Abstract: For visualizing a limited part of a 3D medical image-point-related data set, Selectively, a geometrically selected part of the data set is suppressed and an image rendered based on any non-suppressed part of the data set. The selected geometrically selected part includes a first selection containing all points associated to a nearer region with respect to a first clipping plane, and all points associated to a farther region with respect to a second clipping plane, respectively. The image rendered thereby is based on an intermediate region between the first clipping plane and the second clipping plane.

Abstract: A method is disclosed for generating images of a human or animal body on the basis of 3D-reconstructions from 3D-XRAY or 3D-Computer Tomography measurements, which bodies comprise both natural tissue and one or more high-density objects. The method comprises the steps of executing the measurements, distinguishing the one or more high-density objects and executing a separating procedure thereon for generating an improved image of regions of the natural tissue. In particular, the method comprises the following steps: applying a ramp filter on the various projection measurements to single out the one or more high-density objects; segmenting the singled-out one or more high-density objects into a separate 3D reconstruction; suppressing the reconstructed one or more high-density objects from the original projection measurements; and segmenting said projection measurements without the suppressed one or more high-density objects.

Abstract: A method and a device provide for the registration of two 3D image data sets of an object to be examined. The object to be examined is provided with a plurality of markers In order to enable a registration to be carried out, the positions of the markers in the 3D image data sets are first determined in a co-ordinate system associated with the relevant 3D image data set. The distances between the markers and/or the angles formed between lines which intersect in a marker and extend through two further markers are then determined. Finally, a transformation rule for the transformation of one of the 3D image data sets to the co-ordinate system of the other 3D image data set is determined.

Abstract: An X-ray imaging method comprises forming 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, and reconstruction of a 3-dimensional volume thereof. With a relatively long run length of a scan rotation over substantially 180° of at least 15 sec. and preferably about 20 sec. A sufficient number of images is obtained to perform a more accurate volume reconstruction. This reconstruction method may be combined with existing modelling techniques.

Abstract: For imaging a 3D data set the method of the invention comprises the following steps in succession: acquisition of images, reconstructing a 3D data set, followed by visualization, the reconstruction being started with a limited initial range of orientations around the direction of a local midprojection from a starting point so as to be visualized, the acquisition being continued during visualization and the reconstruction being updated in accordance with the additional acquisition obtained up to a final result. In particular, the selected part comprises a first visualization covering a range of from about 40° to 60°, with a midprojection at about from 20° to 30°.

Abstract: A method and system of forming an X-ray layer image of an object being examined by an X-ray device having an X-ray source and an X-ray detector is described. At least one of the X-ray source and the X-ray detector can be displaced in an angular range around the object in order that X-ray projection images are acquired from different directions. When forming only a single X-ray layer image, or a plurality of X-ray layer images of parallel layers of the object, the time required for the acquisition of the X-ray projection images is notably reduced by forming the X-ray layer image directly from the X-ray projection images, where the resulting X-ray layer image is situated in a plane which extends essentially perpendicularly to the bisector of the angular range of displacement. The angular range of displacement can be less then 180°. The system and method is notably applicable to a C-arm X-ray device, in which the angular range can be chosen at will.

Abstract: An X-ray examination apparatus includes an X-ray source and an X-ray detector and is arranged to provide a series of projection images at respective orientations of the X-ray source (1) and the X-ray detector (2) relative to a predetermined frame of reference. The orientations of the projection images are calibrated relative to this frame of reference. A basic three-dimensional data set (23) is reconstructed from the projection images. A number of directions of observations (121-123) are calibrated relative to the same frame of reference. One or more additional X-ray images (111-113) are formed for the calibrated directions of observation, that is, preferably at successive instants in time. A dynamic series of three-dimensional data sets is formed by updating the basic three-dimensional data set by means of the additional X-ray images.

Abstract: For imaging a 3D data set the method of the invention comprises the following steps in succession: acquisition of images, reconstructing a 3D data set, followed by visualization, the reconstruction being started with a limited initial range of orientations around the direction of a local midprojection from a starting point so as to be visualized, said acquisition being continued during visualization and the reconstruction being updated in accordance with the additional acquisition obtained up to a final result. In particular, the selected part comprises a first visualization covering a range of from about 40° to 60°, with a midprojection at about from 20° to 30°.

Abstract: An X-ray examination apparatus includes an X-ray source (1) for emitting an X-ray beam (8) having a central X-ray extending along a central beam line (4). There is also provided an X-ray detector (2) for picking up X-ray images. The X-ray source (1) and the X-ray detector (2) are rotatable together around an axis of rotation (3). The X-ray examination apparatus is provided with a calibration system (6, 7). Calibration images of the calibration phantom (6) are formed from different, preferably opposed directions of the X-ray beam (8). The zero orientation of the X-ray source (1) with the X-ray detector (2) is derived from differences in positions of the same aspect of the calibration phantom in the respective calibration images. The central beam line (4) extends perpendicularly to the axis of rotation (3) in the zero orientation.

Abstract: The present invention provides an X-ray examination apparatus, comprising an X-ray source, an X-ray detector, a filter arranged between said source and said detector, said filter comprising an array of filter elements having X-ray absorbtivities that can be adjusted by means of control voltages, a control circuit for supplying said control voltages to said filter elements, and an object support arranged between said filter and said detector, said station being adapted to support an object to be exposed to X-ray radiation emanating from said source, the transmitted X-ray radiation being detected by said detector, said control circuit being adapted to supply said control voltages in single-sequence fashion to groups of adjacent filter elements.

Abstract: The invention relates to a method for the simultaneous display of at least two sectional images taken through a volume reconstructed from a 3D image data set.

Abstract: An X-ray examination apparatus includes an X-ray source and an X-ray detector and is arranged to provide a series of projection images at respective orientations of the X-ray source (1) and the X-ray detector (2) relative to a predetermined frame of reference. The orientations of the projection images are calibrated relative to this frame of reference. A basic three-dimensional data set (23) is reconstructed from the projection images. A number of directions of observations (121-123) are calibrated relative to the same frame of reference. One or more additional X-ray images (111-113) are formed for the calibrated directions of observation, that is, preferably at successive instants in time. A dynamic series of three-dimensional data sets is formed by updating the basic three-dimensional data set by means of the additional X-ray images.

Abstract: The invention relates to a method and a device for the registration of two 3D image data sets of an object to be examined which is provided with a plurality of markers which are contained in the 3D image data sets. Such a registration can be used, for example, in digital subtraction angiography.

Abstract: The invention relates to a method of forming an X-ray layer image of an object (9) to be examined by means of an X-ray device which includes an X-ray source (2) and an X-ray detector (3); the X-ray source (2) and the X-ray detector (3) are displaced in an angular range (14) around the object (9) to be examined in order to acquire X-ray projection images from different directions. When only a single X-ray layer image is to be formed, or a plurality of X-ray layer images of parallel layers (S1, S2) of the object (9) to be examined, in accordance with the invention it is possible to reduce the expenditure required, notably the time required for the acquisition of the X-ray projection images, by forming the X-ray layer image directly from the X-ray projection images, the X-ray layer image being situated in a plane which extends essentially perpendicularly to the bisector (20) of the angular range (14), the angular range (14) amounting to less then 180°.

Abstract: An X-ray imaging method comprises forming 2-dimensional X-ray images of an object to be examined, for example the coronary vascular system of a patient, and reconstruction of a 3-dimensional volume thereof. With a relatively long run length of a scan rotation over substantially 180° of at least 15 sec. and preferably about 20 sec. A sufficient number of images is obtained to perform a more accurate volume reconstruction. This reconstruction method may be combined with existing modelling techniques.

Abstract: The present invention provides an X-ray examination apparatus, comprising

Abstract: For visualizing a limited part of a 3D medical image-point-related data set, selectively a geometrically selected part of the data set is suppressed and an image rendered as based on any non-suppressed part of the data set. In particular, the selected part comprises a first selection containing all points associated to a nearer region with respect to a first clipping plane and moreover all points associated to a farther region with respect to a second clipping plane, respectively. Thereby the rendered image is based on an intermediate region between the first clipping plane and the second clipping plane.

Abstract: An X-ray examination apparatus includes an X-ray source (1) for emitting an X-ray beam (8) having a central X-ray extending along a central beam line (4). There is also provided an X-ray detector (2) for picking up X-ray images. The X-ray source (1) and the X-ray detector (2) are rotatable together around an axis of rotation (3). The X-ray examination apparatus is provided with a calibration system (6, 7). Calibration images of the calibration phantom (6) are formed from different, preferably opposed directions of the X-ray beam (8). The zero orientation of the X-ray source (1) with the X-ray detector (2) is derived from differences in positions of the same aspect of the calibration phantom in the respective calibration images. The central beam line (4) extends perpendicularly to the axis of rotation (3) in the zero orientation.