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 filter for an x-ray device to shape an intensity profile of x-ray radiation emanating from an x-ray source of the device has a filter body made of a material that attenuates x-ray radiation. The filter body is designed with a propeller shape and has two blades connected by an axle of the filter. The filter body is rotatable around the axle, which is permeable to the x-ray radiation. The x-ray device embodies at least one such filter.

Abstract: A method is disclosed for reconstructing image data of an examination object from measurement data of a computed tomography system, the examination object having been irradiated simultaneously by a number of X-ray sources while the measurement data was being acquired so that different projections of the examination object associated with the number of X-ray sources were acquired simultaneously for each detector element. In at least one embodiment, different iteration images of the examination object are determined one after the other from the measurement data by way of an iterative algorithm, a computation operation being employed with the iterative algorithm, which is applied to the iteration images and takes the presence of the number of X-ray sources into account.

Abstract: A method is disclosed for reconstructing image data of an examination object from measurement data, wherein the measurement data were captured previously during a relative rotational movement between a radiation source of a computed tomography system and the examination object. Filtered measurement data are calculated from the measurement data. First image data are calculated from the measurement data. Edge information is obtained from the first image data, wherein the edge information, depending on position, specifies strength and direction of edges within the first image data. New measurement data are calculated using the edge information by mixing the measurement data and the filtered measurement data and second image data are calculated from the new measurement data.

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: For improved sampling, an x-ray detector system for a computed tomography scanner is provided. In an embodiment, the x-ray detector system includes at least one detector row which includes a plurality of detector modules each having a plurality of detector elements. Along the at least one detector row, a first portion of the detector elements is arranged in a grid at a first grid spacing in relation to its respective neighboring detector elements, and a second portion of the detector elements is arranged in a grid at a second grid spacing in relation to its respective neighboring detector elements.

Abstract: A method is disclosed for the reconstruction of image data of a moving object to be examined from measurement data, wherein the measurement data has previously been established in a relative rotational movement between a radiation source of a computed tomography system and the object to be examined. In at least one embodiment, first image data is reconstructed from an incomplete measurement data record by way of an iterative algorithm, wherein in the iterative reconstruction a dimension is used which contains probability information relating to pixel values of the image data to be reconstructed.

Abstract: A method and computer system are disclosed with software for artifact reduction in CT image datasets for spiral scans from a CT system with an inclined gantry. In at least one embodiment, for each of at least two positions of the center of rotation, which is moved during the spiral scan, the removal of annular artifacts is carried out around these positions, during which the position concerned is used as the center point of the annular artifacts to be removed.

Abstract: A method is disclosed for reconstruction of image data of an object under examination from measurement data, with the measurement data having been captured during a relative rotational movement between a radiation source of a computed tomography system and the object under examination. In at least one embodiment, first image data is computed by the measurement data being modified to obtain a specific gray value characteristic of the first image data to be reconstructed and the first image data is computed by way of an iterative algorithm using the modified measurement data. Second image data is also computed by a series of chronologically-consecutive images being reconstructed and processing being carried out on the series of images to reduce temporal noise. Finally a combination of the first and the second image data is carried out.

Abstract: A method is disclosed for reconstructing image data of a moving examination object from measurement data, wherein the measurement data was captured in the course of a relative rotational movement between a radiation source of a computed tomography system and the examination object. In at least one embodiment of the method, a first image of the examination object is calculated from a complete measurement data record of the measurement data for an image reconstruction and a second image of the examination object is calculated from an incomplete measurement data record of the measurement data for an image reconstruction. Frequency splitting of the first and second images takes place respectively in at least one low-frequency and one higher-frequency component and the image data of the second image is supplemented in the low-frequency component with image data of the low-frequency component of the first image.

Abstract: A method is disclosed for the reconstruction of picture data of a moving object under examination from measurement, with the measurement data having been recorded beforehand for a relative rotational movement between a radiation source of a computed tomography system and the object under examination. In at least one embodiment, first picture data is computed from a complete measurement dataset of the measurement data for a picture reconstruction, and second picture data is computed from an incomplete measurement dataset for a computed tomography picture reconstruction. The first picture data and the second picture data are combined into third picture data, with the combination being computed using location-dependent movement information of the object under examination.

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: In at least one embodiment, a circuit arrangement of a quanta-counting detector with a multiplicity of detector elements is disclosed, wherein the X-ray quanta registered in each detector element generate a signal profile. In at least one embodiment, the circuit arrangement, in each detector element, includes: at least one first comparator with a first energy threshold lying in the energy range of the measured X-ray quanta and at least one second comparator with a second energy threshold lying above the energy range of the measured X-ray quanta, the at least one first and second comparators being connected to the detector element. Further, the at least two comparators have a logical interconnection, wherein at least a first comparator and a second comparator are connected to the inputs of an XOR gate, and each XOR gate connected to a first comparator is connected to precisely one edge-sensitive counter.

Abstract: A method is disclosed for reconstructing image data of an examination subject from measured data, wherein the measured data was acquired in the course of a relative rotational movement between a radiation source of a computed tomography system and the examination subject. A limited area between the radiation source and a detector represents a field of view in respect of which measured data can be acquired, and parts of the examination subject were located at least temporarily outside the field of view in the course of the measured data acquisition. In at least one embodiment, first image data is reconstructed from the measured data, and a boundary of the examination subject is determined with the aid of the first image data. The first image data is subsequently modified using the determined boundary, and projection data is calculated from the modified first image data. The measured data is modified using the projection data, and finally second image data is reconstructed from the modified measured data.

Abstract: A method is disclosed for detecting X-ray radiation from an X-ray emitter. In at least one embodiment of the method, an electric pulse with a pulse amplitude characteristic of the energy of a quantum is generated when a quantum of the X-ray radiation impinges on a sensor, wherein a number of threshold energies are predetermined. When the pulse amplitude corresponding to the respective energy is exceeded, a signal is emitted each time the pulse amplitude corresponding to a respective threshold energy is exceeded. At least one embodiment of the method permits reliable and high-quality imaging, even in image regions with high X-ray quanta rates. To this end, at least one of the threshold energies is predetermined such that it is higher than the maximum energy of the X-ray spectrum emitted by the X-ray emitter.

Abstract: At least one embodiment of the invention relates to a method for the reconstruction of image data of an examined object from measuring data, wherein the measuring data were detected by a detector within and outside of its Tam-Danielsson window during a relative spiral movement between a radiation source of a computer tomography system and the examined object. As a result of the spiral movement, the measuring data outside of the Tam-Danielsson contain interruptions. A mathematically precise first reconstruction of first image data is realized in at least one embodiment based on the measuring data by using only measuring data from the Tam-Danielsson window.

Abstract: A filter for an x-ray device to shape an intensity profile of x-ray radiation emanating from an x-ray source of the device has a filter body made of a material that attenuates x-ray radiation. The filter body is designed with a propeller shape and has two blades connected by an axle of the filter. The filter body is rotatable around the axle, which is permeable to the x-ray radiation. The x-ray device embodies at least one such filter.

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 and computer system are disclosed with software for artifact reduction in CT image datasets for spiral scans from a CT system with an inclined gantry. In at least one embodiment, for each of at least two positions of the center of rotation, which is moved during the spiral scan, the removal of annular artifacts is carried out around these positions, during which the position concerned is used as the center point of the annular artifacts to be removed.

Abstract: A method is disclosed for transmitting measurement data from a transmitter system to a receiver system by way of a transmission link of a medical device. In an embodiment, the measurement data, as input data of a transformation method, is transformed to output values and, after transmission, back transformed again, the values of the input data lying between a maximum value and a minimum value and an assignment function being used for compression purposes, to allocate an output value to every value of the input data, a root function being used as the assignment function for at least some of the values.