Abstract: An X-ray imaging system, such as a computed tomography (CT) computed tomography (CT) imaging system is provided for material decomposition calibration and intended for use with a calibration phantom. The X-ray imaging system comprises an X-ray source configured to emit X-rays and an X-ray detector arranged in the X-ray beam path configured to generate detector data. The calibration phantom is located in the X-ray beam path. The X-ray imaging system further comprises an X-ray beam limiting device including at least one calibration element in the X-ray beam path. The X-ray imaging system also comprises image processing circuitry configured to acquire projection data for a set of projections based on the detector data, and to determine pathlengths through at least one material of the at least one calibration element and at least one material of the calibration phantom, at least partly based on acquired projection data, for performing material decomposition calibration.

Abstract: An X-ray imaging system, such as a computed tomography (CT) computed tomography (CT) imaging system is provided for material decomposition calibration and intended for use with a calibration phantom. The X-ray imaging system comprises an X-ray source configured to emit X-rays and an X-ray detector arranged in the X-ray beam path configured to generate detector data. The calibration phantom is located in the X-ray beam path. The X-ray imaging system further comprises an X-ray beam limiting device including at least one calibration element in the X-ray beam path. The X-ray imaging system also comprises image processing circuitry configured to acquire projection data for a set of projections based on the detector data, and to determine pathlengths through at least one material of the at least one calibration element and at least one material of the calibration phantom, at least partly based on acquired projection data, for performing material decomposition calibration.

Abstract: Disclosed is a method and corresponding system for correcting the pileup effect in energy-discriminating photon-counting detectors. According to a first aspect, there is provided a method for pileup correction in a non-paralyzable energy-discriminating photon-counting x-ray detector operating based on a number of energy bins. The method includes adding, for each of a number of energy bins, a correction term to the detected signal of the energy bin, the correction term being a product of two separable parameterized functions, each of which includes at least one parameter, where a first parameterized function depends on a weighted sum of the detected signal over the energy bins, and where a second parameterized function depends on the detected signal(s) in one or several energy bin(s). By assuming separability and ignoring any cross correlations, the number of parameters and the complexity of the pileup correction algorithm are reduced substantially.

Abstract: Disclosed is a method and corresponding system for correcting the pileup effect in energy-discriminating photon-counting detectors. According to a first aspect, there is provided a method for pileup correction in a non-paralyzable energy-discriminating photon-counting x-ray detector operating based on a number of energy bins. The method includes adding, for each of a number of energy bins, a correction term to the detected signal of the energy bin, the correction term being a product of two separable parameterized functions, each of which includes at least one parameter, where a first parameterized function depends on a weighted sum of the detected signal over the energy bins, and where a second parameterized function depends on the detected signal(s) in one or several energy bin(s). By assuming separability and ignoring any cross correlations, the number of parameters and the complexity of the pileup correction algorithm are reduced substantially.

Abstract: There is provided an arrangement including an x-ray detector arranged in conjunction with in-line x-ray focusing optics configured for manipulation of x-rays in medical transmission radiography, wherein the in-line x-ray optics includes an array of lenses, in which the lenses cover parts of, or the entire, field of view, and in which the x-ray detector is a photon-counting detector. Furthermore, the x-ray detector is an energy-resolving detector and chromatic aberration of the lens array and/or limited coherence of the source is compensated for by the energy resolution of the energy-resolving detector, and/or the x-ray detector is a depth-resolving detector and chromatic aberration of the lens array and/or limited coherence of the source is compensated for by depth resolution or volumetric resolution in the detector.

Abstract: There is provided an arrangement including an x-ray detector arranged in conjunction with in-line x-ray focusing optics configured for manipulation of x-rays in medical transmission radiography, wherein the in-line x-ray optics includes an array of lenses, in which the lenses cover parts of, or the entire, field of view, and in which the x-ray detector is a photon-counting detector. Furthermore, the x-ray detector is an energy-resolving detector and chromatic aberration of the lens array and/or limited coherence of the source is compensated for by the energy resolution of the energy-resolving detector, and/or the x-ray detector is a depth-resolving detector and chromatic aberration of the lens array and/or limited coherence of the source is compensated for by depth resolution or volumetric resolution in the detector.

Abstract: An x-ray imaging system includes an x-ray source, an x-ray detector including a plurality of detector strips arranged in a first direction of the x-ray detector. Each detector strip includes a plurality of detector pixels arranged in a second direction of the x-ray detector. A phase grating and a plurality of analyzer gratings including grating slits are disposed between the x-ray source and detectors. The x-ray source and the x-ray detector are adapted to perform a scanning movement in relation to an object in the first direction, in order to scan the object. Each of the plurality of analyzer gratings is arranged in association with a respective detector strip with the grating slits arranged in the second direction. The grating slits of the analyzer gratings of the detector strips are offset relative to each other in the second direction.

Abstract: An x-ray imaging system includes an x-ray source, an x-ray detector including a plurality of detector strips arranged in a first direction of the x-ray detector. Each detector strip includes a plurality of detector pixels arranged in a second direction of the x-ray detector. A phase grating and a plurality of analyzer gratings including grating slits are disposed between the x-ray source and detectors. The x-ray source and the x-ray detector are adapted to perform a scanning movement in relation to an object in the first direction, in order to scan the object. Each of the plurality of analyzer gratings is arranged in association with a respective detector strip with the grating slits arranged in the second direction. The grating slits of the analyzer gratings of the detector strips are offset relative to each other in the second direction.

Abstract: An x-ray imaging system includes an x-ray source, an x-ray detector including a plurality of detector strips arranged in a first direction of the x-ray detector. Each detector strip includes a plurality of detector pixels arranged in a second direction of the x-ray detector. A phase grating and a plurality of analyzer gratings including grating slits are disposed between the x-ray source and detectors. The x-ray source and the x-ray detector are adapted to perform a scanning movement in relation to an object in the first direction, in order to scan the object. Each of the plurality of analyzer gratings (162) is arranged in association with a respective detector strip with the grating slits arranged in the second direction. The grating slits of the analyzer gratings of the detector strips are offset relative to each other in the second direction.

Abstract: An x-ray imaging system comprising an x-ray source, an x-ray detector comprising a plurality of detector strips arranged in a first direction of the x-ray detector, each detector strip further comprising a plurality of detector pixels arranged in a second direction of the x-ray detector; a phase grating; a plurality of analyzer gratings comprising grating slits; a phase grating, and a plurality of analyzer gratings comprising grating slits, wherein the x-ray source and the x-ray detector are adapted to perform a scanning movement in relation to an object in the first direction, in order to scan the object, wherein the analyzer gratings are arranged between the x-ray source and the x-ray detector, wherein each of the plurality of analyzer gratings (162) is arranged in association with a respective detector strip with the grating slits arranged in the second direction and wherein the grating slits of the analyzer gratings of the detector strips are displaced relative to each other in the second direction.

Abstract: An x-ray system for narrow bandwidth imaging of in particular small objects is provided. X-radiation from an x-ray source (1) is focused by chromatic x-ray optics (2) on an x-ray energy dependent distance from the optics. Asymmetric focusing of the x-ray optics is compensated for by choosing an asymmetric focal spot of the source. The energy selective focusing makes possible blocking unwanted x-ray energies (3) from reaching an object (4). In that way optimization of the energy according to the size of the object can be done to minimize dose and maximize signal-to-noise ratio (7). Furthermore, a critical edge subtraction image can be obtained at the object dependent optimal energy if the object is injected with a contrast agent having an absorption edge close to the optimal energy (8). Radiation is registered (5) and processed (6) to combine structural and energy subtraction images.