Siemens Healthcare Gmbh

Siemens Aktiengesellschaft

Siemens Healthineers Ag

Bernd Schreiber

Thomas Brunner

Christoph Köhler

Michael Maschke

Klaus Klingenbeck-Regn

Bernhard Scholz

Ernst-Peter Rührnschopf

Michael Zellerhoff

Karl Wiesent

Alois Nöttling

Norbert Karl Strobel

Sebastian Graf

David Wenzel Kaltenbacher

Oxana Gruenwald

A computer-implemented method is for artifact correction during a reconstruction of at least one slice image from at least one projection image. The at least one projection image includes a plurality of pixels, each pixel including a pixel value. The method includes determining at least one corrected projection image based on the at least one projection image via a computing circuit; reconstructing the at least one slice image based on the at least one corrected projection image; and providing the at least one slice image. The determining includes determining an average pixel value in at least one subarea of the at least one projection image, a correction value by multiplying the average pixel value by a scatter factor, and a plurality of corrected pixel values by subtracting the correction value from the plurality of pixel values. The corrected projection image includes pixels including the plurality of corrected pixel values.

Method for artifact correction during a reconstruction of at least one slice image from a plurality of projection images

A method is provided for image-processing an image dataset acquired from a patient by a medical imaging apparatus, (e.g., an X-ray apparatus), wherein the image dataset includes image values associated with image points, and depicts an acquisition region of the patient containing at least one object, (e.g., a medical device), to be enhanced, which is represented by image values within an image-value interval. The method includes determining a non-linearly high-pass filtered enhancement dataset, which is confined to an image portion containing image values lying in the image-value interval. The method also includes determining a result dataset by adding to the image dataset the enhancement dataset weighted by a weighting value. The method further includes outputting the result dataset.

Image-processing of image datasets of patients

A method for improving an image quality of X-ray tomograms includes generating a low-pass filtered X-ray tomogram by applying a low-pass filter to a two-dimensional X-ray tomogram. The low-pass filter is only applied to pixels with image values lying within a predetermined image value interval. A high-pass filtered X-ray tomogram is generated by subtracting the low-pass filtered X-ray tomogram from the two-dimensional X-ray tomogram. A Radon transform image is generated by calculating a Radon transform of the high-pass filtered X-ray tomogram. A modified Radon transform image is generated by modifying values of the pixels of the Radon transform image with values lying outside a predetermined value interval. A modified high-pass filtered X-ray tomogram is generated by calculating an inverse Radon transform of the modified Radon transform image. A modified X-ray tomogram is generated by the addition of the modified high-pass filtered X-ray tomogram to the low-pass filtered X-ray tomogram.

Method for improving the image quality of x-ray tomograms

A method for the reduction of streak artifacts in an image data set reconstructed from projection images of an X-ray device is provided. The method includes determining a first interim data set by applying a non-linear low-pass filter to pixels that satisfy a selection condition. A second non-linear, high-pass-filtered interim data set is determined by pixel-by-pixel subtraction of the first interim data set from the image data set. The second interim data set is Fourier transformed in order to obtain a spatial frequency data set. Frequency portions attributable to artifacts in the spatial frequency data set are removed, and the processed spatial frequency data set is inverse Fourier transformed, such that a third interim data set is obtained. An artifact-reduced result data set is determined by addition of the third interim data set and the first interim data set.

Method for artifact reduction in a medical image data set, X-ray device, computer program and electronically readable data carrier

A method and an apparatus for generating an output image from a volume data set that includes a plurality of voxels are provided. In the method, a rendered 2D image is generated from the volume data set by volume rendering. In order to generate an output image with adjusted brightness, which makes a manual readjustment of the brightness superfluous, an adjustment factor is determined based on a brightness value of pixels in the rendered 2D image. By multiplying a respective voxel brightness value of the voxels in the volume data set by the adjustment factor, a brightness-adjusted volume data set is generated. By volume rendering from the brightness-adjusted volume data set, the brightness-adjusted output image is generated.

Method and apparatus for generating an output image from a volume data set

A method for determining a three-dimensional image dataset by an X-ray device is disclosed herein. The method includes recording projection images of an examination object from a plurality of recording angles, and reconstructing the image dataset from the projection images, wherein, for at least one examined projection image, in each case an interference condition is evaluated the fulfillment of which is dependent upon at least parts of the image data of the (respective) examined projection image and/or upon at least one parameter of the radiation source during the recording of the (respective) examined projection image and indicates that the (respective) examined projection image is a projection image with interference during the recording of which arcing has occurred in the radiation source. The method also includes disregarding at least one projection image with interference, or giving the projection image a lower weighting than all the projection images with no interference, or replacing the projection image with a synthetic projection image.

Method for determining a three-dimensional image dataset by an X-ray device

A method is for determining a transformation for image registration of a first image relative to a second image. The method includes ascertaining a test series of test elements including a test transformation and a test value, the ascertaining including ascertaining the test transformation based on a sequence of test transformations and/or based on previously ascertained test elements, transforming the first image via the ascertained test transformation, ascertaining a difference image, and ascertaining the test value of the test element based on the difference image such that the test value is a measure for an extension of a frequency distribution of values of pixels of the difference image in a direction of pixel value increase. It further includes determining a minimum test value based on test values encompassed by the test elements and determining the transformation which is the test transformation of a test element including the minimum test value.

Transformation determination device and method for determining a transformation for image registration

A method for the reduction of artifacts based on an unequal representation of the same material classes in various locations, in particular of cupping artifacts, in a three-dimensional image data set, reconstructed from two-dimensional x-ray projection images is provided. An image datum, describing an attenuation value, is allocated respectively to a voxel, wherein at least two material class regions are located in a post-processing step, which receive, in particular, image data, which is homogeneously distributed and lies in an expected material class interval of the attenuation values, and, considering at least one characteristic of the material class regions, calculates a smooth homogenization function, which is to be applied to the image data of the entire image data set and is applied to the image data of the image data set.

Method for the reduction of artifacts in image data sets and computing facility

A method for collecting three-dimensional data of an object from a series of projection images recorded by a biplane C-arm system is provided. A cardiac activity is recorded. The cardiac frequency and a start cardiac phase are determined for calculating parameters of the C-arm planes. The C-arm planes are set with the parameters and data is acquired in the start cardiac phase. The C-arm planes are uniformly rotated at a same speed in a forward motion over an angular area and record data at different angular areas at different cardiac phases. Data is acquired in the start cardiac phase after termination of the forward motion. The C-arm planes are uniformly rotated at a same speed in a backward motion over an angular area and records data at different angular areas at different cardiac phases. The captured data are reconstructed after termination of the backward motion upon completed acquisition.

Method for 3-D data collection with a biplane C-arm system with biplane acquisition multiplexing

The invention relates to a method for evaluating an image dataset obtained by a radiation-based image acquisition device. A scatter background dataset is determined as a function of the image data. The image dataset is corrected pixel by pixel by multiplying the image dataset with the inverse of a function dependent on the quotient of the scatter background data and the image data at a respective pixel. The function is a nonlinear, smooth function determined by a coefficient and having positive derivatives. The absolute value of the function is one for the value zero. The image acquisition parameter dependent coefficient is determined by an optimization process.

Method for evaluating an image dataset acquired by a radiation-based image acquisition device

The invention relates to an angiographic x-ray diagnostic device for rotation angiography with an x-ray emitter which can be moved on a circular path about a patient located on a patient support table, with an image detector unit which can moved on the circular path facing the x-ray emitter, with a digital image system for recording a plurality of projection images by means of rotation angiography, with a device for image processing, by means of which the projection images are reconstructed into a 3D volume image, and with a device for correcting physical effects and/or inadequacies in the recording system such as truncation correction, scatter correction, ring artifact correction, correction of the beam hardening and/or of the low frequency drop for the soft tissue display of projection images and the 3D volume images resulting therefrom.

Angiographic x-ray diagnostic device for rotation angiography

In a method for reconstructing a 3D CT image from a number of 2D projection images each 2D projection image is divided at an arbitrarily selectable position by a substantially vertical image line and the projection image is automatically electronically analyzed to detect whether clipping occurs on the left side or on the right side, or on both sides, of the image line. For each side of the image line at which clipping is detected, a horizontal coordinate at which the clipping ends is identified. The grayscale values at the side of the horizontal coordinate opposite to the side at which the image line is located are extrapolated so that the clipping is removed. The corrected 2D projection images are then used to reconstruct a 3D image, in which capping artifacts, that would otherwise be present, or avoided or substantially minimized due to the corrections made in the 2D projections.

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Forchheim, Germany

Bernd Schreiber