Abstract: An image processing apparatus is disclosed for generating a 3D data record from a plurality of 2D data records. The 3D data record represents an object at least partially in three dimensions, and the 2D data records respectively represent a result of a detection of the object by means of a projection through the object onto a detection plane in two dimensions. In at least one embodiment, the image processing apparatus is designed to generate the 3D data record, in particular by back projection or by filtered back projection from the 2D data records. In at least one embodiment, the image processing apparatus is designed to allocate a no object value to at least one area of the 3D data record that does not represent an object, and to allocate a changed object value to at least one area of the 3D data record in which an object location is represented by an object value.

Abstract: A method is provided for recording an examination object using an x-ray recording system having an x-ray source and an x-ray detector rotatable about a common axis of rotation. X-ray detector is displaced in a first direction enclosing a first angle k between a perpendicular bisector from x-ray source to x-ray detector and a plane running through x-ray source and containing the axis, k?0. First x-ray images are recorded in angular positions of x-ray source and x-ray detector displaced in the first direction in a first rotation. X-ray detector is displaced in a second direction enclosing a second angle m between the bisector and the plane, m?0 and is on an opposite side from k. Starting points of the rotations are differed by an angle of displacement ? 0 = k + m + d 2 , where d is the detector fan angle. Starting points and finishing points of the rotations are spanned by ?+?0.

Abstract: A method for producing a 3D image dataset of an object with an imaging system having an x-ray source and an x-ray detector is provided. A series of two-dimensional arrays of cone beam data from the detector is acquired while the source moves along a substantially planar trajectory around the object. The trajectory is described by a series of source points serially numbered by a counter parameter. The cone beam data is differentiated with respect to the counter parameter at a fixed ray direction to produce a derivative of the cone beam data. The derivative is filtered with a Hilbert-like filter to produce filtered cone beam data. The acquired or the filtered cone beam data is multiplied with a redundancy weighting function. The cone beam data is back-projected to reconstruct a 3D image dataset.

Abstract: A method is provided for quickly and simply generating a three-dimensional tomographic x-ray imaging. Tomosynthetic projection images are recorded from different recording angles along a tomosynthetic scanning path and three-dimensional image data is reconstructed from the tomosynthetic projection images. The tomosynthetic projection images are recorded by a tomosynthetic x-ray device with a plurality of x-ray sources arranged on a holder at a distance from one another. Each projection image is recorded by a different x-ray source being fixed in one place during recording the tomosynthetic projection images.

Abstract: A method for determining absorption coefficients corrected with polychromy artifacts for an object composed of a plurality of material types differentiated with absorption attributes is provided. A plurality of x-ray beam projections of the object are recorded with monochrome x-rays from different positions. The recorded projections are reconstructed to determine a first set of absorption coefficients. The projections are calculated by reprojection. The recorded projections are corrected by the calculated projections. A second set of absorption coefficients corrected with polychromy artifacts is finally determined by reconstructing the corrected projections. A formula-based description of a rule taking account of polychromy is used in the calculation. The rule includes parameters to be determined by the reprojection in the course of the calculation of projections. The method combines steps of conventional methods and is thus more efficient.

Abstract: A method is provided for recording an examination object using an x-ray recording system having an x-ray source and an x-ray detector rotatable about a common axis of rotation. X-ray detector is displaced in a first direction enclosing a first angle k between a perpendicular bisector from x-ray source to x-ray detector and a plane running through x-ray source and containing the axis, k?0. First x-ray images are recorded in angular positions of x-ray source and x-ray detector displaced in the first direction in a first rotation. X-ray detector is displaced in a second direction enclosing a second angle m between the bisector and the plane, m?0 and is on an opposite side from k. Starting points of the rotations are differed by an angle of displacement ? 0 = k + m + d 2 , where d is the detector fan angle. Starting points and finishing points of the rotations are spanned by ?+?0.

Abstract: A method and an X-ray image acquisition system for the acquisition of X-ray images of a region of interest of an examination object from a multiplicity of angles of view for an 3-D image reconstruction are provided. The X-ray image acquisition system comprises an X-ray focus and an X-ray detector, which can be separately positioned and oriented relative to each other. The X-ray focus is moved along a combination of straight line segments and/or arc segments for the acquisition of X-ray images. The X-ray detector is oriented relative to the X-ray focus and moved in such a way that the region of interest is projected completely onto the X-ray detector upon each image acquisition.

Abstract: In the acquisition of an image series with an x-ray image acquisition that has an x-ray C-arm rotatable around a center point, movement of the patient table is updated so that table is brought into a specific position calculated relative to the angle position of the x-ray C-arm. This position of the patient table is determined as follows. An envelope is established and a point is established that is the center point of a region of interest. In each position of the patient table that matches the position of the x-ray C-arm, the flat panel detector is perpendicular to a line emanating from the point and simultaneously contacts (is tangent to) the envelope. The region of interest is thereby optimally imaged in the image series so that a good 3D reconstruction can be obtained.

Abstract: The invention relates to a method for generating a 3D reconstruction of an especially large body that cannot be captured by a single projection by capturing at least two projections, which together capture the body, at each of the positions taken up by a C-arm X-ray unit. Data from the two projections is projected onto a virtual detector and the data from the virtual detector is then used for the filtered back projection procedure. It is assumed here that the real source remains motionless and that only the detector moves. A virtual detector D1?/D2? is only used in order to carry out large scale filtering in the event that real sources Q1 and Q2 for the two projections do not coincide. A return is then made to two independent projections. These two independent projections are used separately in the filtered back projection procedure to generate the 3D reconstruction.

Abstract: When recording an image sequence, it is possible to deviate from passing through a perfect curve path. There is described how an alternative curve path can be determined. An envelope is determined, a point is determined, which is the center point of the region of interest and then the detector is moved such that it is at right angles in each instance to a line which emanates from the point and simultaneously touches the envelope tangentially. As a result, the region of interest is mapped as optimally as possible in the image sequence so that as good a 3D reconstruction as possible can be obtained.

Abstract: A method is disclosed for image reconstruction of an object with the aid of at least one-dimensional projections of the object into a three-dimensional volume image data record, it being possible to generate the projections by at least one detector/source system with reference to different positions and angles relative to the object, and at least two projections forming a reconstruction volume in an overlap region as basis for a backprojection of the projections into the three-dimensional volume image data record, in particular computed tomography. An apparatus for carrying out the method is further disclosed. In at least one embodiment, supplemented reconstruction volumes are generated by supplementing reconstruction volumes, covered only partially by projections, by way of virtual projections that are derived from volume image data records.

Abstract: The invention relates to a method for generating tomographical recordings of a partially cyclically moving examination object by a tomography system and a tomography system, comprising the steps of: a spatial scanning of the examination object taking place using at least one detector, which generates detector output data; movement information of the moving subarea of the examination object being recorded during the scanning and being assigned to the detector output data or stored in a manner which correlates to the detector output data; and tomographical image data being reconstructed from the measured detector output data in a number of iteration steps. The invention is characterized in that iteration takes place in at least two iteration stages, with data records being used from the detector output data of different cycle phase regions in at least two iteration stages.

Abstract: In the acquisition of an image series with an x-ray image acquisition that has an x-ray C-arm rotatable around a center point, movement of the patient table is updated so that table is brought into a specific position calculated relative to the angle position of the x-ray C-arm. This position of the patient table is determined as follows. An envelope is established and a point is established that is the center point of a region of interest. In each position of the patient table that matches the position of the x-ray C-arm, the flat panel detector is perpendicular to a line emanating from the point and simultaneously contacts (is tangent to) the envelope. The region of interest is thereby optimally imaged in the image series so that a good 3D reconstruction can be obtained.

Abstract: When recording an image sequence, it is possible to deviate from passing through a perfect curve path. There is described how an alternative curve path can be determined. An envelope is determined, a point is determined, which is the center point of the region of interest and then the detector is moved such that it is at right angles in each instance to a line which emanates from the point and simultaneously touches the envelope tangentially. As a result, the region of interest is mapped as optimally as possible in the image sequence so that as good a 3D reconstruction as possible can be obtained.

Abstract: It is possible that at a predetermined position of the imaging components of a radiographic imaging system the object is not fully viewed. The object can be a calibration phantom, which means that it is not possible to directly determine an imaging rule with the aid of the calibration phantom at this position of the imaging components. According to the invention, an imaging of the calibration phantom at a different position takes place and an imaging rule for this position is determined. This is then converted, provided a movement parameter is known which describes the movement from the position with the record of the calibration phantom to a different position. The imaging rule obtained in this way can be further improved, e.g. with the aid of a recording of the calibration phantom from the position in question, including if the calibration phantom is not completely imaged.

Abstract: The invention relates to a method for generating a 3D reconstruction of an especially large body that cannot be captured by a single projection by capturing at least two projections, which together capture the body, at each of the positions taken up by a C-arm X-ray unit. Data from the two projections is projected onto a virtual detector and the data from the virtual detector is then used for the filtered back projection procedure. It is assumed here that the real source remains motionless and that only the detector moves. A virtual detector D1?/D2? is only used in order to carry out large scale filtering in the event that real sources Q1 and Q2 for the two projections do not coincide. A return is then made to two independent projections. These two independent projections are used separately in the filtered back projection procedure to generate the 3D reconstruction.

Abstract: A method is disclosed for reconstructing a tomographic representation of an object from projection data off a moving radiation source through this object onto a detector, filtering and back projection of the projection data being executed in the reconstruction. In an embodiment of the method, by using at least one identical spatial arrangement of the radiation source, the detector and a test object instead of the object to be scanned, there is determined by test projections and an iterative reconstruction technique, a filter that in the given arrangement results in an optimum filtering and back projection of the projection data of the test object for the tomographic representation. Further, the object is scanned instead of the test object in the given arrangement and projection data are determined. Finally, the reconstruction of the tomographic representation is carried out using these projection data and the filter determined.

Abstract: Incomplete data records owing to an object extent that stretches beyond the scanning field of view (SFOV) constitute a general problem in computed tomography. In these cases, parts of the object are to be reconstructed, for which only incomplete projections from an angular range of less than 180° are available. The application of iterative algorithms such as, for example, the algebraic reconstruction technique (ART) or the simultaneous algebraic reconstruction technique (SART) to this problem of truncated projections cannot lead to a satisfactory solution unless use is made of special boundary conditions. In order to regularize the reconstruction method, in at least one embodiment, information relating to the statistics of the attenuation values of the reconstructed object is also included in the form of the logarithmic probability function of the attenuation values.

Abstract: The invention relates to a method for generating tomographical recordings of a partially cyclically moving examination object by a tomography system and a tomography system, comprising the steps of: a spatial scanning of the examination object taking place using at least one detector, which generates detector output data; movement information of the moving subarea of the examination object being recorded during the scanning and being assigned to the detector output data or stored in a manner which correlates to the detector output data; and tomographical image data being reconstructed from the measured detector output data in a number of iteration steps. The invention is characterized in that iteration takes place in at least two iteration stages, with data records being used from the detector output data of different cycle phase regions in at least two iteration stages.

Abstract: An image processing apparatus is disclosed for generating a 3D data record from a plurality of 2D data records. The 3D data record represents an object at least partially in three dimensions, and the 2D data records respectively represent a result of a detection of the object by means of a projection through the object onto a detection plane in two dimensions. In at least one embodiment, the image processing apparatus is designed to generate the 3D data record, in particular by back projection or by filtered back projection from the 2D data records. In at least one embodiment, the image processing apparatus is designed to allocate a no object value to at least one area of the 3D data record that does not represent an object, and to allocate a changed object value to at least one area of the 3D data record in which an object location is represented by an object value.