Patent application number | Description | Published |
20080205729 | Method And Device For The Iterative Reconstruction Of Tomographic Ilmages - The invention relates to a device and a method for the iterative reconstruction of the attenuation coefficients μ | 08-28-2008 |
20080253502 | Method and Device for the Iterative Reconstruction of Cardiac Images - The invention relates to a method and a device for the iterative reconstruction of cross-sectional images of the heart ( | 10-16-2008 |
20080267342 | Efficient Iterative Four-Dimensional Cardiac Cone-Beam Ct Reconstruction - The increasing cone angle of current high-end and future CT systems leads to a decrease in image quality if approximate cone-beam reconstruction methods are used. According to an exemplary embodiment of the present invention, an iterative four-dimensional cardiac CT reconstruction is provided, in which phase volumes are selected from the four-dimensional data set, each having the same spatial volume at different phase points. Corresponding voxels inside these phase volumes are then forward projected onto the same projection. After calculation of a different projection, these voxels are updated. This may provide for an efficient implementation of an iterative four-dimensional cardiac cone-beam CT reconstruction. | 10-30-2008 |
20080267480 | Iterative Image Reconstruction of a Moving Object From Projection Data - Iterative methods for reconstructing an image sequence of a moving object based on projection data usually require a high computationally effort. According to embodiments of the present invention there is provided such a method wherein a first image representing the object at a first phase is used as an initial image for iteratively reconstructing a second image at a second phase. A first gating function is assigned to the first phase, a second gating function is assigned to the second phase. When executing a first iteration for reconstructing the second image only projection data corresponding to a non-overlapping part of the two gating functions are used. For executing further iterations the amount of projection data corresponding to the overlapping part of the two gating functions may be gradually increased. Therefore, for all further but the last iteration the computationally effort is significantly reduced. However, this low computationally expense has no negative impact on the quality of the finally reconstructed second image because the method benefits from the fact that the first image was used as the initial image for iteratively reconstructing the second image. | 10-30-2008 |
20080273655 | Imaging Method with Back Projection - The invention relates to an imaging method, especially a computerized tomography method, with which an object is penetrated by rays from different directions and measured values, which depend upon the intensity of the rays after penetrating the object, are acquired by a detector unit. From these measured values, an object image is reconstructed by means of back projection of measured-value-dependent back projection values. Therein, the object image is divided into overlapping, quasi-spherically symmetric image segments, each being defined by an image value and a quasi-spherically symmetric base function. Furthermore, during the back projection, the back projection values are added in proportions to the image values, wherein the proportion of a back projection value, which is added during the back projection to an image value, is dependent on a proportionality factor, which is equal to the average value of the line integrals of the base function belonging to the respective image value along those rays that have generated the measured value, on which the respective back projection value is dependent. | 11-06-2008 |
20080273656 | Advanced Convergence for Multiple Iterative Algorithm - Iterative methods for reconstructing of three-dimensional images based on projection data signals obtained by a computer tomography system often result in wrong absorption coefficients in particular for regions including a hollow space of an object under examination. Furthermore iterative methods show a slow convergence for calculating such absorption coefficients. According to embodiments of the present invention there is provided a method for an advanced reconstruction of three-dimensional images based on modified projection data signals. The modification includes an addition of a constant absorption value to the measured projection data. Advantageously the constant absorption value is an absorption line integral through a virtual body having the spatial constant absorption coefficient of water. The virtual body preferably has a volume which is slightly bigger than the object of interest. | 11-06-2008 |
20090060121 | COMPUTED TOMOGRAPHY DATA ACQUISITION APPARATUS AND METHOD - A computed tomography scanner includes a first ( | 03-05-2009 |
20090116612 | MULTI-TUBE IMAGING SYSTEM RECONSTRUCTION - A tomographic apparatus ( | 05-07-2009 |
20090135998 | NOISE REDUCTION IN DUAL-ENERGY X-RAY IMAGING - It is described a method for reducing noise of X-ray attenuation data related to a first and second spectral X-ray data acquisition. The method comprises the steps of (a) acquiring data representing the X-ray attenuation behavior of a region of interest, (b) determining a first and a second attenuation-base line integral for the first and the second X-ray acquisition, respectively, and (c) calculating expected first and second signal to noise ratios for the first and the second attenuation-base line integral based on given signal to noise ratios for the first and second spectral X-ray data acquisition, respectively. The method further comprises the steps of (d) repeating the above mentioned steps of determining the attenuation-base line integrals and calculating the expected signal to noise ratios for a further first spectral X-ray data acquisition and (e) selecting improved spectral X-ray data acquisitions in order to enhance the overall signal to noise ratio of a final X-ray image. | 05-28-2009 |
20090185655 | COMPUTED TOMOGRAPHY METHOD - A computed tomography method and apparatus are provided wherein a radiation source moves circularly relative to an examination zone about an axis of rotation ( | 07-23-2009 |
20090202036 | IMAGE RECONSTRUCTION WITH VOXEL DEPENDENT INTERPOLATION - A radiographic imaging apparatus includes a radiation detector ( | 08-13-2009 |
20090262885 | CONE BEAM COMPUTED TOMOGRAPHY WITH MULTIPLE PARTIAL SCANNING TRAJECTORIES - A computer tomography apparatus ( | 10-22-2009 |
20090268862 | ENERGY DISTRIBUTION RECONSTRUCTION IN CT - The reconstruction of the energy distribution at a detector with a detector element that consists of many small pixels, which count the number of photons above certain thresholds, is performed with a Maximum Likelihood analysis, according to an aspect of the present invention. Thus, the reconstruction scheme may use the redundancy in the measurement and may treat the Poisson statistics accordingly. | 10-29-2009 |
20090310736 | ENERGY SPECTRUM RECONSTRUCTION - A computed tomography system includes an x-ray source ( | 12-17-2009 |
20090310737 | METHOD FOR COMPUTER TOMOGRAPHY, AND COMPUTER TOMOGRAPH - According to the invention, there is provided a method of recording images of the heart in computer tomography, in which, in order to prevent movement artifacts, the images are reconstructed on the basis of similar movement states of the heart and different radiation intensities are used for different movement states. Also provided is a computer tomograph for recording images of the heart in computer tomography by means of time windows which exhibit similar movement states of the heart in order to prevent movement artifacts, said computer tomograph comprising a control device which controls a radiation source with different radiation intensities for different movement states. Furthermore provided is a computer program for a computer tomograph for recording images of the heart in computer tomography by means of time windows which exhibit similar movement states of the heart in order to prevent movement artifacts, and for controlling a radiation source with different radiation intensities for different movement states. | 12-17-2009 |
20100002830 | STEREO TUBE COMPUTED TOMOGRAPHY - A computed tomography system includes at least two x-ray sources ( | 01-07-2010 |
20100232669 | DYNAMIC OPTIMIZATION OF THE SIGNAL-TO-NOISE RATIO OF DUAL-ENERGY ATTENUATION DATA FOR RECONSTRUCTING IMAGES - It is described a method for dynamically optimizing the signal-to-noise ratio of attenuation data related to two different X-ray energies for reconstructing an image of an object under examination. The method comprises (a) estimating the thickness and the material composition of the object at a plurality of different projection angles, (b) for each of the various projection angles calculating for a variety of combinations of different first and second X-ray energies a corresponding common signal-to-noise ratio, (c) for each of the various projection angles choosing the first and the second X-ray energy causing the maximum corresponding common signal-to-noise ratio, and (d) for each of the various projection angles acquiring X-ray attenuation data of the object whereby the two X-ray energies are the X-ray energies causing a maximum signal-to-noise ratio assigned to the respective projection angle. | 09-16-2010 |