Abstract: Various systems and methods are provided for processing computed tomography (CT) data in a CT imaging system. The CT imaging system comprising an X-ray source configured to emit X-rays, an X-ray detector configured to generate sampled digital detector data and a digital processor configured to process the sampled digital detector data. The method comprises filtering, in the digital processor, the sampled digital detector data to generate filtered detector data and resampling, in the digital processor, the filtered detector data to generate resampled detector data. The resampling comprises a reduction in data size of the filtered detector data. The filtering is performed on at least part of the sampled digital detector data according to a filtering setting and the resampling is performed on at least part of the filtered digital detector data according to a resampling setting, wherein the filtering setting and resampling setting are decoupled.

Abstract: A method of x-ray fluoroscopy images a region of interest at distinct first and second imaging projection angles using digital subtraction x-ray fluoroscopic imaging with a fiducial marker board positioned in a field of view containing the region of interest to produce first and second sets of images. Image segmentation information is determined to identify an anatomical feature in the region of interest imaged in the first set of images and the second set of images. The region of interest is then imaged using x-ray fluoroscopic imaging, again with the fiducial marker board positioned in a third field of view containing the region of interest, but without digital subtraction, to produce a third set of images. A virtual image of the anatomical feature is projected onto the third set of images, computed from the image segmentation information and from a predetermined geometric relationship of markers within the fiducial marker board.

Abstract: Methods and systems are provided for downsampling detector data in a computed tomography imaging system. In an example, a method for a photon counting computed tomography (PCCT) system includes, during a scan of an imaging subject, obtaining detector data from a photon counting detector of the PCCT system, the detector data comprising, for each pixel or detector element of the photon counting detector, photon counts partitioned into a plurality of energy bins based on an energy imparted by each photon on the photon counting detector, applying a bin factor to the plurality of energy bins for each pixel to downsample the plurality of energy bins into a reduced number of energy bins, and reconstructing one or more images from the reduced number of energy bins.

Abstract: An x-ray apparatus includes an x-ray source capable of producing an x-ray beam with a focal spot having a spatial shape that is selected to pre-amplify predetermined spatial frequencies exceeding half a cutoff frequency as compared to spatial frequencies below half the cutoff frequency; an x-ray detector capable of detecting the x-ray beam; and a processor adapted to reconstruct an image from the detected x-ray beam using a filter that compensates the pre-amplified predetermined spatial frequencies. The spatial shape comprises two or more disconnected regions that preferably have widths less than that of a nominal focal spot, combined widths greater than or equal to that of a nominal focal spot, and are separated by less than three times a width of a nominal focal spot.

Abstract: A method of x-ray fluoroscopy images a region of interest at distinct first and second imaging projection angles using digital subtraction x-ray fluoroscopic imaging with a fiducial marker board positioned in a field of view containing the region of interest to produce first and second sets of images. Image segmentation information is determined to identify an anatomical feature in the region of interest imaged in the first set of images and the second set of images. The region of interest is then imaged using x-ray fluoroscopic imaging, again with the fiducial marker board positioned in a third field of view containing the region of interest, but without digital subtraction, to produce a third set of images. A virtual image of the anatomical feature is projected onto the third set of images, computed from the image segmentation information and from a predetermined geometric relationship of markers within the fiducial marker board.

Abstract: An x-ray apparatus includes an x-ray source capable of producing an x-ray beam with a focal spot having a spatial shape that is selected to pre-amplify predetermined spatial frequencies exceeding half a cutoff frequency as compared to spatial frequencies below half the cutoff frequency; an x-ray detector capable of detecting the x-ray beam; and a processor adapted to reconstruct an image from the detected x-ray beam using a filter that compensates the pre-amplified predetermined spatial frequencies. The spatial shape comprises two or more disconnected regions that preferably have widths less than that of a nominal focal spot, combined widths greater than or equal to that of a nominal focal spot, and are separated by less than three times a width of a nominal focal spot.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of attenuation elements is provided between the source and object. An actuator is connected to the attenuation elements for moving the attenuation elements. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of attenuation elements. A gantry rotates the x-ray source, the plurality of attenuation elements, and the x-ray detector around an axis of rotation.

Abstract: Spectral x-ray imaging using a photon counting x-ray detector (PCXD) transmits a broad spectrum x-ray beam through an object, detects the transmitted x-ray beam with the PCXD and processes the detected signals to determine material characteristics of the object using both the detected signals as a function of detector layer and the detected signals as a function of the particular energy band. Each detector layer of the multiple detector layers produces at least two signals, each signal representing a detected x-ray intensity in a particular energy band, and the depth information contained in the separate read-out channels.

Abstract: An apparatus for x-ray imaging of an object is provided. An x-ray source for providing alternating x-ray spectrums is placed on a first side of the object. A spectrum separation fixed filter is placed between the x-ray source and the object. An x-ray detector is placed on a second side of the object opposite the x-ray source. A controller controls the x-ray source and the x-ray detector.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation. A detection system measures the relative position of the plurality of wedges. The detection system comprises an optical sensor and a plurality of optical markers, where each wedge has at least one optical marker attached.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section with a length and thickness. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation.

Abstract: A method for performing truncation artifact correction includes acquiring a projection dataset of a patient, the projection dataset including measured data and truncated data, generating an initial estimate of a boundary between the measured data and the truncated data, using the measured data to revise the initial estimate of the boundary, estimating the truncated data using the revised estimate of the boundary, and using the measured data and the estimated truncated data to generate an image of the patient.

Abstract: Spectral x-ray imaging using a photon counting x-ray detector (PCXD) transmits a broad spectrum x-ray beam through an object, detects the transmitted x-ray beam with the PCXD and processes the detected signals to determine material characteristics of the object using both the detected signals as a function of detector layer and the detected signals as a function of the particular energy band. Each detector layer of the multiple detector layers produces at least two signals, each signal representing a detected x-ray intensity in a particular energy band, and the depth information contained in the separate read-out channels.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of attenuation elements is provided between the source and object. An actuator is connected to the attenuation elements for moving the attenuation elements. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of attenuation elements. A gantry rotates the x-ray source, the plurality of attenuation elements, and the x-ray detector around an axis of rotation.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation. A detection system measures the relative position of the plurality of wedges. The detection system comprises an optical sensor and a plurality of optical markers, where each wedge has at least one optical marker attached.

Abstract: A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section with a length and thickness. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation.

Abstract: A method for performing truncation artifact correction includes acquiring a projection dataset of a patient, the projection dataset including measured data and truncated data, generating an initial estimate of a boundary between the measured data and the truncated data, using the measured data to revise the initial estimate of the boundary, estimating the truncated data using the revised estimate of the boundary, and using the measured data and the estimated truncated data to generate an image of the patient.

Abstract: An apparatus for x-ray imaging of an object is provided. An x-ray source for providing alternating x-ray spectrums is placed on a first side of the object. A spectrum separation fixed filter is placed between the x-ray source and the object. An x-ray detector is placed on a second side of the object opposite the x-ray source. A controller controls the x-ray source and the x-ray detector.

Abstract: The present invention provides a radiotherapy treatment apparatus that includes a treatment beam, a magnetic field disposed parallel collinear to the treatment beam, and a target that is disposed along the treatment beam. The treatment beam can be a charged particle beam, a proton beam, an electron beam, or a linear accelerator (Linac) beam. The magnetic field is from a magnetic resonance imager (MRI), a megavolt x-ray imager, or a kilovolt x-ray imager and is disposed to operate in coordination with operation of the treatment beam and to narrow the beam. The tumor is disposed to rotate with respect to the treatment beam and the magnetic field, or the treatment beam and the magnetic field are disposed to rotate up to 360° with respect to the target when mounted to a ring gantry. The apparatus can include a rotation angle dependent shim disposed to account for Earth's magnetic field.

Abstract: A method for determining a composition of an object using a spectral x-ray system is provided. X-ray photons of at least two different energies are transmitted through the object. The energy of each detected x-ray photon using a detector in the x-ray system is estimated. A first weighted sum of the number of detected photons of each energy is found using a first weighting function, wherein the first weighting function is dependent on the attenuation coefficient function of a first material. In another embodiment, the photons are binned into two energy bins wherein there is a gap between the energy bins.