Siemens Aktiengesellschaft

Stefan Schaller

Thomas Flohr

Herbert Bruder

Bernd Ohnesorge

Karl Stierstorfer

Rainer Raupach

Bernhard Schmidt

Kwok C Tam

Klaus Klingenbeck-Regn

Bernhard Scholz

Willi A Kalender

Matthias Niethammer

Ernst Klotz

Heinrich Wallschlaeger

Marc Kachelriess

Jürgen Simon

Christoph Becker

Robert Mayer

Roman Fischbach

Andreas Kopp

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.

Method for producing CT images of a cyclically moving object to be examined

In a method to support the diagnosis and/or therapy of a pathological change of a blood vessel of a patient, in particular in the context of coronary heart disease at a first point in time of a pixel-based or voxel-based first image is acquired with the blood vessel of interest by an imaging method, a determination is made from the first image of a quantity of existing non-calcified plaque and a quantity of existing calcium-rich plaque, a determination of a first indicator value is made from the quantities of the different plaque types that represents a measurement of the quantity and the composition of plaque present in the blood vessel at the first point in time, a comparison of the first indicator value is made with at least one limit value stored in a storage of a data processing device, and dependent on the comparison, a presentation is made on an output unit associated with the electronic data processing device of either a proposal for a measure to be undertaken on the patient, or a proposal for no measure.

Method and data processing device to support diagnosis and/or therapy of a pathological change of a blood vessel

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.

Method for production of tomographic slice images of an examination object using at least two X-ray beams at offset angles, and a computed tomography scanner for carrying out this method

In a method and CT apparatus and software product for reconstructing incomplete projection data sets for dose-reduced sectional spiral scanning along a z axis of a patient on a table that is movable in the z direction in the CT apparatus that has a radiation source supplied with tube current so as to emit a beam that strikes a detector system to obtain scanning data from which in an image computing device generates two-dimensional and three-dimensional scanning images of the examination subject, at a pitch greater or equal to one. For z positions having an incomplete projection data set for reconstruction of the image, in a preprocessing step data from another row of this projection and/or data for a previous or subsequent 360&#xb0; rotation are used to compute a complete projection data set therefor.

Method for reconstructing projection data sets for dose-reduced sectional spiral scanning in computed tomography

A patient bed and a method for reproducibly positioning and supporting a patient in a medical diagnosis or therapy apparatus, such as a CT apparatus or an MRI apparatus, involve supporting at least regions of the patient body in a desired position on the patient bed and using at least one positioning unit to position the regions of the patient body relative to the patient bed. The patient bed has a number of height-adjustable elements arranged like a matrix that are individually adjustable in terms of height.

Patient bed, and method for reproducibly positioning and supporting a patient therewith

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 &#x3b3; around a first axis intersecting the system axis at a right angle and also are inclined by a tilt angle &#x3b4; 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.

Method and apparatus for spiral scan computed tomography

In a method and apparatus for image processing proceeding from a computed tomography (CT) image of a lung as an original image that is registered using a contrast agent, pulmonary parenchyma pixels are determined, the pulmonary parenchyma pixels are presented in false colors, and the remaining image regions are presented in the gray scale values of the original image.

Method and apparatus for processing a computed tomography image of a lung obtained using contrast agent

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.

Imaging method for a multi-slice spiral CT scan with 3D reconstruction, and a computed tomography unit for carrying out this method

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.

Retrospective and/or window-controlled filtering of images for adapting sharpness and noise in computed tomography

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 the system axis, by a tilt angle &dgr;; and spiral segments that immediately succeed one another overlap one another by an overlap angle that is greater than or equal to zero; and the spiral segments are selected, taking into account the signal that reproduces the course over time of the periodic motion, such that they correspond to a phase of the periodic motion that is to be imaged.

Computed tomography method and computed tomography apparatus

In a spiral scan cone beam computed tomography method and apparatus, the output data are divided into sub-segments being shorter than the length required for the reconstruction of a CT image. Segment images having inclined image plane relative to the system axis are reconstructed for the sub-segments. A signal reproducing the time curve of the periodic motion is acquired during the scanning. A z-position on the system axis and a time position with respect to the periodic motion are allocated to the segment images. Segment images belonging to a desired range of z-positions and a desired range of time positions are selected such that the corresponding sub-segments have an overall length adequate for the reconstruction of a CT image. The selected segment images are at least indirectly combined into a resulting CT image with respect to a target image plane.

Computed tomography method and apparatus for acquiring images dependent on a time curve of a periodic motion of the subject

In an image reconstruction method for imaging a periodically moving object with a computed tomography apparatus employing a multi-line detector unit, suitable selection of the rotational speed of the carrier of the computed tomography apparatus and employment of a three-dimensional back-projection algorithm, allow qualitatively high-great images of the object to be produced in every motion phase.

Image reconstruction method

In a method and computed tomography (CT) apparatus for the reconstruction of images from CT measured values acquired by spiral scan that are respectively allocated to one of a number of projection angles and a z-position on the longitudinal axis of the spiral scan, for each projection angle, all measured values belonging thereto and to the corresponding complementary projection angle and lying within a maximum spatial distance from the image plane, and lying within a maximum time from a reference time, are employed in the reconstruction, respectively weighted according to their spatial and time position.

Method for the reconstruction of images from measured values acquired with a CT apparatus by spiral scan and CT apparatus for the implementation of the method

In method and apparatus for the reconstruction of images of a slice of an examination subject having a slice thickness with respect to an image plane from measured values acquired by a spiral scan of the examination subject with an x-ray source rotating around the examination subject with a detector having at least one line of detector elements, measured values lying within a maximum distance from the image plane are thereby involved in the reconstruction and are weighted such that a desired functional dependency of the slice thickness on the pitch is present.

Method for the reconstruction of images from measured values acquired with a CT apparatus by spiral scan of the examination subject and CT apparatus for the implementation of the method

An exact image reconstruction method for computed tomography allows the reconstruction of a sub-volume of interest in a long subject from cone beam or pyramid beam CT data using a spiral focus path. A two-stage reconstruction process is utilized that, by line integration over the detector, first calculates 3D radon values of a sub-volume of interest defined only for the respective .phi.-plane for each .phi.-plane of a 3D spherical coordinate system. For each .phi.-plane, the sub-volume of interest is limited toward the exterior by the radius of the measurement field and is upwardly and downwardly limited by curved surfaces that arise by the locus of a straight line perpendicular to the .phi.-plane under consideration proceeding to each focus point of a spiral segment.

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Fuerth, Germany

Stefan Schaller