Abstract: A Digital Radiograph (DR) acquisition system for generating a scatter-corrected X-ray image is provided. The DR acquisition system includes a digital detector configured to produce a two-dimensional (2D) X-ray image of an object of interest. The digital detector is configured to detect X-rays emitted from an X-ray source and transmit the X-rays through the object of interest and generate the 2D X-ray image in response to the detected X-rays. The DR acquisition system further includes an image processor coupled to the digital detector, and a display unit. The image processor is configured to generate projection image data from the 2D X-ray image and iteratively reconstruct the 2D X-ray image to generate a scatter-corrected X-ray image based on the generated projection image data. The display unit configured to display the scatter-corrected X-ray image in conjunction with the 2D X-ray image.

Abstract: A method for creating a variable slice thickness for displaying an imaged object is disclosed. The method includes acquiring a plurality of projection images from a plurality of different projection angles within a defined sweep angle, reconstructing a plurality of object images from the plurality of projection images, each object image having a first slice thickness, and applying a function rule to combine images, whole images or portions thereof or attributes thereof, of the plurality of projection images, of the plurality of object images, or of both, thereby providing for the display of the object utilizing a second slice thickness that varies from the first slice thickness.

Abstract: A method is proposed for correcting detector signals of a unit for reconstructing tomograms from projection data, in particular of a computer tomography unit, of a ray detector having a multiplicity of individual detector channels that form the projection data, attenuation values of individual X-rays being calculated after the passage through an examination object. In order to reconstruct the tomograms from attenuation values of the X-rays, the detector output signals are subjected to a nonlinearity correction before the calculation of the attenuation values.

Abstract: A method for estimating projection data outside a field of view of a scanning device, including: obtaining measured projection data by scanning an object using the scanning device; selecting a projection angle and a fan angle outside a field of view of the scanning device; determining, based on the selected projection angle and fan angle, a plurality of sinogram curves, each sinogram curve corresponding to a different image point in the object; determining a contribution value for each of the sinogram curves based on the measured projection data; and calculating estimated expanded projection data for the selected projection angle and fan angle based on the determined contribution values.

Abstract: A radiodiagnostic apparatus includes a data collection unit, a primary correction unit, a body contour detection unit, a secondary correction unit, and a reconstruction unit. The primary correction unit calculates a plurality of primary extrapolation expression candidates for correcting second projection data so as to obtain third projection data candidates formed from the second projection data and a plurality of primary extrapolation expression candidates and for obtaining third projection data from the plurality of third projection data candidates.

Abstract: Embodiments of the present invention include a method and apparatus for accurate cone beam reconstruction with source positions on a curve (or set of curves). The inversion formulas employed by embodiments of the method of the present invention are based on first backprojecting a simple derivative in the projection space and then applying a Hilbert transform inversion in the image space.

Abstract: The present invention provides a method comprising the following steps: (a) partitioning an intensity modulated beam into a set of sub-IMBs; and (b) partitioning the sub-IMBs into segments, wherein steps (a) and (b) introduce no machine delivery error. The present invention also provides a method comprising the following steps: (a) recursively partitioning an intensity modulated beam into plateaus; and (b) partitioning the plateaus into segments, wherein step (a) comprises determining a tradeoff between machine delivery error and the number of segments into which the plateaus will be partitioned in step (b).

Abstract: In a method and a device for generating a digital tomosynthetic 3D X-ray image of an examined object, a number of individual images are made of the examined object at different projection angles relative to the normal of the patient examination table by moving the X-ray tube. In a starting position, the X-ray tube is operated with a dose that is lower than that used for subsequent individual images. At least one preliminary image is recorded at the starting position, which is then evaluated to determine the radiographic parameters required for the recording of the subsequent individual images.

Abstract: A data managing system that collectively manages raw data obtained in any of X-ray CT apparatuses with the use of a network. Raw data transmitted from any of the X-ray CT apparatuses is stored in the data managing system, and baked up to various kinds of storage devices. Also, the raw data managed by the data managing system is transmitted, at a request, to an arbitrary X-ray CT apparatus at arbitrary timing to be reconstructed therein.

Abstract: The invention relates to a computer tomography method in which a bundle of rays passes through an object that is moving periodically, in particular a heart. During the acquisition of measured values, a movement signal dependent on the movement of the object is sensed. From this movement signal are determined periodically repeated phases of movement, after which a plurality of intermediate images of a region of the object are reconstructed, in particular at a low resolution, using measured values whose times of acquisition were situated in different phases of movement, thus enabling each intermediate image to be assigned to a phase of movement. The phase of movement in which the object moved least in the region is then identified by determining the intermediate image having the fewest motion artifacts.

Abstract: An apparatus configured for an insertion of a cassette comprises at least one distance sensor operably measuring in a contactless manner a distance from a corresponding location on the apparatus to the inserted cassette. An electronic evaluator is operably connected to the at least one distance sensor to receive at least one distance signal corresponding to distances measured by at least one distance sensor, such that the electronic evaluator generates a position signal, resulting from the at least one distance signal, which is dependent on a dimension and a position of the inserted cassette in the apparatus. A control unit is operably connected to the electronic evaluator such that the control unit receives the position signal from the electronic evaluator.

Abstract: The invention relates to a computer tomography method in which a periodically moving object, in particular an organ of the body, is irradiated by a cone-shaped beam cluster (4) along a trajectory which runs on a cylindrical surface. The radiation transmitted through the object is measured by means of a detector unit (16), and at the same time the periodic movement of the object is recorded. In order to reconstruct the absorption distribution of the object, the measured values or the corresponding beams are rebinned to form a number of parallel projections, where for each of these projections a measured value is determined whose beam irradiates the object. The point in time at which this measured value was acquired is allocated to the respective projection. For the reconstruction, which may for example be carried out using a filtered back-projection, only projections whose allocated points in time lie within a predefined, specific time range (H1) within a period of the object movement are used.

Abstract: An X-ray imaging method forms a set of a plurality of two-dimensional X-Ray projection images of a medical or veterinary object to be examined through a scanning rotation by an X-Ray source viz à viz the object. Such X-Ray images are acquired at respective predetermined time instants with respect to a functionality process produced by the object. From said set of X-Ray projection images by back-projection a three-dimensional volume image of the object is reconstructed. In particular, an appropriate motion correction is derived for the respective two-dimensional images, and subsequently as based on a motion vector field from the various corrected two-dimensional images the intended three-dimensional volume is reconstructed.

Abstract: A method of determining an image data value at a point of reconstruction in a computed tomography (CT) image of a scanned object, including obtaining projection data of the scanned object, filtering the obtained projection data with a one-dimensional ramp filter to generate ramp-filtered data, and applying a backprojection operator with inverse distance weighting to the ramp-filtered data to generate the image data value at the point of reconstruction in the CT image.

Abstract: The invention relates to a computer tomography method in which an examination area is passed through by a cone-shaped bundle of rays. The bundle of rays comes from a radiation source location which moves around the examination area on an overall trajectory. The overall trajectory consists of a first, closed partial trajectory, at least one second, closed partial trajectory and at least one third partial trajectory which connects the first and the at least one second partial trajectories to one another. Measured values which depend on the intensity in the bundle of rays on the other side of the examination area are acquired by means of a detector unit while the radiation source location is moving on the overall trajectory, and a CT image of the examination area is reconstructed from these measured values.

Abstract: A method for iteratively reconstructing image data acquired by a computed tomography system is provided. The method comprises generating a calculated sinogram from an image estimate and generating an error sinogram based on the calculated sinogram and a measured sinogram. Then, one or more backprojections are performed, each based upon a reconstruction parameter. The reconstruction parameter impacts at least one of convergence speed and computational cost of each iterative step and corresponding reconstruction. A filtering step is performed prior to performing the one or more backprojections. Finally, the initial image is updated by adding corresponding results of the one or more backprojections to the image estimate to obtain the reconstructed image.

Abstract: An apparatus for applying x-rays to an interior surface of a body cavity includes a catheter assembly, and one or more flexible probe assemblies. An x-ray generator assembly, including an optically activated x-ray source, is coupled to a distal end of each flexible probe assembly. The catheter assembly includes a body member defining one or more interior channels; an x-ray absorption control layer surrounding the body member; at least one inner tube enclosing the body member and the absorption control layer; at least one outer tube; and one or more inflatable elements coupled to the inner tube. The inflatable elements, when inflated, fixedly position the catheter assembly within the body cavity. Each flexible probe assembly is slidably positionable within at least one of the interior channels, and includes a transmission path adapted to transmit an activating energy, such as light from laser, onto a cathode within the x-ray source.

Abstract: The invention relates to a method for “truncation correction” in an x-ray system, i.e. a correction method during the reconstruction of projection images of an object recorded from different projection angles, if parts of the object do not lie in the field of view of each projection image. The surface of the object is thereby optically detected and used during the reconstruction of projection images to supplement the missing image data.

Abstract: A method for fast inverse planning of IMRT treatment plans is disclosed. The method relies on a computationally efficient algorithm for evaluating the gradient of a general class of objective functions, and also on the efficient optimization that is realized due to the directional conjugacy of the objective functions. Several types of clinically relevant objective functions that belong to this class are described. The computational evaluation relies on operations that are commonly used for signal- and image-processing, and so can benefit from a number of well-known acceleration techniques.

Abstract: A method and system are presented for generating a DRR of an anatomical region so that the visibility within the DRR of one or more skeletal reference structures is enhanced. 3D scan data, which have been obtained from a 3D scan of the object conducted at a 3D scan energy level, are provided. The 3D scan data are modified to compensated for a difference between the ratio of bone-to-tissue attenuation at the 3D scan energy level, and the ratio of bone-to-tissue attenuation at the intensity of the imaging beam which the DRR emulates. The modified 3D scan data are related to the raw 3D scan data by a non-linear, exponential relationship. A plurality of hypothetical rays are cast through the modified 3D scan data, from the known geometry of the imaging beam. The 3D scan data are integrated along each hypothetical ray, and the integrated values are projected onto an imaging plane.