Abstract: The invention relates to an imaging system for imaging a region of interest from energy-dependent projection data, wherein the imaging system comprises a projection data providing unit (1, 2, 3, 6, 7, 8) for providing energy-dependent first projection data of the region of interest. The imaging system comprises further an attenuation component image generation unit (12) for generating attenuation component images of the region of interest by generating energy-dependent second projection data using a model in which the projection data depend on attenuation component images. The component image generation unit (12) is adapted for generating the attenuation component images such that deviations of the second projection data from the first projection data are reduced.

Abstract: To scan an object with differently shaped cone beams (112, 122), the present invention provides a CT scanner with a moveable X-ray tube (the meaning of “move the x-ray tube among a plurality of predefined positions” also covers the situation that the anode disk is moved among a plurality of corresponding positions, while the shell of the x-ray tube does not move). The X-ray tube is not only moveable along the axial direction, but also along the radial direction of the CT scanner gantry. The scanner comprises an X-ray tube, which X-ray tube further comprises: an anode disk (100), comprising a plurality of focal tracks (110, 120) each focal track being cone-shaped with an anode angle (114, 124) different from the anode angle(s) of the other focal track(s); and a first cathode (210), configured to emanate an electron beam targeting at least one of the plurality of focal tracks.

Abstract: A medical imaging system includes a generally stationary gantry (102) and a rotating gantry (106), rotatably supported by the generally stationary gantry (102), that rotates about a longitudinal axis around an examination region. The medical imaging system further includes a radiation source (112) that emits a radiation beam that traverses the examination region. The radiation source (112) is moveably affixed to the rotating gantry (106) so as to translate in a direction of the longitudinal axis with respect to the rotating gantry (106) while scanning a subject in the examination region. The medical imaging system further includes a detector array (120) that detects the radiation beam that traverses the examination region and generates a signal indicative thereof. The detector array (120) is moveably affixed to the rotating gantry (106) so as to move in coordination with the radiation source (112) while scanning the subject in the examination region.

Abstract: An imaging detector includes a radiation sensitive region having first and second opposing sides. One of the first or second sides senses impinging radiation. The detector further includes electronics located on the other of the first or second sides of the radiation sensitive region. The electronics includes a thermal controller that regulates a temperature of the imaging detector.

Abstract: A method includes generating simulated complete projection data based on acquisition projection data, which is incomplete projection data, and virtual projection data, which completes the incomplete projection data and reconstructing the simulated complete projection data to generate volumetric image data. An alternative method includes supplementing acquisition image data generated from incomplete projection data with supplemental data to expand a volume of a reconstructable field of view and employing an artifact correction to correct a correctable field of view based on the expanded reconstructable field of view.

Abstract: The invention relates to a medical X-ray examination apparatus (1) for performing K-edge imaging. The medical X-ray examination apparatus (1) comprises an imaging unit (21), which is configured to spectrally decompose an X-ray absorption spectrum to image the X-ray absorption spectrum as a conventional X-ray absorption image (23a) and a K-edge absorption image (23b). The conventional X-ray absorption image (23a) includes data elements representing the anatomical background of an object of interest. The K-edge absorption image (23b) includes data elements representing quantitative information of local densities of material showing K-edge absorption within the object of interest.

Abstract: To mitigate the influence of charge sharing occurring in semiconductor detectors, an improved semiconductor detector (200) is provided, which comprises: a plurality of anodes (210) arranged to form at least one opening (230), each opening being formed by two anodes in the plurality of anodes; at least one cathode (220); a detector cell (240) located between the plurality of anodes and the at least one cathode; wherein the detector cell comprises at least one groove (250), each of the at least one groove having a first opening (252) aligned with one of the at least one opening being formed by two anodes in the plurality of anodes, each of the at least one groove extending towards the at least one cathode. By forming grooves in the detector cell, the charge cloud generated by a single photon can be received by a corresponding anode instead of several neighboring anodes, which thereby improves the spectral resolution and count rate of a semiconductor detector.

Abstract: A method includes detecting radiation that traverses a material having a known spectral characteristic with a radiation sensitive detector pixel that outputs a signal indicative of the detected radiation and determining a mapping between the output signal and the spectral characteristic. The method further includes determining an energy of a photon detected by the radiation sensitive detector pixel based on a corresponding output of the radiation sensitive detector pixel and the mapping.

Abstract: The present invention relates to an imaging system for imaging an object (20) comprising a polychromatic radiation source (2) and an energy resolving radiation detector (6). The imaging system comprises further a driving device for moving the object (20) and the radiation source (2) relatively to each other, in order to acquire truncated projections from different directions. A calculation unit determines a k-edge component at least of one of the object (20) and a substance within the object (20) from the truncated projections and determines non-truncated projections from the determined k-edge component. A reconstruction unit constructs the object using the non-truncated projections.

Abstract: The invention relates to a medical X-ray examination apparatus (1) for performing K-edge imaging. The medical X-ray examination apparatus (1) comprises an imaging unit (21), which is configured to spectrally decompose an X-ray absorption spectrum to image the X-ray absorption spectrum as a conventional X-ray absorption image (23a) and a K-edge absorption image (23b). The conventional X-ray absorption image (23a) includes data elements representing the anatomical background of an object of interest. The K-edge absorption image (23b) includes data elements representing quantitative information of local densities of material showing K-edge absorption within the object of interest.

Abstract: If, in cardiac CT, the time window becomes shorter than the time required for a complete rotation of the gantry, the volume that can be reconstructed becomes small due to the non-existence of related pi-lines. According to an exemplary embodiment of the present invention, an examination apparatus is provided which generates a radiation beam oscillating in z-direction with an oscillation frequency higher than the rotational frequency of the source. This may provide for an exact image reconstruction of large volumes.

Abstract: A computed tomography system includes at least two x-ray sources (108), a at least one common detector (124), and a reconstruction system (136). The at least two x-ray sources (108) are aligned at different z-axis locations at about a same angular position and concurrently emit radiation that traverses an imaging region (116). The at least one detector (124) detects radiation emitted by the at least two x-ray source (108) and generates composite data indicative of the detected radiation. The reconstruction system (136) reconstructs the composite data to generate one or more images.

Abstract: The invention relates to a CT imaging system for determining the flow of a substance within an object, wherein the CT imaging system comprises a polychromatic X-ray source and an energy-resolving X-ray detector for obtaining detection signals depending on the X-ray radiation after passing through the object. A calculation unit (12) determines a k-edge 5 component of the substance from the detection signals, and a reconstruction unit (13) reconstructs a time series of k-edge image from the determined k-edge component. A flow determination unit (14) determines flow values indicative for the flow within the object from the time series of k-edge images.

Abstract: A computed tomography apparatus (10) includes spaced radiation sources (82, 84), such as anodes, which each propagate a cone-beam of radiation (40, 50) into an examination region (14). A detector (22) detects radiation which has passed through the examination region. An attenuation system (55) interposed between the radiation sources and the examination region for cone-angle dependent filtering of the cone beams. The attenuation system allows rays which contribute little to a reconstructed image to be attenuated more than rays which contribute more.

Abstract: The present invention relates to an imaging system for imaging a region of interest comprising an illumination unit and a detection unit. The imaging system further comprises a grouping unit for grouping the detection values, wherein each group comprises at least one alpha detection value and at least one beta detection value (103). At least one alpha aperture weighting value for the at least one alpha detection value of a group is determined by using at least one position of at least one ray within the aperture (104). Furthermore, at least one beta aperture weighting value for the at least one beta detection value of a group is approximately determined using the at least one alpha aperture weighting value of the group (105). The detection values are than aperture weighted using aperture weighting values (106). The region of interest is reconstructed by backprojecting the weighted detection values (107).

Abstract: Cone-beam CT scanners with large detector arrays suffer from increased scatter radiation. This radiation may cause severe image artefacts. An examination apparatus is provided which directly measures the scatter radiation and uses this measurement for a correction of the contaminated image data. The measurement is performed by utilizing a 1-dimensional anti-scatter-grid and an X-ray tube with an electronic focal spot movement. Image data is detected at a first position of a focal spot and scatter data is detected at a second position of the focal spot. The image data is corrected on the basis of the scatter data.

Abstract: The invention relates to a radiation detector (200), particularly an X-ray detector, which comprises at least one sensitive layer (212) for the conversion of incident photons (X) into electrical signals. A two-dimensional array of electrodes (213) is located on the front side of the sensitive layer (212), while its back side carries a counter-electrode (211). The size of the electrodes (213) may vary in radiation direction (y) for adapting the counting workload of the electrodes. Moreover, the position of the electrodes (213) with respect to the radiation direction (y) provides information about the energy of the detected photons (X).

Abstract: The invention relates to an imaging system for imaging an object (14) in an examination zone (5). The imaging system comprises a radiation source emanating radiation for illuminating the examination zone (5), a detection unit for generating detection values depending on the radiation after having passed the examination zone (5) and a moving unit for moving the 5 radiation source and the examination zone relative to each other along a first trajectory (15) and along a second trajectory (16). The position of at least one of the first trajectory (15) and of the second trajectory (16) with respect to the object is determined by a determination unit. The imaging system further comprises a reconstruction unit for reconstructing an image of the object (14) from the detection values using the determined position of the at least one of 10 the first trajectory (15) and the second trajectory (16).

Abstract: The invention relates to a projection system for producing attenuation components of projection data of a region of interest. The projection system comprises a projection data providing unit (1, 2, 6, 7, 8) for providing energy-dependent projection data of the region of interest. The projection system further comprises a calculation unit (12) for calculating different attenuation components generated by different attenuation effects from the energy-dependent projection data, wherein the different attenuation components contribute to the projection data and a transformation unit (13) for transforming the attenuation components such that a correlation of the attenuations components is reduced. The invention relates further to a corresponding projection method and a corresponding computer program.

Abstract: It is described a filter (300) for at least partially compensating for an X-ray tube (10) the target angle heel effect and preserving the tungsten spectrum of the X-rays. The filter (300) has an anode side (302) and a cathode side (304), wherein the cathode side (304) has a higher attenuation coefficient than the anode side (302). The attenuation coefficient is determined to at least partially compensate for the target angle heel effect. The filter (300) is from the same material as an anode plate (110) or the anode (108) of the X-raysource (10) which is usually tungsten or a tungsten alloy.