X-ray detector provided with integrated cooling

#The invention relates to an X-ray examination apparatus which includes an X-ray detector and an X-ray source which are arranged on a supporting device. The invention also relates to an X-ray detector which includes a sensor unit that converts X-rays into electrical image signals and in which a sensor unit is adjoined by a processing unit that includes a plurality of amplifier units. The invention also relates to a method for cooling X-ray examination apparatus.

#The X-rays emitted by an X-ray source in imaging X-ray examination apparatus traverse a patient or object to be examined and are attenuated in conformity with the different thickness and chemical composition of the tissue or the bones to be examined. In the X-ray detector the X-rays are converted into light in a scintillating material or into charge carriers that can be detected directly.

#X-ray examination apparatus are used, for example in the field of surgery and consist, for example, of a mobile console and a mobile supporting device which is attached thereto and accommodates on the one side an X-ray source and on the opposite side an image pick-up device or the X-ray detector.

#An embodiment of the invention will be described in detail hereinafter with reference to the drawings. Therein:

#FIG. 1 shows an X-ray examination apparatus,

#FIG. 2 shows a cooling circuit with an X-ray detector and an X-ray source, and

#FIG. 1 shows an X-ray examination apparatus which is constructed as a C arm X-ray examination apparatus. The flat dynamic X-ray detector 1 and the X-ray source 2 are both mounted on the supporting device 3 which is connected to the console 4. The supporting device 3 of the present embodiment is constructed as a C arm. As is represented by the unit 5, the flat dynamic X-ray detector 1 may also be replaced by a conventional image intensifier.

#FIG. 2 shows the cooling circuit between the heat exchanger 6, the dynamic X-ray detector 1 and the X-ray source 2. The cooling medium in the form of water or oil of a constant temperature of 20° C. is fed, via a first sub-system 7 of the duct system, to the X-ray detector 1. Therein, a first exchange of heat takes place between the X-ray detector 1 and the cooling medium. The cooling medium, now having a temperature of 25° C., is applied to the X-ray source 2 via a second duct sub-system 8. The X-ray source produces temperatures in excess of 50° C. The supply of the cooling medium to the X-ray source enables a second exchange of heat which reduces the temperature of the X-ray source to a maximum of 50° C. The second exchange of heat heats the cooling medium to, for example 35° C. The cooling medium that has thus been heated again is applied, via the third duct sub-system 9, to the heat exchanger 6 in which the cooling medium is cooled to the temperature of 20° C. again. One or more temperature sensors 17 are provided in the X-ray detector in order to generate a signal 15 that is dependent on the temperature in the X-ray detector and is applied, via the lead 15, to the heat exchanger 6 for the purpose of temperature control.

#FIG. 3 is a detailed representation of a dynamic X-ray detector 1. The X-ray detector 1 consists of an X-ray converter unit 1 la, a sensor layer 11 and a glass layer 10 that is provided underneath the sensor unit 11. Underneath the sensor unit 11 there is provided a processing unit 12 which includes a plurality of amplifier units 13. The amplifier units 13 serve to amplify the image signals read out from individual image zones of the sensor unit 11 and produce heat. The amplifier units 13 are arranged in such a manner that they adjoin the cooling unit 14 and hence a continuous reduction of the temperature can take place, so that all amplifier units 13 can operate at the same low temperature level. This enables all image zones of the sensor unit 11 to be amplified under the same conditions, thus avoiding the formation of incorrect renditions of the overall image. The cooling unit 14 receives the cooling medium of a constant temperature of 20° C. via the first duct sub-system 7 which is not shown in FIG. 3. The cooling medium is transported away from the X-ray detector 1 via a second sub-duct 8 (not shown either). A further processing unit 16 serves for the further processing of the amplified image signals and for the supply to peripheral apparatus.