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 reconstructing image data of an object under examination from measured data, with the measured data having been detected beforehand during a relative rotational movement between a radiation source of a computer tomography system and the object under examination. In at least one embodiment, a radiation scatter correction variable is determined, which is subjected to a low pass filtering. The filtered radiation scatter correction variable is connected with the measured data to correct the measured data, and image data is reconstructed from the measured data thus corrected.

Abstract: A method and a device are disclosed for generating a CT image with a high time resolution using a computed tomography scanner which has at least two recording systems which are operated at different X-ray energy spectra. In at least one embodiment of the process, CT images are firstly reconstructed in each case from a semi-rotation with the two recording systems, with irradiated lengths of the contrast agent-enriched structures and the soft tissue being calculated therefrom. Subsequently, a common X-ray energy is assumed and artificial measurement data records are calculated therefor, using the knowledge of the irradiated lengths for both recording systems at the same common X-ray energy. The artificial measurement data of respectively a quarter-rotation per recording system is then used to calculate the final CT image with a high time resolution. The method affords the use of dual-energy scans without losing the high time resolution available in dual-source systems.

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 medical imaging method and associated device for generating an image data record of a recording region of a patient, which region is influenced by a cyclical cardiac motion, in which an EKG signal is used to derive a series of recording pulses matched to the cardiac motion, by which pulses the imaging is actuated in a pulsed fashion. In at least one embodiment, a time window of a future recording pulse is calculated taking into account at least one dispersion parameter characterizing the variation in the cycle duration and a location parameter characterizing the expected value of the cycle duration, wherein the dispersion parameter is included into the calculation of the time window using a weighting determined on the basis of the location parameter.

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 for producing CT images of at least one second organ cyclically excited to move by a first organ moving on its own, or examination area with rest phases and activity phases of a patient. The second organ or the examination area is scanned, preferably spirally. A three-dimensional image of the absorption coefficient is determined with the aid of a multiplicity of cutting planes on the basis of the data obtained by scanning in the rest phase of the second organ or examination area, and the movement information required to determine the rest phase is collected from the first organ.

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: 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 filter method for tomographic 3D displays is disclosed, in which a volume model is used for display, which reproduces the volume of the examination object in the form of a large number of three-dimensional image voxels, and the image value of each voxel reproduces one object-specific characteristic of the examination object in this volume. According to the method, the original image voxels are processed using a 2D filter which is the same over the entire image area, and two different linear filters with selected directions which are obtained from the extremes of the previously calculated variances thus resulting in three data records with differently filtered image voxels, and in which, furthermore, the original image voxels and the filtered image voxels are mixed using local weights to form a result image.

Abstract: A method and a device are disclosed for generating a CT image with a high time resolution using a computed tomography scanner which has at least two recording systems which are operated at different X-ray energy spectra. In at least one embodiment of the process, CT images are firstly reconstructed in each case from a semi-rotation with the two recording systems, with irradiated lengths of the contrast agent-enriched structures and the soft tissue being calculated therefrom. Subsequently, a common X-ray energy is assumed and artificial measurement data records are calculated therefor, using the knowledge of the irradiated lengths for both recording systems at the same common X-ray energy. The artificial measurement data of respectively a quarter-rotation per recording system is then used to calculate the final CT image with a high time resolution. The method affords the use of dual-energy scans without losing the high time resolution available in dual-source systems.

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 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: An x-ray system is disclosed including a selector for finding an optimum combination between the contrast medium and the energy spectrum of an x-radiation for a scan to optimize the noise-to-contrast ratio. A method for creating X-ray images is also provided. The x-ray images are created with the aid of contrast media by taking into account an optimal combination between the contrast medium and the energy spectrum of an X-radiation used for a scan. A method for the use of a lanthanide-containing complex to produce a contrast medium for optimizing the combination between the contrast medium and the radiation to obtain a maximum contrast-to-noise ratio in an X-ray image is also provided.

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 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 is for filtering tomographic 3D images of an examination object. The examination object is imaged by using a volume model that divides the volume of the examination object into a multiplicity of three-dimensional image voxels with individual image values, wherein the image value of each voxel reproduces an object-specific property of the examination object in this volume. After the reconstruction of the total volume for each voxel, variances are calculated in a prescribed region or radius R in order to determine contrast jumps and their spatial orientation with their tangential planes T. The image values in the tangential plane T are filtered with a two-dimensional convolution, and subsequently the original voxel data are mixed in weighted fashion with the filtered voxel data.

Abstract: A method and a CT system are disclosed for carrying out a cardio-CT examination of a patient. The patient first is scanned using a first X-ray spectrum by way of at least two X-ray tubes at a first relative position, until the measurement data has been gathered from a determined heart phase for parallel projections over a range of in total at least 180° of projection angles. The patient is then scanned, without changing the position of the gantry, at the first relative position by way of at least two X-ray tubes using at least one second X-ray spectrum, until the measurement data has been gathered from a determined heart phase for parallel projections over a range of at least 180° of projection angles, upon which the next relative position between the patient and the gantry is moved to.