Abstract: The present invention relates to a modulation of X-ray radiation for the purposes of imaging an object of interest. For the modulation, the X-ray radiation provided by an X-ray source (12) is in part totally reflected by a mirror (20). Thus, an X-ray radiation at an object receiving space (16) is formed by an unreflected X-ray radiation (24) and a reflected X-ray radiation (26). The mirror (20) is displaceable by an actuator (28), such that the intensity of the reflected X-ray radiation (26) can be adjusted, in particular to a density of the object to be imaged.

Abstract: An image signal processing system (ISP) comprising an input interface (IN) for receiving photon counting projection data acquired by an X-ray imaging apparatus (IA) having a photon counting detector (D). A calibration data memory (CMEM) of the system holds calibration data. The calibration data encodes photon counting data versus path lengths curves for different energy thresholds of i) said detector (D) or ii) of a different detector. At least one of said curves is not one-to-one. A path length convertor (PLC) of the system converts an entry in said photon counting projection data into an associated path length based on said calibration data.

Abstract: The present invention relates to a device for phase stepping in phase contrast image acquisition, the device (1) comprising: a mobile grating (10); a guiding element (11); a restoring element (12); and a locking element (13); wherein the guiding element (11) is configured to guide the mobile grating (10) between a first position (2) and a second position (3); wherein the restoring element (12) is configured to apply a force to the mobile grating (10); wherein the force is directed from the first position (2) to the second position (3); and wherein the locking element (13) is configured to releasably lock the mobile grating (10) in the first position (2). In an example, during the motion of the mobile grating (10) back to equilibrium, a decoder (11a) for the position of the mobile grating (10) along the guiding element (11) may trigger at least four measurement frames over a period of at least 2*Pi.

Abstract: The invention relates to radiation detector for registering incident photons, comprising (i) detection circuitry (202, 206, 207) configured to provide an electric output signal in response to incident photons, the output signal comprising pulses having an amplitude indicative of energies deposited in the radiation detector by the incident photons, and (ii) an energy estimating circuit (2081, . . . , 208N; 2091, . . . , 209N) configured to detect that the output signal is larger than at least one threshold corresponding to an energy value in order to determine energies of incident photons. The radiation detector further comprises a registration circuit (211) configured to detect incident photons independent of a comparison of the output signal with the at least one threshold. Moreover, the invention relates to a method for detecting photons using the radiation detector.

Abstract: The invention relates to an X-ray imaging apparatus (2), comprising: a source (4) for generating X-ray radiation, an object receiving space (6) for arranging an object of interest for X-ray imaging, an X-ray collimator arrangement (8) arranged between the source (4) and the collimator arrangement (8), and an X-ray mirror arrangement (10). The mirror arrangement (10) comprises for example two tapered mirrors (22) facing each other and adapted for guiding X-ray radiation of the source (4) to the collimator arrangement (8). Consequently, the X-ray intensity at the object receiving space (6) is increased. In order to limit the X-ray radiation to an area, where the X-ray radiation can be utilized form imaging, an angle of spread ?m between the mirrors (22) and a length LM of each mirror (22) is adapted, such that a number of total reflections of X-ray radiation, provided by the source (4), at the mirrors (22) is limited.

Abstract: The present invention relates to X-ray differential phase-contrast imaging, in particular to a deflection device for X-ray differential phase-contrast imaging. In order to provide differential phase-contrast imaging with improved dose efficiency, a deflection device (28) for X-ray differential phase-contrast imaging is provided, comprising a deflection structure (41) with a first plurality (44) of first areas (46), and a second plurality (48) of second areas (50). The first areas are provided to change the phase and/or amplitude of an X-ray radiation; and wherein the second areas are X-ray transparent. The first and second areas are arranged periodically such that, in the cross section, the deflection structure is provided with a profile arranged such that the second areas are provided in form of groove-like recesses (54) formed between first areas provided as projections (56). The adjacent projections form respective side surfaces (58) partly enclosing the respective recess arranged in between.

Abstract: Photon-counting x-ray detectors (3) suffer from a degradation of their performance due to polarization. In order to correct the effects of polarization to the generated x-ray images, the invention suggests (i) exposing the radiation detector (3) to a first radiation pulse emitted by a further radiation source (11) and obtaining a first electric pulse signal generated by the radiation detector (3) in response thereto, (ii) later exposing the 5 radiation detector (3) to a second radiation pulse emitted by the further radiation source (11) during the acquisition of the image and obtaining a second electric pulse signal generated by the radiation detector (3) in response thereto, and (iii) comparing amplitudes of the first and second electric pulse signals and generating the x-ray image based on a result of the comparison. The invention provides a corresponding x-ray device and a corresponding method.

Abstract: The present invention relates to determining baseline shift of an electrical signal generated by a photon detector (102) of an X-ray examination device (101). For this purpose, the photon detector comprises a processing unit (103) that is configured to determine a first crossing frequency of a first pulse height threshold by the electrical signal generated by the photon detector. The first pulse height threshold is located at a first edge of a noise peak in the pulse height spectrum of the electrical signal.

Abstract: The invention relates to a correction device (8) for a radiation detector (2) including detector elements each for detecting incident photons. The correction device (8) is configured to read detection signals representative of an incident photon flux detected by the detector elements for different incident photon fluxes, and an evaluation unit (11) configured to determine for each detector element a dead time of the detector element and a parameter representative of an effective area of the detector element on the basis of a collective evaluation of the detection signals of the respective detector element. Further, the correction device (8) is configured to determine for each detector element correction parameters to compensate for differences in the effective areas and in the dead times of the detector elements on the basis of the determined parameters representative of the effective area and the determined dead times of the detector elements.

Abstract: The invention relates to a subject support device (1) to be used in a projection data acquisition apparatus (2) for acquiring projection data of a subject (3). The subject support device comprises a support component (4) providing a support surface (5) for supporting the subject while acquiring the projection data, a diffraction grating (6) for diffracting x-rays, and a moving unit (7, 8) for moving the support component and the diffraction grating relative to each other. This relative movement can allow for a movement of the support component such that the subject is moved through x-rays (16) for determining projection data of different parts of the subject, while the diffraction grating can still be traversed by the x-rays. These projection data can be used for generating a relatively large phase-contrast and/or dark-field projection image.

Abstract: The present invention relates to a dual- or multi-source CT system and method. For suppressing or even completely eliminating the negative effects of cross-scatter, the proposed CT system comprises two x-ray sources (10, 11), two detectors (13, 14), two read-out units (15, 16), a control unit (17) and a reconstruction unit (19). Further, a scatter correction unit (18) is provided or the read-out units (15, 16) are configured to generate scatter-corrected read-out signals from the detected radiation, wherein a scatter-corrected read-out signal is generated from the radiation detected by a detector during a single projection interval (I) including multiple repetitions of three phases, in which the sources are alternately switched on and off and in which the read-out units alternately register primary radiation or cross-scatter radiation.

Abstract: In a conventional phase-contrast X-ray imaging system, a source grating G0 generates an array of partially coherent line sources which illuminate an object and thereafter phase grating G1. The periodicity in the phase grating is self-imaged at certain instances further away from the X-ray source and sampled by a mechanically movable third absorptive analyzer grating G2 before the demodulated fringe intensity is detected by a conventional X-5 ray detector. This application proposes to directly demodulate the fringe intensity using a structured scintillator having a plurality of slabs in alignment with sub-pixels of an optical detector layer, in combination with electronic signal read-out approaches. Therefore, a mechanically movable third absorptive analyzer grating G2 can be omitted from a phase-contrast X-ray imaging system.

Abstract: The present invention relates to an anti-scatter grid (ASG) assembly comprising a first and a second grid, wherein the second grid is arranged on top of the first grid and comprises a lateral shift. The lamella thickness of the first grid is smaller than the lamella thickness of the second grid. The present invention further relates to a detector arrangement comprising a pixel detector and an ASG assembly arranged on top of the pixel detector.

Abstract: The invention relates to a source-detector arrangement (11) of an X-ray apparatus (10) for grating based phase contrast computed tomography. The source-detector arrangement comprises an X-ray source (12) adapted for rotational movement around a rotation axis (R) relative to an object (140) and adapted for emittance of an X-ray beam of coherent or quasi-coherent radiation in a line pattern (21); and an X-ray detection system (16) including a first grating element (24) and a second grating element (26) and a detector element (6); wherein the line pattern of the radiation and a grating direction of the grating elements are arranged orthogonal to the rotation axis; and wherein the first grating element has a first grating pitch varied dependent on a cone angle (?) of the X-ray beam and/or the second grating element has a second grating pitch varied dependent on the cone angle of the X-ray beam.

Abstract: The invention relates to an X-ray detector arrangement (10) for X-ray phase contrast tomo-synthesis imaging, a line detector (1) for X-ray phase contrast tomo-synthesis imaging, an imaging system (24) for X-ray phase contrast tomo-synthesis imaging, a method for X-ray phase contrast tomo-synthesis imaging, and a computer program element for controlling such arrangement and a computer readable medium having stored such computer program element. The X-ray detector arrangement (10) comprises several line detectors (1). Each line detector (1) is configured to detect a Moiré pattern in at least a portion of an X-ray beam (2) impacting such line detector (1). Each line detector (1) comprises several detector lines (11), wherein a width W of each line detector (1) equals one period or an integer multiple of the period of the Moiré pattern.

Abstract: The invention relates to a modification arrangement for an X-ray generating device, a modification method, a computer program element for controlling such device and a computer readable medium having stored such computer program element. The modification arrangement comprises a cathode, an anode (2) and modification means, e.g. a modification device. The cathode is configured to provide an electron beam (15). The anode (2) is configured to rotate under impact of the electron beam (15) and is segmented by slits (21) arranged around the anode's circumference. The modification means are configured to modify the electron beam (15) when the electron beam (15) is hitting one of the anode's rotating slits (21).

Abstract: A phantom body (PB) for use in a differential phase contrast imaging apparatus (IM) for calibration of same. The phantom body (PB) allows for simultaneous calibration of three different image signal channels, namely refraction, phase shift and small angle scattering.

Abstract: Present invention relates to devices and methods for determining a calcium content by analyzing cardiac spectral CT data. CT projection data (9), obtainable by scanning a cardiac region of a subject using a spectral CT scanning unit, is modelled (12) by applying a material decomposition algorithm to the projection data to provide a calcium-specific component. Tomographic reconstructions (13) of the projection data, to provide a first 3D image (8), and of the calcium-specific component, to provide a second 3D image (6), are performed. The first 3D image (8) is segmented (14) to provide an image mask (5) corresponding to a cardiovascular structure of interest, a part of the second 3D image (6) is selected (15) based on the image mask (5), and a calcium content is calculated (16) in the cardiovascular structure of interest based on the selected part of the second 3D image (6).

Abstract: The grating device (1) for an X-ray imaging device comprises a grating arrangement (10) and an actuation arrangement (20). The grating arrangement (10) comprises a plurality of grating segments (11). The actuation arrangement (20) is configured to move the plurality of grating segments (11) with at least a rotational component between a first position and a second position. In the first position, the grating segments (11) are arranged in the path of an X-ray beam (30), so that the grating segments (11) influence portions of the X-ray beam (30). In the second position, the grating segments (11) are arranged outside the portions of the path of an X-ray beam (30), so that the portions of the X-ray beam (30) are unaffected by the grating segments (11).

Abstract: An apparatus and related method for processing image data supplied by a scanning phase contrast or dark-field imaging apparatus (MA). Beam hardening artifact in phase contrast and dark-field imaging can be reduced by applying a beam hardening processing operation by a beam hardening processing module (BHC) in respect of a plurality of detector readings that contribute signals to the same image pixel position or geometric ray of an imaging region of the apparatus (MA). In one embodiment, a phantom body (PB) is used to acquire calibration data on which the beam hardening processing is based.