systems and methods are provided for acquiring and reconstructing projection data that is mathematically complete or sufficient using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a non-sequential activation is employed to acquire mathematically complete or sufficient projection data. In another embodiment, a distributed source is provided as a generally semicircular segment. In such an embodiment, an alternating activation scheme may be employed to allow one or more helices of image data to be acquired.

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.