Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Siemens Healthineers Ag

Martin Petersilka

Karl Stierstorfer

Herbert Bruder

Rainer Raupach

Martin Hupfer

Edgar Goederer

Bjoern Kreisler

Steffen Kappler

Thomas Flohr

Ute Feuerlein

Anja Fritzler

Björn Kreisler

Ernst Klotz

Harald Schöndube

Karl Schwarz

Edgar Göderer

Matthias Baer-Beck

Achim Hillenbrand

Johan Sunnegaardh

Dieter Matuszok

A photon-counting X-ray detector is for acquiring an X-ray image data set of an object penetrated by X-ray radiation. The detector includes a converter element, designed to convert incident X-ray radiation into an electrical signal; and a matrix with a plurality of pixel elements. At least a partial number of the plurality of pixel elements receive a signal input and at least one configurable counter is coupled to the at least a partial number of the plurality of pixel elements, for signaling. Further, the at least one configurable counter is designed to count either a pixel count signal, based on a signal directly received in each respective pixel element, or a coincidence count signal, based on the signal received directly in the respective pixel element and on a coincident signal of at least one further pixel element.

Photon-counting X-ray detector and method for operating a photon-counting X-ray detector

A method is for generating an X-ray image dataset via an X-ray detector having a converter element and a multiplicity of pixel elements. In an embodiment, the method includes first counting of at least one quantity of count signals dependent upon the incident X-ray radiation in each pixel element of the multiplicity of pixel elements; second counting of at least one quantity of coincidence count signals in each pixel element of the subset of pixel elements with at least one further pixel element of the multiplicity of pixel elements; and generating an X-ray image dataset based upon the at least one quantity of count signals counted in each pixel element of the multiplicity of pixel elements and upon the at least one quantity of coincidence count signals counted in each pixel element of the subset of pixel elements.

Method for generating an x-ray image dataset

An X-ray detector includes a converter element for converting X-rays into electric signals; and a plurality of pixel elements. In an embodiment, each pixel element includes a first signal processing stage for processing respective electric signals with at least one signal amplifier and at least one comparator for providing a digital pixel signal. The signal outputs of the first signal processing stage of at least one group of pixel elements are coupled via signal technology to a common second signal processing stage including a multiplicity of digital logic elements. The common second signal processing stage includes a configurable switching matrix for interconnecting at least one partial number of the multiplicity of digital logic elements with the respective signal outputs of the first signal processing stage, so that, following a configuration of the switching matrix, a processing chain can be provided for the digital processing of the digital pixel signals.

A method for correction of an input dataset is disclosed. In an embodiment, the method includes acquisition of an input dataset comprising at least one data error; determination of a correction function; creation of a corrected output dataset by application of the correction function to the input dataset; and outputting of the corrected output dataset. The correction function is embodied to bring about a reduction of at least two data errors that mutually influence one another in the input dataset.

Data correction in X-ray imaging

Method for generating an X-ray image dataset

A method, in an embodiment, is for setting an X-ray intensity using a structured anode or a field emitter cathode or a finger-shaped cathode head. Other embodiments include an associated X-ray device, an associated single X-ray tube CT scanner, an associated dual X-ray tube CT scanner, and an associated computer program product.

Dose modulation

An embodiment of the invention relates to a method for calculating an image matrix size N for reconstructing image data of an examination subject from projection data. The method includes acquiring projection data obtained during a relative rotational movement between a radiation source of a computed tomography system and the examination subject; calculating the image matrix size N as a function of an extent of an axial field of view of the computed tomography system and a sharpness value in the image data to be reconstructed; and making the calculated image matrix size available to a reconstruction unit to reconstruct the image data from the projection data acquired.

Calculating an image matrix size

A method is for scattered ray correction of projection measurement data recorded by a computer tomography system. In an embodiment, the method includes recording, localizing, identifying and correcting. In the recording, projection measurement data is recorded from a plurality of projection angles and the projection measurement data is captured in a sinogram. In the localizing, features in the projection measurement data of the sinogram are localized in a defined angle range about a projection angle. In the identifying, a scatter distribution for the projection angle is identified from the localized features by way of a trained identification algorithm. In the correcting, the projection measurement data of the projection angle is corrected on the basis of the scatter distribution.

Sinogram-based scattered ray correction in computer tomography

A method is disclosed for operating a computed tomography device including an x-ray source embodied to emit a fan-type beam bundle and a detector arrangement interacting therewith and including a plurality of detector elements. An embodiment of the method provides that an integration time provided to read out a detector element is dependent on the position of the detector element within the detector arrangement, wherein with a detector element which detects x-rays which penetrate the isocenter lying between the x-ray source and the detector arrangement, a longer integration time is provided, than with a detector element which detects x-rays which penetrate an examination volume which is further away from the isocenter.

Computed tomography device and method for operating a computed tomography device

A method is disclosed for the reconstruction of image data of an examination object from measurement data. First and second image data are reconstructed from the measurement data with a first and second respective image characteristic, with an enhanced signal-to-noise ratio of the second image characteristic relative to the first image characteristic. Enhanced image data is calculated using an iterative algorithm using the first and the second image data. In the case of the iterative algorithm, a low pass is applied to a difference between the first image data and the image data of an iteration cycle, and a high pass to a difference between the second image data and the image data of the iteration cycle.

Method for iterative image reconstruction for bi-modal CT data

A method is disclosed for reconstructing image data of an examination object from measurement data, wherein the measurement data were acquired in the course of a relative rotational movement between a radiation source of a computed tomography system and the examination object. First image data of the examination object are reconstructed from the measurement data. Scatter signals are calculated from the first image data using a scattered radiation model, wherein the scattered radiation model specifies an angle-dependent scatter distribution for a scatter point as a function of a line integral corresponding to an attenuation integral of a scattered beam from the scatter point to a specific detector element. The calculated scatter signals are used for correcting the measurement data, and second image data are reconstructed using the corrected measurement data.

Method for reconstructing CT images with scatter correction, in particular for dual-source CT devices

A method and a computer system are disclosed for scattered beam correction in a CT examination of an object in a multi source CT. In at least one embodiment, the method includes generating original projection data records; reconstruction of the object with the original projection data records of at least one detector; determining the scattered radiation generated by each emitter exclusively in the direction of the original beams of the at least one other emitter relative to its opposing detector; generating corrected projection data records by removing the calculated scattered radiation from the original projection data records; reconstruction of the object with the corrected projection data records, and implementing a further iteration of the method when determining the scattered radiation or issuing the reconstruction result if at least one predetermined abort criterion applies.

Method and computer system for scattered beam correction in a multi-source CT

A method is disclosed for reconstructing image data of an examination object from measured data, wherein the measured data was captured previously during a relative rotary motion between a radiation source of a computed tomography system and the examination object. In at least one embodiment, the measured data is modified to achieve a particular grayscale characteristic of the image data to be reconstructed. The image data is calculated by way of an iterative algorithm using the modified measured data, wherein no arithmetic step for reducing noise is employed in the iterations.

Iterative reconstruction of CT images without a regularization term

A method is disclosed for generating image data of an object under examination from X-ray projection data of the object under examination, wherein, before a reconstruction of the image data, the X-ray projection data are subjected to scattered radiation correction on the basis of scattered radiation measured values. Here, the scattered radiation measured values are initially subjected to an extra-focal radiation correction before being used for the scattered radiation correction. A projection data processing device is also disclosed for carrying out a method of this kind and an X-ray system, in particular computed tomography system, with a projection data processing device of this kind.

Method for generating image data of an object under examination, projection data processing device, X-ray system and computer program

A method is disclosed for scattered radiation correction in x-ray imaging devices having a number of x-ray sources that can be moved around an examination object in at least one scanning plane during a measurement pass. During the measurement pass, a number of x-ray projections are recorded at different projection angles with simultaneous use of the x-ray sources. In at least one embodiment of the present method, parameters characterizing an outer object contour are determined in the scanning plane from measured data of different x-ray projections. In at least one embodiment, on the basis of one object contour section whose characterizing parameters have been determined from x-ray projections that lie in front of and/or behind the respective x-ray projection by a defined projection angle range, for each x-ray projection an assigned scattered radiation distribution is then retrieved or is interpolated in a database from scattered radiation distributions for object contour sections with similar characterizing parameters. This scattered radiation distribution is then used for the correction of the measured data for the respective x-ray projection. In at least one embodiment, the method enables scattered radiation correction in conjunction with operation of the x-ray sources.

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Adelsdorf, Germany

Martin Petersilka