Abstract: The present invention relates to guidance during a medical intervention. In order to provide an improved navigation support with a facilitated setup, a system (10) for navigation support is provided. An image data input (12) receives a plurality of acquired 2D X-ray images of a subject's body from different angles. A set of markers, which are visible in X-ray images and which are detectable by a navigation system, is assigned to the subject. A marker detecting arrangement (16) is provided that detects a current spatial location of the markers assigned to the subject. A data processor (14) reconstructs a 3D volume of the subject based on the plurality of 2D X-ray images. At least a part of the markers is arranged outside the volume covered by the reconstructed 3D volume of the subject, while the markers are visible in the 2D X-ray images.

Abstract: An X-ray detector is positioned relative to an X-ray source such that at least a part of a region between the X-ray source and the X-ray detector is an examination region for accommodating an object. The X-ray source and X-ray detector are controlled by a processing unit in order to operate in a first imaging operation mode, a second imaging operation mode, and/or a third imaging operation mode. The detector comprises a first scintillator, a second scintillator, a first sensor array, and a second sensor array. The first scintillator is disposed over the second scintillator such that X-rays emitted from the X-ray source first encounter the first scintillator and then encounter the second scintillator.

Abstract: Abstract: An X-ray system (1, 10) for imaging and a gain calibration method are disclosed. An assembly (4, 14) of the system is moveable to different scan coordinates to acquire X-ray projection images at a plurality of said scan coordinates in a dynamic mode while the assembly is moving. The assembly is also moveable to a predetermined reference coordinate to acquire an X-ray projection image at said reference coordinate in a static mode while the assembly is resting. At least one processing unit (5), comprised by the X-ray system, is configured for receiving a plurality of dynamic gain calibration parameters as first inputs, for obtaining a static gain calibration parameter as a second input and for determining a plurality of adjusted dynamic gain calibration parameters. Each dynamic gain calibration parameter is obtained from an X-ray projection image acquired in the dynamic mode at one of the scan coordinates.

Abstract: The invention relates to an apparatus for determining a control protocol for controlling a C-arm system comprising a radiation source. The control protocol comprises a sequence of roll angles and a sequence of propeller angles. The apparatus comprises a tilt plane providing unit for providing a tilt plane tilted with respect to a vertical plane, and a control protocol determining unit for determining a control protocol by determining the sequence of roll angles and the sequence of propeller angles such that the radiation source follows a trajectory that comprises a circular component in the tilt plane and that allows the C-arm system to acquire projection data for image reconstruction. The apparatus allows to acquire computed images, for instance tomographic images, with an improved quality and to reduce radiation in radiation-sensitive areas.

Abstract: The present invention relates to a device for controlling a position of an anti-scatter grid in an X-ray image acquisition system, the device (10) comprising: a measurement unit (12); a control unit (14); and a shifting unit (16); wherein the measurement unit (12) is configured to determine an X-ray beam focus position (37) of an X-ray radiation source of the X-ray image acquisition system with respect to an X-ray detector of the X-ray image acquisition system; wherein the control unit (14) is configured to generate a shifting signal based on a displacement (18) between the X-ray beam focus position (37) and a grid focus position (35) of the anti-scatter grid; and wherein, based on the shifting signal, the shifting unit (16) is configured to shift an anti-scatter grid of the X-ray image acquisition system in at least one direction to align the anti-scatter grid with the X-ray beam focus position (37), provides an improved anti-scatter grid for X-ray acquisition systems.

Abstract: In a first aspect, the present invention relates to a beam shaping filter (1) for use in a cone beam computed tomography system. The filter comprises a radiation attenuating element for positioning between an x-ray source of the cone beam computed tomography system and an object to be imaged. The radiation attenuation as function of position in at least a part (2) of the radiation attenuating element is rotationally symmetric with respect to a point of rotational symmetry (3).

Abstract: The invention relates to off-center detector 3D X-ray or proton radiography reconstruction. Redundancy weighting with a steep weighting function around the iso-axis typically leads to artifacts in the reconstruction, for example, if inconsistencies between two nominal redundant projections occur, e.g. due to slightly incorrect detector calibration or scatter correction, etc. With the present invention, an approach is presented for overcoming or mitigating these problems.

Abstract: The present invention relates to a system for X-ray imaging It is explained to position (210) an X-ray detector (10) relative to an X-ray source such that at least a part of a region between the X-ray source and the X-ray detector is an examination region for accommodating an object. The X-ray source and X-ray detector are controlled (220) by a processing unit in order to: operate (230) in a first imaging operation mode; or operate (240) in a second imaging operation mode; or operate (250) in the first imaging mode and in the second imaging mode; or operate (260) in a third imaging operation mode. The detector comprises a first scintillator (20), a second scintillator (30), a first sensor array (40), and a second sensor array (50). The first sensor array is associated with the first scintillator. The first sensor array comprises an array of sensor elements configured to detect optical photons generated in the first scintillator. The second sensor array is associated with the second scintillator.

Abstract: The present invention relates to a device for controlling a position of an anti-scatter grid in an X-ray image acquisition system, the device (10) comprising: a measurement unit (12); a control unit (14); and a shifting unit (16); wherein the measurement unit (12) is configured to determine an X-ray beam focus position (37) of an X-ray radiation source of the X-ray image acquisition system with respect to an X-ray detector of the X-ray image acquisition system; wherein the control unit (14) is configured to generate a shifting signal based on a displacement (18) between the X-ray beam focus position (37) and a grid focus position (35) of the anti-scatter grid; and wherein, based on the shifting signal, the shifting unit (16) is configured to shift an anti-scatter grid of the X-ray image acquisition system in at least one direction to align the anti-scatter grid with the X-ray beam focus position (37), provides an improved anti-scatter grid for X-ray acquisition systems.

Abstract: An image processing system (IPS) and related method for image reconstruction operations, in particular for spectral computed tomography imaging. The image reconstruction operation is based on optimizing a regularized objective or cost function. The objective function includes a regularization term (R) that incorporates, as a-priori knowledge, a known amount of a material resident within a field of view to be reconstructed.

Abstract: The invention relates to off-center detector 3D X-ray or proton radiography reconstruction. Redundancy weighting with a steep weighting function around the iso-axis typically leads to artifacts in the reconstruction, for example, if inconsistencies between two nominal redundant projections occur, e.g. due to slightly incorrect detector calibration or scatter correction, etc. With the present invention, an approach is presented for overcoming or mitigating these problems.

Abstract: An image processing system (IPS) and related method for image reconstruction operations, in particular for spectral computed tomography imaging. The image reconstruction operation is based on optimizing a regularized objective or cost function. The objective function includes a regularization term (R) that incorporates, as a-priori knowledge, a known amount of a material resident within a field of view to be reconstructed.

Abstract: A Computer Tomography (CT) C-arm system and method for examination of an object is provided.

Abstract: It is described a gain calibration for a two-dimensional X-ray detector (315), in which the gain coefficients for scattered radiation (307b) and direct radiation (307a) are measured or estimated separately. A weighed average may be applied on the appropriate scatter fraction. The scatter fraction depending gain calibration method produces less ring artifacts in X-ray images as compared to known gain calibration methods, which do not take into account the fraction of scattered radiation reaching the X-ray detector (315).

Abstract: A Computer Tomography (CT) C-arm system and method for examination of an object is provided.

Abstract: An imaging system including an artifact reducer arranged to correct for a ring-shaped artifact in a three-dimensional reconstructed volume. The artifact reducer includes a first stage correction arranged to eliminate structured noise of an output screen of an image intensifier of an X-ray imaging apparatus using a first corrective image. A raw image of a patient is first processed with the first corrective image. The gain-corrected images are forwarded to an image deformation correction where a suitable unwarping function performed. The gain-corrected unwarped images are then made available to a second stage gain correction where a second corrective image is applied resulting in a final set of images with a substantially reduced ring-shaped artifact. The final set of images is made available to an image reconstructor arranged for further processing of the final set of images, the result thereof being visualized on a computer monitor for inspection purposes.

Abstract: A method for at least reducing the occurrence of differential ghosting in an X-ray image acquired in respect of a subject, wherein a deghost scan is performed at least once daily so as to generate an underlying strong homogeneous ghost so that further differential (non-homogeneous) ghosting during subsequent scans is minimised. The deghost scan comprises acquiring an ‘air’ image, when no subject is present between the X-ray source (4) and detector (5), as a relatively high detector dose.

Abstract: It is described a gain calibration for a two-dimensional X-ray detector (315), in which the gain coefficients for scattered radiation (307b) and direct radiation (307a) are measured or estimated separately. A weighed average may be applied on the appropriate scatter fraction. The scatter fraction depending gain calibration method produces less ring artifacts in X-ray images as compared to known gain calibration methods, which do not take into account the fraction of scattered radiation reaching the X-ray detector (315).

Abstract: A method for at least reducing the occurrence of differential ghosting in an X-ray image acquired in respect of a subject, wherein a deghost scan is performed at least once daily so as to generate an underlying strong homogeneous ghost so that further differential (non-homogeneous) ghosting during subsequent scans is minimised. The deghost scan comprises acquiring an ‘air’ image, when no subject is present between the X-ray source (4) and detector (5), as a relatively high detector dose.

Abstract: Conditional access system for controlling the access of receivers of end-users to a data content source in an uplink system. Said uplink system comprises a scrambler for scrambling data content supplied from the data content source, an entitlement control message generator for generating entitlement control messages containing a control word and an entitlement identification and a transmitter for transmitting the scrambled data content and the entitlement control messages. A descrambler and an entitlement control message decoder are associated to the receiver. If a match between the entitlement in the entitlement control message and the entitlement of the end-user exists, the entitlement control message decoder supplies a control word to the descrambler for descrambling a part of the received scrambled content for which the receiver is entitled.