Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Christoph Köhler

Bernd Schreiber

Thomas Brunner

Yiannis Kyriakou

Christian Kruschel

David Wenzel Kaltenbacher

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 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 recording a four-dimensional angiography data record using an x-ray facility with a C-arm is proposed. Projection images are recorded from different projection directions at different time points of the cardiac cycle. A number of three-dimensional reconstruction image data records assigned respectively to a time segment of the cardiac cycle are reconstructed from the projection images and combined to form the four-dimensional angiography data record by temporal assignment in respect of the cardiac cycle. At least one recording parameter describing the temporal sequence is selected when recording the projection images as a function of cardiac stimulation performed to ensure a stable heart rate during recording so that the recording of the projection images takes place in such a manner that it is synchronized with the cardiac cycle.

Method for recording a four-dimensional angiography data record

A method for correcting image artifacts is proposed. The artifacts occur as a result of an anti scatter grid connected rigidly to an x-ray detector in recording three-dimensional image datasets. Two-dimensional projection images of an object are recorded from different recording geometries for reconstruction the three-dimensional image dataset. A calibration image is recorded for each recording geometry. An average image from all recorded calibration images is established. Subtraction images are established by subtracting the average image from the corresponding calibration images. Noise is removed from the subtraction images. The subtraction images and the average image are stored. A correction image is established for each recording geometry by addition of the subtraction image assigned to the recording geometry and of the average image and is used for correcting the projection image.

Method for correcting image artifacts occuring as a result of an anti scatter grid

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.

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Forchheim, Germany

Christoph Köhler