Method and device for determining the x-ray radiation attenuation caused by the object to be examined

1. A method for determining an attenuation of x-ray radiation as a result of the x-ray radiation penetrating through an object to be examined, the method comprising:

receiving a signal of x-ray radiation intensity at a computer, the computer including a processor and a memory, wherein the processor

establishes an intensity of the x-ray radiation, respectively before and after penetrating the object;

determines the spectral composition of the x-ray radiation prior to the x-ray radiation penetrating the object, said spectral composition being taken into account when determining the attenuation;

calculates a ratio, between the intensity of the x-ray radiation established after the penetration and the intensity of the x-ray radiation established prior to the penetration, for the respectively same energy range;

determines the attenuation using the calculated ratio and the determined spectral composition in the determination of the attenuation; and

reconstructs an image corrected for inaccuarcies due at least to time variation of the determined x-ray spectrum based on the determined attenuation.

2. The method of claim 1 , wherein the spectral composition of the x-ray radiation is determined by a radiation monitor.

3. The method of claim 1 , wherein the processor back calculates the spectral composition using at least two energy ranges.

4. The method of claim 1 , wherein the processor

determines a further spectral composition of the x-ray radiation after penetrating through the object, wherein a comparison with the corresponding portions of the spectral composition of the x-ray radiation, determined prior to the penetration, is included in the determination of the attenuation.

5. The method of claim 1 , wherein an accelerating voltage for generating the x-ray radiation is measured at time intervals within a period of time and the spectral composition of the x-ray radiation prior to the penetration through the object is derived from the accelerating voltage.

6. The method of claim 2 , wherein the processor back calculates the spectral composition using at least two energy ranges.

7. A device, comprising:

a device configured to establish an intensity of x-ray radiation from an x-ray source and to determine a spectral composition of the x-ray radiation prior to penetration of the x-ray radiation through an object to be examined and configured

to provide the established intensity and determined spectral composition to determine an attenuation of the x-ray radiation after the penetration of the x-ray radiation through the object be examined, wherein the device is arranged directly next to a shutter opening of a shutter of the x-ray source or integrated into the at least one x-ray source.

8. The device of claim 7 , wherein the device is embodied as a radiation monitor for an x-ray machine.

9. The device of claim 7 , wherein the device to accepts the established intensity and the determined spectral composition; and

determines the attenuation of the x-ray radiation after the penetration of the x-ray radiation through the object, wherein the established intensity and the spectral composition of the x-ray radiation are usable for determining the attenuation.

10. The device of claim 7 , further comprising:

at least two radiation monitor elements, wherein the radiation monitor elements have a different spectral sensitivity in respect of the spectral composition, acquirable thereby, of the x-ray radiation.

11. The device of claim 10 , wherein, in terms of the longitudinal alignment thereof, the radiation monitor elements are arranged perpendicular to one another and perpendicular to the direction of the x-ray radiation to be received.

12. The device of claim 10 , wherein a filter element is applied to at least one of the radiation monitor elements in such a way that the radiation monitor elements respectively have a different spectral sensitivity.

13. The device of claim 10 , wherein the radiation monitor elements include different converter materials.

14. The device of claim 13 , wherein the converter materials have different dimensions.

15. The device of claim 7 , wherein the device is embodied in the form of a detector which includes a sensitive layer for converting photons into an electrical signal.

16. The device of claim 7 , wherein the device is embodied in the form of a direct-conversion detector.

17. The device of claim 7 , wherein the device is embodied in the form of a multi-layer detector.

18. An x-ray machine, comprising:

at least one x-ray source; and

at least one x-ray detector for the imaging examination of an object arranged between x-ray source and x-ray detector, including the device of claim 8 .

19. The x-ray machine of claim 18 , wherein the radiation monitor is arranged directly next to a shutter opening of a shutter of the at least one x-ray source or integrated into the at least one x-ray source.

20. The x-ray machine of claim 18 , wherein the device is configured to accept the established intensity and the determined spectral composition and the device is configured to determine the attenuation of the x-ray radiation after the penetration of the x-ray radiation through the object are integrated into the at least one x-ray detector.

21. An x-ray machine comprising the device of claim 7 , wherein the device is embodied as a radiation monitor.

22. The device of claim 8 , wherein the device accepts the established intensity and the determined spectral composition and

determines the attenuation of the x-ray radiation after the penetration of the x-ray radiation through the object, wherein the established intensity and the spectral composition of the x-ray radiation are usable for determining the attenuation.

23. The device of claim 11 , wherein a filter element is applied to at least one of the radiation monitor elements in such a way that the radiation monitor elements respectively have a different spectral sensitivity.

24. The device of claim 11 , wherein the radiation monitor elements include different converter materials.

25. The x-ray machine of claim 18 , wherein the x-ray machine is a CT system.

26. The x-ray machine of claim 19 , wherein the device to accept the established intensity and the determined spectral composition and the device to determine the attenuation of the x-ray radiation after the penetration of the x-ray radiation through the object are integrated into the at least one x-ray detector.