Validity of a reference system

1. A method for a determination of a validity of a reference system between a reference structure and an anatomical structure during an operative intervention on a patient, the method comprising:

acquiring a first image data set of the patient, via an X-ray apparatus, at a first time point during the operative intervention, the first image data set including the reference structure at a first position relative to the patient, the anatomical structure and the reference system between the reference structure and the anatomical structure;

acquiring a second image data set of the patient at a second time point, via the X-ray apparatus, during the operative intervention, wherein the second image data set includes at least the reference structure at the first position relative to the patient;

registering the second image data set to the first image data set, wherein the reference structure represented in the first image data set and the reference structure represented in the second image data set are entered as input parameters in the registering and wherein, as a result of the registering of the second image data set to the first image data set, a registered second image data set is determined, and

determining the validity of the reference system by a comparison of the registered second image data set with the first image data set.

2. The method of claim 1 , wherein the reference structure includes at least one image marker, a first fastening device and a holding structure, and wherein the at least one image marker is releasably connected via the first fastening device to the holding structure.

3. The method of claim 2 , wherein the reference structure includes a second fastening device and a holding structure, wherein the holding structure is connected to the patient via the second fastening device and wherein, by way of a connection between the holding structure and the patient, the reference system is initially defined between the reference structure and the anatomical structure.

4. The method of claim 2 , wherein the reference structure includes at least one image marker which is X-ray-absorbent and wherein the registering of the second image data set to the first image data set includes a determination of the reference structure via the at least one image marker represented in the first image data set and of the at least one image marker represented in the second image data set.

5. The method of claim 2 , wherein the comparison comprises a determination of a third image data set via the first image data set and the second image data set registered.

6. The method of claim 1 , wherein the reference structure includes a second fastening device and a holding structure, wherein the holding structure is connected to the patient via the second fastening device and wherein, by way of a connection between the holding structure and the patient, the reference system is initially defined between the reference structure and the anatomical structure.

7. The method of claim 1 , wherein the reference structure includes at least one image marker which is X-ray-absorbent and wherein the registering of the second image data set to the first image data set includes a determination of the reference structure via the at least one image marker represented in the first image data set and of the at least one image marker represented in the second image data set.

8. The method of claim 1 , wherein the comparison comprises a determination of a third image data set via the first image data set and the second image data set registered.

9. The method of claim 8 , wherein the determination of the third image data set includes a weighting of the first image data set and a weighting of the second image data set registered.

10. The method of claim 9 , wherein the determination of the validity includes a visualization of the third image data set on a display unit.

11. The method of claim 8 , wherein the determination of the validity includes a visualization of the third image data set on a display unit.

12. The method of claim 8 , wherein the determination of the validity includes a pixel-related classification of the third image data set into at least two classes dependent upon a deviation from the reference system, whereby pixel-related classification values are determined and wherein the pixel-related classification values are visualized on a display unit as an overlay at least one of to the first image data set, to the registered second image data set and to the third image data set.

13. The method of claim 8 , wherein the determination of the validity includes a calling up of a threshold value, a segmenting of the third image data set, a calculation of segment-related values in the segmented third image data set and a comparison of the segment-related values with the threshold value.

14. The method of claim 1 , wherein at least one of

the acquiring of the first image data set of the patient via the X-ray apparatus takes place at the first time point via the X-ray apparatus during the operative intervention on a spinal column of the patient, and

the acquiring of the second image data set of the patient takes place at the second time point via the X-ray apparatus during the operative intervention on a spinal column of the patient

and wherein the reference structure is connected to a vertebra of the spinal column before the method for the determination of the validity.

15. The method of claim 1 , wherein dependent upon the determination of the validity of the reference system, the anatomical structure represented in the second image data set is registered to the anatomical structure represented in the first image data set or in a fourth image data set, upon the second image data set including the reference structure and the anatomical structure.

16. The method of claim 1 , wherein a scan region of a fifth image data set is defined dependent upon the reference structure represented in the second image data set and the anatomical structure, upon the second image data set including the reference structure and the anatomical structure.

17. A non-transitory computer program product, directly loadable into a memory store of a computer unit, including program code segments to carry out the method of claim 1 upon the computer program product being executed in the computer unit.

18. A non-transitory computer readable medium, storing program code segments to carry out the method of claim 1 , upon the program code segments being executed in a computer unit.

19. A medical system for a determination of a validity of a reference system between a reference structure and an anatomical structure during an operative intervention on a patient, comprising:

an X-ray apparatus configured to

acquire a first image data set of the patient at a first time point during the operative intervention, the first image data set including the reference structure at a first position relative to the patient, the anatomical structure and the reference system between the reference structure and the anatomical structure, and

acquire a second image data set of the patient at a second time point during the operative intervention, wherein the second image data set includes at least the reference structure at the first position relative to the patient; and

at least one processor, configured to

register the second image data set to the first image data set, wherein the reference structure represented in the first image data set and the reference structure represented in the second image data set are entered as input parameters during registering and wherein, as a result of the registering of the second image data set to the first image data set, a registered second image data set is determined, and

determine the validity of the reference system by a comparison of the registered second image data set with the first image data set.

20. The medical system of claim 19 , wherein the X-ray apparatus includes a C-arm system.