摘要:
It is an object of the invention to provide spiral computer tomography which has a high image quality. It relates to a reconstruction method for computer tomography of the heart, wherein the image is reconstructed from a data component of recordings of a partial detector path of a detector device and from a data component of recordings of a full detector path of the detector device, and to a computer tomograph having a beam source, a drive arrangement for driving the beam source in a spiral path around an object, a detector device for recording the radiation from the beam source which passes at least partially through the object, and a control device for reconstructing data components of a partial detector path and a full detector path.
摘要:
The present invention relates to an apparatus for determining a parameter of a moving object, wherein the apparatus comprises an adaptive model providing unit (12) for providing an adaptive model of the object. The user can define the region of the adaptive model by a user interface (13). The apparatus further comprises an image data set providing unit (14) for providing a spatially and temporally dependent image data set of the moving object and an adaptation unit (15) for adapting at least a defined region of the adaptive model to the spatially and temporally dependent image data set for determining a spatially and temporally dependence of the defined region. The parameter of the moving object is determined depending on the spatially and temporally dependence of the defined region by a parameter determining unit (16).
摘要:
Coronary artery segmentation is a crucial task in cardiac CT image processing. This is often a tedious task performed manually by an operator. According to the present invention, a method is provided which combines data from multiple cardiac phases during the segmentation process in order to deliver a complete and continuous coronary vessel tree. Advantageously, this may allow for an improved visualization and segmentation of vessels, for example, in coronary CTA.
摘要:
Minimizing the temporal width of the gating window during calculation of the gating function in cardiac CT may not result in best image quality with a maximum of signal-to-noise ratio and minimal artifacts. According to an exemplary embodiment of the present invention, the widths of the gating windows in cardiac CT are selected on the basis of a motion model describing the motion of the heart. According to an aspect of the present invention, the widths of the gating windows are determined by considering the duration of stationary cardiac phases. Thus, artifacts, such as motion artifacts or noise, are minimized.
摘要:
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.
摘要:
The invention relates to a process for preparing full esters of alicyclic polycarboxylic acids from partial esters of aromatic polycarboxylic acids by hydrogenation of the partial ester followed by esterification of this compound.
摘要:
A tripentyl citrate having an optionally acylated, preferably acetylated, OH group, a process for making the tripentyl citrate, and the use of the tripentyl citrate as a plasticizer for plastics.
摘要:
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. The concentration of contrast agent in the area of the vascular segments (5, 8) is then determined by evaluation of the X-ray absorption within the local image areas found.
摘要:
A hydrogenation catalyst is used for the catalytic hydrogenation of an ester-containing aldehyde mixture and the catalyst contains a γ-alumina having a BET surface area of from 70 to 350 m2/g as support material, and at least one component having hydrogenation activity and being selected from the group consisting of nickel, cobalt and mixtures thereof.
摘要:
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).