Abstract: A display device has a plurality of display units (D.sub.1, D.sub.2 . . . D.sub.n), each display unit consisting of a number of multiplex-operated display sections, each of which has a plurality of display elements which can be simultaneously but independently switched and each of which has a respective display driver (for example, T.sub.1), and a circuit arrangement for controlling the display device. The circuit arrangement includes a memory (M) in which the information to be output via the display device is stored, a microcontroller (MC) which has at least one synchronous serial interface (2) and a DMA controller (3) for transferring data intended for each time the same display section of the display units (D.sub.1, D.sub.2 . . . D.sub.n) from the memory to the interface, a shift register arrangement (S.sub.1, S.sub.2 . . . S.sub.n) which is connected to the serial interface (2) and which has a parallel output, and storage members (L.sub.1, L.sub.2 . . . L.sub.

Abstract: The invention relates to an MR method with reduced motion artefacts in which the displacement of a pulsating object, or of a part thereof, which is present in an examination zone is continuously measured relative to a reference position, and in which the reconstruction of an MR image utilizes exclusively MR signals acquired from the examination zone while the displacement from the reference position reaches or falls below a threshold value. This gating is enhanced in accordance with the invention in that prior to the acquisition of the MR signals there are generated phase encoding gradients k.sub.y) which act on the examination zone with different time integrals and that the threshold value (v.sub.s) can be varied in dependence on the respective phase encoding gradient (k.sub.y).

Abstract: An image pick-up apparatus (1) for picking up a plurality of sub-images and combining them so as to form a composite image, including a correction unit (5) for correcting brightness values of the composite image. The correction unit (5) includes a selection unit (6) for selecting bright and dark parts from the sub-images. There is also provided an arithmetic unit (10) for deriving a gain correction factor from the bright parts and an offset correction term from the dark parts. The correction unit (5) also includes a multiplier unit (8) and an adder unit (9) for multiplying signal levels of a sub-image signal by the gain correction factor and for adding the offset correction term thereto.

Abstract: MR imaging apparatus includes a magnet (1) for generating in an examination zone (3) a uniform, steady magnetic field having substantially parallel lines of force extending in a first direction (Z), a gradient coil system (5) for generating a magnetic gradient field, and an RF coil system for generating RF pulses and for receiving MR signals. The apparatus also includes devices (25,27,31) for generating data from the MR signals, and a reconstruction unit (39) for reconstructing an MR image of the examination zone (3) from a set of the data. A patient support system includes a table top (7) drive means (11) configured for displacement of the table top in the first direction (Z), and a connection (43) for coupling the drive means and the control unit (29). The magnet (1) has a generally toroidal-shaped housing (15) surrounding a bore (17) and has a longitudinal axis (19) extending substantially parallel to the first direction (Z).

Abstract: An X-ray examination apparatus (1) is provided with an X-ray source (2) and an X-ray detector (5) wherebetween there is arranged an X-ray filter (6) which includes filter elements (7) whose X-ray absorptivity can be adjusted by controlling the quantity of X-ray absorbing liquid (31) in individual filter elements (7). The filter elements (7) are formed by spaces between electrically conductive tracks (9) provided on parallel plates (8). The parallel plates are arranged in a reservoir (31) for the X-ray absorbing liquid. The liquid level in the vicinity of an electrically conductive track is controlled on the basis of an electric voltage applied to the relevant electrically conductive track (9).

Abstract: An image processing method is provided to remove areas from an image made by x-irradiation, said areas corresponding to absorption filters in the x-ray beam. Because such filters, also known as x-ray shutters, are inserted into the x-ray beam from the outside of the x-ray beam, x-ray shutter-areas extend from the periphery of the image. Therefore, once the edge of an x-ray shutter-areas has been determined, the part of the image located between the periphery and the x-ray shutter-edge is removed. X-ray shutter-edges are determined by locating transition-points in the image having brightness-transitions having maxima of both the first and second spatial derivatives of the brightness-value. An x-ray shutter-edge is then determined by fitting a curve through the transition-points. The curve fitting is performed with the use of weight-factors that are representative of the likelihood that a transition-point is on an actual x-ray shutter-edge.

Abstract: An image guided surgery system comprises a position detection system which measures the position of a surgical instrument and displays the surgical instrument in its corresponding position in a CT-image or an MRI-image. The position detection system is provided with an indicator system which shows a region for which the position detection system is sensitive. Preferably, the camera unit of the position detection system incorporates a semiconductor laser which generates a light spot in the center of the operating region.

Abstract: The invention relates to an automatic image analysis method in which two images which have been recorded at different instants are analyzed and a transformation function is determined on the basis of the shifts of image sections, which transformation function describes the shift from one image to another. In order to enable exact determination of this shift, corresponding image sections are determined in the two images by histogram analysis.

Abstract: One requirement imposed on a patient table is that it may occupy only a small floor surface area. Therefore, a patient table having a compact base is required. For a variety of applications, moreover, it is desired that the table is also constructed to be very rigid in the direction of adjustment of its height. To this end, the height adjustment system supporting the table is provided with a drive mechanism which consists of two mutually parallel threaded spindles (54, 56) which pass through an associated nut (50, 52) and expand in two mutually opposed directions. The two threaded spindles are preferably driven by a single motor (70). In order to achieve adequate rigidity in the horizontal direction, the hinge is constructed so as to comprise two arms (28, 30) only.

Abstract: An MR system for interventional procedures, includes an MR device and an invasive device. The MR device is arranged to acquire images of a part of an object. A part of the invasive device can be imaged in an MR image by providing a coil or a conductor loop which has two non-magnetic conductors which are situated at some distance from one another underneath the surface of the invasive device. A reduction of artefacts due to the movement of a patient or the invasive device can be obtained by sampling an MR signal, whereby an auxiliary magnetic field is periodically applied during the time in which the plurality of lines in k-space are scanned.

Abstract: In an MR device in which an MR image can be reconstructed by means of a coil array system, the image data supplied by the coil array system are corrected by means of a reference coil system which consists of a number of coil elements distributed on its circumference. The two coil systems can thus receive MR signals simultaneously.

Abstract: A system for detecting an object (1) in a turbid medium (2) comprises a radiation source (3) for irradiating the turbid medium with radiation components of different wavelengths, preferably in the range between 600 nm and 1 .mu.m. The radiation components are amplitude modulated, preferably in anti-phase. The radiation form the turbid medium is received by a photodetector (4) which is sensitive for the different wavelengths. Inhomogeneities in the turbid medium influence the superposition of the amplitude modulations at the photodetector, so that the photodetector outputs a signal that contains information on the presence and/or location of an object in the turbid medium.

Abstract: The Doppler angle is adjusted to a value close to the optimum Doppler angle DAopt, typically amounting to 60.degree., between the direction of an echographic excitation and the axis of a blood vessel in an echographic image, based on prior designation of an initial point in the vessel. The method includes a first measurement of the Doppler angle DA1 in a first, predetermined excitation direction, comparison of DA1 with Daopt, formation of .DELTA..theta.=.vertline.DAopt-DA1.vertline., and correction of the direction of the echographic excitation by the value .DELTA..theta. in order to shift it to a second direction.

Abstract: A method of heating a target region by ultrasound radiation includes determination of a position of the target region by a magnetic resonance method. The device for carrying out this method includes an ultrasound device and an MR device. By determining movement of the target region utilizing the MR device (100) and an appropriate magnetic resonance method, and by coupling the movement information to the ultrasound device (118) by an electric signal (122, 124), it is achieved that the ultrasound device can be controlled by the movement information. Various possibilities exist for controlling the ultrasound device. According to a first possibility, the focal region is adjusted to be situated within the target region in order to generate ultrasound.

Abstract: The position of an object, for example a catheter, in a body to be examined is determined so as to enable monitoring of its movement through the body at the same time that information concerning the anatomy in the surroundings of the object is to be acquired. An as high as possible temporal and spatial resolution should be achieved for this purpose. To this end, the nuclear magnetization in the surrounding region of the object is determined by means of a micro-coil which is mounted on the inserted object, it being possible to determine the position of the object from the nuclear magnetization. Subsequently, an RF coil system is used to perform a line scan around this position in order to determine the nuclear magnetization in a line-shaped region.

Abstract: A signal processing method includes the steps of construction (100), on the basis of sets of signals (S,X,Y,n) relating to an object (6) comprising moving parts, a sequence of graphic images with graphics (REF1 ,REF2; DP1, DP2) representing the parts (3a, 3b) of the object in motion, at a given scale, with a spatial and temporal marker; construction (30) of a sequence of intensity images ?I(X,Y,n)! corresponding to the graphic images; and encrustation (40, 140) of graphics of the graphic images in the corresponding intensity images. This method can be carried out by an ultrasonic echographic apparatus (1) comprising a diagnostic tool (100) and a display system for the construction of the appropriate image sequences.

Abstract: An MR device for determining the nuclear magnetization distribution in an examination zone by means of a surface coil system includes a plurality of coils, preferably ranging from six to twenty-four in number, which are located at different angular positions and are constructed as respective loops, a part of the loops being bent towards the interior of the surface coil system. The coils are arranged on a straight circular support and each of the coils partly overlaps the loop of the neighboring coils. An MR device including such angular coils enables substantially stronger MR signals to be received from an examination zone. This MR device is particularly suitable for use as a head coil system for examinations of the head.

Abstract: An MR method for the reduction of motion artefacts is applicable to procedures where a plurality of MR data sets concerning an object to be examined are acquired successively in time. Because the object to be examined is liable to move during the period of time required to acquire an MR data set for the reconstruction of a high-resolution MR image, the high-resolution MR image often contains disturbing motion artefacts. In order to avoid such motion artefacts in the high-resolution MR images, first a plurality of MR data sets are acquired for low-resolution MR images; this operation can be performed within a shorter measuring period. Image transformation parameters are determined from the comparison of the low-resolution images so as to be taken into account for the reconstruction of the high-resolution MR image from the MR data sets acquired.

Abstract: The invention relates to A method for imaging jointed movable parts of an object by magnetic resonance, where a third part of the object moves along a trajectory near a pivot between a first and a second part of the object, and where the position of the third part is dependent, in conformity with a predetermined relation, on an orientation of the first and the second part relative to the pivot. The method is used, for example for forming a series of images of the patella during the movement of the knee of a human body. According to the method, the measuring zone is adjusted to the instantaneous position of the patella in order to generate imaging pulse sequences. An angle formed by the orientations of the lower leg and the upper leg with respect to one another is measured in order to determine the instantaneous position of the patella. The angle can be determined from the position of RF coils fastened to the lower leg and the upper leg.

Abstract: An image processing method is for automatically detecting objects of a predetermined type among diffuse objects in an original image, in the form of a two-dimensional matrix of pixels which have digitized intensity values. The method is carried out by a processing chain. A first transformed image (11A, 11B) is formed by a first smoothing (120A, 120B) of the original image (10A) to the resolution of the objects to be detected, in which local intensity optimums (LIST1A, LIST1B) are determined (130A, 140A; 130B, 140B). A second transformed image (13A, 13B) is formed via a second smoothing (220A, 220B) of the original image (10A) to the resolution of diffuse objects, in which homogeneous intensity regions are determined (230A, 230B), local intensity optimums (LIST1A, LIST1B) determined on the basis of the first transformed image are placed (240A, 240B) in the homogeneous regions determined on the basis of the second transformed image.