Abstract: A method is disclosed for generating image data of an object under examination from X-ray projection data of the object under examination, wherein, before a reconstruction of the image data, the X-ray projection data are subjected to scattered radiation correction on the basis of scattered radiation measured values. Here, the scattered radiation measured values are initially subjected to an extra-focal radiation correction before being used for the scattered radiation correction. A projection data processing device is also disclosed for carrying out a method of this kind and an X-ray system, in particular computed tomography system, with a projection data processing device of this kind.

Abstract: A method is disclosed for the reconstruction of image data of an examination object from measurement data. First and second image data are reconstructed from the measurement data with a first and second respective image characteristic, with an enhanced signal-to-noise ratio of the second image characteristic relative to the first image characteristic. Enhanced image data is calculated using an iterative algorithm using the first and the second image data. In the case of the iterative algorithm, a low pass is applied to a difference between the first image data and the image data of an iteration cycle, and a high pass to a difference between the second image data and the image data of the iteration cycle.

Abstract: A method is disclosed for reconstructing image data of an examination object from measurement data, wherein the measurement data were acquired in the course of a relative rotational movement between a radiation source of a computed tomography system and the examination object. First image data of the examination object are reconstructed from the measurement data. Scatter signals are calculated from the first image data using a scattered radiation model, wherein the scattered radiation model specifies an angle-dependent scatter distribution for a scatter point as a function of a line integral corresponding to an attenuation integral of a scattered beam from the scatter point to a specific detector element. The calculated scatter signals are used for correcting the measurement data, and second image data are reconstructed using the corrected measurement data.

Abstract: A method is disclosed for generating image data of an object under examination from X-ray projection data of the object under examination, wherein, before a reconstruction of the image data, the X-ray projection data are subjected to scattered radiation correction on the basis of scattered radiation measured values. Here, the scattered radiation measured values are initially subjected to an extra-focal radiation correction before being used for the scattered radiation correction. A projection data processing device is also disclosed for carrying out a method of this kind and an X-ray system, in particular computed tomography system, with a projection data processing device of this kind.

Abstract: A method and a computer system are disclosed for scattered beam correction in a CT examination of an object in a multi source CT. In at least one embodiment, the method includes generating original projection data records; reconstruction of the object with the original projection data records of at least one detector; determining the scattered radiation generated by each emitter exclusively in the direction of the original beams of the at least one other emitter relative to its opposing detector; generating corrected projection data records by removing the calculated scattered radiation from the original projection data records; reconstruction of the object with the corrected projection data records, and implementing a further iteration of the method when determining the scattered radiation or issuing the reconstruction result if at least one predetermined abort criterion applies.

Abstract: A method is disclosed for reconstructing image data of an examination object from measured data, wherein the measured data was captured previously during a relative rotary motion between a radiation source of a computed tomography system and the examination object. In at least one embodiment, the measured data is modified to achieve a particular grayscale characteristic of the image data to be reconstructed. The image data is calculated by way of an iterative algorithm using the modified measured data, wherein no arithmetic step for reducing noise is employed in the iterations.

Abstract: A method is disclosed for scattered radiation correction in x-ray imaging devices having a number of x-ray sources that can be moved around an examination object in at least one scanning plane during a measurement pass. During the measurement pass, a number of x-ray projections are recorded at different projection angles with simultaneous use of the x-ray sources. In at least one embodiment of the present method, parameters characterizing an outer object contour are determined in the scanning plane from measured data of different x-ray projections.

Abstract: A method for scattered radiation correction of a CT system, including at least two focus/detector systems operated angularly offset from one another, is disclosed. In the method, at at least one phantom, similar to the examined object at least in a subregion, for at least one of the focus/detector systems, the scattered radiation intensity occurring is determined in the detector of a focus/detector system during the operation of the at least one focus of at least one other focus/detector system. Further, the spatial distribution thereof is stored for a number of angles of rotation of the focus/detector systems. During scanning of the object, the scattered radiation intensities, determined with the aid of a similar phantom that originate from the at least one other focus/detector system, are subtracted from the measured intensities of the first focus/detector system while taking account of the spatial orientation of the focus/detector systems and the beam respectively considered.

Abstract: A method is disclosed for scattered radiation correction in x-ray imaging devices having a number of x-ray sources that can be moved around an examination object in at least one scanning plane during a measurement pass. During the measurement pass, a number of x-ray projections are recorded at different projection angles with simultaneous use of the x-ray sources. In at least one embodiment of the present method, parameters characterizing an outer object contour are determined in the scanning plane from measured data of different x-ray projections.

Abstract: In a method for non-iterative focus adjustment in a CT apparatus the position of the center ray with regard to the movement direction of the focus and the correct phase between the detector sampling frequency and the focus springing frequency are calculated with a minimal number of sinogram acquisitions and is adjusted without iterative steps, corresponding to predetermined values.

Abstract: In a tomography apparatus and operating method, at least two acquisition systems are respectively each disposed in the azimuthal direction at respective specific system angles around a common rotation axis. Both system angles can be determined for a substantially constant rotation angle speed of the two acquisition systems on the basis of measurement values, which are calculated at a rotation angle position of a reference object that can be introduced into both measurement planes. The tomography apparatus in this manner enables artifact-free reconstruction of a slice or volume image using the system angles determined in this manner.

Abstract: A method for scattered radiation correction of a CT system, including at least two focus/detector systems operated angularly offset from one another, is disclosed. In the method, at at least one phantom, similar to the examined object at least in a subregion, for at least one of the focus/detector systems, the scattered radiation intensity occurring is determined in the detector of a focus/detector system during the operation of the at least one focus of at least one other focus/detector system. Further, the spatial distribution thereof is stored for a number of angles of rotation of the focus/detector systems. During scanning of the object, the scattered radiation intensities, determined with the aid of a similar phantom that originate from the at least one other focus/detector system, are subtracted from the measured intensities of the first focus/detector system while taking account of the spatial orientation of the focus/detector systems and the beam respectively considered.

Abstract: A method is disclosed for calibrating a CT system having at least two focus/detector systems which are fastened on a rotatable gantry and are arranged angularly offset from one another, in order to scan a patient the angularly offset foci with fanned-open X-ray beams irradiating the respectively oppositely situated detectors with a multiplicity of detector elements arranged like matrices, while the focus/detector systems rotate about the object, preferably a patient, moved, if appropriate, along a system axis, and each detector element of each focus/detector system is assigned an X-ray beam per angle of rotation of the gantry.

Abstract: A method is disclosed for scattered radiation correction of a CT system including two simultaneously operated focus/detector systems, arranged angularly offset from one another on a rotatable gantry. In an embodiment of the method, in order to scan an object, the two focus/detector systems arranged angularly offset from one another scan the object by virtue of the fact that they rotate about a system axis of the CT system. A multiplicity of absorption values of individual rays are then determined from the measured attenuations of the radiation of the foci and the measured values are subjected to scattered radiation correction.

Abstract: In a method for non-iterative focus adjustment in a CT apparatus the position of the center ray with regard to the movement direction of the focus and the correct phase between the detector sampling frequency and the focus springing frequency are calculated with a minimal number of sinogram acquisitions and is adjusted without iterative steps, corresponding to predetermined values.

Abstract: In a tomography apparatus and method for obtaining correction values for two measurement planes, wherein the tomography apparatus an acquisition system disposed in a first measurement plane and a second acquisition system disposed in a second measurement plane that are disposed in the azimuthal direction around a common rotation axis, position correction values for both measurement planes are determined for a substantially constant rotation angle speed of the two acquisition systems using measurement values calculated at a rotation angle position of a reference object that can be introduced into both measurement planes. An artifact-free reconstruction of a slice or volume image can be made using the position correction values.

Abstract: In a method and a tomography apparatus for fast volume scanning of an examination region with at least two acquisition systems. Given a helical scanning of the examination region, a particularly fast scanning of the volume is achieved by projection gaps of the examination region in projections acquired with the first acquisition system being filled by projections with the second acquisition system.

Abstract: In a tomography apparatus and operating method, at least two acquisition systems are respectively each disposed in the azimuthal direction at respective specific system angles around a common rotation axis. Both system angles can be determined for a substantially constant rotation angle speed of the two acquisition systems on the basis of measurement values, which are calculated at a rotation angle position of a reference object that can be introduced into both measurement planes. The tomography apparatus in this manner enables artifact-free reconstruction of a slice or volume image using the system angles determined in this manner.

Abstract: In a tomography apparatus and method for obtaining correction values for two measurement planes, wherein the tomography apparatus an acquisition system disposed in a first measurement plane and a second acquisition system disposed in a second measurement plane that are disposed in the azimuthal direction around a common rotation axis, position correction values for both measurement planes are determined for a substantially constant rotation angle speed of the two acquisition systems using measurement values calculated at a rotation angle position of a reference object that can be introduced into both measurement planes. An artifact-free reconstruction of a slice or volume image can be made using the position correction values.