Abstract: A method and a tomography unit are disclosed for carrying out an analysis of a movement of an object on the basis of at least two images produced with the aid of a tomography unit at consecutive instants. A) vector field, formed from displacement vectors, is determined from in each case two images and at least one divergence value is calculated for analyzing the movement from the vector field. The divergence value renders it possible in a simple way to acquire a contraction movement or expansion movement in a qualitative and quantitative fashion, the sign of the divergence value specifying the type of movement, and the absolute value specifying the magnitude of movement of the object.

Abstract: An imaging method is disclosed for a multi-slice spiral CT scan. A CT unit is disclosed for carrying out this method. In the method, the filtering may be formed by use of multiple applications of a ramp filter and a masking operation to a projection image in a different sequence. The CT unit may include, for filtering purposes, multiple applications of a ramp filter and a masking operation to a projection image in a different sequence.

Abstract: A method is disclosed for generating cardiac CT representations of a beating heart of a patient with the aid of a multi-tube CT system with application of a contrast medium. In at least one embodiment, the method includes carrying out a first CT scan with the multi-tube CT system, wherein at least one tube generates an X-ray spectrum, and reconstructing at least one CT representation of the same cardiac phase with a first temporal resolution; subsequently carrying out a second CT scan with the multi-tube CT system, wherein at least two angularly offset tubes generate different X-ray spectra; reconstructing at least one CT representation of the same cardiac phase per X-ray spectrum with a second temporal resolution; and generating a combined CT representation from results of the first and of the second scan.

Abstract: A detector for x-ray computer tomography scanners, includes a number of adjacent detector lines extending in an x direction, whereby each detector line is formed from a multitude of adjacent scintillator elements. In order to increase the resolution in the z direction and to simplify the design of the detector, the surface of the scintillator elements are partially covered, which further serves to reduce the size of the aperture in the z direction.

Abstract: In a method for computed tomography and a computed tomography apparatus for scanning a subject with a conical ray beam emanating from a focus that detects a matrix-like detector array, the focus is moved relative to the subject on a spiral path around a system axis, and the detector array supplies output data corresponding to the incident radiation, and images having an inclined image plane are reconstructed from output data respectively supplied during the movement of the focus on a spiral segment, the image planes of these images are inclined by an inclination angle ? around a first axis intersecting the system axis at a right angle and also are inclined by a tilt angle ? with respect to the system axis around a second axis that intersects the first axis as well as the system axis at a right angle.

Abstract: A method is disclosed for the production of CT images via a CT spiral reconstruction of object for examination moving in partial areas in a cyclical manner and a CT device therefor. During scanning of the object to be examined, various rates of advancement are used, irrespective of whether the scanned area is at least partially cyclically displaced or is stationary.

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 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 and computed tomography unit are disclosed for producing computed tomograms of a patient's beating heart by voxelwise reconstruction of volume data records from prescribed cardiac cycle phases. Firstly, a multiplicity of voxelwise partial reconstructions are calculated from projection segments substantially smaller than 180° in accordance with small cardiac phase segments. The complete voxel data that cover overall at least 180° and originate from a preselected cardiac phase are subsequently summed up per cardiac phase to be considered from the pool of the incomplete reconstructed voxel data.

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: A method and a CT unit are proposed for producing CT images of an examination object having a periodically moving subregion, preferably a beating heart, by multi-planar reconstruction. Subsequent to joining the axial images with pixels from a number of partial volumes calculated for the rest phases, a reduction takes place to reduce artifacts occurring in overlap regions. This is done by carrying out threshold value formation in the zone of the boundary regions of the partial volumes with result image Dz. A pixel-oriented median filtering then occurs, resulting in image Mz. A differential value image is then produced using Fz=Dz?Mz. Subsequently, two-dimensional lowpass filtering is applied to Fz to produce a result image Gz. Finally, a calculation of Bz?Gz is used to form the final image Ez.

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 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: 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: 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.

Abstract: A method is for production of tomographic section images, in particular X-ray CT images, of an at least partially periodically moving examination object with periodically changing movement and rest phases, preferably of a heart of a living being. A number of focus detector combinations are used, with the time resolution of the CT scanner being significantly increased by supplementary combination of detector data in the correct phase. On the one hand, a number of focus detector combinations which scan an examination object at the same time are used; and on the other hand a number of adjacent movement cycles of a periodically moving examination object are performed.

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 method is disclosed for determining at least one scaling factor for measured values obtained with the aid of a computed tomography unit. The computed tomography unit includes at least two recording systems that can rotate about a common rotation axis. Each of the systems includes an X-ray source and a detector having detector elements for detecting X-radiation emanating from the X-ray source. To reduce artifacts when use is made of measured values of the two recording systems in the reconstruction of an image, a scaling factor is determined for the measured values of the first or of the second recording system on the basis of measured values that originate from projections recorded from an object with the aid of the two recording systems. Each of the two recording systems is used to record at least one projection at at least substantially the same projection angle, whose measured values are compared with one another.