Abstract: Vessel overlap artifacts are reduced in a four-dimensional angiography data set a blood vessel system of a patient with a contrast medium. A three-dimensional vessel data set of the blood vessel system is reconstructed from two-dimensional projection images of digital subtraction angiography showing the blood vessel system, determined by multiplicative back projection of the projection images into the vessel data set or a base data set of the four-dimensional angiography data set derived vessel data set. A plausibility check is performed with vessel sections displayed as filled with contrast medium in partial image data sets of the angiography data set assigned to all individual, and different instants of the covered period are checked against a plausibility check criterion checking for a contrast medium-filled connection to an admissible source point, after which a corrected partial image data set is determined containing only vessel sections satisfying the plausibility check criterion.

Abstract: A method calculates a four-dimensional DSA dataset from x-ray datasets. Each of the x-ray datasets contains a two-dimensional x-ray projection of an examination volume in relation to a direction of projection and a recording time. A first three-dimensional DSA dataset of a first reconstruction volume is determined based on the x-ray datasets. The first reconstruction volume is a part of the examination volume. A second three-dimensional DSA dataset of a second reconstruction volume is determined based on the x-ray datasets. The second reconstruction volume is a part of the first reconstruction volume. The second three-dimensional DSA dataset is segmented. The x-ray datasets are normalized based on the first three-dimensional DSA dataset. A four-dimensional DSA dataset is calculated by back projection of the normalized x-ray datasets onto the segmented second three-dimensional DSA dataset.

Abstract: Described herein are technologies for facilitating reconstruction of flow data. In accordance with one aspect, the framework receives a four-dimensional projection image dataset and registers one or more pairs of temporally adjacent projection images in the image dataset. Two-dimensional flow maps may be determined based on the registered pairs. The framework may then sort the two-dimensional flow maps according to heart phases, and reconstruct a three-dimensional flow map based on the sorted two-dimensional flow maps.

Abstract: Methods and systems are disclosed herein for improved safer planning support during interventional procedures for inserting stents into a hollow organ of a patient by a guide device. One method includes: providing or recording a three-dimensional image data set of the hollow organ in a first position; segmentation or providing a segmentation of the three-dimensional image data set; providing or recording a two-dimensional image of the guide device introduced into the hollow organ; overlaying the three-dimensional image data set with the two-dimensional image; determining at least one corrected position of one or more section(s) of the hollow organ respectively using the overlaying of the three-dimensional image data set with the two-dimensional image; and determining the respective deformation energy of the hollow organ in the section(s) for the case of removal of the guide device using the previously determined corrected position compared to the first position.

Abstract: Systems and methods are provided for refined data reconstruction. In accordance with one aspect, the framework performs a first four-dimensional reconstruction of time-varying data to generate a four-dimensional Digital Subtraction Angiography (DSA) dataset of an object of interest. The framework extracts a volume of interest from the four-dimensional DSA dataset to generate a volume array. The volume of interest may be refined based on the volume array to generate a refined dataset. A second four-dimensional reconstruction may then be performed based on the refined dataset to generate a zoomed-in four-dimensional representation of the volume of interest.

Abstract: Systems and methods are provided for refined data reconstruction. In accordance with one aspect, the framework performs a first four-dimensional reconstruction of time-varying data to generate a four-dimensional Digital Subtraction Angiography (DSA) dataset of an object of interest. The framework extracts a volume of interest from the four-dimensional DSA dataset to generate a volume array. The volume of interest may be refined based on the volume array to generate a refined dataset. A second four-dimensional reconstruction may then be performed based on the refined dataset to generate a zoomed-in four-dimensional representation of the volume of interest.

Abstract: Systems and methods are provided for data reconstruction. In accordance with one aspect, data interpolation is performed on a time-varying three-dimensional (3D) image dataset of one or more vessel-like structures to generate at least one interpolated voxel value. The interpolated voxel value is used to correct at least one value of a vessel voxel representing the one or more vessel-like structures in the time-varying 3D dataset.

Abstract: A method for adapting the brightness of an X-ray image is provided. The X-ray image is recorded using a filter attenuating X-ray radiation used for recording the X-ray image differently in at least two spatial filter regions. The method includes determining image regions mapping the filter regions from filter parameters and recording geometry parameters describing the filter regions from at least one evaluation line running perpendicular to a boundary between image regions. The method also includes determining, for each evaluation line, a correction value describing a difference in brightness between the image regions from an image value profile along the evaluation line in an evaluation area containing the boundary, determining at least one correction factor from the at least one correction value, and adapting the brightness between the at least two image regions by scaling the image values with the correction factor.

Abstract: Systems and methods are provided for data reconstruction. In accordance with one aspect, data interpolation is performed on a time-varying three-dimensional (3D) image dataset of one or more vessel-like structures to generate at least one interpolated voxel value. The interpolated voxel value is used to correct at least one value of a vessel voxel representing the one or more vessel-like structures in the time-varying 3D dataset.

Abstract: Systems and methods are provided for data reconstruction. In accordance with one aspect, data interpolation is performed on a time-varying three-dimensional (3D) image dataset of one or more vessel-like structures to generate at least one interpolated voxel value. The interpolated voxel value is used to correct at least one value of a vessel voxel representing the one or more vessel-like structures in the time-varying 3D dataset.

Abstract: An angiographic examination method for the representation of flow properties of vessels of an object under examination is presented. To determine blood-flow parameters in 3-D with high temporal resolution, at least one 4-D DSA sequence is acquired for the generation of measurement-based 4-D DSA data sets. A model-based method determines time-dependent volume data sets, which, in terms of time, lie between the time-dependent volume data sets of the measurement-based 4-D DSA method.

Abstract: In order to classify a cerebral vascular segment as normal or pathological, a time-series of three dimensional (3D) images representing the cerebral vascular segment is generated. A length of the cerebral vascular segment is determined, and a blood flow speed through the cerebral vascular segment is determined based on the length and the generated time-series of 3D images. The cerebral vascular segment is categorized based on the determined blood flow, and a representation of the cerebral vascular segment is displayed based on the categorization.

Abstract: A method for creating a selective vessel image within a volume section of an examination object using an imaging system is provided. The method includes creating a vessel image of the volume section. The creating of the vessel image includes acquiring imaging data of the volume section within a predetermined time interval using the imaging system, determining a maximum opacity within the time interval on account of a contrast agent administered to the examination object per pixel of the vessel image, and segmenting vessels. The segmenting includes deciding, depending on the maximum opacity of the pixel, whether the respective pixel belongs to the vessel. The method also includes determining a contrast agent arrival time per pixel of the vessel image, and segmenting whether the respective vessel of the vessel image belongs to a vessel of the selective vessel image.

Abstract: A method for obtaining a 3D image dataset of an object of interest is proposed. A plurality of 2D X-ray images are captured and a 3D reconstruction is carried out using filtered back projection. The projection parameters have been measured with the aid of a calibrating phantom, possibly using an interpolation or extrapolation of such measurements. A model of effect strings of the components in an X-ray imaging device is obtained, and the model parameters are identified based on imaging of a calibrating phantom. A projection matrix can then be calculated for any positions on any desired trajectories, without having to use imaging of a calibrating phantom at precisely that position and desired trajectory.

Abstract: A method of visualizing changes in blood flow in a digital subtraction angiography (DSA) image sequence is disclosed. A time-contrast curve is generated for all pixels in each image of the DSA image sequence. A reference parameter for each time-contrast curve to be used as a first time point is specified. The value of the reference parameter for each time-contrast curve is determined and an arbitrary parameter is specified for each time-contrast curve to be used as a second time point. An output image is generated by applying a color-coding of the difference between the first time point and the second time point to all pixels.

Abstract: Systems and methods are provided for data reconstruction. In accordance with one aspect, data interpolation is performed on a time-varying three-dimensional (3D) image dataset of one or more vessel-like structures to generate at least one interpolated voxel value. The interpolated voxel value is used to correct at least one value of a vessel voxel representing the one or more vessel-like structures in the time-varying 3D dataset.

Abstract: An angiographic examination method for the representation of flow properties of vessels of an object under examination is presented. To determine blood-flow parameters in 3-D with high temporal resolution, at least one 4-D DSA sequence is acquired for the generation of measurement-based 4-D DSA data sets. A model-based method determines time-dependent volume data sets, which, in terms of time, lie between the time-dependent volume data sets of the measurement-based 4-D DSA method.

Abstract: A method and a device for determining attenuation coefficients for an object using a movable X-ray source and a detector, which is provided for recording projections, is provided. The method includes specifying a trajectory for the movable X-ray source, specifying positions on the trajectory for determining a derivative of projections recorded by the detector, specifying a plurality of scanning positions for each of the specified positions, following the trajectory with the X-ray source and recording a projection for each scanning position, numerically calculating a projection derivative in relation to the trajectory path for each of the positions using the projections recorded for the associated plurality of scanning positions, and determining attenuation coefficients for the object from the calculated projection derivatives using a theoretically exact or approximate rule for the reconstruction.

Abstract: A method (10, 100) for temporal encoding for digital subtraction angiography (DSA) and other angiographic data.

Abstract: A method for obtaining a 3D image dataset of an object of interest is proposed. A plurality of 2D X-ray images are captured and a 3D reconstruction is carried out using filtered back projection. The projection parameters have been measured with the aid of a calibrating phantom, possibly using an interpolation or extrapolation of such measurements. A model of effect strings of the components in an X-ray imaging device is obtained, and the model parameters are identified based on imaging of a calibrating phantom. A projection matrix can then be calculated for any positions on any desired trajectories, without having to use imaging of a calibrating phantom at precisely that position and desired trajectory.