Abstract: A calibration phantom includes an arrangement of markings with a first X-ray absorption capability and a second X-ray absorption capability, with the arrangement of markings precluding superimposition of an image of a first marking with an image of a second marking for a sufficient number of successive markings for each projection condition, the physical embodiment of a marking representing a value assignment, and the value assignment of a respective specific first number of adjacent markings in each case forming first code information, with each of the first code information items being unique within the first code information which is formed in the totality of markings and in both reading directions.

Abstract: In a registration method for navigation-guided medical interventions using a position acquisition system, an X-ray device and an X-ray calibration phantom having X-ray-positive marks, the coordinates of marks of the X-ray calibration phantom that are present in the measurement volume of the X-ray device and imaged in the reconstructed volume are determined in a coordinate system allocated to the measurement volume of the X-ray device) and in a coordinate system allocated to the position acquisition system. The coordinate transformation between the coordinate system allocated to the measurement volume and the coordinate system allocated to the position acquisition system is determined on the basis of the coordinates of the X-ray-positive marks in the coordinate system allocated to the measurement volume and on the basis of the coordinates of the X-ray-positive marks in the coordinate system allocated to the position acquisition system.

Abstract: A registration method and an apparatus for navigation-guided interventions employing an X-ray device and a position acquisition system and avoid the use of patient-associated markers. By means of a defined arrangement of a carrying arm proceeding from a support mount at the X-ray device and a defined arrangement of an X-ray calibration phantom at the carrying arm, the coordinate transformation between a coordinate system allocated to the support mount and a coordinate system allocated to the X-ray calibration phantom is known. On the basis of the acquisition and evaluation of 2D projections of the X-ray calibration phantom with the X-ray device, a coordinate transformation between the coordinate system allocated to the support mount and a coordinate system allocated to a measurement volume of the X-ray device is produced.

Abstract: An apparatus for determining a coordinate transformation for mixing an image of a first subject into an X-ray image of a second subject has an arrangement for fastening the apparatus to the second subject, markers that can be acquired by a navigation system, and X-ray-positive marks. The positions and orientations of the markers that can be acquired with the navigation system and the positions and orientations of the X-ray-positive marks relative to one another are thus known, so a coordinate transformation can be determined between a coordinate system allocated to the navigation system and a coordinate system allocated to the X-ray image. Thus an image of the first subject that can be acquired with the navigation system can be mixed into an X-ray image of the second subject.

Abstract: In a method and an apparatus for generating a volume dataset of a subject taking a movement of the subject into consideration, a referencing base is arranged at the subject, so that the positions and the orientations of the referencing base can be acquired during a registration of a series of 2D projections of the subject. The volume dataset of the subject is generated on the basis of the series of 2D projections as well as based on the deviations of the positions and of the orientations of the referencing base from a fixed reference position of the referencing base that are determined for all 2D projections of the series.

Abstract: An X-ray calibration dummy (RP) having markings (4) that may be acquired by a position-acquisition system (30). The invention also concerns a method for nonmarker-based registration for use in navigation-guided operations employing the X-ray calibration dummy (RP). A medical system for carrying out the method has a C-shaped X-ray machine (10), a position-acquisition system, 30, and the X-ray calibration dummy (RP).

Abstract: A calibration phantom includes an arrangement of markings with a first X-ray absorption capability and a second X-ray absorption capability, with the arrangement of markings precluding superimposition of an image of a first marking with an image of a second marking for a sufficient number of successive markings for each projection condition, the physical embodiment of a marking representing a value assignment, and the value assignment of a respective specific first number of adjacent markings in each case forming first code information, with each of the first code information items being unique within the first code information which is formed in the totality of markings and in both reading directions.

Abstract: In a method for reconstructing 3D image data, a number of 2D central projections from different projection directions is acquired with a planar detector and radiation emanating from a radiation source, and a volume of interest of an examination subject to be three-dimensionally reconstructed is identified by mixing in variable and mutually dependent marks into at least two 2D central projections.

Abstract: In a method for determining a coordinate transformation between a coordinate system of a first object to be imaged by an X-ray apparatus and a coordinate system of a second object to be navigated relative to a first object, a transformation relationship is determined between a coordinate system of a position-acquisition system and the coordinate system of the first object by an offline calibration run, the position of the X-ray arm is determined while recording X-ray images of the first object, and the position of the second object is determined using the position-acquisition system.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images and direct them towards the camera. The images can then be combined by warping one onto the other.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images. Alignment of one camera with respect to the X-ray source may be achieved using images of reference points in space. The procedure of alignment also provides correlated X-ray and optical images.

Abstract: An X-ray apparatus has an X-ray examination system with an X-ray source and an X-ray detector which can be displaced relative to a subject for the pickup of 2D projections, an arrangement for determining extrinsic imaging parameters and an arrangement for determining intrinsic imaging parameters, for determining the projection geometry in the examination system for each 2D projection, and having a control and computing stage for reconstructing 3D images from the 2D projections using the extrinsic and intrinsic imaging parameters. The arrangement for determining the intrinsic imaging parameters includes X-ray-positive marks which are allocated to the X-ray source and which are in the path of an X-ray beam emanating from the X-ray source, these marks following displacement of the X-ray system.

Abstract: In a method for determining a coordinate transformation between a coordinate system of a first object to be imaged by an X-ray apparatus and a coordinate system of a second object to be navigated relative to said first object, a transformation relationship is determined between a coordinate system of a position-acquisition system and said coordinate system of the first object by an offline calibration run, the position of said X-ray is determined while recording X-ray images of the first object, and the position of the second object is determined using the position-acquisition system.

Abstract: An X-ray calibration dummy (RP) having markings (4) that may be acquired by a position-acquisition system (30). The invention also concerns a method for nonmarker-based registration for use in navigation-guided operations employing the X-ray calibration dummy (RP). A medical system for carrying out the method has a C-shaped X-ray machine (10), a position-acquisition system, 30, and the X-ray calibration dummy (RP).

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images and direct them towards the camera. The images can then be combined by warping one onto the other.

Abstract: An external tracking system for use three dimensional (3D) reconstruction with X-ray C-arm systems comprises a set of marker or tool plates and a sensor system. It measures the 6D pose (position and orientation) of these tool plates relative to the sensor. The tool plate of such a tracking system is rigidly attached to the X-ray source frame of the C-arm system. In order to use an external tracking system for the recovery of projection geometry for 3D tomographic reconstruction, the relations of the external sensor coordinate systems to patient/world and X-ray coordinate systems have to be determined. Previously the transformation from tool plate to X-ray coordinate system has been determined based on CAD drawings and a calibration of the focal point of the X-ray system.

Abstract: Compensation can be provided for rotational and translational motion of a detector relative to the X-ray source in a C-arm X-ray device by warping the image on the detector plane to a virtual detector plane and then mapping the image into three-dimensional space. By using a virtual detector, the computations required to reconstruct the three-dimensional model are greatly simplified.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images. Alignment of one camera with respect to the X-ray source may be achieved using images of reference points in space. Once the X-ray source and the video camera are positioned at the equivalent point in space, the resultant images can be superimposed through warping.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images. Alignment of one camera with respect to the X-ray source may be achieved using images of reference points in space and their respective projections. Once the X-ray source and the video camera are positioned at the equivalent point in space, the resultant images can be superimposed through warping.