Abstract: The invention relates to the field of digital subtraction angiography. An image processing method is applied to a digitized mask (100) and to a sequence of digitized opacified images (101). A logarithmic function (105) is applied to the values of the pixels of the digitized mask and to the values of the pixels of the sequence of digitized opacified images, and then a subtraction (108) is made of the logarithmic value of each pixel of a digitized opacified image from the logarithmic value of the corresponding pixel in the digitized mask. In order to improve the quality of the images processed, a processing step (102) able to decrease certain pixel values of the digitized mask and of the digitized opacified images is applied before applying the logarithmic function.

Abstract: The invention relates to a method of improving the precision of a medical nuclear SPECT or PET image in which notably a nuclear sectional image (n) can be superposed on a two-dimensional ultrasound image (u). For the superposition that nuclear sectional image (n0) which exhibits the best correspondence with a free-hand ultrasound image (u) is chosen from a three-dimensional nuclear image (2). In order to determine this sectional image, an evaluation index f(n,u) is calculated, on the basis of an estimated value (1), for differently situated nuclear sectional images (n). This index assigns a positive value to positions of structures (heart muscle tissue etc.) which correspond in the two images, a neutral value to structures which are represented only in the ultrasound image (u) and a negative value to structures which are represented only in the nuclear sectional image (n).

Abstract: A method and apparatus of generating a hybrid three dimensional reconstruction of a vascular structure affected by periodic motion is disclosed. At least two x-ray images of the vascular structure are acquired. Indicia of the phases of periodic motion are obtained and correlated. Images from a similar phase of periodic motion are selected and a three dimensional modeled segment of a region of interest in the vascular structure is generated. A three dimensional volumetric reconstruction of a vascular structure is generated that is larger than the modeled segment. The modeled segment of interest and the volumetric reconstruction of the larger vascular structure are combined and displayed in human readable form.

Abstract: The invention relates to a device for generating X-rays (41). The device comprises a source (5) for generating an electron beam (35), and a carrier (7) which is rotatable about an axis of rotation (15) and which is provided with a material (9) which generates the X-rays as a result of the incidence of the electron beam thereon. The device further comprises a heat absorbing member (45) which is arranged between the source and the carrier to catch electrons, which are scattered back from an impingement position (39) of the electron beam on the carrier, and to absorb a portion of the radiant heat generated by the carrier when heated during operation. The heat absorbing member is in thermal connection with a cooling system (51) of the device.

Abstract: A power supply for X-ray generators which includes at least one inverter (11, 12, 13), at least one transformer (111, 121, 131) and at least one voltage cascade (112, 122, 132) for generating a supply voltage for an X-ray tube (15). In order to increase the output power that can be achieved with a comparatively small weight and a low ripple or output capacitance, the voltage cascade is conceived in respect of its capacitances and the stray inductance of the transformers (111, 121, 131) in such a manner that it can be made to operate in the resonance mode by appropriate control of the inverter. In respect of the properties mentioned it is notably advantageous to integrate a two-phase embodiment or three-phase embodiment with an X-ray system so as to form a compact tank generator.

Abstract: An X-ray examination apparatus and method that provides fast and accurate control of the X-ray dose by combining a fast and inaccurate sensor dose signal for an X-ray sensor and a slow and accurate detector dose signal from an X-ray detector. The combination of the signals takes into account the delay between the two signals so that they are measured at essentially the same time.

Abstract: A nuclear camera system (10) includes a gantry (22, 23) disposed about an examination region (17) having detector heads (15 a,b,c) mounted to the gantry. The detector heads (15) include an enclosure (30, 34, 54, 56) defining a volume (61). A plurality of solid state detectors (40) are arranged in an array (36) within the enclosure volume. A first cold plate (46) is in thermally conductive contact with the plurality of solid state detectors. A first Peltier cooler (50) is in thermally conductive contact with the first cold plate, the first Peltier cooler provides for cooling the plurality of detectors in the array. A second cold plate (47) is located within the enclosure and is thermally insulated from first cold plate. A second Peltier cooler (52) is in thermally conductive contact with the second cold plate, the second Peltier cooler for removing moisture from the volume (61). A heat sink (56) is in thermally conductive contact with the first and second Peltier coolers.

Abstract: A method and a device provide for the registration of two 3D image data sets of an object to be examined. The object to be examined is provided with a plurality of markers In order to enable a registration to be carried out, the positions of the markers in the 3D image data sets are first determined in a co-ordinate system associated with the relevant 3D image data set. The distances between the markers and/or the angles formed between lines which intersect in a marker and extend through two further markers are then determined. Finally, a transformation rule for the transformation of one of the 3D image data sets to the co-ordinate system of the other 3D image data set is determined.

Abstract: The invention relates to a radiation detector for converting electromagnetic radiation (15) into electric charge carriers. The invention also relates to an X-ray examination apparatus provided with such a radiation detector, and to a method of manufacturing a radiation detector. In order to achieve a small building height of the radiation detector while nevertheless satisfying the same requirements as regards the resetting of the converter arrangement (16, 18) by means of an illumination device (6), it is proposed to provide a supporting layer (8) underneath a glass plate (2a) with a photosensor arrangement (2b), which supporting layer on the one hand provides uniform distribution of the light incident from below and on the other hand imparts the necessary stability to the radiation detector.

Abstract: An X-ray device and method of improving the quality of an image formed by an X-ray device are provided. The X-ray device comprises a source emitting a beam of X-rays toward an object to be examined. A detector for receiving the X-rays that pass through the object is connected to an image processor. An X-ray collimator comprising a translatable element and at least one aperture for narrowing the beam of X-rays is arranged between the X-ray source and the examined object. A method of improving the quality of an image formed by the X-ray device comprises the steps of narrowing the X-ray beam using the aperture of the collimator, moving the aperture through the X-ray beam to expose the object to be examined to the narrowed X-ray beam, and forming an image of the examined object based upon the highest intensity value received for each pixel of the detector.

Abstract: The invention comprises a system and method for creating medical images of a subject patient using a plurality of imaging devices, such as tomographic imaging scanners. The imaging devices each have a bore through which a patient is translated during scanning. The imaging devices can be moved apart to allow greater access to a patient between the bores.

Abstract: A description is given of a method and a device for the calibration of an image pick-up device which is sensitive to magnetic fields and for the imaging by means of such an image pick-up device. The image pick-up device is notably an image intensifier in X-ray systems such as, for example, systems provided with a C-arm. Calibration is performed essentially by forming and storing a look-up table whereby a plurality of magnetic field data acting on the image pick-up device is associated with calibration data required for correcting the distortions caused thereby. During imaging, the magnetic field data acting on the image pick-up device during the formation of an image is measured and the calibration data associated with this magnetic field data in the table is read out and used for the correction of the acquired image.