Abstract: A method is for improving CT image data from a moving examination object, in particular a beating heart. The method includes moving a focus on a circular track about the examination object, wherein scanning data streams, measured in parallel and in a fashion correlated with one another, are collected from a multirow detector. Further, movement data of the examination object are also collected. Angularly complementary data record elements of the same movement phase are retrospectively selected from a number of movement cycles. The data record elements are then reconstructed and reformatted to form incomplete CT images. Subsequently, the incomplete CT images are added up to form complete CT images.

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 correcting for stray radiation in measured intensity values, the measured intensity values are obtained in an X-ray computed tomography scanner by means of a detector matrix that is situated in a tomography measuring field of the computer tomography scanner and has a multiplicity of detector elements arranged next to one another in a number of adjacent detector rows. At least one reference distribution of the stray radiation intensity is determined in the row direction of the detector matrix, and a stray radiation component of each measured value of intensity is determined starting from this at least one reference distribution, and the measured intensity values are corrected as a function of their respective stray radiation component. In this case, the stray radiation component of the measured values of intensity of at least a fraction of the detector rows is determined by using a recursion method on the basis of the reference distribution.

Abstract: A method is for imaging in computer tomography, in which a periodically moved object to be examined is scanned with the aid of a beam of rays coming from a focus. A two-dimensionally designed detector array generates output data which are filtered in a suitable way and back-projected in order to obtain at least one sectional image which represents the absorption values of the section of the object to be examined in a particular movement state. In the method, on the one hand, a weighting function which weights the spatial distance of a ray in question from the voxel in question is used for the back-projection. Further, on the other hand, a weighting function which represents the time difference from the examination area movement state to be represented in each case is also used.

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: In a method and apparatus for three-dimensional imaging of a moving examination subject, particularly heart imaging with an examination apparatus having at least one C-arm with a radiation source and a radiation receiver, the C-arm rotates around the examination subject at least once through 180° plus the radiation fan angle during the time span in which a contrast agent is in the examination subject for the registration of the two-dimensional projection images, on the basis of which a three-dimensional image reconstruction ensues.

Abstract: A method is for window-controlled filtering of CT images. A CT raw data record is acquired, for example, with the aid of a CT unit or of a C-arc unit. A primary data record is then reconstructed from the CT raw data record by way of, for example, a sharp convolution core and, for example, a narrow slice sensitivity profile. A transfer function is then provided as functional relationship between window width and image sharpness. The image sharpness of the CT image of a selected slice is then automatically calculated, situated in the primary data record, as a function of a selected window width for the selected slice by way of an image processing procedure on the basis of the transfer function.

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 CT scanner are proposed for the production of tomographic section images, in particular X-ray CT images, of a periodically moving object with periodically changing movement and rest phases. For scanning, a number of focus detector combinations with flat detectors are moved on coaxial spiral paths and movement signals from the moving object are measured at the same time in order to detect movement and rest phases. Further, the time correlation between the movement data and the detector output data stored and axial segment image stacks are then reconstructed independently of one another from sub-segments of the spiral paths using the detector output data from each detector which represent a rest phase of the moving object. Additionally, segment image stacks from the n spiral paths of the n focus detector combinations at the correct time are added up in a complementary angle form and in layers to form 180° tomography section images.

Abstract: An imaging tomography apparatus, in particular an x-ray computed tomography apparatus, has two acquisition systems capable of rotating around a common rotation axis. Each of the acquisition systems has a radiator as well as a detector. The maximum measurement fields scanned by the two acquisition systems given rotation around the rotation axis are of different sizes, or can be adjusted to different sizes. In particular, the lengths of both detectors measured in the azimuthal direction—are of different sizes. The tomography apparatus can be fashioned to scan the entire body cross-section of an examination subject or of a patient with conventional temporal resolution, and to scan detail region, such as a heart region, with an increased temporal resolution or accelerated data acquisition rate in comparison to a device with only one acquisition system.

Abstract: Cone-beam computed tomography method to scan an object using a multi-row detector system. The focal point is displaced on a focal path about the system axis, without any relative movement between the object to be examined and the focal point, in the direction of the system axis. The detector system supplies measuring data corresponding to the received radiation and the length of the focal path is at least the same as the length of a partial contour interval, the length of the interval being sufficient for completely reconstructing a CT image. Raw images are calculated from measuring data from a partial contour interval, the planes of the images thereof being inclined in relation to a central plane containing the focal path, and a plurality of raw images are collected to form a CT image.

Abstract: A method for computed tomography, includes, in order to scan an object to be examined with a conical beam originating from a focus and with a matrix-like detector array for detecting the beam, the focus is moved, relative to the object to be examined, on a focal path around a system axis. A detector array supplies an output data corresponding to received radiation. The output data is filtered, and the filtered output data is backprojected three-dimensionally in order to produce at least one slice of a layer of the, which has a layer thickness. The slice represents absorption values obtained from the output data of a voxel belonging to the layer for the radiation from the beam. Filtering is carried out at least also in the direction of the tangent to the focal path belonging to a respective focal position, and normalization is carried out for each voxel considered.

Abstract: An imaging method is for a multi-slice spiral CT scan. An object to be examined is scanned with reference to its absorption behavior by a rotating ray bundle moving in the direction of the axis of rotation, and the measured absorption data are collected. In order to reconstruct volumetric images from the measured data, the latter are filtered and the filtered data are subsequently back-projected in three dimensions in order to generate at least one volumetric image of the object to be examined. The volumetric image represent absorption values, obtained from the data, of the voxels, belonging to the layer of the object to be examined, for the radiation of the ray bundle. A CT unit is for carrying out this method. In the method, the filtering is formed by use of multiple application of a ramp filter R{right arrow over (t)} and a masking operation M to a projection image in a different sequence.

Abstract: A method is for organ-specific image optimization in computed tomography. In this case, the HU values of a layer of the body previously recorded with a CT device are calculated and, on this basis, a first CT image is created. For this first CT image, a histogram is also created, in which the frequency distribution of the HU values is reproduced. In a histogram, at least one organ-specific HU region is defined and the latter is allocated an HU-dependent transfer function. Furthermore, a second CT image is created on the basis of the previously calculated HU values for the layer of the body which has been recorded. The first and second CT image are filtered with the HU-dependent transfer function and, finally, the filtered first CT image is mixed with the filtered second CT image.

Abstract: The invention relates to a method for performing computer tomography, and to a computed tomography (CT) apparatus, in which a) for scanning an object by a cone-shaped beam exiting from a focal point and by a matrix-like detector array for detecting the beam, the focal point is moved in relation to the object on a spiral path, whose center axis corresponds to a system axis, and the detector array provides output data corresponding to the received radiation; and b) for imaging an object region that executes a periodic motion, a signal that reproduces the course over time of the periodic motion is obtained during the scanning; c) from output data furnished during the motion of the focal point on a spiral segment, images with an inclined image plane are reconstructed, the image planes being inclined relative to the system axis both about a first axis, which perpendicularly intersects the system axis, by an angle of inclination &ggr; and about a second axis, which perpendicularly intersects both the first axis and

Abstract: An imaging tomography apparatus, in particular x-ray computed tomography apparatus, for examining an examination subject has at least two acquisition systems, each having a radiator and a data acquisition unit to detect the radiation originating from the associated radiator. The acquisition systems are capable of rotating around a common rotation axis with a constant angular separation in the azimuthal direction. Radiation from only one of the radiators is permitted to reach the examination subject during the rotation of the acquisition systems. Signal contributions by the x-ray tubes not supplying this data acquisition unit with primary radiation arrive are prevented, the projection data set generated by one of the data acquisition units.

Abstract: The invention relates to a method for computer tomography, according to which, in order to scan an object using a conical ray beam coming from a local point and a detector system for detecting the ray beam of the focal point, said detector system comprising a plurality of lines of detector elements, the focal point is displaced on a focal path about the system axis, without any relative movement between the object to be examined and the focal point, in the direction of the system axis. Said detector system supplies measuring data corresponding to the received radiation and the length of the focal path is at least the same as the length of a partial contour interval, the length of said interval being sufficient for completely reconstructing a CT image. Raw images are calculated from measuring data from a partial contour interval, the planes of said images thereof being inclined in relation to a central plane containing the local path, and a plurality of raw images are collected to form a CT image.

Abstract: In a method for generating an image of an examination subject with a tomography-capable X-ray device, particularly a computed tomography device, having a multi-row X-ray detector array, an X-ray radiator that rotates about a system axis and emits a conical x-ray beam, and a positioning device by means of which the subject is positionable relative to the X-ray radiator in different z-positions in a direction parallel to the system axis, the image is reconstructed from the raw data that are generated from the X-ray radiator. Raw data are generated from both a rotation scan and a linear scan. In the linear scan, all transmission values for the image reconstruction are acquired in one continuous linear scanning movement, so that the rotation scan can be picked up while the X-ray radiator is in continuous rotation.

Abstract: A method is for producing CT images of a periodically moving object to be examined, in particular a method for cardio volume reconstruction for multi-row CT units in spiral mode. A multi-row CT unit designed is further designed therefore. A small partial revolution segments along a revolution spiral is used to calculate in each case per partial revolution segment a plurality of segment images that are converted in a second step to partial images in the target image plane (for example axial plane) and are assembled with the correct phase to form complete images.

Abstract: An imaging method is for a multi-slice spiral CT scan with 3D back projection. Use is made, for the reconstruction of the absorption value of at least one voxel, of the measured and filtered data that are produced by rays which penetrate the at least one voxel. A CT unit is further used to carry out the method. In the method, the filtering of the data, required for the reconstruction, in the image of the virtual detector is performed in the direction of the projection of spiral segments imaged thereon which are produced by the spiral scanning over a prescribed angular range. The CT unit includes a device for carrying out directional filtering of this type.