Abstract: A method is disclosed for scattered radiation correction in an X-ray computed tomography system having at least two tube-detector systems. It is provided, according to at least one embodiment, to make use of a data record that includes data projections required for the reconstruction and a prescribed number of first scattered radiation projections. Respective scattered radiation components for the scattered radiation correction of all data projections are determined on the basis of the first scattered radiation projections and second scattered radiation projections determined therefrom.

Abstract: A method is for recording and evaluating image data with the aid of a tomography machine. At least two recordings with different spectral distribution are made of an examination area of an object. Further, measured data obtained from the two recordings are evaluated such that additional information relating to the examination area and/or a specific representation of the image of the examination area are/is obtained from the different spectral distributions. The tomography machine includes at least two separate recording systems. Further, it is operated such that the two recording systems operate with a different spectral distribution. As such, the additional information and the specific representation of an image can be obtained in conjunction with a reduced scanning time.

Abstract: It is proposed to estimate the scattered radiation on the basis of a sinogram, which is measured in any case. In at least one embodiment, a method includes determining the potential scattering site for each measuring beam from the object tangents in the sinogram and calculating the scattered intensity from the primary radiation striking the scattering site and the angle ratios of scattering beam, object tangent and measuring beam. Also proposed, in at least one embodiment, is an X-ray CT having at least bifocal detector systems and a control and computer unit for producing tomographic pictures, the control and arithmetic unit of which contains a program code that, upon being executed, carries out the method.

Abstract: In a method and filter and computer product for adaptive filtering of projection data acquired by a medical diagnostic apparatus, raw data-based filtering of the acquired projection data is undertaken using a filter with a filter kernel having a constant filter width, and the filtered projection data are mixed with the acquired projection data with a fixing of the respective quantitative relationships of filtered projection data to acquired projection data ensuing dependent on respective subsets of the acquired projection data.

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: A method is disclosed for producing tomographic pictures with the aid of an X-ray CT system including at least two X-ray sources arranged on a gantry with an angular offset to scan an examination object. In at least one embodiment of the method, in order to determine the scattered radiation distribution, pre-scanning is carried out in which the X-ray sources rotate about the examination object and the dose rate is modulated as a function of the rotation angle, no radiation dose is output over the majority of the revolution, at specific pre-scan angles a dose rate is produced briefly and individually in each case by the X-ray sources of the focus/detector systems, and the received scattered radiation is measured simultaneously by the detectors of the at least one other focus/detector system.

Abstract: A method is disclosed for production of tomographic slice images of an examination object using a computed tomography scanner. In order to scan an examination object, at least two X-ray beams are produced, which each are at offset angles and fan out from a focus to an opposite detector and scan the examination object. The scans at least partially overlap. Detector output data which is emitted from the detector elements is measured together with physical orientation data of the beams and is converted to projection data sets. Slice images are then calculated. In order to calculate the complete slice images, data which is redundant from the measured data of the at least two X-ray beams from overlapping projection intervals is used for each complete slice image. The size of the overlap area of the projection data used from the individual X-ray beams is defined before the calculation of the slice images, in order to vary time resolution and image quality.

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: A method and a CT system are disclosed for determining movement and rest phases of a partial object that moves at times in an examination object during a CT examination. In at least one embodiment, at least two different radiation sources are used for the comparative measurement, and a first radiation source emits a first fan beam at a specific rotation angle at a first instant, the absorption of said beam being measured in beamwise fashion, a second radiation source emits a second fan beam, at the same rotation angle at a second, later instant, the absorption of the beam likewise being measured in beamwise fashion, and the relative movement or relative rest of the partial object between the first and second instants is deduced by comparing deviating absorption values of a multiplicity of spatially equivalent and equidirectional fan beams proceeding from the same angular position of the radiation sources.

Abstract: A method and a tomography unit are disclosed for taking tomographic pictures of a patient's beating heart, in particular X-ray CT pictures. In such a method and tomography unit, only detector data or image data of a portion of the cardiac phase from one or more heart beats is used for taking a picture. Further, at least one pressure signal, produced by the mechanical cardiac pulse and varying temporally with the cardiac cycle, is used for determining the cardiac phase.

Abstract: A computed tomography unit includes at least one X-ray tube, that scans an object in a fashion rotating in a circle or spiral about a z-axis, in combination with an oppositely situated detector having a multiplicity of detector rows. Each detector row includes an aperture ?z in the z-direction, having a multiplicity of detector elements. Between the X-ray tube and detector, a detector diaphragm is arranged that reduces the aperture ?z of the detector rows in the z-direction. The X-ray tube includes a focus, of variable location relative to the X-ray tube and which alternatingly assumes during scanning at least two different positions that have different z-coordinates relative to the X-ray tube R.

Abstract: A method is for determination of at least one of the position and orientation of three-dimensional structures of a patient. One topographic scan of the patient is recorded simultaneously per tube detector combination with the aid of a computed tomography scanner which has at least two tube detector combinations arranged at a fixed angle to one another. Each detector has at least one row with a large number of individual detector elements. The at least two tube detector combinations are moved exclusively linearly parallel to the system axis of the CT and relative to the patient.

Abstract: A method for scanning a beating heart with the aid of a spiral CT system and a cardio CT system are disclosed. In at least one embodiment, rhythm signals of the beating heart are recorded and stored in a temporally correlated fashion, and only detector data that originate from a selected cycle area of the cardiac cycle are measured in order to reconstruct the tomographic section image data or volume data, the scanning being carried out with a runup distance and a runout distance for the purpose of complete scanning of the subarea of the patient with the beating heart on the basis of the spiral scanning. According to at least one embodiment of the invention, at least one of the requisite runup distance and runout distance is determined on the basis of the measured cycles of the current rhythm signal of the patient, and an appropriate program code is present in the cardio CT system.

Abstract: It is proposed to estimate the scattered radiation on the basis of a sinogram, which is measured in any case. In at least one embodiment, a method includes determining the potential scattering site for each measuring beam from the object tangents in the sinogram and calculating the scattered intensity from the primary radiation striking the scattering site and the angle ratios of scattering beam, object tangent and measuring beam. Also proposed, in at least one embodiment, is an X-ray CT having at least bifocal detector systems and a control and computer unit for producing tomographic pictures, the control and arithmetic unit of which contains a program code that, upon being executed, carries out the method.

Abstract: A method is for taking tomograms of a patient's beating heart with the aid of a computed tomography unit. ECG signals of the beating heart are recorded. In order to reconstruct the cardiac tomograms, use is made of detector data that originate from a selected cycle area of the cardiac cycle. The cycle area from which the data for the reconstruction originate is selected automatically and individually per cycle, for at least one cardiac cycle, by use of pattern recognition.

Abstract: A method is disclosed for reducing step artifacts in the forward increment direction of a cardio CT representation. In at least one embodiment, volume recordings or section images of first and second sub-volumes of a heart volume, which lie adjacent to one another in the forward increment direction and partially overlap in an overlap region, are recorded by a computer tomography system. Each sub-volume's detector data is used for the reconstruction coming from different heart cycles. Finally, a displacement vector relative to a second sub-volume is determined at least for a selected point of the overlap region of a first sub-volume and the second sub-volume is subjected at least partially to a spatial transformation according to the at least one displacement vector.

Abstract: A method is disclosed for a multislice computer assisted tomograph, capable of carrying out a spiral scan of an object volume with a pitch p selected to be small enough that each slice of the object volume is multiply detected during the spiral scan. The method includes calculating, using measured data of two temporally consecutive at least one of revolutions and half revolutions, an image of the object volume from which a change inside the object volume between the two temporally consecutive at least one of revolutions and half revolutions is directly visible. An embodiment of the method can permit, for example, the detection and visualization of dynamic processes with an enhanced time resolution.

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.