Abstract: A filter assembly for use in a helical computed tomography system having an x-ray source for projecting x-ray beams along a projection axis is presented, the filter assembly including a first filter element for attenuating at least a portion of the x-ray beams, the first filter element constructed as a background-wedge for attenuating x-rays having a large aperture and a second filter element for attenuating at least a portion of the x-ray beams, the second filter element constructed to create a ridge. The second filter element may be rotated with respect to or adjusted in relation with or removed or replaced from the filter assembly to allow for adaptation to different helical pitch values.

Abstract: The invention relates to an X-ray imaging apparatus and a method, particularly to a CT scanner (100) for generating sectional images of an object such as the body (P) of a patient. A given desired angular intensity distribution (Ides) is reproduced by emitting X-rays (X) in emission angle intervals (EAI) only, wherein the angular distribution of these emission angle intervals and the associated local emission intensities (I(?)) are chosen such that they reproduce, in the angular mean, the desired angular intensity distribution (Ides). Modulation of incident X-ray flux is hence realized by the modulation of the angular sampling density. The X-ray source may preferably be realized by a grid switching tube (101).

Abstract: A method displays spectral image data reconstructed from spectral projection data with a first reconstruction algorithm and segmented image data reconstructed from the same spectral projection data with a different reconstruction algorithm, which is different from the first reconstruction algorithm. The method includes reconstructing spectral projection data with the first reconstruction algorithm, which generates the spectral image data and displaying the spectral image data. The method further includes reconstructing the spectral projection data with the different reconstruction algorithm, which generates segmentation image data, segmenting the segmentation image data, which produces the segmented image data, and displaying the segmented image data.

Abstract: An imaging system (100) includes a direct conversion detector pixel (111) that detects radiation traversing an examination region and generates an electrical signal indicative thereof, wherein the signal includes a persistent current, which is produced by a direct conversion material of the pixel and which shifts a level of the signal. A persistent current estimator (116) estimates the persistent current and generates a compensation signal based on the estimate. A pre-amplifier (112) receives the signal and the compensation signal, wherein the compensation signal substantially cancels the persistent current, producing a persistent current compensated signal, and that amplifies the compensated signal, generating an amplified compensated signal. A shaper (114) generates a pulse indicative of energy of the radiation illuminating the direct conversion material based on the amplified compensated signal.

Abstract: A method for extending initial image data of a subject for dose estimation includes obtaining first image data of the subject for dose calculation, wherein the first image data has a first field of view. The method further includes obtaining second image data for extending the field of view of the first image data. The second image data has a second field of view that is larger than the first field of view. The method further includes extending the first field of view based on the second image data, producing extended image data.

Abstract: The invention relates to an active marker device (100) for being introduced into a human tissue and for tracking a region of interest of a human body. The active marker device comprises a light source (101) for emitting light such that the emitted light can be detected by an optical sensor. In this way, the active marker device and/or the region of interest can be tracked by a tracking system comprising the optical sensor. The active marker device (100) further comprises a switch (102) for turning the light source on and off and for operating the light source in a pulsed mode.

Abstract: An imaging system includes a radiation source (108) configured to rotate about an examination region (106)and emit radiation that traverses the examination region. The imaging system further includes an array of radiation sensitive pixels (112) configured to detect radiation traversing the examination region and output a signal indicative of the detected radiation. The array of radiation sensitive pixels is disposed opposite the radiation source, across the examination region. The imaging system further includes a rigid flux filter device (130) disposed in the examination region between the radiation source and the radiation sensitive detector array of photon counting pixels. The rigid flux filter device is configured to filter the radiation traversing the examination region and incident thereon. The radiation leaving the rigid flux filter device has a predetermined flux.

Abstract: The invention relates to a computed tomography system (30). Several sets of spectral projections, which correspond to different positions of a radiation source (2) along a rotation axis (R), are decomposed into first projections being indicative of a contrast agent and second projections being not indicative of the contrast agent. An image is generated by a) determining for each first projection a contrast value being indicative of a total amount of contrast agent and scaling the first projections such that for different first projections of a same set the same contrast value is determined, and reconstructing an image based on the scaled first projections, and/or b) reconstructing for the different sets first images, scaling the first images such that they have a same intensity in overlap regions and combining the scaled first images. Thus, different contrast agent amounts can be balanced, thereby allowing for an improved image quality.

Abstract: The present invention is directed to a perfusion imaging device and method, wherein perfusion data of at least a tissue of interest is obtained from medical imaging and blood pulsation parameters are determined on or near the tissue of interest without physical contact to a patient.

Abstract: The invention relates to a detection apparatus (12) for detecting photons. The detection apparatus comprises a pile-up determining unit (15) for determining whether detection signal pulses being indicative of detected photons are caused by a pile-up event or by a non-pile-up event, wherein a detection values generating unit (16) generates detection values depending on the detection signal pulses and depending on the determination whether the respective detection signal pulse is caused by a pile-up event or by a non-pile-up event. In particular, the detection values generating unit can be adapted to reject the detection signal pulses caused by pile-up events while generating the detection values. This allows for an improved quality of the generated detection values.

Abstract: An imaging apparatus comprising a radiation source (2) for emitting radiation from a focal region (20) through an imaging area (5), a detection unit (6) for detecting radiation from said imaging area (5), said detection unit comprising an anti-scatter grid (62) and a detector (61), a gantry (1) to which said radiation source (2) and said detection unit (6) are mounted and a controller (9) for controlling said detection unit (6) to detect radiation at a plurality of projection positions and for manipulating the position, setting and/or orientation of at least a part of said radiation source (2) and/or said detection unit (6) at first projection positions (80) so that the radiation incident on the detector (61) at said first projection positions is attenuated by said anti-scatter grid (62) to a larger extent compared to second projection positions (80) representing the remaining projection positions.

Abstract: A method for dark-field imaging includes acquiring dark-field image projections of an object with an imaging apparatus that includes an x-ray interferometer, applying a pressure wave having a predetermined frequency to the object for each acquired projection, wherein the predetermined frequency is different for each projection, and processing the acquired projections, thereby generating a 3D image of the object. In other words, the method corresponds to acoustically modulated X-ray dark field tomography. An imaging system (400) includes a scanner (401) configured for dark-field imaging, the scanner including: a source/detector pair (402/408) and a subject support (416), a pressure wave generator (420) configured to generate and transmit pressure waves having predetermined frequencies, and a console (424) that controls the scanner and the pressure wave generator to acquire at least two dark-field projection of an object with different pressure waves having different frequencies applied to the object.

Abstract: A method includes modulating a flux of emission radiation between a first lower flux level and a second higher flux level in coordination with a cardiac cycle signal so that the flux is at the first lower flux level during a first cardiac motion phase having a first higher cardiac motion and is at the second higher flux level during a second cardiac motion phase having a second lower cardiac motion. The method further includes reconstructing the projection data with a first reconstruction window, which applies a first higher weight to a first sub-set of the projection data that corresponds to the first cardiac motion phase and the lower first flux level and a second lower weight to a second sub-set of the projection data that corresponds to the second cardiac motion phase and the higher second flux level, to generate first volumetric image data.

Abstract: A method includes receiving radiation with a hybrid data detection system of an imaging system. The hybrid data detection system includes a hybrid data detector array with a set of spectral detectors and a set of integrating detectors that are arranged along a transverse axis of an examination region. The method further includes generating a set of truncated spectral projections with the first set of spectral detectors. The method further includes estimating a set of spectral projections for the integrating detectors. The method further includes combining the set of truncated spectral projections and the estimated set of spectral projections. The method further includes estimating a set of spectral projections based on the combined set to produce a complete set of spectral projections. The method further includes processing the complete set of spectral projections to generate volumetric image data.

Abstract: The present invention relates to a stereo tube radiation imaging system in which radiation emitted from each radiation source covers a different area of the detector surface. Furthermore, the present invention relates to a stereo tube imaging method wherein both radiation sources are operated independently and each cover part of the detector surface area. This is advantageous in that it may reduce radiation dose compared to known stereo tube imaging and introduces new possibilities for stereo tube imaging, such as improved object tracking within a body.

Abstract: A computing system (116) includes a reconstruction processor (114) configured to execute computer readable instructions, which cause the reconstruction processor to: receive, in electronic format, non-spectral projection data, reconstruct the non-spectral projection data to generate a non-spectral image, retrieve a non-spectral to spectral voxel value map for a basis material of interest from a set of non-spectral to spectral voxel value maps, generate a spectral iterative reconstruction start image based on the non-spectral image and the non-spectral to spectral voxel value map, and reconstruct a spectral image, in electronic format, for the material basis of interest from the non-spectral projection data with a spectral iterative reconstruction algorithm and the spectral iterative reconstruction start image.

Abstract: An imaging system (200) is configured for grating-based DPCI. The imaging system includes a rotating gantry (204) that rotates around an examination region, a radiation source (208), supported by the rotating gantry, that emits radiation that traverses the examination region, a detector array (212), supported by the rotating gantry, that detects radiation that traverses the examination region, and an interferometer, supported by the rotating gantry, which includes a source grating (214), a phase grating (218), and an absorber grating (220). At least one of the phase grating or the absorber grating continuously translates with respect to the other during an integration period and the detector generates and outputs an electrical signal indicative of the detected radiation, wherein the electrical signal includes an absorption component, a coherence component and a phase component.

Abstract: A method includes re-sampling current image data representing a reference motion state into a plurality of different groups, each group corresponding to a different motion state of moving tissue of interest, forward projecting each of the plurality of groups, generating a plurality of groups of forward projected data, each group of forward projected data corresponding to a group of the re-sampled current image data, determining update projection data based on a comparison between the forward projected data and the measured projection data, grouping the update projection data into a plurality of groups, each group corresponding to a different motion state of the moving tissue of interest, back projecting each of the plurality of groups, generating a plurality of groups of update image data, re-sampling each group of update image data to the reference motion state of the current image, and generating new current image data based on the current image data and the re-sampled update image data.

Abstract: The present invention relates to a device (100) for iterative reconstruction of images recorded by at least two imaging methods, the device comprising: an extraction module (10), which is configured to extract a first set of patches from a first image recorded by a first imaging method and to extract a second set of patches from a second image recorded by a second imaging method; a generation module (20), which is configured to generate a set of reference patches based on a merging of a first limited number of atoms for the first set of patches and of a second limited number of atoms for the second set of patches; and a regularization module (30), which is configured to perform a regularization of the first image or the second image by means of the generated set of reference patches.

Abstract: A computing system (116) includes a reconstruction processor (114) configured to execute computer readable instructions, which cause the reconstruction processor to: receive, in electronic format, non-spectral projection data, reconstruct the non-spectral projection data to generate a non-spectral image, retrieve a non-spectral to spectral voxel value map for a basis material of interest from a set of non-spectral to spectral voxel value maps, generate a spectral iterative reconstruction start image based on the non-spectral image and the non-spectral to spectral voxel value map, and reconstruct a spectral image, in electronic format, for the material basis of interest from the non-spectral projection data with a spectral iterative reconstruction algorithm and the spectral iterative reconstruction start image.