Abstract: The invention relates to an imaging system and a method for generating high-quality X-ray projections (24) of a patient (1). The system comprises a rotational X-ray device (10), for example a cone-beam CT-gantry (12), and an associated data processing unit (20). During a medical intervention, low-dose raw projections (22) of the patient (1) are continuously generated from different directions. A volume of interest (23) is then reconstructed from said projections (22), from which high-quality virtual projections (24) can be calculated for a display on a monitor (25). The number and direction of said virtual projections (24) can be arbitrarily chosen by the user.

Abstract: A method and system for navigation of a medical instrument, including: introducing at least three reference device(s) disposed to at least three reference locations; employing an imaging and guidance system to acquire a plurality of image projections corresponding to a desired anatomy including the reference devices, the plurality of image projections being sufficient to permit generating a three-dimensional modeling or reconstruction images corresponding to the reference devices. The method also includes measuring a position of the reference devices; formulating a transformation matrix based on comparing positions of the reference devices computed from the modeling or reconstruction images with the measured positions of the reference devices; and superimposing an image of a medical instrument in at least one of the plurality of image projections based on the transformation matrix and a position of the medical instrument.

Abstract: A method for the three-dimensional reconstruction of an object, or its surroundings, in a moving body volume of a patient includes obtaining a series of X-ray projection photographs produced from different directions, with a relevant ECG phase or respiration being recorded simultaneously. Projection photographs of the moving body volume are transformed such that the images of feature points that are located on the projection photographs respectively come to rest at a place on which randomly set spatial reference positions for the feature points are projected. With the projection photographs aligned onto the reference positions, three-dimensional reconstruction of the object can subsequently take place.

Abstract: Iso-centering a volume of interest (VOI) (170) within a patient (168) to undergo examination on a rotational X-ray apparatus (100) is achieved by taking two differently-angled pictures (S210) and updating positional settings (172) for the patient's table (112) responsive to respectively displayed centering of the VOI (152). Alternatively, the operator identifies respective VOI centers (S410, S450) for each of the two displayed pictures, and corresponding table movement is automatically calculated (S420).

Abstract: The invention relates to a method and an arrangement for the intravascular or intracardial navigation of a catheter (5). Using an X-ray fluoroscopy device (1), firstly an image database of 2D images is generated, where at the same time as each 2D image (I) is taken the associated heartbeat phase is recorded using an ECG (8). During the catheter intervention, the position of the catheter (5) is measured by means of a position measurement unit (6), and at the same time the ECG and preferably also a signal that is dependent on the breathing movement are recorded. The current spatial position of the catheter (5) that is measured is then assigned the 2D image of the image database which corresponds in terms of the heartbeat phase and also possibly in terms of the breathing phase, on which image the position of the catheter can be represented.

Abstract: A method is provided for analysis of a multi-dimensional structure which includes a tubular structure from two-dimensional datasets for respective pre-determined projection directions. A pair of corresponding initial projected centre points of the tubular structure is identified in two respective initial and further two-dimensional datasets. Projected edges of the tubular structure in said initial two-dimensional datasets and in said further two-dimensional dataset near the respective projected centre points are identified. A local size of the tubular structure is derived at the three-dimensional spatial position of the centre point of the tubular structure from said projected edges and the predetermined projection directions.

Abstract: The invention relates to an examination apparatus and a method for perfusion studies in a patient (1). According to the method, a rotational X-ray device (10) is moved on a closed, preferably non-planar trajectory (T) while continuously generating projections of the patient (1) after the injection of a contrast agent with an injection device (20). The projections are used by a data processing system (30) in a sliding window technique to reconstruct three-dimensional images of the body volume. The resulting sequence of 3D images may be displayed on a monitor (31) to reveal the desired information about the perfusion process.

Abstract: In three-dimensional rotational x-ray coronary imaging problems may arise when estimating the motion of small vessels. According to an exemplary embodiment of the present invention, an examination apparatus is provided which is adapted for performing a hierarchical motion estimation by global affine transformation for every heart phase, followed by vessel branch selective affine and non-affine transformations. This may provide for an improved image quality.

Abstract: The invention relates to a method for the reconstruction of a three-dimensional model of a vascular tree from two-dimensional X-ray projection images (A, B, C) that are taken from different spatial directions. On a first projection image (A) at least one reference point (CA) is specified. The gray-value profiles along the epipolar lines (EB, EC) for said reference point (CA) in other projection images (B, C) are then projected on the projection line (L) of the reference point (CA) and added there punctiformly to form a sum profile (S). The sum profile (S) has an extreme, for example, a gray-value minimum, at the position of the space point (C3D) belonging to the reference point (CA). In this way, it is possible to reconstruct semiautomatically a vascular tree from X-ray projections.

Abstract: This invention discloses an improved method for the calibration and tracking of an electromagnetic or acoustic based catheter within a catheter tracking space for use in cardiac intervention for a specific patient, utilizing prior-acquired medical imaging data for the patient.

Abstract: The invention relates to a method of determining the position of a catheter introduced along a guide wire inserted into a body, in which method an image of the guide wire and the body region at the area of the guide wire is acquired by means of an imaging method, the distance traveled by the catheter on the guide wire is measured and the position of the catheter in the body is determined on the basis of the measured distance. The invention also relates to a device for determining the position of a catheter introduced along a guide wire inserted into a body, which device includes sensor means for measuring the distance traveled by the catheter on the guide wire and means for determining the position of the catheter on the basis of the measured distance.

Abstract: The invention provides a method for 3D modeling of a three-dimensional tubular structure of an examination object from 2D projection images (D) of the structure taken from different projection directions. The method has the following steps: reconstruction of a 3D image from the 2D projection images (D); selection of at least one 3D central line point (MO) in the 3D image, said 3D central line point being located in the structure; segmentation of 3D central line points (M) of the structure in the 3D image; forward projection of the 3D central line points (M), which have been segmented in the 3D image, into 2D projection images (D?); determination of border points of the structure in the 2D projection images (D?) on the basis of 3D central line points (Z) that have been projected in; and back-projection of the border points from the 2D projection image (D?) into the 3D image.

Abstract: The invention relates to an X-ray imaging device for visualizing the blood flow in a coronary vascular tree of a patient. According to the invention a first set (1) of X-ray projection images of the vascular tree is recorded during various phases of the heart cycle with simultaneous recording of the ECG (2) of the patient. By means of a suitable program control, computer means (17) of the device according to the invention a reconstruction then follows of the three-dimensional structure of the vascular tree during the various phases of the heart cycle. The invention proposes, to determine the time-dependent concentration of contrast agent within the reconstructed three-dimensional structure of the vascular tree, that local image areas within the X-ray projection images of the second set (6) assigned to individual vascular segments (5, 8) are located in accordance with the spatial positions of the vascular segments (5, 8) in the relevant phase of the heart cycle.

Abstract: The invention relates to a device and a method for producing an image of the heart (5), in which the image is preferably three-dimensional and is reconstructed from a series of X-ray projection pictures from various projection directions. In this connection, the electrocardiogram (7) is recorded in parallel with the X-ray pictures and used by a data processing device (10) to control the picture-taking rate, the X-ray pulse duration, the tube current and/or the tube voltage of the X-ray device (1) in such a way that, during the phase to be displayed of maximum movement of the heart, the mean X-ray exposure rate is higher than during the other phases. The data processing device (10) may furthermore use the electrocardiogram to drive an injection pump (8) for the contrast agent in such a way that an approximately constant contrast display of the vessels is produced with minimum contrast-agent injection despite a variable flowrate in the vascular system.

Abstract: The invention relates to an imaging system and a method for generating high-quality X-ray projections (24) of a patient (1). The system comprises a rotational X-ray device (10), for example a cone-beam CT-gantry (12), and an associated data processing unit (20). During a medical intervention, low-dose raw projections (22) of the patient (1) are continuously generated from different directions. A volume of interest (23) is then reconstructed from said projections (22), from which high-quality virtual projections (24) can be calculated for a display on a monitor (25). The number and direction of said virtual projections (24) can be arbitrarily chosen by the user.

Abstract: The invention relates to a method and a device for the three-dimensional reconstruction of the flow conditions in a vascular system (3), in which, in a first phase after the beginning of a contrast-medium injection, X-ray projection pictures are produced from the same direction (A) at a high picture-taking rate in order to observe the inflow of the contrast medium. When the contrast medium fills the vascular system (3), a rotation of the Xray device (1) takes place during which projection pictures are produced at a lower picture taking rate and/or at a lower radiation dose, from which pictures the three-dimensional structure of the vascular tree can be reconstructed. Optionally, at the end of the rotation, projection pictures may again be taken from a fixed direction that observe the drainage of the contrast medium from the vascular system (3).

Abstract: The invention relates to an image processing system that is adapted to generate a three-dimensional image (32) from projections (P, 31) of a body volume which may for example be generated by a rotational X-ray system (10). The image processing system is further adapted to display on a monitor (30) simultaneously at least one of the original projections (31) and the generated 3D-image (32) together with a superimposed representation of a target region like an implantable stent. The user may then change the dimensions and the shape of the target region in any of the displayed images (31, 32) and watch the results in all images (31, 32). As the original projections (31) are free of errors generated by the reconstruction and visualization of the 3D-image (32), their consideration yields an improved geometrical accuracy.

Abstract: System and method for enabling intra-operative selection of an image registration transformation for use in displaying a first image dataset and a second image dataset in correspondence with one another. Image dataset acquisition devices (12, 14) obtain the first and second image datasets. A similarity function indicative of a likelihood that the first and second image datasets are in correspondence with one another is computed by a processor (16) and then a ranking of each of a plurality of local maxima of the similarity function is determined. Registration transformations derived from a plurality of the local maxima are displayed on a display (18), and using a user-interface (22), a physician can select each registration transformation to ascertain visually whether it is the clinically-optimal registration transformation for subsequent use.

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 for generating or reconstruction of three-dimensional (3D) images corresponding to a structure of interest (60) including: acquiring a plurality of image projections corresponding to a structure of interest (60); applying a shape model (66) at a selected 3D seed point (64); and adapting the shape model (66) to represent the structure of interest (60), yielding an adapted shape model. A system for generation and reconstruction of three-dimensional (3D) images. The system (10) includes: an imaging system (12) configured to provide projection data corresponding to a structure of interest (60); and a controller (50) in operable communication with the imaging system (50). The controller (50) is configured to: receive the projection data, (64); apply a shape model (66) at a selected 3D seed point (64); and adapt the shape model (66) to represent the structure of interest (60), thereby yielding an adapted shape model.