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 producing tomographic images relating to different movement phases of a periodically moving object with the use of a tomography unit that includes a recording system that is arranged rotatably about a z-axis of the tomography unit, the recording system including an X-ray tube to which a tube current can be applied and a detector (17, 18) for acquiring projections. In at least one embodiment, the recording system is initially positioned relative to the object at a first z-position, and projections are acquired from a multiplicity of different projection dimensions at this z-position, in a fashion triggered by a movement signal representing the movement of the object, projections relating to a first movement phase of the object being acquired in a prospectively defined first time window and projections relating to at least a second movement phase of the object being acquired in a prospectively defined second time window.

Abstract: A method and an image reconstruction device are disclosed for reconstructing image data on the basis of input projection data obtained via an X-ray computerized tomography system. A target convolutional kernel is selected, which, when reconstructing image data from the input projection data using simple filtered back projection, would lead to target image characteristics. Image data is then reconstructed using an iterative reconstruction method of at least one embodiment.

Abstract: A method is disclosed for reconstruction of image data of an examination object from measured data, wherein the measured data was captured during a relative rotational motion between a radiation source of a computed tomography system and the examination object. Image data of the examination object is determined from the measured data. In at least one embodiment, new image data is obtained by noise-reducing processing of the image data, in which weighted high-pass filtering of the image data is performed, the weighting taking account of differences between pixel values of different pixels such that increasing differences result in a weaker high-pass effect. A noise-reducing smoothing of the image data is performed using the weighted high-pass filtering.

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 described for imaging an organ in a human or animal body via a computed tomography system having an X-ray radiation source which rotates around the body along a circumferential ring. In at least one embodiment, the circumferential ring in each case is fixed in one position for recording of an image data segment on one slice plane during one revolution of the X-ray radiation source relative to the body, and the X-ray radiation source is triggered by a cycle signal which represents a movement cycle of the organ and is activated for a limited measurement time interval. In at least one embodiment, the circumferential ring is moved sequentially to further positions relative to the body between each of the recordings, in order to record image data on further slice planes. In at least one embodiment, the timing and duration of the measurement time interval for an image data segment to be recorded are dynamically matched to a structure of the cycle signal.

Abstract: At least one embodiment of the present invention relates to a CT scanner and/or a method for helical scanning of an examination object which has at least one portion undergoing periodic motion.

Abstract: A method is disclosed for generating computed tomography displays, in which with the aid of at least one X-ray source, an examination object is scanned in a rotationally circulating fashion with a measured dose rate dependent on the circulation angle, projection data are collected from a multiplicity of viewing angles, and at least similarly redundant projection data from angularly identical or angularly complementary projection angles with a different measured dose are interpolated with distance weighted relative to a projection value and are used for reconstruction. According to at least one embodiment of the invention, during the distance weighted interpolation of the at least similarly redundant projection data an additional noise optimizing weighting is carried out as a function of the noise present per projection value.

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 the course of an imaging method that is particularly suitable for creating an image data record of the heart and/or the blood vessels of a patient, a series of recording pulses, tuned to the cardiac rhythm, are derived from an ECG signal of the cardiac rhythm of the patient. The imaging is driven in a pulsed fashion from the series of recording pulses. In this case, an initial instant and a final instant of a future recording pulse are determined by taking account of at least one variability parameter characterizing the irregularity of the cardiac rhythm.

Abstract: A method and an image reconstruction device are disclosed for reconstructing image data on the basis of input projection data obtained via an X-ray computerized tomography system. A target convolutional kernel is selected, which, when reconstructing image data from the input projection data using simple filtered back projection, would lead to target image characteristics. Image data is then reconstructed using an iterative reconstruction method of at least one embodiment.

Abstract: A method is disclosed for reconstructing image data of an examination object from measured data, the measured data being captured during a rotating movement of a radiation source of a computed tomography system around the examination object. In at least one embodiment, different iteration images of the examination object are determined successively from the measured data by way of an iterative algorithm, wherein with the iterative algorithm the current iteration image at any one time is high-pass-filtered and weighted as a function of contrast using a variable which contains contrast information relating to the current iteration image at that time.

Abstract: Method for the noise reduction of CT image data and an image processing system are disclosed, with a scanning of an examination object and generation of at least two CT image data records each taking place on the basis of a different x-ray energy spectrum. In at least one embodiment, a break-down of the data image records into at least two broken-down image data records takes place in each instance, with a lowest local frequency band (f(1)) with the index k=1 and at least one high local frequency band (f(k)) with the index k=2 to N.

Abstract: At least one embodiment of the invention relates to a method for the scanning of a moving examination object with a CT system, in which during a rotational movement of a transmitter/receiver pair around the examination object, data is captured. Further, sectional images of the examination object are determined from the data by way of an iterative algorithm, where motion information relating to the movement of the examination object during the data acquisition is taken into account in the iterative algorithm. At least one embodiment of the invention further relates to a CT system and a computer program.

Abstract: A multi-emitter computed tomography scanner is disclosed, including a plurality of x-ray emitter/detector arrangement pairs arranged offset at an angle to one another. In at least one embodiment, the detector arrangements of the pairs are designed to be energy selective.

Abstract: A method is disclosed for scanning an examination object with a CT system and the generation of at least one computed tomographic sectional view from data obtained from the scanning and a CT system. In at least one embodiment, data used for generating the at least one sectional image is filtered out with different intensities as a function of a predetermined time range and/or projection angle range of the measurement of high local frequencies.

Abstract: A method is for generating tomograms of a cyclically and complexly moving examination object using a tomography unit that reconstructs tomograms in at least one slice plane from detector output data. At least two tomograms from different phases of the movement cycle of the examination object are reconstructed in the region of at least one slice plane. The tomograms are subdivided automatically into subregions with good and bad image quality, and at least one complete tomogram is assembled from subregions with relatively good image quality per slice plane.

Abstract: A method is disclosed for compiling computer tomographic representations using a CT system with at least two angularly offset ray sources. A first ray cone with a relatively larger fan angle and a second ray cone with a relatively smaller fan angle scan an object circularly or spirally. The first ray cone generates a first dataset A and the second ray cone generates a dataset B. The dataset B of the smaller ray cone is supplemented with other data at the edge to give an expanded dataset B+ for reconstruction of the CT representation. The expanded dataset B+ of the second, smaller ray cone and the dataset A of the first, larger ray cone is subjected to a convolution operation to give datasets B+? and A?. Finally, a back projection to reconstruct sectional images or volume data is respectively carried out from the convoluted datasets B+? and A?. The dataset B is supplemented with data of the dataset A and supplementary data are removed from the dataset B+? after the convolution but before the back projection.

Abstract: An x-ray CT system and a method are disclosed for creating tomographic recordings with the aid of an x-ray CT system, with two emitter/detector arrangements operating with an angular offset on a gantry with at least two different x-ray energy spectra. In at least one embodiment, at least one first recording is reconstructed from detector data from two quarter rotations with different x-ray energy spectra and at least one second recording is created from detector data of a scan of at least one of the emitter/detector arrangements over a half rotation. According to at least one embodiment of the invention, the recordings are subjected to high-pass filtering or low-pass filtering in respect of their spatial frequencies and then the filtered recordings are combined to give a resulting recording.

Abstract: A method and a CT unit are disclosed for taking cardio X-ray CT pictures, in the case of which a synthetic clock signal is used to display a clock, during each cycle phase of the synthetic clock signal. Test volume data records of the heart are reconstructed at a number of different phase instants of the synthetic clock over the complete scan, which are respectively associated with their phase instants and their z-position. Subsequently, a correlation calculation between test volume data records that are temporally neighboring and spatially identical or at least belong to the same slice plane are used to determine maxima of the correlation. Finally, imaging volume data records are subsequently calculated from the spatiotemporally associated detector data.