Abstract: A method of registering two sets of medical image data taking into account scene changes can include providing a first and a second medical image data set by means of a medical device, subdividing the first and second medical image data sets into an equal number of sub-images, performing a number of individual registrations between the first and second medical image data sets with respective optimization of a similarity measure, identifying the sub-images that have a scene change, and performing a final registration between the first and the second medical image data set by masking out the identified sub-images or a masked out sub-image combination. For each individual registration, at least one sub-image of the first and/or second medical image data set can be masked out by means of a random process when determining the respective measure of similarity.

Abstract: A method of registering two sets of medical image data taking into account scene changes can include providing a first and a second medical image data set by means of a medical device, subdividing the first and second medical image data sets into an equal number of sub-images, performing a number of individual registrations between the first and second medical image data sets with respective optimization of a similarity measure, identifying the sub-images that have a scene change, and performing a final registration between the first and the second medical image data set by masking out the identified sub-images or a masked out sub-image combination. For each individual registration, at least one sub-image of the first and/or second medical image data set can be masked out by means of a random process when determining the respective measure of similarity.

Abstract: Medical imaging systems and methods for representing a 3D volume containing at least one foreign object introduced into a tissue. Imaging methods may include provision of a 3D volume containing voxels of at least one foreign object and voxels of tissue surrounding the at least one foreign object, identification of the voxels of the at least one foreign object by application of a processing rule, segmentation of the voxels of the at least one foreign object from the voxels of the tissue surrounding the at least one foreign object while maintaining the 3D volume, generation of a synthetic volume from a residual volume and the volume of the at least one foreign object, and representation of the synthetic volume on a display device using a windowing system.

Abstract: A method of registering two sets of medical image data taking into account scene changes can include providing a first and a second medical image data set by means of a medical device, subdividing the first and second medical image data sets into an equal number of sub-images, performing a number of individual registrations between the first and second medical image data sets with respective optimization of a similarity measure, identifying the sub-images that have a scene change, and performing a final registration between the first and the second medical image data set by masking out the identified sub-images or a masked out sub-image combination. For each individual registration, at least one sub-image of the first and/or second medical image data set can be masked out by means of a random process when determining the respective measure of similarity.

Abstract: The present technology is the field of intraoperative imaging, wherein a planning trajectory, for example a planned drilling channel, can be displayed in a 2D X-ray image. This planning trajectory can be plotted by the surgeon in a provided 3D image data set and then displayed in the 2D X-ray image by determining the position in space via a projection geometry into an arbitrary position and orientation of a C-arm X-ray apparatus during 2D imaging.

Abstract: Medical imaging systems and methods for representing a 3D volume containing at least one foreign object introduced into a tissue. Imaging methods may include provision of a 3D volume containing voxels of at least one foreign object and voxels of tissue surrounding the at least one foreign object, identification of the voxels of the at least one foreign object by application of a processing rule, segmentation of the voxels of the at least one foreign object from the voxels of the tissue surrounding the at least one foreign object while maintaining the 3D volume, generation of a synthetic volume from a residual volume and the volume of the at least one foreign object, and representation of the synthetic volume on a display device using a windowing system.

Abstract: This disclosure generally relates to a method and an apparatus for recording a 3D data set of an ROI (50) complete in the central layer by using a cone-beam C-arm X-ray apparatus (1) having a cone beam (32) with a cone angle (35) in the plane of the C-arm and having a virtual scan center (51) in the center of the ROI (50), wherein the scan is performed with a trajectory pair situated in the virtual scan center (51) and composed of a focus trajectory and a detector trajectory and wherein the rotational portion (402) of the detector trajectory is formed from piece-wise defined superellipses.

Abstract: This disclosure generally relates to a method and an apparatus for recording a 3D data set of an ROI (50) complete in the central layer by using a cone-beam C-arm X-ray apparatus (1) having a cone beam (32) with a cone angle (35) in the plane of the C-arm and having a virtual scan center (51) in the center of the ROI (50), wherein the scan is performed with a trajectory pair situated in the virtual scan center (51) and composed of a focus trajectory and a detector trajectory and wherein the rotational portion (402) of the detector trajectory is formed from piece-wise defined superellipses.

Abstract: The invention relates to a method and device for performing coordinate transformation for navigation-guided procedures using an imaging diagnostic tool, especially an X-ray diagnostic tool, and a position-determining system. In the vicinity of the image receiver, the diagnostic tool has one or more three-dimensional reference structure that can be touched with a pointer of a position-determining system. From the known geometry of the three-dimensional reference structure and the coordinates of the touched points determined by the position-determining system, a coordinate transformation is created between the coordinate system of the diagnostic tool and the coordinate system of the position-determining system. Navigation for an instrument captured by the position-determining system can be performed in reconstructed images of the diagnostic tool after the registration procedure.

Abstract: Methods for empirical determination of a correction function for correcting beam hardening and stray beam effects of water-equivalent tissue in projection radiography or computed tomography using an imaging detector, and apparatuses for implementing the same are disclosed. The projection values obtained from the logarithmic values of the detector signals are corrected, the corrected projection values being represented by a correction function dependent on the tube voltage applied during the X-ray projection recording, the coefficients of which function are determined from a single calibration scan on an object-like calibration phantom made of water-like material.

Abstract: A method of improving the volume reconstruction in navigationally guided operations is provided. In certain implementations, a phantom which contains X-ray positive marks and marks detectable by a position detection system in a fixed spatial relation to each other is positioned in the region of the volume being investigated on the subject. For the volume reconstruction, a series of 2D X-ray projection images can be created, each of them containing, alongside the structures of the subject being examined, the images of the X-ray positive marks of the phantom as image information. Each 2D data set is transformed by a familiar method, in which, for example, the mechanical deviations of a real-world C-arm type X-ray diagnostic machine are identified by a kinematic model and are corrected. The transformed 2D data can be used for the volume reconstruction, and the volume model with the position information of the X-ray positive marks is relayed to a navigation system.

Abstract: The invention relates to a method and device for performing coordinate transformation for navigation-guided procedures using an imaging diagnostic tool, especially an X-ray diagnostic tool, and a position-determining system. In the vicinity of the image receiver, the diagnostic tool has one or more three-dimensional reference structure that can be touched with a pointer of a position-determining system. From the known geometry of the three-dimensional reference structure and the coordinates of the touched points determined by the position-determining system, a coordinate transformation is created between the coordinate system of the diagnostic tool and the coordinate system of the position-determining system. Navigation for an instrument captured by the position-determining system can be performed in reconstructed images of the diagnostic tool after the registration procedure.

Abstract: A method of improving the volume reconstruction in navigationally guided operations is provided. In certain implementations, a phantom which contains X-ray positive marks and marks detectable by a position detection system in a fixed spatial relation to each other is positioned in the region of the volume being investigated on the subject. For the volume reconstruction, a series of 2D X-ray projection images can be created, each of them containing, alongside the structures of the subject being examined, the images of the X-ray positive marks of the phantom as image information. Each 2D data set is transformed by a familiar method, in which, for example, the mechanical deviations of a real-world C-arm type X-ray diagnostic machine are identified by a kinematic model and are corrected. The transformed 2D data can be used for the volume reconstruction, and the volume model with the position information of the X-ray positive marks is relayed to a navigation system.