Abstract: A 3D result image of an object is reconstructed from a set of X-ray two-dimensional projections of the object. A 3D reference image of the object is reconstructed by employing a compressed sensing technique based on at least some of the 2D projections at a reference motion state of the object. By employing an algebraic and/or analytic reconstruction technique, 3D intermediate images are reconstructed for various motion states of the object. The 3D intermediate images are registered with the 3D reference image to obtain spatial transformations for the various motion states of the object. Based on the spatial transformations, the 3D intermediate images are transformed to a joint phase and combined to obtain the 3D result image.

Abstract: A three-dimensional model dataset of a blood vessel system of a patient including at least one the vessel system is determined from a number of projection images, which have been recorded from different recording angles, of the blood vessel system The projection images are divided up into image areas each containing at least one pixel. A feature vector is determined for each of the image areas. Classification information, which describes how the respective image area belongs or does not belong to a vessel segment of the blood vessel system defined in accordance with anatomical specification data, is defined for each of the image areas by applying a classification function to the feature vector assigned to the image area. The classification function has been trained by training data records annotated with classification information obtained from at least one person other than the patient.

Abstract: A method for ascertaining a fluid-dynamic characteristic value of a resilient vascular tree, through which a fluid flows in a pulsating manner, is provided. At least one 2D projection, respectively, of the resilient vascular tree is generated by a projection device from different angles of projection, and a digital 3D reconstruction of the vascular tree is generated by an analysis device based on of the 2D projections. A geometry of at least one vessel of the resilient vascular tree is estimated based on the 3D reconstruction, and at least one fluid state in the resilient vascular tree is ascertained from the geometry and predetermined resilient properties of the resilient vascular tree. The at least one fluid-dynamic characteristic value is calculated as a function of the at least one fluid state.

Abstract: Background information is subtracted from projection data in medical diagnostic imaging. The background is removed using data acquired in a single rotational sweep of a C-arm. The removal may be by masking out a target, leaving the background, in the data as constructed into a volume. For subtraction, the masked background information is projected to a plane and subtracted from the data representing the plane.

Abstract: A method for three-dimensional visualization of a moving structure by a rotation angiography method is described. A series of projection images is recorded by an image acquisition unit from different recording angles during a rotation cycle. A three-dimensional image data can be reconstructed from the projection images. A continuous rotation cycle is proposed to be performed with simultaneous recording of at least one ECG. A three-dimensional reconstructed reference image is generated through a first correction of the motion of the moving structure by affine transformations. A three-dimensional image data of the moving structure is reconstructed from the data acquired in the continuous rotation cycle when using the reconstructed reference image while performing an estimation and correction of the motion by elastic deformations.

Abstract: A 3D result image of an object is reconstructed from a set of X-ray two-dimensional projections of the object. A 3D reference image of the object is reconstructed by employing a compressed sensing technique based on at least some of the 2D projections at a reference motion state of the object. By employing an algebraic and/or analytic reconstruction technique, 3D intermediate images are reconstructed for various motion states of the object. The 3D intermediate images are registered with the 3D reference image to obtain spatial transformations for the various motion states of the object. Based on the spatial transformations, the 3D intermediate images are transformed to a joint phase and combined to obtain the 3D result image.

Abstract: A method and system for estimating 3D cardiac motion from a single C-arm angiography scan is disclosed. An initial 3D volume is reconstructed from a plurality of 2D projection images acquired in a single C-arm scan. A static mesh is extracted by segmenting an object in the initial 3D volume. The static mesh is projected to each of the 2D projection images. A cardiac phase is determined for each of the 2D projection images. A deformed mesh is generated for each of a plurality of cardiac phases based on a 2D contour of the object and the projected mesh in each of the 2D projection images of that cardiac phase.

Abstract: A method for generating a four-dimensional representation of a periodically moving target region is proposed. A motion-compensated three-dimensional image dataset is determined from two-dimensional projection images recorded from different projection directions. Estimation parameters that describe a non-periodic motion and are derived from a motion model formulated independently of the phase of the periodic motion with respect to the recording instants of the projection images are determined from the projection images, such that the three-dimensional image dataset represents a static reconstruction based on all projection images for a specific instant. The three-dimensional image dataset is animated from the estimation parameters used in its reconstruction. The motion information that is missing in the estimation parameters due to the two-dimensionality of the projection images is additionally determined using a boundary condition that describes the periodicity of the motion, and used for the animation.

Abstract: A method is provided for supplying a 3D X-ray image data record for a moving object. The said object contains highly X-ray radiation-absorbent material. A correction is made in respect of the highly absorbent material in 2D forward projections obtained from a 3D-X-ray image data record. The forward projections are calculated using 3D motion fields, which are derived from original 2D X-ray image data records.

Abstract: Automatic measurement of morphometric and motion parameters of a coronary target includes extracting reference frames from input data of a coronary target at different phases of a cardiac cycle, extracting a three-dimensional centerline model for each phase of the cardiac cycle based on the references frames and projection matrices of the coronary target, tracking a motion of the coronary target through the phases based on the three-dimensional centerline models, and determining a measurement of morphologic and motion parameters of the coronary target based on the motion.

Abstract: Background information is subtracted from projection data in medical diagnostic imaging. The background is removed using data acquired in a single rotational sweep of a C-arm. The removal may be by masking out a target, leaving the background, in the data as constructed into a volume. For subtraction, the masked background information is projected to a plane and subtracted from the data representing the plane.

Abstract: The left ventricle epicardium is estimated in medical diagnostic imaging. C-arm x-ray data is used to detect an endocardium at different phases. The detected endocardium at the different phases is compared to sample endocardiums at different phases. The sample endocardiums have corresponding sample epicadriums. The transformation between the most similar sample endocardium or endocardiums over time and the detected endocardium over time is applied to the corresponding sample epicardium or epicardiums. The transformed sample epicardium over time is the estimated epicardium over time for the C-arm x-ray data.

Abstract: A method is provided for supplying a 3D X-ray image data record for a moving object. The said object contains highly X-ray radiation-absorbent material. A correction is made in respect of the highly absorbent material in 2D forward projections obtained from a 3D-X-ray image data record. The forward projections are calculated using 3D motion fields, which are derived from original 2D X-ray image data records.

Abstract: A system and method of obtaining perfusion data for cerebral tissue is described. The system includes a C-arm X-ray device and a computing system configured to obtain sets of rotational projection X-ray data suitable for reconstructing 3D voxel data sets. A first data set is obtained of the patient, and then contrast material is injected into the vascular system to obtain a second 1 data set. A first voxel data set is subtracted from the second voxel data set, and the resultant data set is processed so as to segment the contrast-enhanced vasculature from the remaining data. The segmented voxels are subtracted from the resultant voxel data set, so as to yield a functional data set representing the difference between the attenuation of the tissues after administering contrast agent and the tissues prior to administering the contrast agent, without the contrast enhanced vasculature. The attenuation of the functional data set represents the perfusion or cerebral blood volume (CBV).

Abstract: A method and system for estimating 3D cardiac motion from a single C-arm angiography scan is disclosed. An initial 3D volume is reconstructed from a plurality of 2D projection images acquired in a single C-arm scan. A static mesh is extracted by segmenting an object in the initial 3D volume. The static mesh is projected to each of the 2D projection images. A cardiac phase is determined for each of the 2D projection images. A deformed mesh is generated for each of a plurality of cardiac phases based on a 2D contour of the object and the projected mesh in each of the 2D projection images of that cardiac phase.

Abstract: The invention relates to a method for three-dimensional presentation of a moved structure using a tomographic method, in which a plurality of projection images are recorded from different imaging angles between a start angle with a start node point and an end angle with an end node point by an imaging unit during a number of rotation passes, with three-dimensional image data being able to be reconstructed from the projection images, with the projection images being spaced by a path or an edge. For determining the three-dimensional presentation for each angle of projection only those projection images are selected which minimize the sum of the paths or weighted edges between adjacent projection angles for a gating.

Abstract: The invention relates to a method for correcting truncation artifacts in a reconstruction method for computed tomography recordings. The projection images are recorded by an x-ray image detector being extended by determining the attenuation of the radiation outside the projection image for pixels. Non-horizontal filter lines are extended by transaxial and axial artificial extension of the x-ray image detector for the purposes of truncation correction. The truncation correction for non-horizontal filter lines being carried out according to a method from at least one of the following groups: truncation correction takes place regardless of the specific location and orientation of the filter lines; truncation correction takes place as a function of the specific position and orientation of the filter lines, with the filter lines themselves being retained; and truncation correction takes place by introducing new modified filter lines, with filtering taking place along offset artificially extended filter lines.

Abstract: The invention relates to the use of 2D projection images which belong to a specific common heart phase. A 3D image data set can be used to generate a reference projection image for the same projection angle for each of the 2D projection images and a differential image can be derived from the reference projection image and 2D projection image. The differential images are back-projected and combined in one 3D differential image data set and, by using this, a deformed 3D image data set is obtained from the previously recorded 3D image data set. Iterations guarantee that the deformed 3D image data set ensues with the smallest possible distance from the 2D projection images for the existing common heart phase. Finally, a 3D image data set is available for a different heart phase other than the reference heart phase and the possibilities for imaging a patient's heart are extended.

Abstract: A method for three-dimensional visualization of a moving structure by a rotation angiography method is described. A series of projection images is recorded by an image acquisition unit from different recording angles during a rotation cycle. A three-dimensional image data can be reconstructed from the projection images. A continuous rotation cycle is proposed to be performed with simultaneous recording of at least one ECG. A three-dimensional reconstructed reference image is generated through a first correction of the motion of the moving structure by affine transformations. A three-dimensional image data of the moving structure is reconstructed from the data acquired in the continuous rotation cycle when using the reconstructed reference image while performing an estimation and correction of the motion by elastic deformations.

Abstract: X-ray images are recorded of a patient's heart and the heartbeat phase is registered as that is done. The heartbeat phases are coarsely divided into intervals and all X-ray images that have been assigned heartbeat phase from the interval are used for reconstructing a 3D image dataset. The movement fields of the other 3D image datasets are then calculated for one of said 3D image datasets. Movement fields are vector fields indicating the movements of similar structures from one local area to the other. A departure is then made from the coarse interval division, and for each heartbeat phase a movement field is interpolated individually or at least for fairly short intervals from the movement fields determined in advance, which field is used for generating a deformed 3D image dataset that has been imaged onto a reference heartbeat phase. The deformed 3D image datasets are then added together.