Abstract: The invention relates to a method of position detection in X-ray imaging, and to a device for carrying out such a method by means of an X-ray apparatus, a detector device, including at least two detector elements, and an indicator device. The exact association of the X-ray image with the object imaged is very important notably for intraoperative imaging. Exact knowledge of the position and orientation of the components of the X-ray apparatus associated with the imaging system is required for this purpose. However, it is often problematic that the lines of sight of the position measuring system are obscured by attending staff or other apparatus. Therefore, in the device according to the invention the detector device is mounted on the X-ray apparatus and the indicator device is provided so as to be stationary on the object to be examined or stationary relative to the object to be examined. Also described is a method of position detection in X-ray imaging by means of such a device.

Abstract: A method of processing a digital image representing ribbon-shaped objects of non-uniform intensity contrasting with a background of lower intensity includes an automatic segmentation phase having one or more morphological opening operations effected, respectively, with one or more three-dimensional structuring elements. The latter have a two-dimensional base parallel to the image plane and have a non-binary intensity function in a third dimension. Preferably, the automatic segmentation phase is carried out by means of a set of two-dimensional spatial structuring elements with a third intensity dimension. The set contains N anisotropic structuring elements oriented from .pi./N to .pi./N and one isotropic structuring element.

Abstract: A method for magnetic resonance imaging of a density distribution of a first substance and a second substance in a part of a body which is arranged in a substantially uniform, steady magnetic field, said first substance having a J-coupling. In order to image the contribution to the MR spectrum by said first substance having the J-coupling separately from the contribution to the MR spectrum by the second substance, repetition of refocusing pulses is used for the generating of the spin echo signals, so that in the direction of a first dimension of a data matrix, in which the measured values are arranged, a phase modulation of 180.degree. occurs in the successive values. Furthermore, the method according to the invention utilizes spatial encoding in which the maximum strength of a phase encoding gradient is equal to half the maximum strength of a corresponding phase encoding gradient used in a customary phase code, so that the field of vision is doubled in comparison with the customary field of vision.

Abstract: An MR apparatus includes an MR coil system of the so-called bird cage type which operates in a degenerate mode of operation in which all resonance modes and all resonance frequencies coincide. It has been found that the individual meshes of the MR coil system are then decoupled from one another, thus enabling operation as a coil array, the individual MR signals being processed in separate processing channels so as to form MR sub-images which can be combined in a reconstruction unit so as to form an MR overall image having an improved signal-to-noise ratio.

Abstract: An X-ray examination apparatus is arranged to convert an X-ray image of an object into an optical image, and to derive an image signal from the optical image by means of an image pick-up apparatus. The image pick-up apparatus includes a controllable amplifier. The X-ray examination apparatus includes an exposure control system with a photosensor for measuring the brightness of the optical image. The exposure control system adjusts the controllable amplifier on the basis of the photosensor signal, representing the brightness of the optical image, and a correction number. The correction number is derived from the image signal.

Abstract: An image display system is provided with an image display apparatus (1) for displaying an image, the image being dependent on the position and orientation of the image display apparatus and independent of the position and posture of a user of the image display apparatus. An image guided surgery system is provided with such an image display system in order to show the user, during a medical treatment utilizing an instrument, where within the patient the instrument is situated, without the user having a direct view of said instrument.

Abstract: The invention relates to a magnetic resonance (MR) imaging method for forming images of a part of a human or animal body which is arranged in a steady magnetic field, an MR image being made of the part which is directed transversely to a major axis of an ellipsoid which approximates the part. The method is used, for example for functional examination of a heart of a human body during which MR images are made of the left ventricle of the heart. Because the heart in every body may be oriented differently relative to a feet-to-head axis and relative to an axis transversely to the feet-to-head axis, the major axis of the ellipsoid should be determined so as to enable an MR image to be formed of an imaging plane which extends transversely of the major axis and contains a minor axis of the ellipsoid.

Abstract: An image sensor comprises switching elements 30 on a substrate 1. An insulating separation layer 9 is disposed over the switching elements so that a photodiode arrangement 20a disposed over the insulating separation layer 9, can overlap the switching elements 30 and occupy a maximum area of the image sensor. A barrier layer 10 is interposed between the insulating separation layer 9 and the photodiode arrangement 20a, which prevents degradation of the photodiode characteristics over time.

Abstract: An X-ray examination apparatus utilizes an image sensor matrix for picking up an X-ray image, i.e. for converting incident X-rays into electric charges. The X-ray examination apparatus includes a control circuit for controlling the image sensor matrix so as to form a dark signal. The X-ray examination apparatus also includes a correction unit which is arranged to derive the electronic image signal from the primary image and the dark signal. The electronic image signal represents image information in the X-ray image and has not been disturbed by electric charges which have been read with a delay.

Abstract: A device for imaging a turbid medium, for example a breast of a female, includes a holder for receiving the medium, a light source, a photodetector and a processing unit for deriving the image from the intensities measured. The holder is adapted to receive besides the turbid medium also an adaptation medium for influencing a photon path distribution of the turbid medium. The use of different values of optical parameters of the adaptation medium introduces different photon path distributions in the turbid medium. By means of these different photon path distributions the resolution of the image can be improved by utilizing the light sources and/or photodetectors in the same positions. When a liquid is used as the adaptation medium the shape of the adaptation medium can be perfectly matched between the holder and the turbid medium.

Abstract: An x-ray examination apparatus comprises an x-ray detector with a sensor matrix for deriving an image signal from an x-ray image. The x-ray detector is provided with a scatter grid having a regular pattern of x-ray attenuating partitions. The spatial resolution of the sensor matrix is such that the size of the smallest detectable detail in the x-ray image is larger than the distance between adjacent partitions. In particular the x-ray detector comprises an x-ray sensitive photoconductor layer for converting x-rays into electric charges, separate sensor elements include respective collecting electrodes and a semiconductor cladding layer being disposed between the photoconductor layer and the collecting electrodes. The semiconductor cladding layer has a substantial lateral electric conductivity. For example, the semiconductor cladding layer is a chlorine doped selenium layer, or a selenium, sulphur or telluride doped lead-oxide layer.

Abstract: An image-guided surgery system includes an alignment device (1) which measures the direction of a target position (2) with respect to a starting position (4). Subsequently, the alignment device (1) places one end of the surgical instrument (3) in the starting position and rotates the surgical instrument in such a manner that it is oriented along the measured direction. It is ensured that the end meanwhile remains in the starting position. The image-guided surgery system includes a system of arms (7), one end of which is provided with an alignment member (5) for supporting the surgical instrument. The alignment member is preferably a sphere provided with an opening (6) in which the surgical instrument fits.

Abstract: An image-guided surgery system is used to show a user, for example a surgeon, a position of a surgical instrument in an operating area in the body of a patient during a surgical operation. The image-guided surgery system includes an alignment system for deriving an alignment line through a target position, for selecting a starting plane through an end of the surgical instrument, for deriving a starting point on the alignment line and in the starting plane, and for reproducing a position of said end and of said starting point relative to one another in the starting plane. For example, the positions of the end and the starting point in the starting plane are reproduced in a guide image.

Abstract: A method of determining the spatial and/or spectral distribution of nuclear magnetization in separate regions (which are not coherent in respect of space or frequency) utilizes multi-dimensional RF pulses which are configured such that it is possible to determine the nuclear magnetization distribution in the individual regions from a linear combination of the MR signals occurring subsequent to an excitation (or from MR data derived therefrom). This results in shorter measuring times or a more attractive signal-to-noise ratio.

Abstract: A method of and operation for controlling the motions of a radiation source (24) and a radiation detector, for example a film cassette (25), in relation to an adjusted slice position, for example a slice level (19), in a linear tomography apparatus without coupling rod, which tomography apparatus includes a table (10) for accommodating an object (18) to be imaged by tomography includes adjustment of a light indicator (17), adjustably mounted on the table (10), to the position of the slice in the object (18), measurement of data indicating the adjusted slice position, application of the measured slice position data to a system control unit (22), and adjustment of the source (24) and the radiation detector (25) in relation to the measured slice position (19) in conformity with the data applied.

Abstract: A multi-media data processing device has a visual display, storage, and a user interface with voice input and a manually actuatable remote control. In particular, the remote control and the voice input device are physically integrated to a hand-sized unit. Combining discrete manipulatory control signals and voice input signals allows to select and annotate transiently displayed pictures. Advantageously, the hand-sized unit is wireless.

Abstract: Magnetic resonance apparatus includes an examination zone (29) for receiving an object (37) to be examined, a component (41) of an electrically non-conductive plastic material being located in the examination zone at least when the apparatus is in an operating condition. In order to reduce the visibility of this component (41) in MR experiments, the plastic material contains an additive of a paramagnetic material.

Abstract: A method of imaging a portion of a body placed in a static magnetic field by means of magnetic resonance (MR) includes the measurement of ECG data of the body in the form of a vector cardiogram, and determination of an acquisition period from the ECG data, including directional information in the vector cardiogram, in order to synchronize measurement of MR signals to a cyclic movement of the body.

Abstract: The invention relates to a method which enables distributed or dilute structures, for example a vascular system filled with a contrast medium, to be reproduced in a synthetic projection image which reproduces the parts of the vascular system which are situated in a selectable sub-volume more clearly than the X-ray images, formed from different perspectives, wherefrom the projection image is derived. The voxel image values associated with the voxels of the sub-volume are first determined and from these voxel image values there is calculated a synthetic projection image in which the selected sub-volume is reproduced.

Abstract: A method and a device for optically ascertaining the mutual binding of a first and a second reactant are described. Use is made of the fact that a dipolar layer (7) having a non-linear optical behavior is formed upon a reaction between the two reactants. The formation of such a layer is ascertained by illuminating the substance with radiation (8) having one or two frequencies, and by detecting whether radiation (10) from the substance contains a component at a frequency which is twice the frequency, or a mixed term of the frequency of the radiation incident on the substance.