Abstract: A method for setting a control variable of a filter for noise reduction in medical images is provided. Image data of the medical images is classified into at least one noise region and at least one structure region. A variance measurement is performed either for all the image pixels or a subset of them to determine the edge thicknesses. A histogram is generated from the edge thicknesses. The maximum of the histogram is determined and a Gaussian curve is fitted to the histogram. A threshold value for noise and structure is determined as a function of the standard deviation of the Gaussian curve. The noise and structure are measured in the regions. The standard noise and structure deviations are determined and compared. The control variable is setup as a function of the comparison of noise and structure. The invention can be used for reduction of temporal noise in bandpass images.

Abstract: A method for checking an x-ray diagnostic apparatus is provided. Fluoroscopic series of x-ray images of a technical phantom are digitally acquired and stored. Difference between a dynamic image and a background image is calculated. A measuring field is predicted. Priori information about the shape of a clinically relevant object is determined. Hough transformation on a gray value image corresponding to the difference is applied. Contrast of the object from the Hough-transformed gray value image is determined. A square of the determined contrast is calculated. A noise variance is calculated by determining a sum of a noise variance of a homogenous image region and a variance of the background image. A contrast-to-noise ratio of the determined contrast and the calculated noise variance is determined. A square of the contrast-to-noise ratio is dynamically averaged. A Clinical Relevant Fluoroscopy Performance index for the x-ray diagnostic apparatus is determined.

Abstract: The invention relates to a method for noise suppression in medical images comprising steps of measuring the gradient field strength of an image pixel and selecting a suitable filter mask for noise suppression as a function of the gradient field strength, with the value of the gradient field strength being compared with a predetermined threshold value. The method is repeated when an additional image pixel is selected. A decision is made per read-in image pixel as to which type of filter mask is used for filtering. A selection can be made between filter masks of different sizes or isotropic or anisotropic or directional filter masks. The decision is based on the measured gradient field strength of the respective pixel. The use of different filter masks allows the signal-to-noise ratio to be improved, without distorting structures like edges for instance and without generating artificial structures in homogenous noise regions.

Abstract: The invention relates to a method for presentation of medical images by a reproduction facility of a diagnostic device with suppression of the noise with the following steps: one-off calibration of the signal-dependent noise; separation of the signal and noise components in the image; adaptation of the two components according to set parameters; and composition of the signals.

Abstract: A method and system for correcting butting artifacts in x-ray images is disclosed. In order to correct a butting artifact in an x-ray image, a butting artifact region in the x-ray image is normalized. Multiple intensity shift estimators are calculated for each pixel of each line of the butting artifact. Confidence intervals are calculated for each intensity shift estimator. A multiple hypothesis hidden Markov model (MH-HMM) is formulated based on the intensity shift operators and confidence measures subject to a smoothness constraint, and the MH-HMM is solved to determine intensity shift values for each pixel. A corrected image is generated by adjusting the intensity of each pixel of the butting artifact based on the intensity shift value for that pixel.

Abstract: A method and system for vessel segmentation in fluoroscopic images is disclosed. Hierarchical learning-based detection is used to perform the vessel segmentation. A boundary classifier is trained and used to detect boundary pixels of a vessel in a fluoroscopic image. A cross-segment classifier is trained and used to detect cross-segments connecting the boundary pixels. A quadrilateral classifier is trained and used to detect quadrilaterals connecting the cross segments. Dynamic programming is then used to combine the quadrilaterals to generate a tubular structure representing the vessel.

Abstract: A virtual map of vessels of interest in medical procedures, such as coronary angioplasty is created so that doses of contrasting agent given to a patient may be reduced. A position of a coronary guidewire is determined and locations of vessel boundaries are found. When the contrast agent has dissipated, virtual maps of the vessels are created as new images. The locations of the determined vessel boundaries are imported to a mapping system and an image obtained without using a contrast agent is modified based on the imported locations of vessel boundaries. This creates a virtual map of the vessels.

Abstract: The invention relates to a method for determining a position for at least one semi-transparent diaphragm during a radiological observation of a body region of a patient by means of a radiological facility, in particular during an observation accompanying an interventional measure, comprising: producing at least one radiological image recording and/or a sequence of image recordings by means of the radiological facility; analyzing the image recording and/or the sequence of image recordings by means of automatic image processing by a computing facility for identifying less absorbent image regions which may be present; and automatically determining the position for the at least one semi-transparent diaphragm as a function of the image analysis result by means of the computing facility.

Abstract: The invention provides the use of mixtures based on aqueous dispersions of polychloroprene to produce fiber products finished therewith, a process for the production thereof and the use of these finished fiber products to produce textile-reinforced and fiber-reinforced concrete and other products based on cement.

Abstract: The invention relates to a new, advantageous method for the preparation of dialkyl ?-fluoromalonates.

Abstract: Use of a hotmelt adhesive is disclosed for fixing at least one micro device on a carrier. A pasty fixation compound is further disclosed for micro devices including a powdered hotmelt adhesive, an anti-flow additive and a solvent for the anti-flow additive. Furthermore, a method is disclosed for fixing at least one micro device on a carrier, a hotmelt adhesive being applied to a carrier, the micro device being positioned at a predetermined distance from the carrier and fixed by the hotmelt adhesive until a solid adhesive bond has been produced between the at least one micro device and the carrier by cooling the hotmelt adhesive, the gap produced being filled by an epoxy resin and the two devices being adhesively bonded securely by curing of the epoxy resin. Furthermore, a detector is disclosed for detecting ionizing radiation which has a multiplicity of detector elements disposed in a two-dimensional arrangement.

Abstract: The present invention relates to a method, which assists a doctor for instance in orientation in 2D fluoroscopy images. The present invention relates here to a method for displaying co-registered 2D-3D images in medical imaging, comprising the following steps: determine a 3D or 2D projection which is congruent with a 2D image from a 3D image data set, and overlaid display of the 2D image with the 3D or 2D projection on a monitor, characterized in that the two image parts of the two overlaid images can be adjusted and a shift in the two overlaid images which can be adjusted in at least one direction is enabled.

Abstract: With a method for controlling the dose or dose rate when recording x-ray images by means of a detector comprising image elements which record a plurality of dose data values, an actual value is determined for the dose or dose rate from the totality of the data values recorded by the image elements of a predetermined image segment, said actual value being compared with a predetermined target value in order to control the dose or dose rate when recording a further x-ray image. In accordance with the invention, the actual value is determined such that on the basis of a frequency distribution of the dose data values of the image elements assigned to the dominant, a p-quantile is determined, and that the dose data value assigned to the p-quantile is used to determine the actual value.

Abstract: The invention relates to an angiographic x-ray diagnostic apparatus with an x-ray radiator having an x-ray tube, with a patient positioning table having a radiation-transparent positioning plate and mattress, with an x-ray detector, with an imaging system, an image processing unit and a measuring device to which the output signals of the x-ray detector are fed and which has a first device for determining a value determining the reproduction quality of clinically relevant objects, a second device for determining local variances of the noise in a homogenous image region of different x-ray images and a device for taking the ratio of the output values of the two devices.

Abstract: The present invention provides a process for finishing fibrous products with a preparation based on aqueous dispersions of polychloroprene and a process for preparing textile-reinforced and fiber-reinforced concrete and other cement-based products including those finished products.

Abstract: The present invention relates to a method for image reproduction, in particular for single or serial medical exposures, whereby one or more main images are reproduced on a display device. The method is characterized in that additional or interim images are generated using image interpolation prior to image reproduction from the one or more main images and in that additional image noise which varies from image to image is applied to the one or more main images and the additional or interim images, said image noise being generated by a noise generator, and image reproduction taking place by displaying in chronological order the one or more main images and additional or interim images to which the additional image noise has been applied. The method in particular improves the visual image impression in the case of fluoroscopic X-ray image exposures, without having to in-crease the applied X-ray dose.

Abstract: In a method for reconstructing a three-dimensional subject a number of projections of a three-dimensional subject is acquired by an acquisition arrangement. Each projection is a dataset of spatially contiguous data values. The projections are provided to a computer. A first part of the data values of the projections is replaced by new data values, and a second part of the data values of the projections remains unchanged. Thus changed projections are generated, using which a reconstruction of an image of the subject is determined by the computer.

Abstract: In a computer-assisted method for detecting diaphragm edges caused in an image by a diaphragm, the image and information about an inner structure of the diaphragm are provided to a computer. The computer first detects all image edges that are present in the image. Using the information about the inner structure of the diaphragm, it then determines the diaphragm edges from among the detected image edges.

Abstract: In a method and apparatus for determining and documenting, from current x-ray image data, x-ray exposure values employed for producing an x-ray exposure or a sequence of x-ray exposures by irradiation of a radiation detector with x-rays form an x-ray diagnostic source, an exposed image region of the radiation detector is determined, and a region of interest within the exposed image region also is determined. An x-ray image exposure value is determined from the grey scale values of the pixels in the region of interest. The x-ray image exposure value is normalized with respect to a signal value. Measurement values employed for producing the exposed image region are independently measured, and, using these measurement values, the normalized value is converted into a physical unit. The physical unit is stored, associated with the measurement values, for documentation.

Abstract: An x-ray diagnostic device has an x-ray source to generate x-rays, an x-ray detector to acquire x-ray images and transduce them into an electrical signal sequence, an image system to process the electrical signal sequence, and a playback device. The image system has a unit to detect edges in individual x-ray images and a unit to filter the individual x-ray images along these edges. The individual image processing can ensue in real time. Based on a signal adaptation by the detection of the weighting of the edges, the filtering can be implemented along these edges.