Abstract: A method includes analyzing a spectral projection image of a portion of a subject, generating a value quantifying an amount of a target specific contrast material in a region of interest of the spectral projection image, and generating a signal indicative of a presence of the target in response to the value satisfying a predetermined threshold level.

Abstract: The invention relates to an imaging system (30) for imaging an object. A projection data providing unit (31) provides acquired spectral projection data of an object comprising at least two components, and a reconstruction unit (10) iteratively reconstructs at least two final component images of the object by performing several iteration steps, in which at least two intermediate component images are updated based on the acquired spectral projection data and a penalty term, which is indicative of the correlated noise between the at least two intermediate component images. Since the at least two intermediate component images are updated based on the acquired spectral projection data and a penalty term, which is indicative of the correlated noise, correlated noise is penalized during the iterative reconstruction. The finally resulting component images of the object are therefore less corrupted by correlated noise and have an improved image quality.

Abstract: The invention relates to an imaging apparatus for imaging an object of interest. An analytical reconstruction unit (12) analytically reconstructs an analytical image of the object from detection data, in particular, from projection data, and an iterative reconstruction unit (13) iteratively reconstructs an iterative image of the object from the detection data, wherein a combination unit (14) combines the analytical image and the iterative image for generating a combination image. An iterative image can comprises shading artifacts, which may be caused by preprocessing the detection data before performing the iterative reconstruction. An analytical image shows reduced shading artifacts, in particular, shows no shading artifacts at all. Thus, by combining the analytical image and the iterative image a combination image can be generated, in which the shading artifacts are reduced in comparison to an iterative image, thereby improving the quality of the reconstructed final image of the object of interest.

Abstract: A scanning method and apparatus useful for correcting artifacts which may appear in a primary short circular CT scan are provided. A secondary helical scan performed on a stationary subject, or a secondary circular scan, may be used to correct for artifacts. The secondary scan may be performed with a smaller radiation dosage than the primary circular CT scan.

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 invention relates to a beam filter (10) that can particularly be used in spectral CT-applications for producing a desired intensity profile of a radiation beam without changing its spectral composition. In a preferred embodiment, the beam filter (10) comprises a stack of absorbing sheets (111) that are separated by wedge-shaped spaces (112) and focused to a radiation source (1). Furthermore, the absorbing sheets have a varying width in direct ion of the radiation. Different fractions of the radiation source (1) area are therefore masked by the beam filter (10) at different points (A, B) on a detector area (2). The absorbing sheets preferably comprise a material that is highly absorbing for the radiation to be filtered.

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: Tomosynthesis system with a rotating anode X-ray tube enabling a circular scan trajectory, wherein the X-ray tube 1 may be equipped with a large number of cathodes (21, 22) distributed around an anode. This allows to generate X-rays (41, 42) at focal spot positions (11, 12), for example evenly distributed on a for example circular line (14) on the surface (15) of an anode (10). The object (61) may be located on the (10) axis of rotation (6) of the anode at some distance to the source. For an examination, the object (61) may be exposed to X-ray beams (41, 42) generated successively on all focal spot positions (11, 12), wherein no movement of the X-ray tube 1 is necessary. The transmitted X-ray intensities may be measured by a flat panel detector (50) to achieve a reconstructed three-dimensional image data.

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: According to an exemplary embodiment an imaging system (100) for examining an object under examination comprises a scanning unit, wherein the scanning unit comprises a radiation source (106, 108), and a detection unit (107, 109), wherein the scanning unit is adapted to emit a radiation beam (123), which radiation beam follows a linear movement of the object under examination such that a predetermined region of the object under examination is scanned while the object under examination moves.

Abstract: The invention relates to a beam filter (10) that can particularly be used in spectral CT-applications for producing a desired intensity profile of a radiation beam without changing its spectral composition. In a preferred embodiment, the beam filter (10) comprises a stack of absorbing sheets (111) that are separated by wedge-shaped spaces (112) and focused to a radiation source (1). Furthermore, the absorbing sheets have a varying width in direct ion of the radiation. Different fractions of the radiation source (1) area are therefore masked by the beam filter (10) at different points (A, B) on a detector area (2). The absorbing sheets preferably comprise a material that is highly absorbing for the radiation to be filtered.

Abstract: A scanning method and apparatus useful for correcting artifacts which may appear in a primary short circular CT scan are provided. A secondary helical scan performed on a stationary subject, or a secondary circular scan, may be used to correct for artifacts. The secondary scan may be performed with a smaller radiation dosage than the primary circular CT scan.

Abstract: According to an embodiment of the present invention, a reconstruction scheme for a CSCT is provided which is capable of reconstructing data acquired just over a half turn, i.e. 180° plus fan angle. The reconstruction scheme may provide for an extension of the reconstruction towards smaller and larger q-regions as compared with a 360°-reconstruction, if the short scan reconstruction technique is applied to a full scan data set.

Abstract: The invention relates to a device for generating X-rays (18) comprising an electron source (3) for emitting electrons accommodated in a vacuum space (2), a liquid metal circuit including a liquid metal for emitting X-rays as a result of the incidence of electrons and a pumping means (11) for causing a flow of the liquid metal through a constriction (7) where the electrons emitted by the electron source (3) impinge upon the liquid metal, and a radiation window (12) bounding said constriction (7), which is transparent to electrons and X-rays and separates the constriction (7) from the vacuum space (2).

Abstract: The invention relates to a device for generating X-rays (18) comprising an electron source (3) for emitting electrons accommodated in a vacuum space (2), a liquid metal circuit including a liquid metal for emitting X-rays as a result of the incidence of electrons and a pumping means (11) for causing a flow of the liquid metal through a constriction (7) where the electrons emitted by the electron source (3) impinge upon the liquid metal, and a radiation window (12) bounding said constriction (7), which is transparent to electrons and X-rays and separates the constriction (7) from the vacuum space (2).

Abstract: Whereas the CT image can be acquired in a single revolution, the CSCT image acquisition may require several revolutions. According to an exemplary embodiment of the present invention, a CT/CSCT apparatus may be provided which uses CT data acquired during the first revolution to optimize acquisition parameters for the subsequent revolutions. Furthermore, projection data acquired with a pre-scanner may also be used for determining current modulation or setting an optimum voltage for the subsequent CSCT scan.

Abstract: The application of CSCT to baggage inspection necessitates a large field of view, resulting in a large gantry that has to sustain large centrifugal forces. Accordingly, various CSCT geometries are described which enable smaller gantry sizes. In particular, a CSCT scanner comprising a detector unit that is not focus-centred is described.

Abstract: According to an aspect of the present invention, a correction of X-ray intensities measured in an energy-resolved diffraction method may be provided for multiple scattered radiation without any assumptions on the geometry of the object examined. According to an exemplary embodiment of the present invention, the characteristic lines of the anode material in the primary spectrum are evaluated, resulting in a component analysis of the detected spectrum which may allow for a correction for its multiple scatter part.

Abstract: The invention relates to a device for generating X-rays (31). The device has a source (5) for emitting electrons (27) accommodated in a vacuum space (3). The X-rays are emitted by a liquid metal as a result of the incidence of the electrons. The liquid metal flows through a constriction (13) where the electrons emitted by the source impinge upon the liquid metal. The constriction is bounded by a thin window (23), which is made from a material which is transparent to electrons and X-rays and which separates the liquid metal in the constriction from the vacuum space, and by a wall (25) opposite to the window. According to the invention, the wall (25) has a profile (p) which matches a profile (p?) which the window (23) has, during operation, as a result of a deformation of the window caused by a pressure of the liquid metal in the constriction (13).