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: 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: 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 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 disclosed for noise reduction of CT image data and an image processing system is disclosed. An object under examination is scanned and at least two CT image datasets are created, each being undertaken on the basis of a different x-ray generation process. Subsequently, the image datasets are split up into at least two split-up image datasets, with a lowest local frequency band and at least one high local frequency band. In at least one embodiment, this is followed by the determination of the noise in at least one of the image datasets for each x-ray spectrum and calculation of at least one new image dataset using an unchanged split-up image dataset in each case with the lowest frequency band and an image dataset created from a noise-minimized weighted combination of split-up image datasets, which originate from the scans with different x-ray energy spectrums.

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 diaphragm and diaphragm device for the specific manipulation of x-ray radiation that emanates from an x-ray focus of a CT apparatus and serves for scanning an examination subject, wherein the x-ray focus and the diaphragm arranged relatively near to the focus can be rotated together around a system axis (z-axis), and the diaphragm has movable diaphragm elements that dynamically adjust a diaphragm aperture (and therefore the spatial divergence of the x-rays passing through the diaphragm aperture). The diaphragm elements have a transmission factor for x-ray radiation that is different than zero. With such a diaphragm or diaphragm device the acquisition of the projection data necessary for the reconstruction of an artifact-free image of a region of interest (ROI) is possible with lower radiation exposure of the examination subject.

Abstract: A motion control method is disclosed for controlling a relative scan feed motion of an object bearing device toward a scanner unit of a computed tomography system. Here, scan motion control signals are generated parallel to the scan feed motion for controlling the scan feed motion, which scan motion control signals are derived from variable input data obtained in parallel during a scan procedure. In at least one embodiment, the variable input data includes motion signals which represent the object motion cycle determined with the aid of an electrocardiogram, and the speed of the scan feed motion is reduced if an extrasystole is detected. Furthermore, at least one embodiment of the invention relates to a motion control module suited to this and/or an image processing actuation method and/or an image processing actuation module for actuating an image processing system.

Abstract: A method is disclosed for generating computed tomography image data records of a patient in a heart CT scan during a perfusion control by applying contrast agent. In at least one embodiment, a plurality of temporally consecutive CT data records are recorded as an exposure series with a CT system and if necessary are reconstructed. These CT data records are improved for better visualization of the perfusion by way of electronic filtering and post-processing, with all projection and/or image data determined during a CT scan being used, however with the aid of frequency filtering only the data of a projection or of a reconstructed image for generating a final representation being used which does not fall within a predetermined local frequency range of a heart movement.

Abstract: A method is disclosed for creating computed tomography recordings of a patient with metallic components.

Abstract: A method of at least one embodiment has three method sections. In the first method section, 3D projection data is generated by 3D scanning of the examination subject and first 3D image data is reconstructed therefrom by means of convolution back projection. In the second method section, the image artifacts present in the first 3D image data because of the metal parts are corrected via simple correction methods which produce at least a coarse reduction in the image artifacts involving a low degree of computational complexity. In the third method section, 2D image data is selected from the corrected 3D image data and made available. For image artifacts still contained in the 2D image data, more complex correction methods than in the second method section are used which permit effective elimination of the image artifacts.

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 is disclosed for differentiating and displaying moving and stationary heart regions of a patient in X-ray CT. In at least one embodiment, the method includes carrying-out circular or helical scanning of a patient in the region of his or her heart using an X-ray CT scanner including a detector with a multiplicity of detector elements, and storing at least one sinogram from a multiplicity of projection data from encircling projection directions; and reconstructing at least one tomographic display of the heart from the at least one sinogram and displaying the at least one reconstructed display of the heart. According to at least one embodiment of the invention, the projection data are Fourier transformed, filtered with respect to a predetermined frequency, inverse transformed, reconstructed, and output together with the tomographic display of the heart.

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 is disclosed for production of computer-tomographic scans via a CT system of a patient during an intervention with an instrument. An X-ray tube is moved on a rotation plane around the patient in order to produce a beam cone, and a detector with a plurality of detector elements measuring the radiation intensity after passing through the patient. Computer-tomographic scans are reconstructed from the measured values in a computation unit. The central direction of the beams of the scanning beam cone is set at an angle to the intervention axis, and at least one slice plane which differs from the rotation plane of the beam cone is displayed on a display.

Abstract: A method and a computed tomography system are disclosed for producing computed tomograms of an object. A set of detector output data that represent beams over a specific angular range and a scan of a specific subregion of the object, are divided into m?2 complete partial detector output data records that respectively cover the same complete angular range, but are reduced with their sampling density by 1/m and have mutually independent data records. Intermediate image data records (m records) that represent the identical object region are reconstructed from the m complete partial detector output data records. A correlation analysis is carried out between the m intermediate image data records. Finally, an image data record is produced that consists only of correlated data and includes no uncorrelated data.

Abstract: A method and an x-ray computed tomography system are disclosed for visualizing at least two different types of cardiac tissue, such as normally perfused tissue, hypoperfused tissue and scarred tissue.

Abstract: A method, a computational unit and a CT system are disclosed for improving the quality of CT image series. In at least one embodiment, the method includes scanning an examination object over a period of time which permits the acquisition of at least two temporally offset projection data records of an identical recording region; generating at least two temporally offset tomographic image data records, each having a multiplicity of pixels, by reconstructing the projection data records; transforming the image data records into transformation data records of at least two spatial frequency ranges; calculating temporal fitted values of the transformation data records for some of the spatial frequency ranges, and replacing the values of the transformation data records which were fitted by the calculated fitted values; performing an inverse transform of the transformation data records with the fitted values to form new image data records; and displaying the new image data records.

Abstract: A method is disclosed for increasing the quality of computer tomographic recording series, to a computation unit and to an X-ray CT system. An embodiment of the method includes scanning a subject over a period of time which makes it possible to record at least two temporally offset projection data sets of the same recording region; transforming the projection data sets into transformation data sets for at least two spatial frequency ranges; calculating temporal compensation values of the transformation data sets for some of the spatial frequency ranges and replacing the compensated values of the transformation data sets with the calculated compensation values in new transformation data sets, projection data of congruent rays always being compared; transforming the new transformation data sets back into new projection data sets; reconstructing image data sets on the basis of the new projection data sets and representing the image data sets.