Abstract: In the CT imaging of non-homogeneously moving objects such as the heart or the coronary vessel tree, there is a problem that different parts of the objects are at rest at different points in time. Thus, a gated reconstruction with a globally selected time point does not yield a sharp image of such objects. According to the present invention, a motion of the objects is estimated, describing the motion of selected regions of these objects. Then, on the basis of the estimated motion, time points are determined, where these areas have minimal motion. Then, an image is reconstructed, wherein the data from which the respective regions are reconstructed, correspond to the respective time points, where the regions have minimal motion. Due to this, an improved image qualify maybe provided.

Abstract: Iterative algorithms which may be used for image reconstruction, consisting of alternating projections and backprojections usually have a slow convergence, due to correlations between simultaneously processed data and consequently a low image quality. According to the present invention, a filtering step is introduced before backprojection, allowing a parallel processing without the loss of convergence speed or image quality. Advantageously, this may allow to perform several projections/backprojections simultaneously.

Abstract: The invention relates to a computer tomography method in which an examination area is passed through by a cone-shaped bundle of rays. The bundle of rays comes from a radiation source location which moves around the examination area on an overall trajectory. The overall trajectory consists of a first, closed partial trajectory, at least one second, closed partial trajectory and at least one third partial trajectory which connects the first and the at least one second partial trajectories to one another. Measured values which depend on the intensity in the bundle of rays on the other side of the examination area are acquired by means of a detector unit while the radiation source location is moving on the overall trajectory, and a CT image of the examination area is reconstructed from these measured values.

Abstract: The invention relates to an iterative method of determining a spatial distribution of values of a property of an object, and particularly values of its absorption, in an examination region, on the basis of measured values that values are acquired with a measuring device, and particularly with a computer tomograph. The reliability of each measured value is taken into account when this is done. The measured values can each be represented as a sum of values of the property that have each been multiplied by a proportional factor, the proportional factor being a measure of the proportion that a value of the property forms of the measured value.

Abstract: An important prerequisite for the reconstruction of the emission map in a PET scan is a proper reconstruction of the attenuation map. According to the present invention, transmission data acquired with a helical source trajectory are parallel rebinned. Then, the data are weighted with the cosine of the cone angle and ramp filtered row by row. The filtered data are back-projected by using the rebinned geometry. Advantageously, according to the present invention, all available data are taken into account, thus allowing for a high efficiency in terms of dose utilization. Furthermore, since the correct cone-beam geometry is taken into account, an improved image quality is achieved.

Abstract: The invention relates to a computer tomography method in which a periodically moving object, in particular an organ of the body, is irradiated by a cone-shaped beam cluster (4) along a trajectory which runs on a cylindrical surface. The radiation transmitted through the object is measured by means of a detector unit (16), and at the same time the periodic movement of the object is recorded. In order to reconstruct the absorption distribution of the object, the measured values or the corresponding beams are rebinned to form a number of parallel projections, where for each of these projections a measured value is determined whose beam irradiates the object. The point in time at which this measured value was acquired is allocated to the respective projection. For the reconstruction, which may for example be carried out using a filtered back-projection, only projections whose allocated points in time lie within a predefined, specific time range (H1) within a period of the object movement are used.

Abstract: The invention relates to a method of reconstructing the current flow, or the bolus arrival times, in a vessel system (6). For the sections (i) of the vessel tree (6), bolus arrival times (mi) are measured, for example in connection with an injection of contrast medium. Based on this measured data, linear programming is then used to calculate model bolus arrival times (ti), which, on the one hand, through minimization of the function E=?|mi?ti|, are as close as possible to the measured data, and, on the other, by adherence to the boundary condition ?i=ti?tp(i)?0, ensure the monotony of the propagation, wherein p(i) is the index of the vessel section in front of vessel section (i).

Abstract: The present invention relates to a process for preparing organopolysiloxanes by reacting halosilane with alcohol and water in the presence of the desired organopolysiloxane in a reaction unit comprising a distillation column, optionally a reflux condenser, and a vessel already containing desired organopolysiloxane, by heating the vessel contents to boiling under reflux, introducing halosilane into the column above the lower column end, removing hydrogen halide from the distillation column and continuously removing organopolysiloxane from the vessel at the same rate in which it is formed, by constantly adding halosilane, alcohol and water to the reaction unit in such amounts that more water is always present in the reaction unit than is consumed by the added Si-halogen units of the halosilanes.

Abstract: The invention relates to a computer tomography method in which a radiation source moves relative to an examination region along, in particular, a helical or circular trajectory. Measured values are acquired by a detector unit and a CT image of the examination region is reconstructed from these measured values. In the reconstruction, a complementary measured value, whose ray is oriented parallel to the ray of the respective measured value that has been acquired but in the opposite direction thereto, is determined for each of at least some measured values that lie within a reconstruction window. Redundant measured values are used to calculate the complementary measured values, with the help in particular of John's equation.

Abstract: Method for determining a state variable x from at least one sensor value by a cost function prepared for a measured value y for implementation in an arithmetic unit of a sensor system having at least one sensor and wherein the cost function depends on the respective state x to be measured and gives a deviation of an actual measured value from the calibration as a function of state x in order to determine the sought state x from this minimum. For the cost function, at least one approximation function is set up on the basis of at least one approximation region within the state region x, by which an approximation of the cost function is carried out with approximation functions with negligible error, wherein the sums of the approximation regions cover the entire relevant state region, and at least all local minima are determined on the basis of the approximation, in a selection of approximation regions, wherein optionally a global minimum is determined from the comparison of local minima.

Abstract: The reconstruction of computer tomography data is very often based on a parallel rebinning step of the projection data prior to the filtered back projection. In case of cardiac reconstruction, a gating technique is applied to select appropriate projections for a time-dependent image reconstruction. Usually, the gating window is a function of the fan-beam/cone-beam projection only. According to the present invention, a function corresponding to the location on the detector surface, where the respective projection was detected is used to further verify whether the respective projection is truly within the selected gating window or not.

Abstract: The invention relates to a computed tomography method in which an examination zone is irradiated along a helical trajectory by a conical radiation beam. The radiation transmitted by the examination zone is measured by means of a detector unit and therefrom the absorption distribution in the examination zone is reconstructed without approximations. The reconstruction comprises a derivation of the measuring values of parallel rays of different projections, an integration of these values along K lines, a weighting of these values and a back projection.

Abstract: The invention relates to a computed tomography method in which an examination zone is irradiated from two mutually offset, preferably circular trajectories. In an intermediate region the absorption distribution is reconstructed by means of measuring values from both trajectories, the weight with which the measuring values are used being larger as the distance between the voxel to be reconstructed and the relevant trajectory is smaller.

Abstract: Particles of metal and non-metal oxides may be readily functionalized with organosilyl groups, even in the absence of catalysts, when methylene-spaced alkoxysilanes are used for functionalizing. When an excess of alkoxy groups relative to metal-OH groups are present, the resulting functionalized particles exhibit high reactivity, particularly upon exposure to moisture. Functionalization is particularly useful with particles of organopolysiloxane resins.

Abstract: The invention relates to a method for isolating polyorganosiloxanes from an aqueous dispersion, wherein the polyorganosiloxanes are separated from water in a dissolved form with the aid of an extraction agent.

Abstract: The invention relates to a computed tomography method in which an examination zone is irradiated from two mutually offset, preferably circular trajectories. In an intermediate region the absorption distribution is reconstructed by means of measuring values from both trajectories, the weight with which the measuring values are used being larger as the distance between the voxel to be reconstructed and the relevant trajectory is smaller.

Abstract: The invention relates to standard reaction areas containing complex, storage-stable reagent formulations and thus suited to acceptance and, if need be, storage of complex liquid patient samples, thereafter to be examined for the existence of pathogenic nucleic acids (bacteria, viruses etc.). Preferably, the reaction areas manifest complex, storage-stable reagent formulations permitting detection and quantitative isolation of viral and bacterial nucleic acids in a test kit, even in the existence of extremely low copy numbers from a complex biological sample. At the same time, a simple archiving system for the clinically relevant nucleic acids can be provided. Thanks to the use of said reaction areas containing the complex, storage-stable reagent formulations, necessary process steps of sample handling are drastically reduced and thus potential risks of infection and risks of contamination distinctly lowered.

Abstract: The present invention relates to an inspection apparatus for tires having a positioning device for the tire to be inspected and a laser inspection device. In accordance with the invention, the inspection device comprises several measuring heads, in particular laser measuring heads in order to reduce the inspection time. In accordance with one aspect of the invention, several observation units and associated lighting sources are integrated in each measuring head.

Abstract: A method of determining a relative position of first and second imaging devices includes setting an image of a group of mutually different reference patterns and a basic pattern on an imaging medium, with the second imaging device. Each reference pattern of the group is assigned uniquely to one relative position. An image of at least one test pattern is set over the basic pattern by the first imaging device, for forming a combination pattern. A reference pattern having an area coverage coinciding with an area coverage of the combination pattern is identified from the group of reference patterns. A relative position associated with the identified reference pattern of the group of reference patterns is then identified. A printing form exposer, a printing unit, a printing unit group and a printing press for performing the method are also provided.

Abstract: The invention relates to a method for isolating polyorganosiloxanes from an aqueous dispersion, wherein the polyorganosiloxanes are separated from water in a dissolved form with the aid of an extraction agent.