Determining a status of an X-ray tube of an X-ray system
The present invention relates to a device ( 34 ) and a method ( 70 ) for determining a status of an X-ray tube ( 10 ) of an X-ray system ( 36 ). Due to ageing and/or wear of the X-ray tube, the spectrum of the X-ray radiation ( 30 ) provided by the X-ray tube may change over the operation time of the X-ray tube. The present invention therefore suggests evaluating spectrally different values detected with an X-ray detector arrangement ( 32 ) of the X-ray system. A reference data set representing a reference condition of the X-ray tube by a plurality of spectrally different reference-values ( 44 ) and a working data set representing an aged condition of the X-ray tube by a plurality of spectrally different working-values ( 46 ) of detected X-ray radiation are used to determine an equivalent filtration function for an filtration material influencing a source X-ray radiation ( 26 ) emitted by an anode ( 16 ) of the X-ray tube. Accordingly, the filtration function provides the information about the material being used for the filtration and/or its length, which may provide the basis to determine the condition and thus the status of the X-ray tube.
1. A device for determining a status of an X-ray tube in an X-ray system, comprising:
an input interface configured to receive a reference data set representing a plurality of spectrally different reference-values of a detected X-ray radiation of the X-ray tube under a predefined control scheme of the X-ray system; the input interface being configured to receive a working data set representing a plurality of spectrally different working-values of the detected X-ray radiation of the X-ray tube under the predefined control scheme of the X-ray system, wherein an X-ray filtration, caused by the X-ray tube, is applied at an X-ray radiation path of the X-ray tube;
a processing unit configured to determine, based on the reference data set and the working data set, a filtration function for the X-ray radiation of the X-ray tube indicating the X-ray filtration; the processing unit being configured to determine a status of the X-ray tube based on the filtration function; the processing unit being configured to determine, based on the filtration function, an absorption spectrum; and
an output interface configured to provide the status of the X-ray tube.
2. The device according to claim 1 , wherein the processing unit is configured to determine, based on the filtration function, an absorption length; and wherein the processing unit is configured to determine the status of the X-ray tube based on the absorption length.
3. The device according to claim 1 , wherein the processing unit is configured to determine a further data set corresponding to a ratio of the reference data set and the working data set; and wherein the processing unit is configured to determine the filtration function based on the further data set.
4. The device according to claim 1 , wherein the processing unit is configured to determine, based on the filtration function, an absorption material; and wherein the processing unit is configured to determine the status of the X-ray tube based on the absorption material.
5. A method for determining a status of an X-ray tube of an X-ray system, comprising:
providing a reference data set representing a plurality of spectrally different reference-values of a detected X-ray radiation of the X-ray tube under a predefined control scheme of the X-ray system;
providing a working data set representing a plurality of spectrally different working-values of the detected X-ray radiation of the X-ray tube under the predefined control scheme of the X-ray system, wherein an X-ray filtration, caused by the X-ray tube, is applied at an X-ray radiation path of the X-ray tube;
determining, based on the reference data set and the working data set, a filtration function for the X-ray radiation of the X-ray tube indicating the X-ray filtration;
determining an absorption spectrum based on the filtration function; and
determining the status of the X-ray tube based on the absorption spectrum and the filtration function.
6. An X-ray system, comprising:
an X-ray tube;
an X-ray detector;
an X-ray system controller; and
a device for determining a status of an X-ray tube in an X-ray system, comprising:
an input interface configured to receive a reference data set representing a plurality of spectrally different reference-values of a detected X-ray radiation of the X-ray tube under a predefined control scheme of the X-ray system; the input interface being configured to receive a working data set representing a plurality of spectrally different working-values of the detected X-ray radiation of the X-ray tube under the predefined control scheme of the X-ray system, wherein an X-ray filtration, caused by the X-ray tube, is applied at an X-ray radiation path of the X-ray tube;
a processing unit configured to determine, based on the reference data set and the working data set, a filtration function for the X-ray radiation of the X-ray tube indicating the X-ray filtration; the processing unit being configured to determine a status of the X-ray tube based on the filtration function; the processing unit being configured to determine, based on the filtration function, an absorption spectrum; and
an output interface configured to provide the status of the X-ray tube;
wherein the X-ray system controller is configured to control the X-ray system according to the predefined control scheme.
7. The X-ray system according to claim 6 , wherein the X-ray detector is configured to detect the X-ray radiation of the X-ray tube under the control scheme resulting in the plurality of spectrally different working-values.
8. The X-ray system according to claim 7 , wherein the X-ray system controller is configured to control the X-ray system in accordance with the control scheme, such that different X-ray tube voltages, which correspond to different X-ray tube voltages applied for detecting the reference-values, are subsequently applied for detecting the working-values.
9. The X-ray system according to claim 7 , wherein the X-ray detector comprises a plurality of X-ray detector layers, wherein the X-ray system controller is configured to control the X-ray system in accordance with the control scheme; wherein the X-ray detector layers comprise different effective responses, such that each X-ray detector layer provides a detector sub-signal representing one of the working-values.
10. The X-ray system according to claim 7 , wherein the X-ray detector comprises a photon counting detector with energy discrimination configured to detect individual X-ray photons, to estimate its photon energy, and to count these photons in respective energy bins, each of the bins representing an energy interval.
11. A non-transitory computer-readable medium having one or more executable instructions stored thereon, which when executed by a processor, cause the processor to perform a method for determining a status of an X-ray tube of an X-ray system, the method comprising:
providing a reference data set representing a plurality of spectrally different reference-values of a detected X-ray radiation of the X-ray tube under a predefined control scheme of the X-ray system;
providing a working data set representing a plurality of spectrally different working-values of the detected X-ray radiation of the X-ray tube under the predefined control scheme of the X-ray system, wherein an X-ray filtration, caused by the X-ray tube, is applied at an X-ray radiation path of the X-ray tube;
determining, based on the reference data set and the working data set, a filtration function for the X-ray radiation of the X-ray tube indicating the X-ray filtration;
determining an absorption spectrum based on the filtration function; and
determining the status of the X-ray tube based on the absorption spectrum and the filtration function.