Computer-implemented method for operating x-ray device, x-ray device, computer program and electronically readable data carrier

Abstract

The invention relates to a computer-implemented method for operating an X-ray device (2) in an imaging process on an examination object, in which an image data set covering a reconstruction region is reconstructed from a projection image of the examination object (1) in a reconstruction process, the projection image is recorded in different projection geometries of an X-ray emitter (4) of the X-ray device (2) relative to an X-ray detector (3), extension information describing an extension (10) of the examination object (1) in at least one spatial direction (17) is determined from measurement data of at least one measuring device (6), and parameterizing the reconstruction process according to the extension information.

Description

Technical Field

[0001] The invention relates to a computer-implemented method for operating an X-ray device in an imaging process at an object under examination, wherein in a reconstruction process an image data set covering a reconstruction region is reconstructed from projection images of the object under examination, the projection images being recorded in different projection geometries of an X-ray radiator relative to an X-ray detector of the X-ray device. The invention also relates to an X-ray device, a computer program and an electronically readable data carrier. Background Art

[0002] X-ray devices have been established in the medical field in the prior art. Tomographic fusion as a sub-area of ​​X-ray imaging is intended to obtain three-dimensional information at a low cost by recording projection images from different projection geometries, from which image data sets can be reconstructed, for example, from one or more tomographic images (section images) in the recording area of ​​the examination object. For this purpose, it can be proposed, for example, to move the X-ray radiator relative to the X-ray detector and, for example, place it in different angular positions, so that a specific recording trajectory of the X-ray radiator is achieved, while the X-ray detector (at least substantially) remains fixed in position. This is used, for example, in mammography. It is also known that the X-ray radiator and the X-ray detector move in parallel in the recording direction, so that different radiation directions through the corresponding voxels to be absorbed occur due to the cone beam geometry of the X-ray radiator and provide depth information. This technology can be used, for example, in X-ray radiography and / or fluoroscopy devices.

[0003] The use of such tomosynthesis for recording an enlarged field of view when reconstructing specific layers in the object under examination is known, whereas in conventional tomosynthesis, for example in mammography, a plurality of slice images or section images, for example through a female breast, are usually calculated, which are in particular at least substantially arranged one after the other or "stacked" in the direction of the central beam of the intermediate projection geometry. This direction of the central beam can then also be referred to as the slice direction.

[0004] For diagnosticians, for example diagnostic radiologists, usually only the slice images that image the examination object are important, but on the other hand, they also want to see the examination object in its entirety. In other words, when reconstructing a layer in a slice direction, for example, the layer should cover the entire depth of the displayed examination object. For this purpose, it is known, for example, that the extension area to be reconstructed in the slice direction is fixedly predetermined or selected according to user input depending on the application, for example, according to the recording protocol. This is not accurate and is not compatible with the current examination object, for example, a patient.

[0005] It has also been proposed in the prior art to estimate the reconstruction region to be reconstructed based on the image, for example within the scope of a first rough reconstruction. However, this process is quite complex and requires additional calculations, in particular additional reconstructions and reliable segmentation methods or detection methods. Summary of the invention

[0006] The invention is therefore based on the object of ascertaining and using extended information of an individual examination subject in a simple, realizable and reliable manner for consideration in the reconstruction.

[0007] According to the invention, this object is achieved by a computer-implemented method, an X-ray device, a computer program and an electronically readable data carrier according to the invention. Advantageous developments are disclosed herein.

[0008] In a method of the type mentioned at the outset, it is provided according to the invention that

[0009] - determining extension information describing the extension of the examination object in at least one spatial direction from the measurement data of at least one measuring device, and

[0010] -Parameterize the reconstruction process based on the extension information.

[0011] The projection images are preferably recorded in a cone beam geometry in order to be able to obtain different beam courses in a simplified manner when at least the X-ray radiator is moved. The extension information is determined in the coordinate system of the X-ray device, in which the reconstruction is also performed. This indicates the boundaries of the examination object in at least one spatial direction. If the spatial direction is, for example, the direction of the central beam of the X-ray device in the projection geometry, in particular in at least one central projection geometry along the recording trajectory of the X-ray radiator, the boundaries of the examination object on the X-ray radiator side ("upper end") and on the X-ray detector side ("lower end") are known from the extension information.

[0012] According to the present invention, it is also proposed that the extension information is not obtained from preset, estimated user input or image data, such as projection images and / or reconstruction results, but is obtained with the help of an additional measuring device independent of the recording device (including X-ray radiator and X-ray detector), which preferably automatically detects and provides measurement data, and then the extension information can be automatically obtained and automatically used.

[0013] According to the invention, it is also proposed that the boundaries of the examination object in at least one (interesting) spatial direction are determined particularly preferably fully automatically with the aid of the measuring device and used for parameterization of the reconstruction, i.e., when selecting at least one reconstruction parameter. In this way, extension information describing the extension of the examination object, in particular a patient, in a spatial direction in the coordinate system of the x-ray device can be determined reliably, precisely, but in a simple manner and method, in particular without complex image evaluation. It should be noted here that it is not mandatory to derive the two boundaries from the measurement data of the measuring device, but it is also possible to determine a boundary in another way, for example by placing the examination object on a component of the x-ray device. If the determination of the extension information is carried out fully automatically, manual (correction) steps can be omitted.

[0014] In order to be able to determine the extension information in the coordinate system of the X-ray device, the measuring device is preferably aligned or alignable with the coordinate system of the X-ray device. For this purpose, the measuring device can be positioned in a defined manner on the X-ray device or at least relative to the X-ray device.

[0015] Particularly expediently, the invention can be used within the scope of tomosynthesis, so that it can be provided that the imaging process is a tomosynthesis process and / or that different projection geometries are produced either by a parallel displacement of the X-ray emitter and the X-ray detector or by a movement of the X-ray emitter relative to the fixed X-ray detector. The last-mentioned variants can in particular include a movement of the X-ray emitter along a circular path or a movement of the X-ray emitter along a rectilinear recording trajectory with tilting and / or adaptation of the collimation of the X-ray emitter. In the case of a rectilinear recording trajectory, as mentioned, different radiation directions through the voxel of interest are generated due to the cone beam geometry used (often also called fan beam geometry).

[0016] Here, the X-ray device can be an X-ray radiography and / or fluoroscopy device. In the X-ray device, the tomosynthesis process can be implemented in a manner that the X-ray radiator and the X-ray detector are moved parallel to each other in the recording direction, wherein a cone beam geometry or a fan beam geometry is used. However, X-ray radiography and / or fluoroscopy devices have also been proposed, in which other degrees of freedom of movement of the X-ray radiography and / or fluoroscopy device are feasible, so that more complex recording geometries can also be implemented in order to perform tomosynthesis. In particular, it is also conceivable in principle to use a C-arm device as an X-ray device within the scope of the present invention, in which the recording trajectory can be achieved by the rotation of the C-arm. However, it is preferred to use it in a simply designed X-ray radiography and / or fluoroscopy device, which is extended with a purposeful and comfortable tomosynthesis function. According to the present invention, this can also be improved in a simple manner and method with respect to obtaining extended information.

[0017] However, it can also be provided that the X-ray device is a mammography device. In the case of a mammography device, the mammography device can have an object holder for the breast to be accommodated, which is delimited, for example, on one side directly by the X-ray detector (or its cover), so that the boundaries there are known in the system. On the other hand, an adjustable compression plate can be provided in the compression device, the position of which can be detected via a measuring device. In order to determine the extension in other spatial directions or then when no compression plate is used, other measuring devices, for example one of the measuring devices described below, can be used particularly advantageously.

[0018] In a particularly advantageous development of the invention, it can be provided that at least one distance sensor and / or at least one three-dimensional measuring camera is used as the measuring device. The distance sensor can be, for example, a radar sensor. However, a three-dimensional measuring camera (3D camera) is particularly preferred, wherein different specific designs can be used within the scope of the invention, as they are known in principle in the prior art. Thus, for example, a terahertz camera and / or a TOF camera (time of flight camera) and / or a stereo camera can be used as a three-dimensional measuring camera (3D camera). The use of a camera that also provides optical image information has the advantage that already known image processing algorithms can be used in order to detect, for example, the inspection object.

[0019] In general, it can be said that the measurement data can be evaluated particularly preferably to form a model which at least partially describes the examination object, in particular the patient, in particular the surface of the patient. At least one boundary of the examination object in at least one spatial direction can then be derived from the model. When creating such a model, it is also expedient to take into account at least one prior knowledge information, for example provided by an information system (such as a radiology information system), for example prior knowledge information about the height and / or weight and / or sex and / or orientation of the examination object. This can be achieved, for example, by selecting a suitable starting point for creating the model.

[0020] In particular, if the measuring device or one of the at least one measuring device is primarily intended to determine a specific limit, such as an "upper limit", it can be provided that at least one of the at least one distance sensor and / or at least one of the at least one camera is fastened to the X-ray radiator or to a component of the X-ray device that is fixedly connected to the X-ray radiator, in particular to the collimator device. The device at the X-ray radiator or adjacent to the X-ray radiator in a fixed spatial relationship allows the determination of the distance (source-object distance, SOD) between the X-ray radiator and a limit of the examination object facing the X-ray radiator in a particularly simple manner. For example, the measuring device can detect the distance to the irradiation area of ​​the central beam in a targeted manner. For example, it is conceivable to fasten the distance sensor and / or the 3D camera to the collimator device.

[0021] However, in a preferred embodiment, it can also be provided that, in addition or as an alternative, a plurality of distance sensors and / or cameras arranged at different positions are used, the measurement data of which are evaluated at least in the spatial direction in order to form a model describing the boundaries of the object under examination. Thus, for example, measuring devices, in particular three-dimensional measuring cameras, can be used, which are distributed in particular at the X-ray device and / or in the space in which the X-ray device is arranged in such a way that the entire (visible or visible) surface of the object under examination can be measured, so that a corresponding, as complete as possible three-dimensional model of the object under examination can also be determined. Corresponding technologies for three-dimensionally measuring objects and for generating corresponding models, in particular, as mentioned, taking into account prior knowledge information, are in principle known in the prior art and can also be used advantageously within the scope of the present invention.

[0022] It can be proposed that the extended information is obtained by using user input. In principle, it is conceivable, for example, to also obtain the a priori knowledge information mentioned via user input. However, it is also conceivable that the following embodiments, in which the user input includes at least a part of the measurement data. If at least one of the at least one measuring mechanism can be at least partially manually manipulated, this is particularly suitable for the purpose. For example, a tape measure can be provided to the user as at least one of the at least one measuring mechanism, which is provided for measuring the distance to the X-ray radiator and / or the X-ray detector. Such a tape measure as at least one of the at least one measuring mechanism can be provided, for example, at the X-ray radiator or a component of the X-ray device that is fixedly connected to the X-ray radiator, in particular at the collimator device, so that the distance to the side of the examination object facing the X-ray radiator can be manually measured and entered as user input. This is also conceivable in particular when an independent patient is used as the examination object. The input on the user side can usually be performed, for example, at the input device of the X-ray device, in particular at the so-called touch user interface (Touch-UI).

[0023] However, an automatic measuring device, in particular a three-dimensional measuring camera, is preferred over the use of a manually operated measuring device.

[0024] In a further development of the invention, as already indicated, it can be provided that, when the examination object is supported on a component of the X-ray device, a known position of a boundary of the component on the examination object side and / or a position detectable by means of at least one of the at least one measuring device is used as at least one boundary of the extension of the examination object in the spatial direction. As already mentioned, this is known in some imaging procedures, for example in mammography, when the breast to be recorded lies on the X-ray detector, and / or in other tomosynthesis examinations, in which the patient lies on and / or is arranged in a sitting position on an examination couch. In this case, a boundary of the examination object is known by the position of the corresponding component, which is known to the control device of the X-ray device. The component on which the examination object is arranged can be, for example, an examination couch (for example a patient table), an X-ray detector (or its cover) or the like.

[0025] Different variants are conceivable within the scope of the invention for the specific use of the extended information for the reconstruction process.

[0026] Thus, on the one hand, it can be provided that the reconstruction region is limited in the spatial direction to the area of ​​the examination object. For example, it can be achieved that the reconstruction is only carried out from the beginning in places where the examination object is also present, but the entire examination object is nevertheless covered. In general, the spatial direction can be a slice direction and / or for at least one projection geometry can be the direction of the central beam of the X-ray emitter. For example, when determining a slice image (sectional image) as a stack of slice images in a slice direction corresponding to the direction of the central beam at least in the central projection geometry, in other words in the transmission direction, the layers can be limited to layers that cover the examination object as accurately as possible. On the other hand, by completely covering the examination object, it is ensured that image data for the entire examination object are present in the image data set in the spatial direction.

[0027] However, it is particularly useful to use the extended information in so-called slit scanning techniques or other recording techniques, in which, in particular in X-ray radiography and / or fluoroscopy devices, the X-ray radiator and the X-ray detector are moved parallel to the examination object in order to record a larger area based on the current cone beam geometry while additionally obtaining 3D information.

[0028] Therefore, it can be proposed that during the imaging process, an image area enlarged relative to the detection area of ​​the X-ray device is recorded in a recording direction perpendicular to the spatial direction by the parallel operation of the X-ray radiator and the X-ray detector in the recording direction, and the reconstructed focal area is selected according to the extension information. Here, the image area can, for example, cover at least ten times the detection area. This is in line with the purpose when, for example, the head and torso should be completely recorded and / or the legs should be completely recorded for the purpose of checking the spine. For example, it is usually called a so-called body scan. It is known that at least one usually slightly thick layer is reconstructed from the projection image, which layer can, for example, contain a bone or bone arrangement of interest. Here, the selection of the focal depth is extremely important, whereby the interesting structure to be imaged of the inspection object, such as a bone or a bone arrangement, is displayed with sufficient clarity. With the help of the extension information, a particularly automatic setting of the focal area can be performed with improved accuracy. Specifically, it can be proposed here that the focal area is selected according to the orientation of the structure to be imaged in the spatial direction within the inspection object. Here, for example, the orientation of the structure to be imaged in the extension can be preset as orientation information, for example, as part of the prior knowledge information.

[0029] Preferably, the recording of the projection images can be performed with collimation in the recording direction, in particular as a slot scan. In this case, the detection area can be reduced by at least a factor of five, in particular by at least a factor of ten, in the recording direction by means of the collimation. However, the cone or fan shape is retained by the cone beam geometry, which allows different radiation directions through the voxels of interest and thus allows the determination of three-dimensional information. As a result, in particular the focal area also retains special importance.

[0030] In addition to the method, the invention also relates to an X-ray device having an X-ray emitter, an X-ray detector, at least one measuring device and a control device, which is designed to carry out the method according to the invention. All the embodiments of the method according to the invention can be transferred analogously to the X-ray device according to the invention, so that the advantages mentioned above can also be achieved with the X-ray device.

[0031] In particular, the control device can include at least one processor and / or at least one storage device. Functional units for executing the steps of the method according to the invention can be formed by hardware and / or software components. The control device can, for example, include a recording unit that controls the recording operation of the X-ray device, in particular during a tomosynthesis process, the recording unit can also control the imaging process for recording the projection image. In the acquisition unit, measurement data of at least one measuring device can be evaluated in order to determine extension information. The extension information can be used in a reconstruction unit that is configured to perform a reconstruction process in order to parameterize the reconstruction process. Of course, other functional units are also conceivable. The X-ray device can, for example, be an X-ray radiography and / or fluoroscopy device and / or a mammography device.

[0032] The computer program according to the invention can be directly loaded into a storage device of a control device of an X-ray device and has program means which, when the computer program is executed on the control device, cause the control device to carry out the steps of the method according to the invention. The computer program can be stored on an electronically readable data carrier according to the invention, which thus has control information stored thereon, which includes at least one computer program according to the invention and is designed such that, when the data carrier is used in a control device of an X-ray device, the control device is designed to carry out the method according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further advantages and details of the invention are apparent from the exemplary embodiments described below and from the accompanying drawings.

[0034] Figure 1 A flow chart showing an embodiment of a method according to the present invention;

[0035] Figure 2 shows a possible positioning of the test object and the measuring device in a first recording situation,

[0036] Figure 3 shows a possible positioning of the test object and the measuring device in the second recording case,

[0037] Figure 4 shows a possible positioning of the test object and the measuring device in the third recording case,

[0038] Figure 5 Shows the inspection object through the layer coverage,

[0039] Figure 6 shows the focal area in the slit scan,

[0040] Figure 7 A schematic diagram showing the functional principle of an X-ray device according to the invention, and

[0041] Figure 8 The functional structure of a control device of an X-ray device is shown. DETAILED DESCRIPTION

[0042] Figure 1 A general flow chart showing an embodiment of the method according to the invention is shown, wherein the Figures 2 to 6 Describe the specific application.

[0043] In this case, in step S1, a tomosynthesis process is performed as an imaging process with an X-ray device, in which a plurality of projection images of the examination object are recorded with different recording geometries by moving at least one X-ray emitter of the X-ray device. In this case, a cone beam geometry is used, so that even in the case of a parallel movement of the X-ray emitter and the associated X-ray detector, different transmission directions are present for the voxels of interest, which allow the derivation of three-dimensional information, in particular depth information.

[0044] In step S2 , measurement data are recorded with the examination object, here a patient, positioned, ie before and / or during and / or after the recording of the projection images in step S1 , using at least one measuring device which detects the examination object.

[0045] In step S3 , the measurement data are evaluated in order to at least partially ascertain information about the extension of the examination object in at least one spatial direction.

[0046] The extension information is used in step S4 in order to parameterize a reconstruction process for obtaining the final image data set, whereby at least one reconstruction parameter is determined depending on the extension information.

[0047] In step S5 , a reconstruction of the image data set then takes place from the projection images using at least one determined reconstruction parameter.

[0048] In the following exemplary embodiments, the spatial direction in which the extension is described by the extension information corresponds to a direction described by the central beam of the X-ray emitter in at least one of the projection geometries, for example in a central or otherwise characteristic and / or predetermined projection geometry. The spatial direction can correspond, for example, to a slice direction in which tomosynthesis slice images of the image data set follow one another; in another case, the spatial direction can be a direction in which, in particular in the case of an enlarged field of view, a focal region for reconstructing a slice is defined, i.e. perpendicular to the slice.

[0049] In this case, in the following examples, for the sake of simplicity, the names of corresponding components are used with the same reference numerals even when devices of different designs are used.

[0050] Figure 2 A first example is shown for positioning a part of an object to be examined 1 to be recorded, which can be used as an X-ray device 2 in a mammography apparatus, for example. In this case, the object to be examined 1 is placed on an X-ray detector 3, more precisely on a cover of the X-ray detector 3. In the present case, no compression plate is used, so that in order to determine the distance from the X-ray emitter 4 to the boundary of the object to be examined 1 along the central beam 5 as a spatial direction, a measuring device 6 is used, in the present case a three-dimensional measuring camera 7, which is fastened to a collimator device 8 of the X-ray emitter 4 and is registered with the coordinate system of the X-ray device 2. For example, a terahertz camera, a TOF camera and / or a stereo camera can be used as a three-dimensional measuring camera; alternatively to a three-dimensional measuring camera, other distance sensors, such as radar sensors, can also be used. The measuring device 6 is clearly directed toward the object to be examined 1, wherein the measured distance 9 can be easily converted into the distance between the X-ray emitter 4, more precisely its X-ray focus, and the upper boundary of the object to be examined 1 in the present case due to the known arrangement of the measuring device 6. The lower limit of the extension 10 of the object under examination 1 can be easily determined in another way without measurement data from the measuring device 6 by the position of the upper side of the X-ray detector through the flat position of the object under examination 1 on the X-ray detector 3, since the position of the X-ray detector 3 is known in the control device that controls the operation of the X-ray device 2.

[0051] exist Figure 3In the second example, the object to be examined 1, here a whole patient 11, is arranged lying on an examination table 12 of an X-ray device 2, which is in the present case designed as an X-ray radiography and fluoroscopy device. Since it is also possible to record corresponding parts of the patient 11 which do not lie on the examination table 12, for example, in the case of recording the knee with the knee bent, in addition to the measuring device 6 arranged on the X-ray emitter 4, further measuring devices 6, in the present case a camera 7 for three-dimensional measurement, are arranged at different known positions in the coordinate system of the X-ray device 2.

[0052] The measurement data of different distributed measuring devices 6, here cameras 7, can be used in combination to determine a three-dimensional model of the object under examination 1, more precisely the surface course of the object under examination, in the coordinate system of the X-ray device 2. This allows the determination of extension information for different positions and spatial directions covered in the three-dimensional model. This of course also applies to other examples using a plurality of measuring devices 6, in particular cameras 7 for three-dimensional measurement.

[0053] It should be pointed out here that it is also conceivable in principle to use a manually operated measuring device 6, such as a measuring tape, in particular at the X-ray radiator 4 (or the collimator device 8). The corresponding manually determined measurement data can then be input via an input device of the X-ray device 2, such as a touch user interface.

[0054] Figure 4 A further example is shown for positioning an object for examination 1, here again a patient 11, in an X-ray device 2, which is in turn designed as an X-ray radiography and fluoroscopy device. In the present case, the patient 11 stands in front of a detector wall 13, in which an X-ray detector 3 can be moved according to an arrow 14 in the recording direction. Correspondingly, see arrow 15, an X-ray radiator 4 is arranged on a support 16 so that it can be moved in the recording direction according to arrow 15, so that a larger area of ​​the patient 11, for example the head and torso and / or at least one leg of the patient 11, can be scanned by parallel movement of the X-ray radiator 4 and the X-ray detector 3. In this case, in particular, a so-called slit scan can be performed, in which the detection area in the recording direction is clearly limited, for example by means of a collimator device 8. However, the cone beam geometry is retained, in which the voxels are irradiated in different directions.

[0055] Also there Figure 4In the third example, in addition to the measuring device 6 arranged at the X-ray radiator 4 (or the collimator device 8), further measuring devices 6 designed as three-dimensional measuring cameras 7 are distributed in space, so that the patient 11 can be modeled three-dimensionally as completely as possible, and in particular it can also be determined at which distance the patient is from the detector wall 13. In particular, a central beam direction perpendicular to the recording direction is used as a spatial direction for the extension information at at least one, in particular multiple positions of the recording device composed of the X-ray radiator 4 and the X-ray detector 3.

[0056] Figure 5 The first application of the extension information in the spatial direction 17, which corresponds here to the slice direction, is shown for limiting the reconstruction region in the slice direction / spatial direction 17 so that the examination object 1 is covered as accurately as possible but completely in the spatial direction 17 in the slices or slice images 18 of the slice stack 19. For this purpose, the extension information is used, i.e., from Figure 5 The lower boundary is 20 to Figure 5 The upper limit 21 in FIG. 1 defines the slices over the entire extension 10 of the examination object 1 , for which a slice image 18 is then ascertained which covers the entire examination object 1 .

[0057] Figure 6 A second application of the extension information is shown in the case of slit scanning, in which the X-ray emitter 4 and the X-ray detector 3 are moved on parallel tracks 22 in order to cover a larger area of ​​the patient 11 as the examination object 1. The extension of the patient 11 perpendicular to the track 22 in the recording direction is known to the coordinate system of the X-ray device via the extension information, so that together with the position information about the position of the structure of interest, such as the spine, in the patient, the region, the focal region 23, in which the tomographic image is sharp, can be determined very accurately for a single slice image of the image data set. Here, the extension information is also used in order to define the focal region 23 so that the structure of interest is displayed as clearly as possible.

[0058] In particular, preferably exactly one slice image is determined which can clearly show the focal region 23 over the entire image area on the patient 11 , also in a manner reproducing the true size (“true to scale”), in particular depth information from the tomosynthesis process also contributing to this.

[0059] Figure 7 A general embodiment of an X-ray device 2 according to the invention is shown in a schematic functional diagram. As already described, the X-ray device comprises a recording device 24 with an X-ray radiator 4 and an X-ray detector 3. The operation of the X-ray device 2 is controlled by a control device 25, which in the present case also receives measurement data of the measuring device 6.

[0060] Figure 8 The functional structure of the control device 25 is shown in more detail. In addition to the storage device 26, the control device currently includes a recording unit 27 that controls the recording operation of the X-ray device 2 and is also designed to execute step S1. In addition to recording the projection images, the recording unit 27 can also control the recording activities of the measuring device 6, so that step S2 is executed in coordination with step S1.

[0061] In the determination unit 28, the extension information is determined according to step S3 in the coordinate system of the x-ray device 2. The extension information is then evaluated for parameterizing the reconstruction process by the reconstruction unit 29 (step S4), wherein the reconstruction unit 29 also performs the reconstruction process according to step S5 in order to determine the image data set.

[0062] Although the details of the present invention have been illustrated and described in detail by means of preferred embodiments, the present invention is not limited to the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of protection of the present invention.

[0063] Regardless of the grammatical part of speech of a particular term, people with either male or female gender identity are included.

Claims

1. A computer-implemented method for operating an X-ray device (2) during an imaging process at an object to be examined (1), wherein in a reconstruction process an image data set covering a reconstruction region is reconstructed from projection images of the object to be examined (1), the projection images being recorded in different projection geometries of an X-ray radiator (4) relative to an X-ray detector (3) of the X-ray device (2), It is characterized in that - determining extension information describing the extension (10) of the examination object (1) in at least one spatial direction (17) from measurement data of at least one measuring device (6), and - parameterizing said reconstruction process according to said extension information.

2. The method according to claim 1, characterized in that The imaging process is a tomosynthesis process and / or different projection geometries are produced either by parallel displacement of the X-ray radiator (4) and the X-ray detector (3) or by a movement of the X-ray radiator (4) relative to the fixed X-ray detector (3).

3. The method according to claim 1 or 2, characterized in that: The X-ray device (2) is an X-ray radiography and / or fluoroscopy device or a mammography device.

4. The method according to any one of the preceding claims, characterized in that At least one distance sensor and / or at least one three-dimensional measuring camera (7) is used as the measuring device (6).

5. The method according to claim 4, characterized in that At least one of the at least one distance sensor and / or at least one of the at least one camera (7) is fastened to the X-ray radiator (4) or to a component of the X-ray device (2) which is fixedly connected to the X-ray radiator (4), in particular to a collimator device (8).

6. The method according to claim 4 or 5, characterized in that: Using a plurality of distance sensors and / or cameras (7) arranged at different positions, the measurement data of the distance sensors and / or cameras are evaluated at least in the spatial direction (17) in order to form a model describing the boundaries (20, 21) of the inspection object (1).

7. The method according to any one of the preceding claims, characterized in that When the examination object (1) is supported on a component of the X-ray device (2), a known position of a boundary of the component on the examination object side and / or a position detectable by means of at least one of the at least one measuring device (6) is used as at least one boundary (20, 21) of the extension (10) of the examination object (1) in the spatial direction (17).

8. The method according to any one of the preceding claims, characterized in that The reconstruction region is limited in the spatial direction (17) to the extent of the examination object (1).

9. The method according to claim 8, characterized in that The spatial direction (17) is a slice direction and / or, for at least one projection geometry, a direction of a central beam (5) of the x-ray radiator (4).

10. The method according to any one of the preceding claims, characterized in that During the imaging process, an image area enlarged relative to a detection area of ​​the X-ray device (2) is recorded in a recording direction perpendicular to the spatial direction (17) by parallel movement of the X-ray radiator (4) and the X-ray detector (3) in the recording direction, and a reconstructed focal area (23) is selected based on the extension information.

11. The method according to claim 10, characterized in that The recording of the projection image takes place with collimation in a recording direction, in particular as a slit scan.

12. The method according to claim 10 or 11, characterized in that: The focal region (23) is selected as a function of the position of the structure to be imaged in a spatial direction (17) within the examination object (1).

13. An X-ray device (2) comprising an X-ray emitter (4), an X-ray detector (3), at least one measuring device (6) and a control device (25) which is designed to carry out the method according to any of the preceding claims.

14. A computer program which, when executed on a control device (25) of an X-ray device (2), causes the control device (25) to execute the steps of the method according to any one of claims 1 to 12.

15. An electronically readable data carrier on which a computer program according to claim 14 is stored.

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