| Patent application number | Description | Published |
|---|
| 20080205737 | Method and apparatus for the artifact-reduced detection of a 3D object in tomographic imaging - 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. This information can be obtained from the regions of those image parts which are still completely contained in the SFOV, but nevertheless lie in the vicinity of the region where the object leaves the SFOV. Furthermore, the information can be used in an algebraic reconstruction method by adding a boundary condition term to the cost function to be minimized. Experiments indicate that taking account of this information leads to good estimates with reference to the object in the event of insubstantially truncated projections such as are customary in CT applications, for example. | 08-28-2008 |
| 20080304617 | Method for generating a 3D reconstruction of a body - 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 D | 12-11-2008 |
| 20090067583 | Method for determining an imaging rule and method for generating a 3D reconstruction - 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. | 03-12-2009 |
| 20090074135 | Method for generating an image sequence for a 3D reconstruction - 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. | 03-19-2009 |
| 20090202046 | METHOD AND SYSTEM FOR ACQUIRING PROJECTION FOR 3D RECONSTRUCTION OF AN OFF-CENTER ROI - 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. | 08-13-2009 |
| 20100329534 | METHOD AND DEVICE FOR THE ACQUISITION OF X-RAY IMAGES FOR A THREE-DIMENSIONAL IMAGE RECONSTRUCTION - 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. | 12-30-2010 |
| 20110051887 | Method for Recording an Examination Object - 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 | 03-03-2011 |
| 20110075794 | Method and Device for Generating a Three-Dimensional X-Ray Imaging - 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. | 03-31-2011 |
| 20110075899 | Efficient correction of polychromy effects in image reconstruction - 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. | 03-31-2011 |
| 20110085637 | Reconstruction of 3D image datasets from x-ray and cone-beam data - 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. | 04-14-2011 |
| 20110268335 | Increased Temporal Resolution In The Case Of CT Images By Means Of Iterative View Reconstruction With Limiting Conditions - A method is disclosed for the reconstruction of image data of a moving object to be examined from measurement data, wherein the measurement data has previously been established in a relative rotational movement between a radiation source of a computed tomography system and the object to be examined. In at least one embodiment, first image data is reconstructed from an incomplete measurement data record by way of an iterative algorithm, wherein in the iterative reconstruction a dimension is used which contains probability information relating to pixel values of the image data to be reconstructed. | 11-03-2011 |
| 20110274335 | Method for recording and reconstructing a three-dimensional image dataset and x-ray apparatus - A method for recording and reconstructing a three-dimensional image dataset is proposed. A plurality of projection images are acquired under different recording geometries in relation to an object to be recorded by an X-ray apparatus, in particular a C-arm X-ray apparatus. At least two projection images are recorded for at least one recording geometry, in particular for every recording geometry. The three-dimensional image dataset is reconstructed from the project images. | 11-10-2011 |
| 20140163736 | COLLISION AVOIDANCE DURING CONTROLLED MOVEMENT OF IMAGE CAPTURING DEVICE AND MANIPULATABLE DEVICE MOVABLE ARMS - A system and method for movement control includes a controller coupled to a computer-assisted surgical device having a first movable arm coupled to a manipulatable device having a working end and a second movable arm coupled to an image capturing device. The controller is configured to receive first configurations for the first movable arm; receive second configurations for the second movable arm; receive a plurality of images of the working end from the image capturing device; determine a position and an orientation of the working end; determine a first movable arm position and trajectory for the first movable arm; determine a second movable arm position and trajectory for the second movable arm; determine whether motion of the movable arms will result in an undesirable relationship between the movable arms; and send a movement command to the first or second movable arm to avoid the undesirable relationship. | 06-12-2014 |
