摘要:
A method is disclosed for production of computer-tomographic scans via a CT system of a patient during an intervention with an instrument. An X-ray tube is moved on a rotation plane around the patient in order to produce a beam cone, and a detector with a plurality of detector elements measuring the radiation intensity after passing through the patient. Computer-tomographic scans are reconstructed from the measured values in a computation unit. The central direction of the beams of the scanning beam cone is set at an angle to the intervention axis, and at least one slice plane which differs from the rotation plane of the beam cone is displayed on a display.
摘要:
A method is disclosed for production of computer-tomographic scans via a CT system of a patient during an intervention with an instrument. An X-ray tube is moved on a rotation plane around the patient in order to produce a beam cone, and a detector with a plurality of detector elements measuring the radiation intensity after passing through the patient. Computer-tomographic scans are reconstructed from the measured values in a computation unit. The central direction of the beams of the scanning beam cone is set at an angle to the intervention axis, and at least one slice plane which differs from the rotation plane of the beam cone is displayed on a display.
摘要:
A method for creating a resultant image for a specifiable, virtual x-ray quanta energy distribution includes capturing a first image dataset of the patient, capturing at least one second image dataset of the patient, and specifying a virtual x-ray quanta energy distribution. The method also includes establishing a spatial density distribution of the patient for at least two materials based on the first image dataset and the at least one second image dataset. The method includes creating a third image dataset of the patient based on the specified virtual x-ray quanta energy distribution and the established spatial material density distributions. The third image dataset represents an x-ray attenuation distribution of the patient corresponding to the specified virtual x-ray quanta energy distribution. The method also includes creating the virtual image from the third image dataset.
摘要:
A method and image reconstruction facility are disclosed for reconstructing an image dataset based on a projection dataset acquired with the aid of an x-ray computed tomography apparatus. With an embodiment of the method, a first image dataset is reconstructed based on the projection dataset and an edge image dataset is generated, which indicates a measure of an edge strength of edges occurring in at least one spatial/temporal direction in the first image dataset, as a function of location. An output image dataset is then generated based on the first image dataset, with the resolution in the first image dataset being increased as a function of location in at least one spatial/temporal direction taking into account the edge image dataset.
摘要:
A method is disclosed for reducing step artifacts in the forward increment direction of a cardio CT representation. In at least one embodiment, volume recordings or section images of first and second sub-volumes of a heart volume, which lie adjacent to one another in the forward increment direction and partially overlap in an overlap region, are recorded by a computer tomography system. Each sub-volume's detector data is used for the reconstruction coming from different heart cycles. Finally, a displacement vector relative to a second sub-volume is determined at least for a selected point of the overlap region of a first sub-volume and the second sub-volume is subjected at least partially to a spatial transformation according to the at least one displacement vector.
摘要:
A method is disclosed for reducing metal artifacts in CT image datasets. An embodiment of the method includes reconstructing a first CT image dataset with and a second CT image dataset without metal artifact correction, weighted summation of a high-pass-filtered first and a high-pass-filtered second CT image dataset plus a low-pass-filtered second CT image dataset, wherein the weightings are dependent on the proximity to metal in the CT image datasets. A computing unit, a CT system and a C-arm system designed to execute the method are also disclosed.
摘要:
A method is disclosed for reconstructing image data of an examination object from measured data, wherein the measured data was captured previously during a relative rotary motion between a radiation source of a computed tomography system and the examination object. In at least one embodiment, the measured data is modified to achieve a particular grayscale characteristic of the image data to be reconstructed. The image data is calculated by way of an iterative algorithm using the modified measured data, wherein no arithmetic step for reducing noise is employed in the iterations.
摘要:
A method is disclosed for increasing the quality of computer tomographic recording series, to a computation unit and to an X-ray CT system. An embodiment of the method includes scanning a subject over a period of time which makes it possible to record at least two temporally offset projection data sets of the same recording region; transforming the projection data sets into transformation data sets for at least two spatial frequency ranges; calculating temporal compensation values of the transformation data sets for some of the spatial frequency ranges and replacing the compensated values of the transformation data sets with the calculated compensation values in new transformation data sets, projection data of congruent rays always being compared; transforming the new transformation data sets back into new projection data sets; reconstructing image data sets on the basis of the new projection data sets and representing the image data sets.
摘要:
Method for the noise reduction of CT image data and an image processing system are disclosed, with a scanning of an examination object and generation of at least two CT image data records each taking place on the basis of a different x-ray energy spectrum. In at least one embodiment, a break-down of the data image records into at least two broken-down image data records takes place in each instance, with a lowest local frequency band (f(1)) with the index k=1 and at least one high local frequency band (f(k)) with the index k=2 to N. In at least one embodiment, the determination of the noise into at least one of the image data records per x-ray energy spectrum and calculation of at least one new image data record takes place in each instance by using an unchanged broken-down image data record with the lowest local frequency band and an image data record, generated from a noise-minimized weighted combination of broken-down image data records, which originate from the scannings using different x-ray energy spectra.
摘要:
A method is disclosed for reconstruction of image data of an examination object from measured data, wherein the measured data was captured during a relative rotational motion between a radiation source of a computed tomography system and the examination object. Image data of the examination object is determined from the measured data. In at least one embodiment, new image data is obtained by noise-reducing processing of the image data, in which weighted high-pass filtering of the image data is performed, the weighting taking account of differences between pixel values of different pixels such that increasing differences result in a weaker high-pass effect. A noise-reducing smoothing of the image data is performed using the weighted high-pass filtering.