摘要:
The invention relates to an arrangement for producing X-ray images, which arrangement comprises an X-ray source (1) for the generation of an X-ray beam (10), a layer (41) sensitive to X-rays and situated on a cylindrical drum (4), and a read unit (5) for converting the X-ray image detected in the layer into electrical image values. In order to improve the X-ray images which can be produced by the arrangement an image processor (21) includes a module (212) for transforming the X-ray image (I) situated on the layer into an X-ray image (I.sub.v) situated in a virtual plane (12), and a module (211) for improving the uniformity of the modulation transfer function (MTF) over the X-ray image produced.
摘要:
An X-ray imaging system comprising a motorised X-ray tube located at a fixed focus position (12) relative to an object (14) to be imaged, and a motorised detector (18) for detecting the intensity distribution of radiation transmitted through the object. A control system (22) is provided for calculating two or more angles (Ot1) from which the object (14) should be exposed to radiation in order to cover the entire exposure field (H) occupied by the object (14) and for causing the X-ray tube to be rotated around the fixed focus position (12) so as to expose the object (14) to radiation from each of the respective angles (Ot1). The movement of the detector (18) is also performed automatically so as to correspond with the exposure angles so as to create two or more respective images of respective regions of the object (14) which can be subsequently stitched together to create a complete image thereof.
摘要:
The dynamic range of density or intensity values of pixels in an X-ray image is compressed in a manner preserving the range which is of primary interest for diagnosis, while still allowing recognition of detailed structure in the further ranges. This is accomplished by forming low-pass picture values (L) from input-picture values (E), determining equalizing values as a function (C) of the low-pass picture values (L) and forming output picture values by superposition of the input-picture values (E) and the equalizing values (C) . The equalizing values are chosen such that the output picture values are greater than the input-picture values (E) at relatively small low-pass picture values (L), below the range of primary interest, and the output picture values are less than the input-picture values at relatively large low-pass picture values (L), above the range of primary interest. Further, the output picture values substantially equal the input picture values for low-mass picture values (L) within the range of primary interest for diagnosis.
摘要:
The invention relates to an X-ray device in which a set of exposure parameters is fetched from among a number of such sets stored in a first storage arrangement for APR X-ray exposures. The exposure parameters which result therefrom during the subsequent X-ray exposure and have possibly been modified by the user are stored in a second storage arrangement. The X-ray device includes means for evaluating the second sets of exposure parameters which are associated with the same first set of exposure parameters and for deriving therefrom a new set of exposure parameters which is stored in the first storage arrangement instead of the first set of exposure parameters and forms the basis for APR X-ray exposures from then on.
摘要:
The invention relates to a method of generating X-ray images by means of a photoconductor which is provided on a conductive substrate and whose surface potential can be read by means of probes, and also relates to a device suitable for carrying out the method. In order to avoid image artefacts which could be caused by deviating sensitivities of the probes or by frequency-dependent distortions, after the charging of the photoconductor the substrate potential is varied during a test phase. Test data is generated which correspond to the spatial or temporal variation of the potential on the surface of the photoconductor; from this test data there is formed correction data which is stored in order to correct the image data of a subsequent X-ray exposure.
摘要:
In phase-contrast imaging, different types of image information, such as absorption image information and differential phase-contrast image information, may be obtained by a single image acquisition process and have different image properties. A frequency dependent combination of different types of image information is obtained, the combined image having improved properties over the image information and respective image information types. Accordingly, an apparatus and a method for image processing in X-ray imaging of an object is provided, including receiving first and second image information of the object of first and second image information types, respectively, where the second image information type is different from the first image information type. The first and second image information is combined to obtain combined image information of the object, where the combined image information is frequency-dependent, depending on spatial frequencies of the first and second image information, respectively.
摘要:
A calibration device (140) for calibrating an X-ray image apparatus is described (100), the device (140) comprising a receiving unit (200) for receiving an image captured by a detection unit (108) of the X-ray image apparatus (100) under reference conditions, an analyzing unit (201) for analyzing the captured image to derive gain correction information, and a calibration unit (202) for providing calibrating information for calibrating the X-ray image apparatus (100) based on the derived gain correction information disregarding gain correction of a heel effect.
摘要:
A portable X-ray detector unit comprising a portable, hand-held cassette (10) having a plurality of exposure detection fields (identified by markings (12)) for measuring the level of radiation to which a subject to be imaged is exposed. Automatic exposure control means (26), for terminating radiation supply to the subject (4) when it is determined that the level of exposure exceeds a predetermined threshold, are interpreted in the portable detector unit, and a user-interface (16, 18) is provided to control the exposure detection fields (12) and/or the control means (26).
摘要:
A security system for preventing unauthorised removal of a portable electronic device, such as a portable X-ray detector (106) or the like, from a docking station (100). The docking station (100) is provided with an electromagnetic lock (102) which is activated by means of a software command (112) issued by a screensaver function (110) running on a remote host PC (108). When triggered after some predetermined period of user inactivity, the screensaver function (110) locks the screen and keyboard of the host PC (108) to prevent unauthorised use thereof, and also issues the above-mentioned software command (112) to activate the electromagnetic lock (102) and prevent removal of the detector (106) from the docking station (100).
摘要:
A device 16 for displaying X-ray images, the device comprises a display 20 for displaying an X-ray image, a workstation 22 for processing image data and a user interface 24 for receiving commands from a user of the device. The user interface 24 is adapted for allowing the user to select a master image 34a and a slave image 34b from a plurality of images. The workstation 22 is adapted for transforming the slave image 34b by generating a color transformation 40 based on the master image 34a and the slave image 34b for optically adapting the slave image to the master image and by applying the color transformation 40 to the slave image 34b. The display 20 is adapted for displaying the transformed slave image 42.