摘要:
The invention relates to a method for the 3D modeling of a three-dimensional tubular structure of an examination object from a number of 2D projection images (D) of the tubular structure (H) taken from different projection directions. In order to be able to implement such a method with considerably less user interaction while retaining the same degree of accuracy, the following steps are proposed according to the invention: a) reconstruction of a 3D image (B) from the 2D projection images (D), b) selection of at least one 3D central line point (MO) in the 3D image (B), said 3D central line point being located in the tubular structure (H), c) segmentation of other 3D central line points (M) of the tubular structure (H) in the 3D image (B), d) forward projection of the 3D central line points (M), which have been segmented in the 3D image (B), into the 2D projection images (D′), e) determination of border points of the tubular structure (H) in the 2D projection images (D′) on the basis of the 3D central line points (Z) that have been projected in, and f) back-projection of the border points from the 2D projection images (D′) into the 3D image (B).
摘要:
The invention relates to a method of and a device for the formation of a three-dimensional image data set of a periodically moving body organ (11) of a patient (5) by means of an X-ray device (1) which includes an X-ray source and an X-ray detector (3), a motion signal (H, B) which is related to the periodic motion of the body organ (11) being measured simultaneously with the acquisition of the projection data sets (D0, D1, . . . , D16). In order to improve such a method or such a device, notably in order to improve the construction and to reduce the time required for data processing while keeping the radiation dose for the patient as small as possible and while ensuring an as high as possible image quality, the invention proposes to acquire the projection data sets (D0, D1, . . . , D16) necessary for the formation of the three-dimensional image data set successively from different X-ray positions (p0, p1, . . . , p16) which are situated in one plane, to control the X-ray device by means of the motion signal (H, B) in such a manner that a projection data set (D0, D1, . . . , D16) is acquired during a low-motion phase of the body organ (11) in each X-ray position (p0, p1, p16) required for the formation of the three-dimensional image data set, and to use the projection data sets (D0, D1, . . . , D16) acquired during the low-motion phase for the formation of the three-dimensional image data set.
摘要:
MR imaging apparatus includes a magnet (1) for generating in an examination zone (3) a uniform, steady magnetic field having substantially parallel lines of force extending in a first direction (Z), a gradient coil system (5) for generating a magnetic gradient field, and an RF coil system for generating RF pulses and for receiving MR signals. The apparatus also includes devices (25,27,31) for generating data from the MR signals, and a reconstruction unit (39) for reconstructing an MR image of the examination zone (3) from a set of the data. A patient support system includes a table top (7) drive means (11) configured for displacement of the table top in the first direction (Z), and a connection (43) for coupling the drive means and the control unit (29). The magnet (1) has a generally toroidal-shaped housing (15) surrounding a bore (17) and has a longitudinal axis (19) extending substantially parallel to the first direction (Z). The housing (15) has a radial thickness (r) in a direction transverse to said axis (19) and a longitudinal thickness (1) in a direction substantially parallel to said axis, the radial thickness being greater than the longitudinal thickness.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Position measurements are often performed using a localization system with a given fixed capture range and accuracy and resolution. Having a fixed capture range often comes at the cost of decreased accuracy and resolution. At the start, a large capture range is provided where the accuracy and resolution is low. In this large capture area, the target area can be identified and aimed at. With this identification, a smaller capture range is iteratively provided and centered around the region of interest, which leads to an increased accuracy and resolution.
摘要:
The invention relates to a method for the three-dimensional reconstruction of an object such as for example a stent (5) in the coronary vessels of a patient. In the course of this, a series of X-ray projection photographs (A,) are produced from different directions, with the relevant ECG phase (E,) being recorded simultaneously. On the projection photographs (A,), the position of feature points (R, Q) is segmented (a). The photographs (A,) are furthermore allocated (b) into classes (Kp) according to their belonging to different sections (Epcl) of the heartbeat phase. For each of these classes, the corresponding spatial position ((x,y,z)Qp) of the feature points is established (e). In the next step (d), from the positions of the feature points (R, Q) that are now known for various heartbeat phases, the displacement vectors (SRp-m, SQp-m) or generally the transformations (Epm) are calculated which link (d) the positions of the feature points for different heartbeat phases (p, m). With the aid of these transformations, in a last step (e) a three-dimensional reconstruction can then be carried out for the whole stent (5) or its surroundings, by referring back to all the X-ray projection photographs from different heartbeat phases (p1, p2). In an alternative embodiment of the invention, projection photographs of a moving body volume are transformed such that the images of feature points that are located on the 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 that are thus aligned onto the reference positions, three-dimensional reconstruction of the object can subsequently take place.
摘要:
The invention relates to an imaging process with a beam source attached at a first end of an holder device, and with a detector unit attached to a second end of the holder device. The holder device is moved so that the beam source is guided about an examination area along a non-circular trajectory, where the beams emitted by the beam source pass through the examination area. The detector unit acquires measurement values which depend on the intensity of the beams on the far side of the examination area. From these measurement values using a filtered back projection an image of the examination area can be reconstructed, where each measurement value is filtered along a filter line which runs parallel to the tangent of the trajectory at the respective position of the beam source.