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 system and method for scanning objects using a non-translational x-ray diffraction (XRD) system is disclosed. The system includes a scanning area through which an object to be scanned traverses and a distributed x-ray source having a plurality of focal spot locations. The distributed x-ray source is affixed on the scanning area and is configured to emit x-rays towards the object as a series of parallel x-ray beams. A stationary detector arrangement is affixed on another side of the scanning area generally opposite the distributed x-ray source and is configured to measure a coherent scatter spectra of the x-rays after passing through the object. A data acquisition system (DAS) is connected to the detector arrangement and is configured to measure the coherent scatter spectra, which is utilized to generate XRD data and determine a material composition of at least a portion of the object from the XRD data.

Abstract: A system and method for scanning objects using a non-translational x-ray diffraction (XRD) system is disclosed. The system includes a scanning area through which an object to be scanned traverses and a distributed x-ray source having a plurality of focal spot locations. The distributed x-ray source is affixed on the scanning area and is configured to emit x-rays towards the object as a series of parallel x-ray beams. A stationary detector arrangement is affixed on another side of the scanning area generally opposite the distributed x-ray source and is configured to measure a coherent scatter spectra of the x-rays after passing through the object. A data acquisition system (DAS) is connected to the detector arrangement and is configured to measure the coherent scatter spectra, which is utilized to generate XRD data and determine a material composition of at least a portion of the object from the XRD data.

Abstract: A method and apparatus for reducing artifacts in image data generated by a computed tomography system is provided. The artifacts are due to the presence of a high density object in a subject of interest. CT data is acquired at a number of differing tilt angles. The data is then combined and reconstructed to generate an improved composite image substantially free of artifacts caused by the high density object.

Abstract: A CT imaging system includes a rotatable gantry having an opening to receive an object to be scanned. A plurality of x-ray emission sources are attached to the rotatable gantry, each x-ray emission source configured to emit x-rays in a conebeam toward the object. The CT imaging system also includes a plurality of x-ray detector arrays attached to the gantry and positioned to receive x-rays passing through the object. At least one x-ray detector array of the plurality of x-ray detector arrays is configured to receive x-rays from more than one x-ray emission source.

Abstract: A system and method for increasing apparent axial sampling resolution include acquiring CT data from scans which are offset due to a scan subject motion. Thus, in certain embodiments, a first scan or gantry rotation may be performed, followed by a subject shift. A second scan or gantry rotation may then be performed to acquire overlapping data which is offset from the data of the first scan. The system and method may also be incorporated in helical scanning techniques. By increasing the number of axial samples, some embodiments provide for reduced aliasing artifacts and improved x-ray interlacing.

Abstract: A method and apparatus for reducing artifacts in image data generated by a computed tomography system is provided. The artifacts are due to the presence of a high density object in a subject of interest. CT data is acquired at a number of differing tilt angles. The data is then combined and reconstructed to generate an improved composite image substantially free of artifacts caused by the high density object.

Abstract: A CT imaging system includes a rotatable gantry having an opening to receive an object to be scanned having a small field-of-view (FOV) inside a large FOV. A plurality of area sources is attached to the rotatable gantry, each area source includes a plurality of x-ray emission sources, wherein the plurality of area sources are configured to emit x-rays toward the object. A plurality of x-ray detector arrays is attached to the gantry and positioned such that at least a first detector array and a second detector array each receive x-rays that pass through at least the entire small FOV of the object.

Abstract: A CT imaging system includes a rotatable gantry having an opening to receive an object to be scanned having a small field-of-view (FOV) inside a large FOV. A plurality of area sources is attached to the rotatable gantry, each area source includes a plurality of x-ray emission sources, wherein the plurality of area sources are configured to emit x-rays toward the object. A plurality of x-ray detector arrays is attached to the gantry and positioned such that at least a first detector array and a second detector array each receive x-rays that pass through at least the entire small FOV of the object.

Abstract: A CT imaging system includes a rotatable gantry having an opening to receive an object to be scanned. A plurality of x-ray emission sources are attached to the rotatable gantry, each x-ray emission source configured to emit x-rays in a conebeam toward the object. The CT imaging system also includes a plurality of x-ray detector arrays attached to the gantry and positioned to receive x-rays passing through the object. At least one x-ray detector array of the plurality of x-ray detector arrays is configured to receive x-rays from more than one x-ray emission source.

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 combined 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: An adaptive CT data acquisition system and technique is presented whereby radiation emitted for CT data acquisition is dynamically controlled to limit exposure to those detectors of a CT detector assembly that may be particularly susceptible to saturation during a given data acquisition. The data acquisition technique recognizes that for a given subject size and position that pre-subject filtering and collimating of a radiation beam may be insufficient to completely prevent detector saturation. Therefore, the present invention includes implementation of a number of CT data correction techniques for correcting otherwise unusable data of a saturated CT detector. These data correction techniques include a nearest neighbor correction, off-centered phantom correction, off-centered synthetic data correction, scout data correction, planar radiogram correction, and a number of others.

Abstract: An adaptive CT data acquisition system and technique is presented whereby radiation emitted for CT data acquisition is dynamically controlled to limit exposure to those detectors of a CT detector assembly that may be particularly susceptible to saturation during a given data acquisition. The data acquisition technique recognizes that for a given subject size and position that pre-subject filtering and collimating of a radiation beam may be insufficient to completely prevent detector saturation. Therefore, the present invention includes implementation of a number of CT data correction techniques for correcting otherwise unusable data of a saturated CT detector. These data correction techniques include a nearest neighbor correction, off-centered phantom correction, off-centered synthetic data correction, scout data correction, planar radiogram correction, and a number of others.