Indirect detection of x-ray radiation

Abstract

The invention describes an X-ray emitter (10). The X-ray emitter (10) has an X-ray source (1) for emitting X-ray radiation (PR, NPR). Furthermore, the X-ray emitter comprises a housing-like shield (2), which is formed around the X-ray source (1), for shielding the area surrounding the X-ray source (1) from the X-ray radiation (R) and an opening (3) in the housing-like shield (2) for directed emission of the X-ray radiation (R). At least one sensor (5) for dose detection, which is arranged outside a radiation field of primary X-ray radiation (PR) from the X-ray source (1), is also part of the X-ray emitter (10). The X-ray emitter (10) also comprises an evaluation unit (6) designed to determine a dose of primary X-ray radiation (PR) and / or non-primary X-ray radiation (NPR) on the basis of the dose detection by the sensor (5). The invention also describes an X-ray imaging system (30). The invention additionally describes a method for detecting a dose of X-ray radiation.

Description

[0001] 202414213

[0002] 1

[0003] Description

[0004] Indirect detection of X-rays

[0005] The invention relates to an X-ray source. The invention also relates to an X-ray imaging system. Furthermore, the invention relates to a method for detecting an X-ray dose. The invention also relates to a computer program product. Finally, the invention relates to a computer-readable storage medium.

[0006] Knowing the output dose of an X-ray source is crucial for assessing the patient dose or for detecting deviations in the tube's output that might indicate damage or the end of its service life. For this purpose, X-ray systems, such as interventional C-arm angiography systems, are often equipped with dose chambers or X-ray measurement chambers that measure the kerma (kerma being an acronym for "kinetic energy released per unit mass," referring to the kinetic energy transferred by X-rays to a unit mass of matter) of air or the dose-area product in the X-ray field near the tube. These dose chambers are not only expensive, but they also interact with the X-ray field by scattering X-rays. This can lead to potentially harmful X-ray leakage from the entire X-ray system.

[0007] The dose rate of X-ray sources can also be calculated. However, this approach is subject to uncertainties due to the imperfections of the X-ray sources and aging effects, especially of the anode.

[0008] Furthermore, in X-ray systems such as C-arm angiography systems, non-primary radiation occurs as extrafocal radiation emitted by the X-ray source due to internal scattering or electron backscattering, and as primary radiation scattered by additional hardware in the X-ray area, such as X-ray filters, collimators, tube housings, or dose chambers. Non-primary radiation leads to reduced contrast and resolution in 2D X-ray imaging, as well as reduced contrast, reduced resolution, artifacts, and uncertainties regarding the measured Hounsfield unit values ​​in 3D cone-beam computed tomography. Characterizing non-primary radiation is crucial for improving image quality.

[0009] 2

[0010] The task is therefore to specify a device and a method for detecting X-rays and, in particular, the dose of X-rays generated during the production of X-rays by an X-ray source and / or by the influence of other hardware located in the radiation field of the X-rays, which operate or are feasible with reduced resource expenditure and / or improved efficiency compared to conventional devices and methods.

[0011] This problem is solved by an X-ray emitter according to claim 1, an X-ray imaging system according to claim 12, a method for detecting an X-ray dose according to claim 13, a computer program product according to claim 14 and a computer-readable memory according to claim 15.

[0012] The X-ray emitter according to the invention comprises an X-ray source for emitting X-rays. Such an X-ray source, also known as an X-ray tube, has a cathode for emitting electrons and an anode onto which the emitted electrons strike. In the latter process, X-rays are generated as bremsstrahlung. The X-ray emitter according to the invention also includes a housing-like shield formed around the X-ray source to shield the area surrounding the X-ray source from the X-rays. In this context, "housing-like" means that the shield surrounds the X-ray source like a housing. Such a housing-like shield comprises an absorption material for absorbing X-rays. Lead is particularly well suited for this purpose and is preferably the material comprised of the housing-like shield.The X-ray emitter according to the invention also includes an opening in the housing-like shield for the directed emission of the X-rays. This opening comprises a window which is transparent to X-rays and allows directed emission of the X-rays at this point.

[0013] Furthermore, the X-ray source according to the invention comprises at least one sensor for dose detection, which is arranged outside the radiation field of primary X-rays from the X-ray source, i.e., in the radiation field of non-primary X-rays. Primary X-rays are understood to be X-rays that, after their generation and emission, have not been scattered and form an X-ray beam for illuminating an object under investigation. This is to be distinguished from non-primary X-rays, which arise from additional scattering or conversion effects acting on the primary X-rays and are associated with scattering or deflection of the primary X-rays. Such effects, which cause non-primary X-rays, 202414213

[0014] 3. In addition to extrafocal emission due to internal scattering, electron backscattering and scattering of primary X-rays by additional components in the radiation field, in particular collimators, X-ray tube housings or dose chambers or dose measurement chambers, can also occur.

[0015] Furthermore, the X-ray source according to the invention has an evaluation unit which is configured to determine a dose of primary X-rays and / or non-primary X-rays based on the dose detection of the sensor. Advantageously, dose detection takes place outside the radiation field of the primary X-rays, so that the primary X-rays are not affected or influenced by the measurement or detection. As will be explained in detail later, such dose detection can be used to compensate for image artifacts, to improve image contrast and resolution, and to improve the precision in determining attenuation values ​​in image data, particularly in 3D cone-beam computed tomography.

[0016] Knowledge of the total dose can be used to determine the patient dose or to identify drift effects related to the X-ray tube's power output, which indicate a malfunction or the end of the tube's service life. If the aforementioned sensors are used outside the radiation field of the primary X-rays relevant for imaging, they can serve as an alternative to dose chambers, which are relatively resource-intensive, and the scattering effects mentioned above can be reduced. Furthermore, the scattering effects to be detected can cause an X-ray leak, which can lead to harmful radiation exposure. Such an X-ray leak can therefore be avoided by the arrangement according to the invention.In this case, the observation is advantageously used to allow the dose of radiation detected outside the radiation field of the primary X-ray radiation to be related to the total dose as well as to the dose of the X-ray radiation emitted as primary X-ray radiation, and on this basis conclusions can be drawn regarding the extent of undesirable effects in X-ray emission.

[0017] The X-ray imaging system according to the invention comprises an X-ray source according to the invention for generating and emitting X-rays and an X-ray detector for detecting the X-rays. Part of the X-ray imaging system according to the invention is also a control device for controlling the X-ray source and the X-ray detector for performing an X-ray image of an object under investigation. The 202414213

[0018] 4. The X-ray imaging system according to the invention shares the advantages of the X-ray source according to the invention.

[0019] In the inventive method for detecting an X-ray dose, X-rays are emitted by an X-ray source.

[0020] The area around the X-ray source is shielded from the X-ray radiation by a housing-like shield formed around the X-ray source.

[0021] Furthermore, the X-rays are emitted in a directed manner through an opening in the housing-like shielding.

[0022] Subsequently, an X-ray dose is detected by at least one sensor, which is arranged outside the radiation field of a primary X-ray emission from the X-ray source. The at least one sensor can comprise exactly one sensor or a plurality of sensors. The at least one sensor preferably comprises a sensor of the following types, or, if a plurality of sensors are used for detecting the X-ray dose, preferably several sensors of one of the following types, or alternatively, a combination of sensors of the following different types:

[0023] - an acoustic sensor, preferably on the side of a component facing away from the X-ray source,

[0024] - a photoacoustic sensor based on the photoacoustic effect,

[0025] - an X-ray detector, preferably on the side of a component facing the X-ray source,

[0026] - a dose-sensitive sensor, preferably on the side of a component facing the X-ray source.

[0027] The term X-ray detector is intended to encompass, in particular, an energy-integrating detector or a photon-counting detector. With a dose-sensitive sensor, X-ray doses can be determined with exceptional accuracy. It should be explicitly mentioned again here that sensors of different types can be combined, arranged side-by-side, and / or positioned differently to measure X-ray radiation. The advantage of simultaneously measuring X-ray radiation using different methods is that the robustness of the measurement and dose determination is improved compared to using only a single type of sensor. 202414213

[0028] 5

[0029] Based on the sensor's dose detection, a dose of primary X-ray radiation and / or non-primary X-ray radiation is determined. The method according to the invention shares the advantages of the X-ray source according to the invention.

[0030] A large proportion of the aforementioned components of the X-ray tube and the X-ray imaging system according to the invention can be implemented wholly or partially as software modules in a processor of a corresponding computing system, e.g., by a control unit of an X-ray imaging system or X-ray tube, or by a computer used to control such a system. A largely software-based implementation has the advantage that even previously used computing systems can be easily retrofitted by means of a software update to operate in the manner of the invention.

[0031] Therefore, the problem is also solved by a corresponding computer program product with a computer program that can be directly loaded into a computer system, containing program sections to perform the step of determining a dose of primary X-ray radiation and / or non-primary X-ray radiation based on the dose detection of the sensor in the inventive method for detecting an X-ray dose. In addition to the computer program, such a computer program product may optionally include additional components such as documentation and / or additional components, including hardware components such as hardware keys (dongles, etc.) for using the software.

[0032] For transport to and / or storage on or in the computer system, a computer-readable medium, such as a memory stick, a hard drive, or other portable or permanently installed data carrier, can be used, on which the program sections of the computer program that can be read and executed by a computer system are stored. The computer system may, for example, have one or more cooperating microprocessors or similar components for this purpose.

[0033] The dependent claims and the following description each contain particularly advantageous embodiments and further developments of the invention. In particular, the claims of one claim category may also be further developed analogously to the dependent claims of another claim category. Furthermore, the invention may include the following: 202414213

[0034] Six different features of different embodiments and claims can also be combined to form new embodiments.

[0035] In a preferred embodiment of the X-ray tube according to the invention, the sensor is configured and arranged such that a total dose of the emitted X-rays can be determined based on indirect dose detection. The total dose is determined based on the sensor readings and additional prior information. Advantageously, the sensor can be arranged outside the radiation field of the primary X-rays and thus does not affect the portion of the X-rays used for imaging.

[0036] Preferably, the sensor is arranged on the housing-like shield. If the sensor is arranged on the outside of the housing-like shield, an interaction of the non-primary X-ray radiation with the shield can be detected by the sensor and used to determine the total dose.

[0037] In one embodiment of the X-ray tube according to the invention, the at least one sensor comprises an acoustic sensor for measuring a measured value of acoustic pressure waves. These pressure waves are caused by the X-rays emitted from the X-ray source in a hardware component of the X-ray tube, preferably in the housing-like shielding, based on the photoacoustic effect. Furthermore, the evaluation unit is configured to determine a total X-ray dose of the X-rays emitted by the X-ray source based on the measured value of the acoustic pressure waves. In this embodiment, the X-rays initially generate heat upon absorption by the shielding. This heat is converted by the hardware component, preferably the housing-like shielding, into acoustic pressure waves, which are detected by the sensor.The total dose of X-ray radiation emitted by the X-ray source is then determined based on the acoustic pressure waves.

[0038] To determine the total dose, the evaluation unit is preferably configured to calculate the X-ray dose or the total dose based on the measured value of the acoustic pressure waves using an artificial intelligence-based algorithm. Advantageously, the algorithm can be adapted to specific boundary conditions of the X-ray source through a training process. In the case of so-called supervised training, labeled training data can be used in the training process. This data relates measured values ​​of acoustic pressure waves to an X-ray dose or total dose measured by a previously calibrated measurement setup or a reliable measurement method.

[0039] 7. During training, so-called artificial neural networks are preferably adapted to the labeled training data. For this purpose, connections between artificial neurons are generated or deleted, and in particular, the weights of input signals to artificial neurons, as well as thresholds that must be exceeded during processing, especially summation, of input signals to generate an output signal, are adjusted to the values ​​of the labeled training data. Further possibilities for adapting such an artificial neural network include adding or deleting artificial neurons and modifying activation functions, propagation functions, or output functions.An activation function of an artificial neuron ensures that the neuron only outputs a signal when the sum of all its input signals exceeds a threshold. The propagation function determines how input data or signals are processed. A simple propagation function comprises a weighted sum of all input signals. The output function of an artificial neuron determines the value of its output signal. In the simplest case, the output function is simply the identity function, so that the output corresponds to the activity level of the artificial neuron.

[0040] Preferably, the evaluation unit is configured to determine the X-ray dose, in particular the total dose, based on a known relationship between the X-ray dose and the measured value of the acoustic pressure waves. In this variant, a relationship between the total dose and the measured value of the acoustic pressure waves is determined experimentally or computationally and applied to determine the dose.

[0041] The relationship preferably includes one of the following types:

[0042] - a relationship determined by calibrating the X-ray tube,

[0043] - a lookup table that represents the relationship through numerical data,

[0044] - a function determined by fitting a parameterized function, which represents the relation.

[0045] During the calibration of an X-ray source, a relationship is determined between the measured amplitude and / or frequency of the acoustic waves and the total dose of the X-ray radiation emitted by the X-ray source. The total dose is measured and determined using a conventional measuring method or instrument, in particular a dose chamber or dose measurement chamber. Advantageously, this relationship only needs to be determined once.

[0046] 8 can be determined, then information about the X-ray dose emitted by the X-ray source can be obtained without affecting the radiation field of the primary radiation.

[0047] The determined calibration data can be stored in the form of a table or a parameterized function and used during operation of the X-ray tube to determine the total dose of the X-ray radiation emitted by the X-ray tube. If a parameterized function is used to represent the relationship, the amount of data stored can be minimized compared to a stored table. The parameterized function can also be used to interpolate a stored table if intermediate values ​​between stored table values ​​are required. Therefore, the two methods can also be advantageously combined.

[0048] It is particularly advantageous if the housing-like shielding of the X-ray emitter according to the invention comprises a material that converts X-rays into thermal energy with exceptional efficiency. Such a material preferably comprises the element lead, which on the one hand absorbs X-rays exceptionally well and on the other hand generates a great deal of thermal energy.

[0049] Particularly preferably, the at least one sensor of the X-ray source according to the invention is arranged at the opening in the housing-like shield. "At the opening" means that the sensor is not located within the radiation field of the primary X-ray radiation, but outside of it, yet as close as possible to it or directly at the opening. A measurement directly at the opening is most advantageous because the least attenuation from other components in the X-ray source is to be expected there.

[0050] The area around the opening exhibits the lowest self-absorption due to internal components of the tube. This means that the radiation arriving here is most similar to the actual primary radiation.

[0051] Arranging multiple sensors around the opening is also advantageous because it allows for the determination of the spatial distribution of the X-ray dose emitted by the X-ray source. This would allow, for example, the imaging of the so-called heel effect. The heel effect refers to a variation in the intensity of the X-ray radiation depending on 202414213

[0052] 9 from the emission direction along the anode-cathode axis of an X-ray source. In principle, however, a single sensor can be used to determine an X-ray dose with sufficient accuracy.

[0053] The X-ray emitter according to the invention can also be designed such that the at least one sensor comprises at least one separate sensor, preferably an acoustic sensor, which is arranged at a predetermined distance from the housing-like shielding outside a radiation field of the primary X-ray radiation, for detecting non-primary X-ray radiation, and the evaluation unit is configured to determine a value of an X-ray dose of the non-primary X-ray radiation at the predetermined distance from the housing-like shielding on the basis of the detected non-primary X-ray radiation.

[0054] This variant aims to determine the non-primary X-ray radiation already generated at a predetermined distance. The non-primary X-ray radiation can increase significantly with increasing distance due to scattering effects from separate components, particularly X-ray filters, collimators, dose chambers, and housings.

[0055] In a preferred embodiment, the evaluation unit is also preferably configured to indirectly determine the predominant dose of the primary radiation at a predetermined distance, based on knowledge of the total dose (i.e., the total dose of the X-rays emitted by the X-ray source) and the determined dose of the non-primary X-rays. In this embodiment, knowledge of the non-primary X-rays, or their dose, and the total dose is used to determine the dose of the primary X-rays at a specific distance from the X-ray source.

[0056] The X-ray source according to the invention preferably comprises a component which is positioned at a predetermined distance in a radiation field of the non-primary X-rays, on which the separate sensor is arranged. Advantageously, because the separate sensor is arranged on the component, it can be positioned at a predetermined distance, namely the distance of the component, from the opening of the X-ray source, without the need for additional elements for precise positioning.

[0057] In a preferred variant, the evaluation unit is configured to determine a spatial distribution of the X-ray dose based on the X-ray dose of the non-primary X-ray radiation 202414213

[0058] 10. The non-primary X-ray radiation is to be determined. For this purpose, the X-ray dose is measured at different positions and at different distances from the opening of the X-ray tube, and a spatial distribution is determined by interpolation or by adapting a parameterized model to the measured values. The term "spatial distribution" includes, in particular, a distribution at different distances from the X-ray tube or a distribution on a circumferential surface around the X-ray tube.

[0059] In a particularly practical embodiment of the X-ray source according to the invention, the at least one component comprises a plurality of components arranged one behind the other in a radiation field of the primary X-ray source, and the at least one separate sensor comprises a plurality of separate sensors arranged on several of the plurality of components for detecting the non-primary X-rays occurring at a respective component. Furthermore, the evaluation unit is configured to determine a respective value of the non-primary X-ray dose for each component based on the detected non-primary X-rays and to determine a spatial distribution of the non-primary X-ray dose based on the respective values ​​of the non-primary X-ray dose.The spatial distribution of the sensors makes it possible to determine the spatial distribution of non-primary X-ray radiation.

[0060] The evaluation unit is preferably configured to determine the contribution of each component to the generation of non-primary X-ray radiation by calculating the difference between measured values ​​from separate sensors positioned on different, preferably adjacent, components. Advantageously, the scattering properties of individual components, especially filters, can be determined based on this difference calculation.

[0061] In one embodiment of the X-ray emitter according to the invention, the at least one component comprises a component of one of the following types:

[0062] - an X-ray filter,

[0063] - a collimator,

[0064] - an X-ray source housing,

[0065] - a dose chamber or dose measurement chamber.

[0066] The components mentioned can convert primary X-rays into non-primary X-rays. The arrangement according to the invention allows the contributions of individual grains to be... 202414213

[0067] Eleven components for generating non-primary X-ray radiation can be determined. By arranging multiple separate sensors per component, the spatial distribution of the non-primary X-ray radiation can be determined even more precisely.

[0068] In variants with a separate component or sensor(s) arranged separately from the housing-like shielding, the at least one separate sensor has at least one of the following sensor types:

[0069] - an acoustic sensor, preferably on the side of a component facing away from the X-ray source,

[0070] - an X-ray detector, preferably on the side of a component facing the X-ray source,

[0071] - a dose-sensitive sensor, preferably on the side of a component facing the X-ray source.

[0072] As already mentioned in connection with the method according to the invention, the term X-ray detector is intended to include, in particular, an energy-integrating detector or a photon-counting detector. X-ray doses can be determined with particularly high quantitative accuracy using a dose-sensitive sensor. It should be expressly mentioned here that sensors of different types can be combined with one another, arranged side by side, and / or used in different positions to measure non-primary X-ray radiation. Advantageously, the robustness of the measurement and dose determination is improved by the different types of simultaneous measurement of the X-ray radiation using different methods, compared to the use of sensors of only one type.

[0073] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The figures show:

[0074] FIG 1 shows a schematic representation of an X-ray source according to an embodiment of the invention, wherein only the primary X-ray radiation is shown.

[0075] FIG 2 is a schematic representation of an X-ray tube according to an embodiment of the invention, wherein the primary X-ray radiation and the secondary X-ray radiation are shown, 202414213

[0076] FIG 3 shows a schematic representation of an X-ray source with sensors arranged on the X-ray source side according to an embodiment of the invention, wherein the primary X-ray radiation and the secondary X-ray radiation are shown.

[0077] FIG 4 shows a schematic representation of an X-ray emitter with sensors arranged facing away from the X-ray source according to an embodiment of the invention, wherein the primary X-ray radiation and the secondary X-ray radiation are shown.

[0078] FIG 5 shows a sectional view of an X-ray tube according to an embodiment of the invention.

[0079] FIG 6 shows a view from below towards the opening of an X-ray tube according to an embodiment of the invention,

[0080] FIG 7 is a flowchart illustrating the method for detecting an X-ray dose according to an embodiment of the invention.

[0081] FIG 8 shows a schematic representation of an X-ray tube according to an embodiment of the invention,

[0082] FIG 9 shows a schematic representation of an X-ray imaging system according to an embodiment of the invention.

[0083] FIG. 1 shows a schematic representation of an X-ray emitter 10 for the emission of X-rays R according to an embodiment of the invention, in which only the primary X-rays PR are shown. The primary X-rays PR are emitted from an aperture 3 of an X-ray source 1, which is shown at the bottom of FIG. 1. The primary X-rays PR are passed through three components 7, in this case X-ray filters. The three components 7 are arranged at different distances from the aperture 3 of the X-ray source 1 in the radiation field of the primary X-rays PR and the non-primary X-rays (not shown).

[0084] FIG 2 shows a schematic representation of an X-ray source 10 according to an embodiment of the invention, wherein the primary X-ray radiation PR and additionally also the secondary X-ray radiation or non-primary X-ray radiation NPR are shown 202414213

[0085] 13 are. The non-primary X-ray radiation NPR surrounds the radiation cone of the primary X-ray radiation PR and also passes through the components located in the radiation field of the primary and non-primary X-ray radiation 7.

[0086] Figure 3 illustrates a schematic representation of an X-ray source 10 with sensors 5a arranged on the X-ray source side according to an embodiment of the invention, wherein the primary X-ray radiation PR and the non-primary X-ray radiation NPR are shown. The sensors 5a arranged on the X-ray source side are positioned in the radiation field of the non-primary X-ray radiation NPR, so that a location-dependent radiation dose detection of the non-primary X-ray radiation NPR can be carried out.

[0087] Figure 4 shows a schematic representation of an X-ray source 10 with sensors 5b arranged facing away from the X-ray source 1, according to an embodiment of the invention, wherein the primary X-ray radiation PR and the non-primary X-ray radiation NPR are indicated. The sensors 5b are designed as photoacoustic sensors and can perform a location-dependent radiation dose detection of the non-primary X-ray radiation NPR based on sound waves emitted by the components 7.

[0088] Figure 5 shows a sectional view of an X-ray source 10 according to an embodiment of the invention. The X-ray source 10 comprises an X-ray source 1, also referred to as an X-ray tube. The X-ray source 1 includes a cathode 1a for the emission of electrons and an anode 1b, on which the emitted electrons strike and generate X-rays in the form of bremsstrahlung and characteristic X-rays. The X-ray source 1 is surrounded by a glass tube 1c, from which the term "X-ray tube" is derived. Primary X-rays PR are emitted from the anode 1b through a window 1d of a housing-like shield 2 in the direction of an X-ray detector (not shown). In addition to the primary X-rays PR, the X-ray source 1 also emits non-primary X-rays NPR in various directions, which differ from the direction in which the primary X-rays PR are emitted.The non-primary X-ray radiation (NPR) is absorbed by the housing-like shield 2, generating heat that partially leads to sound waves. These sound waves are detected by acoustic sensors 5b located on the housing-like shield 2. In this embodiment, the total dose of X-ray radiation is thus measured indirectly by sensors 5b arranged on the housing or the housing-like shield 2. 202414213.

[0089] 14

[0090] FIG. 6 shows a view looking towards the opening 3 of an X-ray tube 10 according to an embodiment of the invention. Four photoacoustic sensors 5b are distributed around the opening 3 of the housing-like shield 2 of the X-ray tube 10.

[0091] FIG 7 shows a flowchart 700 illustrating a method for detecting a primary X-ray dose PR according to an embodiment of the invention.

[0092] In step 1.1, X-rays R are emitted by an X-ray source 1. The X-rays are split into primary X-rays PR and non-primary X-rays NPR by components 7 arranged in the radiation field.

[0093] In step 1.11, the area around the X-ray source 1 is shielded from the X-ray radiation R by a housing-like shield 2 formed around the X-ray source 1.

[0094] In step 1.111, the X-ray radiation R is emitted in a directed manner through an opening 3 in the housing-like shielding 2.

[0095] In step 1.1V, non-primary X-ray radiation NPR is measured by sensors 5, which are located outside a radiation field of primary X-ray radiation PR.

[0096] In step 1.V, a total dose of primary X-ray radiation PR is calculated based on the dose detection of sensors 5.

[0097] Figure 8 shows a schematic representation of an X-ray emitter 10 according to an embodiment of the invention. The X-ray emitter 10 comprises an X-ray source 1 for the emission of X-rays PR, NPR. A housing-like shield 2 is formed around the X-ray source 1 to shield the surroundings of the X-ray source 1 from the X-rays R. An opening 3 for the directed emission of the X-rays R is located in the housing-like shield 2.

[0098] Furthermore, two sensors 5 are arranged on the housing-like shielding, which can be used for dose detection. Part of the X-ray tube 10 is also an evaluation unit 6, 202414213

[0099] 15, which is configured to determine a dose of primary X-ray radiation PR and / or non-primary X-ray radiation NPR based on the dose detection of sensor 5. The evaluation unit 6 receives measurement data MD from the sensors, which it uses to determine an X-ray dose emitted by the X-ray source 1.

[0100] FIG 9 illustrates a schematic representation of an X-ray imaging system 30 according to an embodiment of the invention.

[0101] The X-ray imaging system 30 comprises an X-ray source 10 according to the invention, as illustrated in FIG. 8. The X-ray imaging system 30 also includes an X-ray detector 31 for detecting the X-rays emitted by the X-ray source 10. Furthermore, the X-ray imaging system 30 has a control unit 32 for controlling the X-ray source 10 and the X-ray detector 31 using control data SD to perform X-ray imaging of an object under investigation, wherein raw data RD are received by the control unit 32 from the X-ray detector 31 and measurement data MD are received by the X-ray source 10, representing the dose of the X-rays emitted by the X-ray source 10.

[0102] Finally, it should be noted once again that the methods and devices described above are merely preferred embodiments of the invention and that the invention can be varied by a person skilled in the art without departing from the scope of the invention, insofar as it is defined by the claims. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, the term "unit" does not preclude the possibility that it consists of several components, which may also be spatially distributed. Regardless of the grammatical gender of a particular term, persons of male, female, or other gender identities are included.

Claims

202414213 16 Patent claims 1. X-ray source (10), comprising: - an X-ray source (1) for the emission of X-ray radiation (R), - a housing-like shield (2) formed around the X-ray source (1) to shield the area around the X-ray source (1) from the X-ray radiation (R), - an opening (3) in the housing-like shielding (2) for the directed emission of the X-ray radiation (R), - at least one sensor (5) for dose detection, which is arranged outside a radiation field of a primary X-ray radiation (PR) of the X-ray source (1), - an evaluation unit (6) which is set up to determine a dose of primary X-ray radiation (PR) and / or non-primary X-ray radiation (NPR) on the basis of the dose detection of the sensor (5).

2. X-ray emitter according to claim 1, wherein the sensor (5) is configured and arranged such that a total dose of the emitted X-ray radiation (R) can be determined on the basis of an indirect dose detection.

3. X-ray emitter according to claim 1 or 2, wherein the sensor (5) is arranged on the housing-like shield (2).

4. X-ray tube according to one of the preceding claims, wherein - comprising at least one sensor (5) an acoustic sensor for measuring a measured value (MD) of acoustic pressure waves which are caused by the X-ray radiation (R) emitted by the X-ray source (1) in a hardware component of the X-ray emitter (10), preferably in the housing-like shielding (2), on the basis of the photoacoustic effect, - the evaluation unit (6) is set up to determine a total dose of the X-ray radiation (R) emitted by the X-ray source (1) on the basis of the measured value (MD) of the acoustic pressure waves.

5. X-ray emitter according to claim 4, wherein the evaluation unit (6) is configured to determine the total dose based on the measured value (MD) of the acoustic pressure waves by means of an algorithm based on artificial intelligence. 202414213 17 6. X-ray emitter according to claim 4 or 5, wherein the evaluation unit (6) is configured to determine the total dose on the basis of a previously known relationship between the total dose and the measured value (MD) of the acoustic pressure waves.

7. X-ray source according to claim 6, wherein the relation comprises one of the following types: - a relationship determined by calibrating the X-ray tube, - a lookup table that represents the relationship through numerical data, - a function determined by fitting a parameterized function, which represents the relation.

8. X-ray emitter according to one of the preceding claims, wherein the housing-like shielding (2) comprises a material which converts X-rays (R) into thermal energy particularly effectively.

9. X-ray emitter according to one of the preceding claims, wherein the at least one sensor (5) is arranged at the opening (3) in the housing-like shielding (2).

10. X-ray tube according to one of the preceding claims, wherein - the at least one sensor (5) comprises at least one separate sensor (5a), preferably an acoustic sensor, which is arranged at a predetermined distance from the housing-like shield (2) outside a radiation field of the primary radiation (PR), for detecting non-primary X-ray radiation (NPR), and - the evaluation unit (6) is set up to determine a value (W) of an X-ray dose of the non-primary X-ray radiation (NPR) at the predetermined distance to the housing-like shielding (2) on the basis of the detected non-primary X-ray radiation (NPR).

11. X-ray emitter according to claim 10, wherein the evaluation unit (6) is configured to determine, on the basis of the knowledge of the total dose of the X-ray radiation (R) emitted by the X-ray source (1) and on the basis of the determined X-ray dose of the non-primary X-ray radiation (NPR), a predominant X-ray dose of the primary X-ray radiation at the predetermined distance.

12. X-ray imaging system (30), comprising: - an X-ray tube (10) according to one of the preceding claims, - an X-ray detector (31), 202414213 18 - a control device (32) for controlling the X-ray emitter (10, 20) and the X-ray detector (31) for performing X-ray imaging of an object under investigation.

13. Method for detecting X-ray radiation (PR), comprising the steps: - Emission of X-ray radiation (PR, NPR) by an X-ray source (1), - Shielding the area around the X-ray source (1) from the X-ray radiation (R) by means of a housing-like shield (2) formed around the X-ray source (1), - Directed emission of the X-ray radiation (R) through an opening (3) in the housing-like shielding (2), - Detecting an X-ray dose by means of at least one sensor (5) which is located outside a radiation field of primary X-ray radiation (PR), - Determining a dose of primary X-ray radiation (PR) and / or non-primary X-ray radiation (NPR) based on the dose detection of the sensor (5).

14. Computer program product comprising instructions which, when the program is executed by a computer, cause it to perform the step of determining a dose of primary X-ray radiation (PR) and / or non-primary X-ray radiation (NPR) based on the dose detection of the sensor (5) of the method according to claim 13.

15. Computer-readable storage medium comprising instructions which, when executed by a computer, cause it to perform the step of determining a dose of primary X-ray radiation (PR) and / or non-primary X-ray radiation (NPR) based on the dose detection of the sensor (5) of the method according to claim 13.

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