Abstract: A method (10) to compensate for cardiac and respiratory motion in cardiac imaging during minimal invasive (e.g., trans-catheter) AVI procedures by image-based tracking (20, 25) on fluoroscopic images.

Abstract: A method for displaying a motion compensated overlay includes receiving a model of a structure of interest, capturing an image depicting a region of interest and an instrument, determining whether the structure of interest is visible in the image, registering the model of the structure of interest to the image upon determining that the structure of interest is visible, and combining the model of the structure of interest with the image according to a registration to determine an overlay image.

Abstract: A method for displaying a motion compensated overlay includes receiving a model of a structure of interest, capturing an image depicting a region of interest and an instrument, determining whether the structure of interest is visible in the image, registering the model of the structure of interest to the image upon determining that the structure of interest is visible, and combining the model of the structure of interest with the image according to a registration to determine an overlay image.

Abstract: A method for guiding transcatheter aortic valve implantations includes receiving an interventional 3D image of an aortic root reconstructed from a sequence of 2D images acquired from a C-arm computed tomography (CT) system being rotated about a patient through a predetermined number of degrees, segmenting the aortic root and detecting aortic root landmarks in the 3D image, where the aortic root landmarks include three lowest points of aortic root cusps, two coronary artery ostia, and three commissures points where the cusps meet, cropping an area inside the segmented aortic root out of the 3D volume for volume rendering, centering the 3D image on an intersection of two orthogonal planes, each containing the two detected coronary ostia, that are orthogonal to a plane spanned by three lowest points of the aortic root cusps, and volume rendering the 3D cropped aortic root image together with the detected landmarks onto a 2D image.

Abstract: A method for assisting a person performing a minimally invasive intervention with a catheter involving a puncture of a septum, in particular of a heart, is proposed. A three-dimensional image data record is recorded showing an anatomical structure in the region of the septum. An item of septum information showing the position of the septum is determined in the image data record and additional information is derived from the position of the anatomical structure influencing or showing the selection of a puncture site. During the intervention, the fluoroscopic images of the region are continuously recorded and a current fluoroscopic image is displayed and superimposed with the septum information and/or the additional information based on a registration of the image data record with the fluoroscopic images.

Abstract: A method for centering a left atrium and pulmonary veins at an isocenter of an imaging device is provided. The method includes positioning an injection catheter at a bifurcation of a pulmonary artery; obtaining an anterior or posterior flouroscopic image of area including and/or surrounding the left atrium and pulmonary veins; and moving the imaging device, patient support, or the combination thereof, such that the injection catheter and a spine of a patient are displayed in the fluoroscopic image.

Abstract: A method for guiding transcatheter aortic valve implantations includes receiving an interventional 3D image of an aortic root reconstructed from a sequence of 2D images acquired from a C-arm computed tomography (CT) system being rotated about a patient through a predetermined number of degrees, segmenting the aortic root and detecting aortic root landmarks in the 3D image, where the aortic root landmarks include three lowest points of aortic root cusps, two coronary artery ostia, and three commissures points where the cusps meet, cropping an area inside the segmented aortic root out of the 3D volume for volume rendering, centering the 3D image on an intersection of two orthogonal planes, each containing the two detected coronary ostia, that are orthogonal to a plane spanned by three lowest points of the aortic root cusps, and volume rendering the 3D cropped aortic root image together with the detected landmarks onto a 2D image.

Abstract: A method (10) to compensate for cardiac and respiratory motion in cardiac imaging during minimal invasive (e.g., trans-catheter) AVI procedures by image-based tracking (20, 25) on fluoroscopic images.

Abstract: The invention relates to a computed tomography method. The airgap associated with a projection direction is determined by determining, in the projection images, edge pixels which map object edges on a detector. By back-projecting the edge pixels in an object image space it is possible to determine an envelope polygon for an outline contour of the examination object. The width of the airgap associated with a specific projection direction can then be determined on the basis of the envelope polygon. Exact knowledge of the current airgap serves to improve the scattered radiation correction.

Abstract: 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.

Abstract: The invention relates to a method for speeding up the scattered radiation correction in a computed tomography system with a radiation source and a detector constructed in large-area format with a number of rows of detectors, by which an object is scanned from numerous projection angles, uses the measured values for the attenuation of the radiation in generating projection data which is postprocessed for the purpose of reconstructing tomographic views, in doing which a beam hardening correction is applied directly to the projection data, whereby according to the invention the scattered radiation correction is also applied directly to the projection data.

Abstract: The invention relates to an angiographic x-ray diagnostic device for rotation angiography with an x-ray emitter which can be moved on a circular path about a patient located on a patient support table, with an image detector unit which can moved on the circular path facing the x-ray emitter, with a digital image system for recording a plurality of projection images by means of rotation angiography, with a device for image processing, by means of which the projection images are reconstructed into a 3D volume image, and with a device for correcting physical effects and/or inadequacies in the recording system such as truncation correction, scatter correction, ring artifact correction, correction of the beam hardening and/or of the low frequency drop for the soft tissue display of projection images and the 3D volume images resulting therefrom.

Abstract: The invention relates to a method and an apparatus for reconstructing a three-dimensional image volume from two-dimensional projection images of a subject which have been taken from different projection directions by rotating the recording system around the subject, wherein the grayscale values of the voxels of the image volume are calculated by back projection of the projection images. The invention is characterized in that prior to back projection at least one projection image is modified in such a way that it corresponds to a projection image taken with a virtual detector whose axes are aligned parallel to the rotational axis of the recording system.

Abstract: The invention relates to a method for three-dimensional image reconstruction of a dynamically moved object from projection data of an imaging device comprising: a) determining a reference volume from the projection data which simulates a similar static object instead of the dynamically moved object; b) assigning the projection data to at least two disjoint consistent subsets, with a volume part reconstruction of the dynamically moved object being undertaken for each subset from projection data assigned to the subsets; c) applying a transformation to the respective volume part reconstructions representing a dynamic movement of the object; d) comparing the volumes of the transformed part reconstructions with a corresponding part of the reference volume, whereby, depending on the comparison, result step c) may be at least partly repeated; and e) summing the volume part reconstructions resulting from step c) and d) to form an overall three-dimensional image reconstruction.

Abstract: The invention relates to a computed tomography method. The airgap associated with a projection direction is determined by determining, in the projection images, edge pixels which map object edges on a detector. By back-projecting the edge pixels in an object image space it is possible to determine an envelope polygon for an outline contour of the examination object. The width of the airgap associated with a specific projection direction can then be determined on the basis of the envelope polygon. Exact knowledge of the current airgap serves to improve the scattered radiation correction.

Abstract: A method for centering a left atrium and pulmonary veins at an isocenter of an imaging device is provided. The method includes positioning an injection catheter at a bifurcation of a pulmonary artery; obtaining an anterior or posterior flouroscopic image of area including and/or surrounding the left atrium and pulmonary veins; and moving the imaging device, patient support, or the combination thereof, such that the injection catheter and a spine of a patient are displayed in the fluoroscopic image.

Abstract: The invention relates to a method for speeding up the scattered radiation correction in a computed tomography system with a radiation sources and a detector constructed in large-area format with a number of rows of detectors, by which an object is scanned from numerous projection angles, uses the measured values for the attenuation of the radiation in generating projection data which is postprocessed for the purpose of reconstructing tomographic views, in doing which a beam hardening correction is applied directly to the projection data, whereby according to the invention the scattered radiation correction is also applied directly to the projection data.

Abstract: The invention relates to a method and an apparatus for reconstructing a three-dimensional image volume from two-dimensional projection images of a subject which have been taken from different projection directions by rotating the recording system around the subject, wherein the grayscale values of the voxels of the image volume are calculated by back projection of the projection images. The invention is characterized in that prior to back projection at least one projection image is modified in such a way that it corresponds to a projection image taken with a virtual detector whose axes are aligned parallel to the rotational axis of the recording system.

Abstract: The invention relates to an angiographic x-ray diagnostic device for rotation angiography with an x-ray emitter which can be moved on a circular path about a patient located on a patient support table, with an image detector unit which can moved on the circular path facing the x-ray emitter, with a digital image system for recording a plurality of projection images by means of rotation angiography, with a device for image processing, by means of which the projection images are reconstructed into a 3D volume image, and with a device for correcting physical effects and/or inadequacies in the recording system such as truncation correction, scatter correction, ring artifact correction, correction of the beam hardening and/or of the low frequency drop for the soft tissue display of projection images and the 3D volume images resulting therefrom.

Abstract: The present invention relates to an x-ray imaging device as well as a method for its calibration. With the method for calibrating the x-ray imaging device with at least two separate recording systems arranged for different recording planes (1 to 4) a 2D x-ray image (9, 10) of an area under examination is recorded during an intervention with an instrument (8) at any different positions of the instrument (8) with the two recording systems (1 to 4) simultaneously or immediately adjacent in time in order to obtain in number of pairs of images. From the 2D x-ray images (9, 10) a marker point (5) of the instrument (8) recognizable in the 2D x-ray images (9, 10) is extracted with an image processing algorithm. The image coordinates of the extracted point (5) of each pair of images are assigned to one another and from the assignments a relative imaging geometry of the two recording systems (1 to 4) is calculated.