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: The present invention relates to an apparatus for characterization of a feature in a body part. It is describe to provide (210) tomosynthesis medical data comprising a plurality of images of the body part, wherein the plurality of images comprise image data associated with a plurality of rays of radiation that have passed through the body part, wherein the image data comprises spectral data associated with at least two photon energy levels of the plurality of rays of radiation, wherein the medical data comprises data of the feature. A delineated boundary of the feature is determined (220). At least one material composition of the body part inside the delineated boundary is determined (240) comprising a function of the spectral data inside the delineated boundary. The feature is characterised (250) as a function of the at least one material composition inside the delineated boundary of the feature. Data representative of the feature is output (260).

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: The invention proposes to combine spectral image data with non-spectral image data in order to overcome limitations of the different data taking methods. Results from the methods are preferably combined as functions of spatial frequency so that spectral image data provide high accuracy at low frequencies, whereas the non-spectral image data helps reducing the noise at high frequencies. The invention enables a range of applications in different fields of X-ray imaging such as improved tissue contrast and tissue characterization.

Abstract: The invention proposes to combine spectral image data with non-spectral image data in order to overcome limitations of the different data taking methods. Results from the methods are preferably combined as functions of spatial frequency so that spectral image data provide high accuracy at low frequencies, whereas the non-spectral image data helps reducing the noise at high frequencies. The invention enables a range of applications in different fields of X-ray imaging such as improved tissue contrast and tissue characterization.

Abstract: The present invention relates to X-ray imaging technology as well as image post-processing. Particularly, the present invention relates to a method for computer aided detection of structures in X-ray images as well as an X-ray system. A computer aided detection algorithm visibly determines tissue structures in X-ray image information and subsequently matches the shape of a determined tissue structure with a library of known tissue structures for characterizing the type of determined tissue structure. The determination of a tissue structure and thus the characterization of the type of the tissue structure may be enhanced when employing also spectral information, in particular energy information of the acquired X-ray image.

Abstract: The present invention relates to an apparatus for characterization of a feature in a body part. It is describe to provide (210) tomosynthesis medical data comprising a plurality of images of the body part, wherein the plurality of images comprise image data associated with a plurality of rays of radiation that have passed through the body part, wherein the image data comprises spectral data associated with at least two photon energy levels of the plurality of rays of radiation, wherein the medical data comprises data of the feature. A delineated boundary of the feature is determined (220). At least one material composition of the body part inside the delineated boundary is determined (240) comprising a function of the spectral data inside the delineated boundary. The feature is characterised (250) as a function of the at least one material composition inside the delineated boundary of the feature. Data representative of the feature is output (260).

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: A method for generating an energy-resolved X-ray image is proposed, usable e.g. for mammography or CT applications. First, a preferably low-dose X-ray beam (5) is directed through a region of interest of an object (15) such as a female breast and initial X-ray intensity values are acquired. Based on these initial X-ray intensity values, energy threshold values of for example a photon-counting energy-resolving X-ray detector (9) are specifically adapted to local properties and features of the object (15). With such adapted energy threshold values, energy-resolved main X-ray intensity values are acquired for finally generating the energy-resolved X-ray image.

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: A method for generating an energy-resolved X-ray image is proposed, usable e.g. for mammography or CT applications. First, a preferably low-dose X-ray beam (5) is directed through a region of interest of an object (15) such as a female breast and initial X-ray intensity values are acquired. Based on these initial X-ray intensity values, energy threshold values of for example a photon-counting energy-resolving X-ray detector (9) are specifically adapted to local properties and features of the object (15). With such adapted energy threshold values, energy-resolved main X-ray intensity values are acquired for finally generating the energy-resolved X-ray image.

Abstract: The present invention relates to X-ray imaging technology as well as image post-processing. Particularly, the present invention relates to a method for computer aided detection of structures in X-ray images as well as an X-ray system. A computer aided detection algorithm visibly determines tissue structures in X-ray image information and subsequently matches the shape of a determined tissue structure with a library of known tissue structures for characterizing the type of determined tissue structure. The determination of a tissue structure and thus the characterization of the type of the tissue structure may be enhanced when employing also spectral information, in particular energy information of the acquired X-ray image.

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.