This application claims priority to the German application No. 10 2004 012 050.1, filed Mar. 11, 2004 which is incorporated by reference herein in its entirety.
The invention relates to a diaphragm unit for an x-ray emitter and an x-ray device having a diaphragm unit, wherein an examination area can be at least partly exposed to the x-ray emitter.
X-ray systems are equipped with diaphragms which are used for variably restricting the x-rays to the required height and width. The undesired x-ray components are absorbed by the diaphragm blades which are normally made of lead. The diaphragms of such x-ray devices normally feature two pairs of lead blades. These pairs of blades are activated symmetrically to the center of the detector and isocentrically to the x-ray tube. The plate-type diaphragm blades cannot just be enlarged as required since this would also enlarge the aperture which for example leads to limitations in angulations on a C-arm of the x-ray device. An asymmetric display of an area under examination by means of a mechanical movement of the detector or the C-arm is known from DE 101 33 657 A1.
It is therefore an object of the invention to adjust the area of the image that can be displayed, especially by expanding it asymmetrically in a simple manner.
This object is achieved by the claims.
The diaphragm unit in accordance with the invention or the diaphragm unit and the x-ray emitter in accordance with the invention or the inventive method for adjusting a diaphragm unit or a diaphragm unit and an x-ray emitter offer expanded options for adjusting the area able to be displayed. The user is therefore not exclusively confined to the conventional symmetrical settings. With the present invention different sized areas of the detector can be displayed in different forms as well as at different positions in a particularly simple way. This variability of the display areas is especially advantageous if patients are not to be examined in standard positions. A further advantage of the invention lies in the fact that existing diaphragms can continue to be used. Only the mechanical control and linkage for the inventive adjustment of diaphragm unit or diaphragm unit and x-ray emitter have to be expanded.
In accordance with the first embodiment of the invention the diaphragm unit and the x-ray emitter constitute one unit which can be tilted in its entirety such that the area under investigation can be displayed asymmetrically. This embodiment offers a particularly simple construction since only one mechanism for tilting the otherwise unchanged unit has to be provided but no modifications have to be made to the x-ray emitter and diaphragm unit. The unit is advantageously able to be tilted isocentrically to the tube focus. The retention of the x-ray tube focus brings the advantage that the scatter ray grid in front of the detector for reduction of scatter rays can continue to be used.
In a further embodiment of the invention there is provision for the diaphragm unit to be moveable in a circumferential direction of an x-ray housing accommodating the x-ray emitter relative to the former An especially simple construction here provides a system which advantageously moves isocentrically to the tube focus; This allows the diaphragm unit to be tilted relative to the x-ray emitter and the distance between diaphragm unit and tube focus to remain unchanged. Expediently the diaphragm unit is only moved far enough to remain in the exit opening of the X rays. With the inventive tilting of the diaphragm unit edge areas of the detector can also be displayed which is not achievable with the conventional design.
The invention as well as further advantageous embodiments in accordance with features of the subclaims are explained in more detail below with reference to schematic exemplary embodiments in the drawing; The Figures show:
In accordance with
The constructional unit 1;4 in accordance with the invention shown in
If the diaphragm unit 4 is moved in accordance with the invention on the rail system 10 from the position shown in
The invention can be briefly summarized as follows: the invention relates to a diaphragm unit 4 or a diaphragm unit 4 and an associated x-ray emitter 1 with an adjustment option for displaying an asymmetrical area under investigation, with the diaphragm unit 4 being able to be titled in accordance with the invention relative to the x-ray emitter 1, preferably by movement on a rail system 10 attached isocentrically to the tube focus 9 on the tube housing 2, and/or the unit 1;4 made up of diaphragm unit 4 and x-ray emitter 1 being able to be tilted isocentrically to the tube focus 8 of the x-ray tube 2.
Number | Date | Country | Kind |
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10 2004 012 050.1 | Mar 2004 | DE | national |