Abstract: In a process for creating media content, media submissions are requested and electronically received from end users and stored in a computer database. The submissions are searched for material to be included in the media content, and cross-checked against the other submissions for originality and timeliness. After the material is selected from one or more submissions, the content is developed and released to an audience for review. The end users whose submission material was included in the released content are rewarded. In one embodiment, third parties are permitted to access and search the submissions on an open exchange. The third parties can bid for rights in submissions on the open exchange. After receiving these bids, they are forwarded to the particular submission's end user for acceptance or rejection. Appropriate billing and payment processes are used to bill and pay the parties involved.

Abstract: The invention relates to an X-ray examination apparatus which can be universally used for X-ray fluoroscopy and X-ray exposures. It includes a tiltable patient table, a horizontally displaceable stand on which an X-ray source is mounted so as to be vertically displaceable, and a coupling member which couples the stand or the X-ray source to the image converter arrangement provided in the patient table. Depending on the type of coupling, either X-ray fluoroscopy and Bucky exposures or slice exposures are possible. Furthermore, other exposure modes can be performed when the stand is decoupled from the coupling member.

Abstract: A method for temporal filtering of noise in an image of a sequence of digital images, formed as from a first instant (to) until a last instant (t), with pixels having intensity values which correspond to each instant and are referred to as samples, includes an evaluation, for a given pixel, of a temporally filtered sample (Ptp) of the last instant by means of a first linear combination of the filtered sample (Pt-1c) of the last instant by means of a first linear combination of the filtered sample (Pt-1c) of the last instant but one whereto a first weight (W1) has been assigned, and the noisy sample (ItP) of the last instant, modulated by a second weight (W2) which is a probability value (W2=&bgr;tp) concerning absence of a noise peak in this sample.

Abstract: An X-ray examination apparatus of this invention comprises an X-ray source, an X-ray detector and an X-ray filter which is located between the X-ray source and the X-ray detector. The X-ray filter includes filter elements, notably capillary tubes, and the X-ray absorption of separate filter elements can be controlled by controlling a quantity of X-ray absorbing liquid in the respective filter elements. The quantity of X-ray absorbing liquid in the individual filter elements is controlled by way of electric voltages applied to the individual filter elements. The filter elements are formed as spaces between deformed foils which are arranged in a stack which is expanded in the direction transversely of the foils. Adjacent foils are locally attached to one another along seams. The stack is arranged between rigid plates and buffer elements are provided between the rigid plates and the stack. The buffer elements are contractable in the direction transversely to the direction of expansion of the stack.

Abstract: A method of detecting elasticity variations in a soft tissue which is subjected to an external compression in a predetermined axial direction includes the steps of: estimating a field of axial displacements in the tissue, determining an elasticity modulus estimator, including an operation for minimizing a distance between an image of a distribution of elementary elasticity moduli, by a Finite Element Model, and the axial displacement field, and regularizing the solution of the estimator by means of a diagonal matrix (R) whose coefficients &agr;ii are functions of the axial displacements (di) and are applied to the respective values of the elementary elasticity moduli (ei) in order to ensure that these elementary elasticity modulus values remain within an uniform interval which is centered around a mean value of each elementary modulus.

Abstract: The invention discloses a method of processing an image including the steps of decomposing the image into detail images at successive resolution levels. The detail images at successive resolution levels contain image information at respective spatial scales. Filtering of detail images is carried-out in dependence on at least one subsequent detail image having a lower resolution level than the current detail image. A processed image is reconstructed from the filtered detail images.

Abstract: The invention relates to an image processing method for estimation of motion in a sequence of temporal images on the basis of a block matching algorithm, which method includes the steps of: acquiring a sequence of three successive temporal images, including an image to be processed (J.sub.t) between a preceding, so-called causal image (J.sub.t-1) and a later, so-called anti-causal image (J.sub.t+1), determining a reference block (RB.sub.t) in the image to be processed, and of a pair of blocks (CB.sub.t-1, CB.sub.t+1) which are located in the causal image and the anti-causal image, respectively, and best match the reference block (RB.sub.t) in conformity with an intensity similarity criterion, and determining a motion vector relating to the reference block on the basis of the location of the blocks of the pair with respect to the location of the reference block.

Abstract: The invention relates to a method and a device for the processing of medical image data so as to determine output function data (S(k)), situated at grid points (8) of a selected grid, from input function data (I.sub.c (r)) situated at grid points (2, 7) of a Cartesian grid (1, 6). A method of this kind is used, for example in magnetic resonance tomography or computer tomography, so as to calculate arbitrary projections from given function data. The method of the invention includes the following steps: determination of modified input function data (I.sub.c '(r)) by division of the input function data (I.sub.c (r)) by the Fourier transform (c(r)) of a convolution kernel (C(k)), determination of the Fourier transform (S.sub.c '(k)) of the modified input function data (I.sub.c '(r)), and determination of the output function data (S(k)) by convolution of the Fourier transform (S.sub.

Abstract: The invention relates to a system for the processing of a noisy image in a sequence of noisy images which includes means for extracting a noisy temporal sample at a given location in the noisy image and for supplying a corresponding temporally filtered sample in order to form a noise-filtered image. The system includes recursive temporal filtering means which include means for forming a sum of a corresponding sample (Y.sub.t-1) of an already filtered preceding image of the sequence and a corresponding sample [.DELTA..sub.t (x,y)] of a difference image (S.sub.t -Y.sub.t-1) formed between the noisy image and the filtered preceding image and weighted by a recursion factor (K.sub.t); they also include two-dimensional spatial filtering means (F.sub.2D) which are applied to said difference image in order to enhance spatially coherent samples and to supply a measure of probability of motion (.beta..sub.t) which is linked to said spatially coherent samples, and means for applying a scalar function (f.sub.

Abstract: The gradient coil system in a conventional MRI apparatus is optimized in respect of the shielding effect by the shielding coil of the system. Consequently, the system generally is not optimized in respect of the Lorentz forces occurring in the system, resulting in noise of a level such that it is annoying to the users. In order to avoid such noise, the system can be force-optimized. Because the shielding effect is partly lost in that case, however, eddy currents and hence disturbing noise would occur again. However, if the eddy currents are made to occur in acoustically insulated eddy current conductors which also have a large time constant for the decay of the eddy currents, the adverse effects of these eddy currents are adequately counteracted and the disturbing noise is reduced to an adequate extent. Particularly, the (cold) radiation shields of a cryogenic magnet system, arranged in vacuum, can be used as eddy current conductors. The vacuum then constitutes the acoustic insulation.

Abstract: The invention relates to a method of determining the spatial transformation between an object which is three-dimensionally reproduced by a data set and the object itself. According to the method at least one X-ray image of the object is formed. A pseudo-projection image is calculated for a part of the volume represented by the data set, said pseudo-projection image being compared with the X-ray image. The parameters on which the calculation of the pseudo-projection image is based are varied until optimum registration is achieved.

Abstract: The invention relates to a drive device for a rotary anode of an X-ray tube, including an induction motor (13) whereto an alternating voltage can be applied by means of an inverter (20), and also including a control unit (22) for controlling the inverter (20), the switching frequency of the inverter (20) being variable in time, in conformity with a frequency time characteristic, by means of the control unit (22). It is the object of the invention to provide a drive device for a rotary anode of an X-ray tube as well as a suitable control method which ensures the temperature-independent starting up of the rotary anode.

Abstract: A power amplifier for delivering large currents as well as high voltages of the order of some hundreds of amperes and 1000 or more volts, notably for MRI. The amplifier is constructed as a multilevel inverter in order to comply with the requirement of high voltages while utilizing transistors capable of withstanding lower voltages only. The amplifier is arranged for soft switching, so that the switching losses at said large currents are limited.

Abstract: This invention includes a method of determining the viscosity and the pressure gradient in a blood vessel, including the acquisition of n.gtoreq.2 blood speed values, corresponding to the same number of n radii of the blood vessel, determined along a diameter situated in a given axial position, formation of a blood speed vector by means of said n blood speed values, and evaluation of said viscosity and pressure gradient on the basis of a transformation of said blood speed value, including formation of a linear relation which directly links a flow rate vector (y) to the speed derivative vector (h), factorized by the viscosity (.mu.), and to the pressure gradient vector (.sigma.), and simultaneous evaluation of the two values to be determined for the viscosity (.mu.) and the pressure gradient (.sigma.) on the basis of said direct equation. The velocities are advantageously determined by correlation of ultrasonic signals supplied by an echography apparatus.

Abstract: An image guided surgery system comprises an endoscope (11) with an image pick-up apparatus and a posi ion measuring system (10,21) for measuring the position of the endoscope (11). A data processor (2) is arranged to process image data according to the measured position of the endoscope and derive updated image data from the processed image data and imae information from the image pick-up apparatus. The processed image data are derived from said image data and said image information from the image pick-up apparatus and said measured position. For example the image data are CT or MRI images or the image data represents one or several anatomical landmarks in the body of a patient (12) to be examined.

Abstract: The image pick-up apparatus includes a plurality of image sensors (2, 3) for picking up sub-images by deriving sub-image signals from sub-images and also a correction system (4, 43, 44, 45) for deriving corrected brightness values from brightness values of the sub-images and a correction signal. The correction system is provided with a light source (4), for example a LED, for exposing at least one of the image sensors in order to generate one or more measurement signals from the exposed image sensor or sensors. The correction system is arranged to derive the correction signal from the one or more measurement signals. An image pick-up apparatus of this kind is used, for example in an X-ray examination apparatus.

Abstract: The invention relates to an ultrasonic echograph apparatus and method for locally determining biological data constituted by the time varying part of the blood pressure and the arterial wall compliance variations in function of the arterial radius variations, and includes the steps of measuring blood flow rate, arterial radius variation, and the mean arterial radius variation for two neighboring excitation lines and a hydrodynamic inductance. The method further includes steps of modelling, based on the measures, arterial wall behaviors by arterial wall stress-strain laws according to parametric relationships giving the biological data to determine, in the case of purely elastic or visco-elastic arterial behavior the parameters of the parametric relationships being related to the arterial dilatation and contraction phases over a whole cardiac cycle.

Abstract: An image-guided surgery system includes a position measuring system (9, 10) for measuring a position of an instrument (20). The image-guided surgery system includes a test system (9, 10, 30) which is arranged to measure the instrument, using the position measuring system, by measuring a calibration position of a reference part (42) of the instrument while an object part (23) of the instrument is situated in a calibration location. The test system is also arranged to measure a test position of the reference part of the instrument while the object part of the instrument is situated in a test position.

Abstract: Magnetic resonance apparatus includes a magnet system for generating a steady magnetic field in a measuring space, which steady magnetic field is oriented mainly parallel to one of the axes of an orthogonal coordinate system, a gradient system with gradient coil systems and with a controlled source for supplying the gradient coil systems with excitation currents with a predetermined variation in time. The gradient coil systems include a number of linear gradient coil systems, each of which is arranged to generate a main gradient field which is dependent on the location of the field in the measuring space in such a manner that a magnetic field formed by superposition of one of the main gradient fields on the steady magnetic field can be described, as a function of the coordinates of the coordinate system, as a series containing first-order terms and higher-order terms, the first-order terms having predetermined coefficients which are equal to zero for two of the coordinates.

Abstract: Sub-images are merged in order to form an assembled image representing an elongate scene. In order to counteract artifacts in the assembled image such as disturbing transitions at the boundaries of adjacent sub-images in the image assembly method in accordance with the invention, pixel-values of overlapping portions of consecutive sub-images are interpolated so as to form pixel-values of the assembled image. The relative shift between consecutive sub-images with respect to the elongate scene is calculated from image information contained in the sub-images themselves. Correlations of pixel-values in overlapping portions of consecutive sub-images are determined as a function of the shift-value of the shift between consecutive sub-images with respect to the elongate scene. The actual shift between consecutive sub-images is found as the shift-value for which the correlation attains its maximum-value.