Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on opposing sides of a primary radiation delivery window. The first and second leaves can include first and second gratings having a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members.

Abstract: A method and calculation unit are disclosed for reconstructing an image from measured projection data. In an embodiment, the method includes reconstructing an initial image from the projection data via back-projection; dividing the initial image into contiguous blocks of voxels; defining groups of voxels, wherein each group is defined by selecting one voxel from each block, each voxel having the same position relative to the other voxels within its block; updating the voxel values for all voxels within one group by minimizing a function consisting of a weighted sum of a first term representing the geometry of the data acquisition process, and a second regularization term; and repeating the updating of the voxel values for all voxels within one group until all groups have been updated at least once.

Abstract: A method for a practical model based computed tomography construction may include assuming that a filtered back projection reconstruction of a computed tomography image is available and acquiring a deviate of a multivariate random variable computed tomography data set. A filtered back projection reconstruction of the image may be estimated, and the filtered back projection reconstruction may be identified as a deviate of a multivariate random variable. A maximum a posteriori estimate may be generated for the filtered back projection reconstruction.

Abstract: A method of contrast-enhanced computed tomography (CT) imaging can include repeatedly scanning a target region at a frequency during a session, the frequency initially being a first rate. After detecting an increase of the attenuation of radiation by a contrast-enhanced first structure within a target region, the frequency can be increased to a second rate. After detecting a subsequent decrease in the attenuation, the frequency can be decreased to a third rate.

Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on and bounding opposing sides of a radiation delivery window. The first and second leaves can be movable to adjust at least one of a size or a location of the primary radiation delivery window relative a the radiation source in a direction non-parallel to an axis of rotation of the radiation source.

Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on opposing sides of a primary radiation delivery window. The first and second leaves can include first and second gratings having a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members.

Abstract: A method of contrast-enhanced computed tomography (CT) imaging can include repeatedly scanning a target region an applied power during a session. The applied power can be a first power for a first scan. After the first scan, the applied power for each of a plurality of scans can be selected based on an algorithm. The algorithm can be based on, for example, the attenuation indicated from a preceding scan in the session.

Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on opposing sides of a primary radiation delivery window. The first and second leaves can include first and second gratings having a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members.

Abstract: A method and calculation unit are disclosed for reconstructing an image from measured projection data. In an embodiment, the method includes reconstructing an initial image from the projection data via back-projection; dividing the initial image into contiguous blocks of voxels; defining groups of voxels, wherein each group is defined by selecting one voxel from each block, each voxel having the same position relative to the other voxels within its block; updating the voxel values for all voxels within one group by minimizing a function consisting of a weighted sum of a first term representing the geometry of the data acquisition process, and a second regularization term; and repeating the updating of the voxel values for all voxels within one group until all groups have been updated at least once.

Abstract: A method for a practical model based computed tomography construction may include assuming that a filtered back projection reconstruction of a computed tomography image is available and acquiring a deviate of a multivariate random variable computed tomography data set. A filtered back projection reconstruction of the image may be estimated, and the filtered back projection reconstruction may be identified as a deviate of a multivariate random variable. A maximum a posteriori estimate may be generated for the filtered back projection reconstruction.

Abstract: At least one embodiment of the invention relates to a method for the reconstruction of image data from an examined object, using measuring data, wherein the measuring data were first recorded during a relative movement between a radiation source on a computer tomography system and the examined object. In at least one embodiment, the image reconstruction is based on a back projection of the filtered measuring data. During the back projection, a back projection weight that depends on the respective image point is used and the power with which the back projection weight is used is selectable.

Abstract: For filtered back-projection of a projection image data set, the projection image data set is cosine-weighted. The cosine-weighted projection image data set within the image plane of the projection image data set is subjected to a two-dimensional Radon transformation. The Radon transform of the cosine-weighted projection image data set differentiated with respect to the distance from an image origin of an image coordinate system. The derivative of the Radon transform is redundancy-weighted. The redundancy-weighted derivative is subjected to a two-dimensional Radon back-transformation. The Radon back-transform is differentiated and back-projected with respect to an image column coordinate. A differentiation step width entering into the differentiation is varied depending on depth.

Abstract: A method of contrast-enhanced computed tomography (CT) imaging can include repeatedly scanning a target region an applied power during a session. The applied power can be a first power for a first scan. After the first scan, the applied power for each of a plurality of scans can be selected based on an algorithm. The algorithm can be based on, for example, the attenuation indicated from a preceding scan in the session.

Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on opposing sides of a primary radiation delivery window. The first and second leaves can include first and second gratings having a plurality of attenuating members with a plurality of secondary radiation delivery windows extending between adjacent attenuating members.

Abstract: A collimator for a computed tomography imaging device can include first and second leaves positioned on and bounding opposing sides of a radiation delivery window. The first and second leaves can be movable to adjust at least one of a size or a location of the primary radiation delivery window relative a the radiation source in a direction non-parallel to an axis of rotation of the radiation source.

Abstract: A method of contrast-enhanced computed tomography (CT) imaging can include repeatedly scanning a target region at a frequency during a session, the frequency initially being a first rate. After detecting an increase of the attenuation of radiation by a contrast-enhanced first structure within a target region, the frequency can be increased to a second rate. After detecting a subsequent decrease in the attenuation, the frequency can be decreased to a third rate.

Abstract: For filtered back-projection of a projection image data set, the projection image data set is cosine-weighted. The cosine-weighted projection image data set within the image plane of the projection image data set is subjected to a two-dimensional Radon transformation. The Radon transform of the cosine-weighted projection image data set differentiated with respect to the distance from an image origin of an image coordinate system. The derivative of the Radon transform is redundancy-weighted. The redundancy-weighted derivative is subjected to a two-dimensional Radon back-transformation. The Radon back-transform is differentiated and back-projected with respect to an image column coordinate. A differentiation step width entering into the differentiation is varied depending on depth.

Abstract: At least one embodiment of the invention relates to a method for the reconstruction of image data of an examined object from measuring data, wherein the measuring data were detected by a detector within and outside of its Tam-Danielsson window during a relative spiral movement between a radiation source of a computer tomography system and the examined object. As a result of the spiral movement, the measuring data outside of the Tam-Danielsson contain interruptions. A mathematically precise first reconstruction of first image data is realized in at least one embodiment based on the measuring data by using only measuring data from the Tam-Danielsson window.

Abstract: Certain embodiments provide staggered circular scans for CT imaging. In certain embodiments, a CT imaging system comprises a plurality of source-detector assemblies that are axially offset from one another and rotate about a rotation axis to provide staggered circular CT scanning.

Abstract: A method is disclosed for generating computed tomography image data of a volume of interest from X-ray CT data sets generated by a computed tomography system during scanning of an examination subject on a helical path rotating around a longitudinal system axis in the infeed direction. In at least one embodiment, at least two volume-based reconstructions of the volume of interest are performed by way of differential back-projection over surfaces constituted by different groups of M-lines, followed in each case by an inverse Hilbert transformation. The method further includes combining different reconstructed volumes to form a final reconstruction of the volume of interest.