Abstract: There is provided a method and corresponding system and apparatus for image reconstruction based on image data from a photon-counting multi-bin x-ray detector. The method includes determining (S1) parameter(s) of a given functional form of the relationship between comparator settings expressed in voltage in the read-out chain of the x-ray detector and the corresponding energy threshold values expressed in energy based on a fitting procedure between a first set of data representative of a measured pulse height spectrum and a second set of data representative of a reference pulse height spectrum. The method also includes performing (S2) image reconstruction based on the image data and the determined parameter(s). In this way, efficient high-quality image reconstruction can be achieved.

Abstract: There is provided a method of image reconstruction based on energy-resolved image data from a photon-counting multi-bin detector or an intermediate storage. The method comprises processing (S1) the energy-resolved image data by performing at least two separate basis decompositions using different number of basis functions for modeling linear attenuation, wherein a first basis decomposition is performed using a first smaller set of basis functions to obtain at least one first basis image representation, and wherein a second basis decomposition is performed using a second larger set of basis functions to obtain at least one second basis image representation. The method also comprises reconstructing a first image based on said at least one first basis image representation obtained from the first basis decomposition, and combining the first image with information representative of said at least one second basis image representation.

Abstract: The proposed technology relates to an x-ray detector arrangement having x-ray detector sub-modules arranged in two or more layers, where the separation between adjacent sub-modules in a lower layer is smaller than the corresponding separation between sub-modules in an upper layer.

Abstract: There is provided a method for at least partly determining the orientation of an edge-on x-ray detector with respect to the direction of x-rays from an x-ray source. The method includes obtaining (S1) information from measurements, performed by the x-ray detector, representing the intensity of the x-rays at a minimum of two different relative positions of a phantom in relation to the x-ray detector and the x-ray source, the phantom being situated between the x-ray source and the x-ray detector and designed to embed directional information in the x-ray field when exposed to x-rays. The method also includes determining (S2) at least one parameter associated with the orientation of the x-ray detector with respect to the direction of x-rays based on the obtained information from measurements and a geometrical model of the spatial configuration of the x-ray detector, x-ray source and phantom.

Abstract: There is provided a method of image reconstruction based on energy-resolved image data from a photon-counting multi-bin detector or an intermediate storage. The method comprises processing (S1) the energy-resolved image data by performing at least two separate basis decompositions using different number of basis functions for modeling linear attenuation, wherein a first basis decomposition is performed using a first smaller set of basis functions to obtain at least one first basis image representation, and wherein a second basis decomposition is performed using a second larger set of basis functions to obtain at least one second basis image representation. The method also comprises reconstructing a first image based on said at least one first basis image representation obtained from the first basis decomposition, and combining the first image with information representative of said at least one second basis image representation.

Abstract: A method and corresponding arrangement for reconstructing an image based on spectral image data acquired for at least two different effective energies includes: obtaining a first set of spectral image data related to an object to be imaged and a second set of spectral image data related to a calibration phantom including at least one reference material; performing basis decomposition based on the first set of spectral image data, providing estimated basis images of the object to be imaged with respect to associated basis functions; performing basis decomposition based on the second set of spectral image data, providing calibrated estimates of reference basis coefficients corresponding to the at least one reference material; and determining image values representing the object based on a system model of an imaging system to be emulated, the estimated basis images and their associated basis functions, and the calibrated estimates of reference basis coefficients.

Abstract: The current invention applies to photon counting silicon x-ray detectors with energy discriminating capabilities and applications in x-ray imaging systems. The overall image quality produced by such a system is improved by the presented novel methods for optimally using the energy information in Compton events and making selective use of counts induced from charges collected in neighboring pixels. The pile-up problem during high-flux imaging regimes is reduced by a novel method for signal reset, which improves the count efficiency by reducing the risk of losing event due to signal pile-up in the read out electronics chain.