Scattered beam filter, x-ray detector apparatus, medical imaging apparatus, and computed tomography system

Abstract

The utility model relates to a scattered beam filter, X-ray detector equipment, medical imaging equipment and a computed tomography system. The utility model relates to a scattered beam filter for an X-ray detector, said scattered beam filter having a collimator element with a plurality of collimator walls and at least one alignment element, said collimator walls being arranged so as to intersect one another in a grid-like manner in a collimator plane transverse to a first spatial direction, the collimator walls are arranged on the collimator surface such that a plurality of radiation channels extending longitudinally in a first spatial direction are formed between the intersecting collimator walls, and wherein the collimator surface is delimited by an outer wall formed by the collimator walls arranged on the outer side, wherein at least one alignment element is formed on the outside of at least one of the outer walls of the collimator element as a structural element having at least two contact surfaces which adjoin one another and do not run parallel to one another, the X-ray absorption capacity of the at least one outer wall is not reduced by the alignment element, and the contact surface of the at least one alignment element is designed to align the scattered beam filter in a first spatial direction and / or at least one further spatial direction.

Description

Technical Field

[0001] The utility model relates to a scattered beam filter, an X-ray detector device, a medical imaging device and a computer tomography system. Background Art

[0002] X-ray imaging devices (X-ray devices for short) typically have an X-ray source and an X-ray beam detector (X-ray detector for short) arranged relative to one another. During operation of the X-ray device, X-ray radiation emitted by the X-ray source and possibly partially attenuated by the examination object (e.g., a female and / or male patient and / or an examination phantom and / or a workpiece) is detected by means of the X-ray detector. The X-ray detector is designed to output a (measurement) signal corresponding to the intensity of the incident X-ray radiation. In particular, the X-ray detector has a plurality of image points, in particular pixels and / or voxels, which are used to detect the intensity distribution of the incident X-ray radiation in an area-resolved manner. Optionally, the X-ray detector is divided into a plurality of detector elements, each of which includes a plurality of image points, in particular pixels. This allows for the simple construction of a large-area X-ray detector, curved, for example, for use in computed tomography, by correspondingly arranging ("tiling") the detector elements relative to one another.

[0003] During operation of an X-ray device, the X-ray radiation emitted by an X-ray source is not only attenuated to varying degrees by the object under examination but is also partially scattered at angles to the original radiation direction, which typically extends radially relative to the X-ray source. These scattered beams ("scatter beams"), when they impinge on an X-ray detector, distort the image reconstructed from the intensity distribution due to their superposition with the (primary) X-rays emitted in the original radiation direction. In particular, these scattered beams reduce the contrast of the reconstructed image.

[0004] In order to reduce the influence of the scattered beam, a so-called scattered beam filter (also called "anti-scatter grid") is usually associated with the X-ray detector, which is connected upstream of the X-ray sensitive element of the X-ray detector in the radiation direction. Such a scattered beam filter usually has a grid-like structure, wherein each grid opening forms a radiation channel extending in the main X-ray direction. Here, the individual radiation channels are separated by walls made of a material that absorbs X-rays. Here, usually each radiation channel is associated with a single pixel or at least a small number of pixels. The radiation channel is also constructed in an elongated manner, in particular in the direction of the main X-ray with a length that is several times greater than the extension in the transverse direction of the main X-ray. As a result, it is advantageously achieved that scattered beams that are different from the main X-ray direction are incident on the walls surrounding the radiation channel and are absorbed by the walls.

[0005] Since the individual pixels of an X-ray detector typically have an edge length in the range of approximately 1000 μm and for high image quality all main X-rays should be incident on the corresponding pixels as unhindered as possible by the scattered beam filter, the most precise positioning of the scattered beam filter is desired, in particular the most precise positioning of the individual beam channels relative to the pixels of the X-ray detector is desired.

[0006] The detector element usually comprises a scattered beam filter, a sensor and a digital application specific integrated circuit (ASIC). In an integrated system, the sensor can comprise a photodiode. The corresponding detector element can extend over multiple sensors, in particular in the z-direction of a computed tomography scanner ("bridge design"). To this end, the scattered beam filter must be aligned with the device or with the surrounding structure in the longitudinal and transverse directions in order to achieve the most precise possible alignment with the sensor during installation. When aligning the scattered beam filter, very strict tolerances must be adhered to with the underlying sensor. For this purpose, stop surfaces or forming elements, such as drilled holes and / or elongated holes, are usually introduced into the scattered beam filter. The stop surfaces and alignment elements must have a high degree of precision so that the required tolerances can be adhered to when the scattered beam filter is mounted on one or more sensors. For this purpose, the stop surfaces must also be correspondingly free of attachments, which may appear, for example, in a 3D-printed scattered beam filter made of tungsten powder. Typically, the shaped elements are introduced into the scattered beam filter, which is manufactured from tungsten powder by 3D printing (selective laser melting), by means of line etching. Usually, a technically complex, multi-stage process with measurement is required to position the shaped elements as precisely as possible relative to the inner wall of the scattered beam filter. Utility Model Content

[0007] It is therefore an object of the present invention to provide a scattered beam filter that is precisely alignable and efficiently manufacturable.

[0008] This object is achieved by a scattered beam filter, an X-ray detector device, a medical imaging device and a computed tomography system according to the present invention. Advantageous embodiments with advantageous developments are the subject matter of the present invention.

[0009] In a first aspect, the present invention relates to a scattered beam filter for an X-ray detector. The scattered beam filter comprises a collimator element and at least one alignment element, wherein the collimator element comprises a plurality of collimator walls. The collimator walls are arranged in a grid-like manner, intersecting one another, in a collimator surface transverse to a first spatial direction, so that a plurality of radiation channels extending longitudinally in the first spatial direction are formed between the intersecting collimator walls. Furthermore, the collimator surface is bounded by an outer wall formed by collimator walls arranged on the outside. The at least one alignment element is also configured as a structural element having at least two abutment surfaces adjacent to one another and not extending parallel to one another, on the outside of at least one of the outer walls of the collimator element. The absorption capacity of the at least one outer wall for X-rays is not reduced by the alignment element relative to the remaining collimator walls. Preferably, the thickness of the outer wall at the location of the at least one alignment element, in particular, at least the thickness perpendicular to the first spatial direction, is at least as great as that of the remaining collimator walls. Alternatively, the outer wall can have a smaller thickness than the remaining collimator walls, in particular a smaller thickness at least perpendicular to the first spatial direction, and comprise, in particular be formed from, a material having a correspondingly higher absorption capacity for X-ray radiation than the remaining collimator walls. Furthermore, the contact surface of the at least one alignment element is designed for aligning the scattered beam filter in the first spatial direction and / or in at least one further spatial direction.

[0010] The scattered beam filter according to the present invention is designed and arranged for use at an X-ray detector of an X-ray device. To this end, the scattered beam filter includes a plurality of collimator walls, which are arranged in a grid-like manner and cross each other in a collimator surface transverse to a first spatial direction, so that a plurality of radiation channels stretched along the first spatial direction are formed between the crossed collimator walls. The grid-like cross arrangement can, for example, include corner angles between the crossed collimator walls that are equal to or not equal to 90 degrees or a grid consisting of polygons, especially hexagons. Here, the collimator surface is delimited by an outer wall formed by the collimator walls arranged on the outside. That is to say, the collimator walls that limit the outside of the collimator surface are referred to as outer walls here and hereinafter.

[0011] The scattered beam filter has at least one alignment element, in particular a plurality of alignment elements, which are configured as structural elements protruding from the outside of at least one of the outer walls of the collimator elements. In particular, the at least one alignment element can be formed as a structural element at the outside of the at least one outer wall by the outer wall, in particular the base of the outer wall. The structural element can be configured as a three-dimensional (3D) structure at the outside of the at least one outer wall, such as a ridge and / or a depression. In particular, the at least one alignment element can be formed by the 3D structure of the base of the outer wall. The outside of the outer wall can mean a side and / or a face of the outer wall, in particular an external collimator wall, which faces away from the remaining collimator walls, in particular the built-in collimator wall.

[0012] The collimator walls preferably comprise a material that strongly absorbs X-ray radiation, such as a metallic material, in particular tungsten. The X-ray absorption capacity of the at least one outer wall, on which the at least one alignment element is formed, is not reduced by the alignment element compared to the remaining, in particular internal, collimator walls. This can be achieved, in particular, by having the at least one outer wall, at least in the region of the alignment element, have a greater wall thickness than the remaining collimator walls.

[0013] At least one alignment element may have at least two contact surfaces that are adjacent to each other and do not extend parallel to each other. The at least two contact surfaces may be arranged at a predetermined angle relative to the first spatial direction, in particular at a right angle or parallel to the first spatial direction.

[0014] The term “substantially” is understood here and hereinafter to mean exactly or approximately, for example within the range of customary manufacturing tolerances or with a maximum deviation of 5%.

[0015] In a simple approximation, the first spatial direction is a coordinate of a Cartesian coordinate system. However, preferably, the first spatial direction is a direction starting in the form of a radial beam from a starting point remote from the scattered beam filter, so that the direction is at a different angle (however aligned with the starting point) at each point in a flat, extending plane, wherein the plane is transverse to the spatial direction. In this case, the first spatial direction preferably corresponds to the X-ray radiation direction of a fan-shaped X-ray beam starting from a (particularly approximately point-shaped) X-ray source during operation of the X-ray device, specifically to the corresponding direction of each sub-beam of the X-ray radiation, wherein the X-ray device includes an X-ray detector with a scattered beam filter. Therefore, in the latter case, the adjacent collimator walls are preferably tilted in such a way that the radiation channels formed between the intersecting collimator walls extend conically in the direction of the X-ray source when normally installed in the X-ray device, or at least tilted towards the X-ray source. In this case, the collimator surface of the scattered beam filter is particularly radial with respect to this first spatial direction and forms, for example, a tangential surface. Optionally, the collimator surface is also curved similar to the side surface of a cylinder. This is particularly advantageous for situations where the X-ray detector of an X-ray device (e.g., a computed tomography scanner) is also curved like a side surface, so that the X-rays originating from the X-ray source always emerge orthogonally from the detector surface. This allows the scattered beam filter to be particularly easily and fully applied to the X-ray detector and fastened thereto.

[0016] The term "stretched" is to be understood here and hereinafter to mean, in particular, that the collimator walls are designed such that the radiation channels arranged between the intersecting collimator walls have an aspect ratio (as viewed in the first spatial direction) of greater than or equal to 5:1. This ensures that the scattered radiation is sufficiently absorbed by the scattered beam filter.

[0017] The term "post-processing-free" is to be understood herein and hereinafter to mean, in particular, that the primary shaping process results in the production of the scattered beam filter (at least its corresponding layers) in a final or nearly final shape. Specifically, it is to be understood herein and hereinafter that the production steps downstream of the primary shaping process for forming the desired profile of the scattered beam filter or its individual layers are no longer performed. However, the gates and / or risers typically present in the primary shaping process can still be removed.

[0018] The scattered beam filter, in particular its detector surface, is preferably designed as a polygonal shape, for example a rectangular or triangular or hexagonal shape. Due to the polygonal shape, in particular the rectangular shape, a plurality of scattered beam filters can be arranged side by side (tile-like) in a particularly simple manner to form a particularly large total area.

[0019] Furthermore, the original shaping method, which does not require post-processing, also allows for a precise formation of the collimator wall and thus also of the at least one alignment element, in particular the at least two contact surfaces, without requiring additional post-processing steps that increase production costs. Advantageously, the at least one alignment element allows for a precise and robust alignment of the scattered beam filter.

[0020] In a further advantageous embodiment of the proposed scattered beam filter, the collimator walls can also be arranged substantially parallel to one another and parallel to the first spatial direction.

[0021] In particular, the grid-like cross-sectional arrangement of the collimator walls can have corner angles of 90 degrees. The radiation channel can also have a substantially rectangular, in particular square, cross section. This allows for improved illumination of the, in particular, rectangular and / or square, detector pixels of the X-ray radiation extending through the radiation channel.

[0022] In a further advantageous embodiment of the proposed scattered beam filter, the at least one alignment element can be designed as a protrusion and / or a depression on the outer side of at least one outer wall of the collimator element.

[0023] The at least one alignment element, in particular the plurality of alignment elements, can each be designed as a depression, in particular a groove and / or a step, and / or a raised portion, for example a spring and / or a rod and / or a pin.

[0024] The proposed embodiment advantageously allows for precise alignment of the scattered beam filter relative to another component by means of a form-fitting contact of at least two contact surfaces with corresponding contact surfaces of the other component. Advantageously, the introduction of forming elements, such as drilled holes and / or slotted holes, at the flange of the scattered beam filter can be omitted. Advantageously, no process step for defining a ground line corrosion forming element is required in the scattered beam filter according to the utility model. As a result, the manufacture of the scattered beam filter can be simplified and a cost-effective design can be achieved.

[0025] In another advantageous embodiment of the proposed scattered beam filter, at least one alignment element can be designed as a stepped section on the outer side of at least one outer wall of the collimator element. In this case, two of the at least two contact surfaces arranged at an angle to one another can form a stepped section.

[0026] The stepped section may comprise at least two contact surfaces arranged at an angle to one another, in particular arranged perpendicularly. Advantageously, the edge at which the two contact surfaces meet may extend perpendicularly or parallel to the first spatial direction.

[0027] The proposed embodiment advantageously allows precise, in particular geometrically defined, alignment of the scattered beam filter relative to the other component in two spatial directions by means of a shape-matched contact of at least two contact surfaces with corresponding contact surfaces of the other component.

[0028] In a further advantageous embodiment of the proposed scattered beam filter, at least one alignment element can extend over the entire width and / or height of at least one outer wall.

[0029] Advantageously, the outer wall can have a substantially rectangular and / or trapezoidal outer surface. The width of the outer wall can denote the extent of the outer wall in a spatial direction substantially perpendicular to the first spatial direction. Furthermore, the height of the outer wall can denote the extent of the outer wall substantially parallel to the first spatial direction.

[0030] At least one alignment element, in particular at least two abutment surfaces can advantageously extend, in particular stretch, over the entire width and / or height of at least one outer wall. At this, at least one alignment element can be arranged at an edge and / or a face of at least one outer wall.

[0031] The proposed embodiment may advantageously enable more degrees of freedom of movement when aligning the scattered beam filter.

[0032] In a further advantageous embodiment of the proposed stray beam filter, the stray beam filter can have a plurality of alignment elements which are at least partially, in particular, formed identically.

[0033] The plurality of alignment elements can each be designed as structural elements on the outside of one or more outer walls of the collimator element. In this case, the plurality of alignment elements can be designed at least partially, in particular identically, with respect to the 3D structure, for example, the shape and / or arrangement and / or extent and / or alignment of the contact surface. In particular, the alignment elements can be designed identically on opposite outer walls of the collimator element.

[0034] The proposed embodiment advantageously allows precise alignment of the scattered beam filter relative to the other component in multiple spatial directions by means of a form-fitting contact of multiple contact surfaces with corresponding contact surfaces of the other component.

[0035] In a further advantageous embodiment of the proposed stray beam filter, the stray beam filter can have a plurality of alignment elements which are at least partially, in particular, designed to be completely different.

[0036] The plurality of alignment elements can each be designed as structural elements on the outside of one or more outer walls of the collimator element. In this case, the plurality of alignment elements can be designed at least partially, in particular completely differently, with respect to the 3D structure, for example, the shape and / or arrangement and / or extent and / or orientation of the contact surface.

[0037] The proposed embodiment advantageously allows precise alignment of the scattered beam filter relative to the other component in multiple spatial directions by means of a form-fitting contact of multiple contact surfaces with corresponding contact surfaces of the other component.

[0038] In a further advantageous embodiment of the proposed scattered beam filter, the at least one alignment element can adjoin at least an edge of at least one outer wall of the field collimator element.

[0039] Advantageously, at least one outer wall of the collimator element can have at least one edge, in particular a plurality of edges, which spatially delimit the outer side, in particular the outer surface, of the outer wall. In this case, the at least one alignment element can be arranged at the edge of the at least one outer wall of the collimator element, in particular adjacent to the edge or including the edge, in particular forming the edge. Thus, the at least one alignment element can at least be adjacent to the edge of the at least one outer wall of the collimator element.

[0040] The proposed embodiment may advantageously enable more degrees of freedom of movement when aligning the scattered beam filter.

[0041] In a further advantageous embodiment of the proposed scattered beam filter, the collimator element and the at least one alignment element can be formed in one piece.

[0042] By producing the collimator element in one piece, in particular in one piece, the construction complexity of assembling the collimator element and the at least one alignment element from individual components can advantageously be avoided. For example, material and connecting means and time-consuming processing steps can thereby be saved.

[0043] In a further advantageous embodiment of the proposed scattered beam filter, the collimator element and the at least one alignment element can be produced by means of additive manufacturing technology.

[0044] Additive manufacturing involves the process of building components layer by layer by depositing material based on digital 3D design data. This allows for a high degree of design variability. Advantageously, this allows for the time-efficient and resource-efficient production of complex, yet stable, structures and shapes. Depending on the raw material and application, components can be produced using methods such as stereolithography, laser sintering, or 3D printing. Various metals, plastics, and composite materials can be used as materials.

[0045] For example, the collimator element and at least one alignment element can be produced using selective laser melting or laser sintering. A powder material comprising metal powder is preferably used. A thin layer of the powder material is first applied to the build platform. Using a laser, the powder is melted precisely at the locations predefined in the computer-generated component design data. The build platform is then lowered and another layer of powder is applied. The material re-melts and connects to the underlying layer at the defined locations.

[0046] Advantageously, a high volume density of the metallic material in the collimator wall and the at least one alignment element can also be achieved by means of additive manufacturing techniques, and particularly advantageously here by means of a selective laser melting method or a laser sintering method.

[0047] In a further advantageous embodiment of the proposed scattered beam filter, the collimator element and the at least one alignment element can be produced by means of a selective laser melting or laser sintering method of metal powder.

[0048] In one variant, the collimator element and the at least one alignment element are manufactured using a method of selective laser melting or laser sintering of metal powder. For example, in the selective laser melting (SLM) or laser sintering (SLS) method, powder layers of metal powder can be used to construct the collimator wall and the at least one alignment element. Advantageously, the collimator element and the at least one alignment element can be constructed more quickly or lower-cost materials can be used.

[0049] In a second aspect, the invention relates to an X-ray detector device comprising an X-ray detector and the proposed scattered beam filter in a stacked arrangement along a first spatial direction, in particular an X-ray incidence direction.

[0050] The advantages of the proposed X-ray detector device essentially correspond to the advantages of the proposed scattered beam filter. Features, advantages or alternative embodiments mentioned here can also be applied to the other claimed subject matter, and vice versa.

[0051] The X-ray detector may be a direct conversion X-ray detector or an indirect conversion X-ray detector.

[0052] X-ray radiation or X-ray photons can be converted into electrical pulses in direct-conversion X-ray detector devices using suitable converter materials. For example, CdTe, CZT, CdZnTeSe, CdTeSe, CdMnTe, InP, TlBr2, HgI2, GaAs or other materials can be used as converter materials. The electrical pulses are evaluated by an electronic circuit in an evaluation unit, for example in the form of an integrated circuit (application-specific integrated circuit, ASIC). In counting X-ray detector devices, the incident X-rays can be measured by counting the electrical pulses triggered by the absorption of X-ray photons in the converter material. The size of the electrical pulses is generally proportional to the energy of the absorbed X-ray photons. Spectral information can thus be extracted by comparing the magnitude of the electrical pulses with a threshold value.

[0053] In an indirect conversion X-ray detector device, X-rays or photons are converted into light by a suitable converter material and then into electrical pulses by means of an optically coupled photodiode. Scintillators such as GOS (Gd2O2S), CsJ, YGO, or LuTAG are typically used as converter materials. The resulting electrical signal is further processed, read out, and then forwarded to a computing unit via an evaluation unit with electronic circuitry.

[0054] The X-ray detector may comprise a matrix arrangement of a plurality of pixel elements for spatially resolved measurement of incident X-ray radiation. The position of the scattered beam filter, in particular the position of the radiation channel and the collimator wall, may be aligned relative to the matrix arrangement of a plurality of pixel elements. For example, the collimator wall may be associated with each pixel element or a group of pixel elements, respectively. For example, the collimator wall may be arranged between two adjacent pixel elements or between adjacent groups of pixel elements (e.g. macropixels), respectively. Preferably, it is arranged so that the sensitive surface of the pixel element is covered as little as possible by the collimator wall, so that degradation of the dose efficiency can be avoided. However, in a variant embodiment, it is also conceivable that the collimator wall is arranged completely or partially above the detection surface of the pixel element that is sensitive to X-rays.

[0055] Advantageously, the image-significant scattered radiation impinging on the x-ray detector is reduced, so that an improvement in image quality is achieved, while at the same time a cost-effective provision can be ensured.

[0056] In another advantageous embodiment of the proposed X-ray detector device, the X-ray detector device can also include a holding element for fixing the scattered beam filter in a stacked arrangement, the holding element having a corresponding alignment element for the at least one alignment element of the scattered beam filter. Here, the corresponding alignment element in the stacked arrangement can abut against the at least one alignment element in a form-fitting manner. The at least one corresponding alignment element can in particular have all the features and characteristics already described with respect to the at least one alignment element of the scattered beam filter, and vice versa. Here, the corresponding alignment element can advantageously have at least two corresponding stop surfaces, which can be arranged in a form-fitting manner to the at least two stop surfaces of the at least one alignment element.

[0057] In a third aspect, the present invention relates to a medical imaging device having the proposed X-ray detector device and an X-ray source opposite to the X-ray detector device, wherein the X-ray source is configured to expose the X-ray detector device with X-rays along a first spatial direction, in particular an X-ray incident direction.

[0058] The advantages of the proposed imaging device essentially correspond to the advantages of the proposed scattered beam filter and / or the proposed X-ray detector device. Features, advantages or alternative embodiments mentioned here can also apply to the other claimed subject matter, and vice versa.

[0059] To record an X-ray image data set, the object to be imaged can be placed between an X-ray source and an X-ray detector and illuminated by the X-ray source. In particular, the medical imaging device can be designed as a computed tomography system. However, the medical imaging device can also be designed as, for example, a C-arm X-ray device and / or a Dyna-CT, or as another X-ray-based imaging device.

[0060] In a fourth aspect, the present invention relates to a computed tomography system having the disclosed medical imaging device. The computed tomography system may include a gantry having a rotor. The rotor may include an X-ray source and a detection unit. The detection unit may include at least one X-ray detector device according to the present invention. The rotor may be supported for rotation about an axis of rotation. An examination subject may be supported on a patient bed and may be moved through the gantry along the axis of rotation. The computed tomography system may include a computing unit for controlling the computed tomography system and calculating slice images or volume images of the examination subject. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Embodiments of the present invention are shown in the accompanying drawings and described in more detail below. In different drawings, the same reference numerals are used for the same features.

[0062] Figure 1 A schematic diagram shows an advantageous embodiment of an X-ray detector device comprising a scattered beam filter having a collimator element arranged in a stack with the X-ray detector,

[0063] Figure 2 a schematic diagram showing an advantageous embodiment of a collimator element of a scattered beam filter,

[0064] Figure 3 A schematic diagram shows an advantageous embodiment of a medical imaging device. DETAILED DESCRIPTION

[0065] Figure 1 A schematic diagram shows an advantageous embodiment of an X-ray detector device comprising an X-ray detector 4 and a scattered beam filter having a collimator element 2 and an alignment element AE1 arranged in a stacked arrangement along a first spatial direction (parallel to the x-axis in the drawing). The stacking direction and the beam incidence direction extend essentially parallel to the x-axis in the illustrated view.

[0066] The scattered beam filter is arranged upstream of the X-ray detector 4 in the radiation incident direction in order to reduce scattered radiation impinging on the X-ray detector 4 during exposure of the X-ray detector device with X-rays.

[0067] The X-ray detector 4 has a converter element 11 for converting incident X-rays into electrical signals. Furthermore, the converter element 11 is coupled via an electrically conductive connection 15 to an evaluation unit 13, which is designed to forward the electrical signals from the converter element 11. The evaluation unit can also be coupled to a readout unit 17 for collecting and reading out the signals for further processing, or to a substrate. The X-ray detector can, in particular, include a matrix-like arrangement of a plurality of pixel elements for spatially resolved measurement of the incident X-ray radiation. The X-ray detector 4 can be a direct-conversion or indirect-conversion X-ray detector 4.

[0068] The scattered beam filter has a collimator element 2 for stacking with the X-ray detector 4 along a first spatial direction, in particular the direction of incidence of the X-rays. The collimator element has a plurality of collimator walls 1 arranged substantially parallel to the first spatial direction, wherein each of the plurality of collimator walls 1 has a wall height h along the first spatial direction. The wall height of the respective collimator wall extends substantially along the first spatial direction. The wall height h can, for example, be in the range of 3 mm to 40 mm, preferably between 4 mm and 28 mm, and more preferably is greater than 8 mm.

[0069] The collimator walls 1 of the collimator element 2 are arranged adjacent to each other and spaced apart from each other at least along another spatial direction (parallel to the z-axis in the drawing) so that a radiation channel 3 is provided along the first spatial direction between two adjacent collimator walls 1. In a top view of the arrangement, this can correspond to a grid structure or a lamella structure (in Figure 2 According to a preferred embodiment of the scattered beam filter, the collimator wall 1 is formed in another direction perpendicular to the first spatial direction and the stacking direction, so that the collimator element 2 has a two-dimensional grid-like structure in a horizontal section transverse to, in particular perpendicular to, the first spatial direction (in Figure 2 (shown in FIG). Such a scattered beam filter can also be referred to as a 3D collimator. The collimator wall 1 and the radiation channel 3 are aligned substantially parallel to the stacking direction, wherein this can include the collimator wall 1 and the radiation channel 3 formed thereby also being slightly tilted toward the focal point of the X-ray source 37 arranged for exposing the X-ray detector 4.

[0070] The collimator wall 1 preferably comprises a material that strongly absorbs X-rays, such as a metal material. For example, the collimator wall comprises tungsten.

[0071] In the stacked arrangement, the collimator elements 2 have a radiation entrance side 6 that faces the X-ray source 37 for irradiating the X-ray detector 4 and faces away from the X-ray detector 4. Along the radiation entrance side 6, opposite the radiation entrance direction, the collimator elements 2 each have a radiation exit side 8 that faces away from the X-ray source 37 for irradiating the X-ray detector 4 and faces away from the X-ray detector 4.

[0072] In addition to the components shown here, the scattered beam filter can also have other components. For example, the scattered beam filter includes a retaining element for fixing the collimator element 2 to the X-ray detector 4 or to a module holder of the X-ray detector system. In an embodiment variant, the collimator element 2 can also be attached directly to the converter element 11.

[0073] The X-ray detector device may further comprise a holding element (not shown here) for fixing the scattered beam filter in the stacked arrangement, the holding element having a corresponding alignment element for at least one alignment element of the scattered beam filter. The corresponding alignment element in the stacked arrangement may bear against the at least one alignment element in a form-fitting manner.

[0074] Figure 2A schematic diagram of an advantageous embodiment of a collimator element 2 of a scattered beam filter is shown. The collimator surface can be delimited by an outer wall AW formed by a collimator wall 1 arranged on the outside. In addition, at least one alignment element AE1 can be formed as a structural element having at least two contact surfaces adjacent to each other and not extending parallel to each other on the outside of at least one outer wall adjacent to the outer walls AW of the collimator element. Advantageously, the X-ray absorption capacity of at least one outer wall AW is not reduced by the at least one alignment element AE1 compared to the remaining collimator walls 1. The scattered beam filter can in particular have a plurality of alignment elements AE1, AE2 and AE3, which in the present embodiment are at least partially identical and at least partially differently configured. The alignment elements AE2 and AE3 can be configured, for example, as flanges. Here, the contact surface of at least one alignment element can be configured to align the scattered beam filter in a first spatial direction and / or at least one other spatial direction. In addition, at least one alignment element can be configured as a protrusion and / or a recess on the outside of at least one outer wall of the collimator element. In particular, alignment element AE1 can be designed as a stepped section on the outer side of at least one outer wall AW of the collimator element. Here, the at least two contact surfaces can be arranged at an angle to each other to form the stepped section. Advantageously, each alignment element can extend across the entire width of the at least one outer wall AW. Furthermore, alignment elements AE1, AE2, and AE3 can each be arranged at the edge of at least one outer wall AW of the collimator element.

[0075] Advantageously, the collimator and alignment elements AE1, AE2, and AE3 can be constructed in one piece. Furthermore, the collimator and alignment elements AE1, AE2, and AE3 can be manufactured using additive manufacturing techniques. In particular, the collimator and alignment elements AE1, AE2, and AE3 can be manufactured using selective laser melting or laser sintering of metal powder.

[0076] Figure 3An exemplary embodiment of a medical imaging device 32 is shown. The medical imaging device comprises a detection unit 36 ​​including at least one X-ray detector device according to the present invention, comprising an X-ray detector 4 and a scattered beam filter having a collimator element 2 according to the present invention; and an X-ray source 37 opposite the detection unit 36. The X-ray source 37 is designed to expose the detection unit 36 ​​and, consequently, the X-ray detector 4, with X-ray radiation along a first spatial direction, in particular, an X-ray incident direction. The illustrated medical imaging device 32 is designed, in particular, as a computed tomography system. The computed tomography system comprises a gantry 33 having a rotor 35. The rotor 35 comprises the X-ray source 37 and the detection unit 36. The detection unit 36 ​​comprises at least one X-ray detector device. The rotor 35 is rotatably mounted about an axis of rotation 43. An examination subject 39 (here, a patient) is mounted on a patient couch 41 and can be moved through the gantry 33 along the axis of rotation 43. A computing unit 45 is used to control the computed tomography system and to compute slice images or volume images of the examination subject. An input device 47 (eg keyboard) and an output device 49 (eg screen and / or display) are connected to the computer unit 45. The input device 47 can advantageously be integrated into the output device 49, for example in the case of a resistive and / or capacitive input display.

[0077] The schematic views contained in the described figures do not reflect any scale or size relationships.

[0078] Finally, it should be noted again that the methods described in detail above and the devices shown are merely exemplary embodiments that can be modified in various ways by those skilled in the art without departing from the scope of the present invention. Furthermore, the use of the indefinite article "a" or "an" does not exclude the presence of multiple features. Similarly, the terms "unit" and "element" do not exclude the presence of multiple components, which may be spatially distributed if necessary.

[0079] In the context of this application, the expression "based on" can be understood in particular to mean "by using." In particular, the expression "a first feature is generated (alternatively: determined, determined, etc.) based on a second feature" does not exclude: the first feature is generated (alternatively: determined, determined, etc.) based on a third feature.

Claims

1. A scattered beam filter, the scattered beam filter being used for an X-ray detector (4), characterized in that The scattered beam filter comprises a collimator element (2) with a plurality of collimator walls (1) and at least one alignment element (AE1, AE2, AE3), The collimator walls (1) are arranged in a grid-like manner across one another in a collimator surface transverse to a first spatial direction, so that a plurality of radiation channels (3) extending longitudinally in the first spatial direction are formed between the intersecting collimator walls (1), and the collimator surface is bounded by an outer wall (AW) formed by collimator walls arranged on the outside. The at least one alignment element (AE1, AE2, AE3) is formed as a structural element having at least two contact surfaces adjoining one another and not extending parallel to one another on the outer side of at least one of the outer walls (AW) of the collimator element (2), The X-ray absorption capacity of the at least one outer wall (AW) is not reduced by the alignment elements (AE1, AE2, AE3) relative to the remaining collimator walls (1), The contact surface of the at least one alignment element (AE1, AE2, AE3) is designed for aligning the scattered beam filter in the first spatial direction and / or in at least one further spatial direction.

2. The scattered beam filter according to claim 1, wherein The collimator walls (1) are also arranged parallel to each other and to the first spatial direction.

3. The scattered beam filter according to claim 1, wherein The at least one alignment element (AE1, AE2, AE3) is designed as a protrusion and / or a depression at the outer side of the at least one outer wall (AW) of the collimator element (2).

4. The scattered beam filter according to claim 3, wherein The at least one alignment element (AE1, AE2, AE3) is configured as a stepped section at the outer side of the at least one outer wall (AW) of the collimator element (2), Two of the at least two contact surfaces that are arranged at an angle to each other form the stepped section.

5. The scattered beam filter according to claim 4, wherein The at least one alignment element (AE1, AE2, AE3) extends over the entire width and / or height of the at least one outer wall (AW).

6. The scattered beam filter according to any one of claims 1 to 5, characterized in that The scattered beam filter has a plurality of alignment elements (AE1, AE2, AE3) which are at least partially designed in the same way.

7. The scattered beam filter according to any one of claims 1 to 5, characterized in that The scattered beam filter has a plurality of alignment elements (AE1, AE2, AE3) which are at least partially designed in a different manner.

8. The scattered beam filter according to any one of claims 1 to 5, characterized in that The at least one alignment element (AE1, AE2, AE3) adjoins at least an edge of the at least one outer wall (AW) of the collimator element (2).

9. The scattered beam filter according to any one of claims 1 to 5, characterized in that The collimator element (2) and the at least one alignment element (AE1, AE2, AE3) are designed as a single piece.

10. The scattered beam filter according to claim 9, wherein The collimator element (2) and the at least one alignment element (AE1, AE2, AE3) are manufactured by means of additive manufacturing technology.

11. The scattered beam filter according to claim 10, wherein The collimator element and the at least one alignment element (AE1, AE2, AE3) are produced by means of a method of selective laser melting or laser sintering of metal powder.

12. An X-ray detector device, characterized in that: The invention comprises an X-ray detector (4) and a scattered beam filter according to any one of claims 1 to 11 in a stacked arrangement along a first spatial direction.

13. The X-ray detector device according to claim 12, characterized in that: further comprising a holding element for fixing the scattered beam filter in the stacked arrangement, the holding element having a corresponding alignment element for the at least one alignment element (AE1, AE2, AE3) of the scattered beam filter, The corresponding alignment elements in the stacked arrangement bear against the at least one alignment element (AE1, AE2, AE3) in a form-fitting manner.

14. A medical imaging device, characterized in that: An X-ray detector device according to claim 12 or 13 and an X-ray source (37) opposite the X-ray detector device, the X-ray source being designed to expose the X-ray detector device with X-rays in a first spatial direction.

15. A computer tomography system (33), characterized in that There is a medical imaging device according to claim 14.

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