Siemens Aktiengesellschaft

Bernd Ohnesorge

Thomas Flohr

Stefan Schaller

Herbert Bruder

Karl Stierstorfer

Klaus Klingenbeck-Regn

Christoph Becker

Bernhard Scholz

Thomas Von Der Haar

Karl Schwarz

Heinrich Wallschlaeger

Ernstpeter Ruehrnschopf

Rainer Kurt Rienmueller

Roman Fischbach

Andreas Kopp

Robert Mayer

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

In a method and device for, generating computed tomography images of a periodically moving organ of an organism, the organ having regions with rest phases and movement phases and the rest phases of different regions ensuing at different points in time, an x-ray source is moved around the body of the organism to be examined to generate projections serving for the image generation during at least one rotation of the x-ray source around the subject to be examined and during a duration that is at least equal to a period of the motion. The projection data are analyzed as to whether the data were acquired during a rest phase or movement phase of a respective region of interest of the organ, and an image of the organ is reconstructed using only data acquired during a rest phase of a respective region of interest of the organ.

Method and apparatus for producing a computed tomography image of a periodically moving organ

A method is for examining a body region of an examination object, which body region performs a periodic movement in the form of a sequence of movement cycles including phases of the periodic movement. The method preferably uses a CT apparatus with a radiation source for generating a radiation that penetrates through the examination object at different projection angles, and a detector system for the radiation emerging from the radiation source. An image, at least of the body region that performs the periodic movement, is determined by way of an electronic computing device from the output data of the detector system, which correspond to the detected radiation and are used as measurement data. In this case, it is provided that, from a number n&#x2267;1 of preferably successive movement cycles, data intervals are taken with respect to the same phase of the periodic movement. The overall length of these intervals produces at least one reconstruction interval that suffices for determining an image. The number of movement cycles from which the data intervals of a reconstruction interval originate increases as the frequency of the periodic movement increases, and the length of the data intervals falls as the frequency of the periodic movement increases.

Method for examining a body region of an examination object, which body region performs a periodic movement, and CT apparatus for carrying out such a method

A computed tomography apparatus has a radiation source from which a beam is emitted which has a fan angle and can be moved about a system axis within a measuring field defined by the fan angle in order to scan an object under examination, and a detector system for detecting the radiation from the radiation source and which supplies output signals corresponding to the received radiation, which are fed to a computer. From these output signals, the computer reconstructs images of the object under examination with reference to a reconstruction field which is larger than the measuring field.

Computed tomography apparatus wherein an image of a subject is reconstructed for a reconstruction field that is larger than the measuring field

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 CT device with a multi-line detector system, different columns of the detector system can be connected to different numbers of electronic elements in order to read the signals generated in the detector elements. Thus, by using the detector systems, regions of the object to be examined can be scanned with a high resolution, and other regions can be scanned with a lower resolution. A high resolution in regions can therefore be achieved with a simplified and less expensive detector system, which generates a comparatively low data rate and amount of data.

Computed tomography device with a multi-line detector system

An X-ray computed tomography apparatus has a beam filter arrangement with regions of different filter material or/and different thickness profile of the filter material. This beam filter arrangement is disposed in the beam path preceding an examination subject. For multi-spectra beam hardening correction with estimation of the base material lengths, the computed tomography apparatus is fashioned for implementing projections of the examination subject with different effective material thickness or/and different effective material of the beam filter arrangement.

X-ray computed tomography apparatus and multi-spectra correction using a radiation pre-filter

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 a method for examining a body region executing a periodic motion in an examination subject with a diagnostic apparatus having a radiation source for generating radiation penetrating the examination subject and a detector system for the radiation emanating from the radiation source, the intensity of the radiation emanating from the radiation source is modulated between a reference value and a reduced value compared to the reference value, substantially synchronously with the movement, so that the reference value is present during a phase of the periodic motion to be imaged with the diagnostic apparatus, and substantially only the data that were output by the detector system during the presence of the reference value of the radiation are utilized for the determination of the image.

Method for examining a body region executing a periodic motion

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 for examining a body region of an examination subject executing a periodic motion with a CT apparatus having a multi-line detector system in spiral mode, the X-ray source is activated and deactivated for the emission of X-rays substantially synchronously with the periodic motion so that the X-ray source is activated only during a phase of the periodic motion to be imaged with the CT apparatus.

In a method for image reconstruction for a CT apparatus and CT apparatus for the implementation of such a method, acquisition of the data underlying an image reconstruction for an image plane at a specific position on the system axis ensues by combining measured values, for each individual projection angle needed for this image reconstruction, that are registered exclusively for this projection angle with different lines of detector elements, to form data apparently registered with a detector having only one line of detector elements, with a weighting of the measured values ensuing. The image reconstruction is then undertaken using a conventional algorithm for operating on data from a detector having only one line of detector elements.

Method for image reconstruction for a CT apparatus and CT apparatus for the implementation of such a method

In a method and CT apparatus for producing CT images of a body region periodically moving with resting or motion phases, data corresponding to a number of projections serving the purpose of imaging are analyzed to determine whether each projection was acquired during a resting or motion phase, and only those data that were acquired during a resting phase are employed for image reconstruction.

Method and apparatus for producing CT images

In a method for image reconstruction in a computed tomography apparatus, whereby only the minimally possible projection angle range &agr;,(&bgr;) for the respective fan angle &bgr; is employed for all measured values S(&bgr;, &agr;) of the same fan angle &bgr;.

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Erlangen, Germany

Bernd Ohnesorge