ROI filter module with a smaller installation space requirement

Abstract

The invention relates to an ROI filter module, a depth stop, an X-ray source and an imaging modality. The ROI filter module according to the invention has - a filter unit and - a kinematic guide device for moving the filter unit within a plane of movement, - wherein the filter unit has a holding device and a filter disc connected to the holding device with at least one cylindrical filter cutout, characterized in that - that the kinematic guide device has a first rotary joint and a second rotary joint, - wherein a rotation axis of the first rotary joint and a rotation axis of the second rotary joint are spaced apart from each other and aligned parallel and are perpendicular to the plane of movement, - wherein the second pivot joint is rotatably mounted around the axis of rotation of the first pivot joint and - wherein the filter unit is mounted so as to be rotatable about the axis of rotation of the second rotary joint.

Description

[0001] The invention relates to an ROI filter module, a depth stop, an X-ray tube source and an imaging modality.

[0002] Traditionally, ROI filter modules are used to attenuate X-rays from an X-ray source in an examination area to a maximum extent. For this purpose, a filter disc typically has a filter cutout through which a specific region of interest (ROI) can be examined without reducing the X-rays.

[0003] In the section of the filter disk adjacent to the filter cutout, however, the X-rays are at least partially attenuated, so that the area outside the ROI typically remains visible, but usually only with reduced image quality. This advantageously allows the user of the X-ray source to reduce the total radiation dose of a patient located in the examination area while maintaining consistent image quality, particularly in the ROI area.

[0004] US 5,278,887 A relates to an apparatus and method for reducing the X-ray dose during a fluoroscopy procedure, wherein a filter element is used to selectively attenuate the X-ray radiation impinging on a patient's body. The filter element allows unattenuated X-rays to image a region of interest selected by a physician, thus producing a high-intensity, low-noise image. However, the areas surrounding the region of interest are imaged with attenuated radiation, resulting in a less intense, noisier image. A real-time image processing system is used to compensate for image brightness and possibly filter the compensated region to reduce noise.This restores image quality so that a physician can orient the site of a procedure within a patient's body and view the position of the area of ​​interest relative to its surroundings from a perspective.

[0005] US 2012 187 312 A1 provides a radiation control system and method for minimizing the radiation delivered to a patient and / or the device operator. The radiation control system can be used in a variety of applications, including applications where a radiation source is used to inspect an object, such as medical imaging, diagnostics, and therapy, manufacturing processes involving radiation, airport scanning systems, various security facilities, and nuclear reactor automation and process control. The radiation control system and method can also be used with 3D imaging.

[0006] US 2016 192 892 A1 discloses a multi-image imaging system capable of varying X-ray exposures at different input areas of an image intensifier or other X-ray detector. Collimators are provided to control the amount of radiation in different areas of the image, and image processing ensures the display of images of varying quality. Motion methods are available to move the collimators to create optimal image frames.

[0007] The X-ray imaging device from US 2016 211 045 A1 comprises an X-ray source configured to radiate X-rays onto an object; an X-ray detector configured to detect X-rays emitted by the X-ray source; and a disk rotatably disposed between the X-ray source and the X-ray detector, with region-of-interest (ROI) filters configured to filter X-rays emitted by the X-ray source. Openings of varying sizes are provided on the disk of the ROI filters.

[0008] The invention of US 2016 317 104 A1 relates to a multi-image imaging system comprising a radiation source, a detector having an input region, a monitor configured to display acquired images, means for determining at least one region of interest (ROI) of an object on the displayed image, and a collimator having means for projecting the at least one region of interest (ROI) onto at least a selected portion of the input surface exposed by the x-ray source. The collimator comprises at least three substantially non-overlapping plates mounted in a plane generally parallel to the plane of the detector input surface. Each plate includes a first edge in contact with an edge of a first adjacent plate and a second edge adjacent to the first edge in contact with an edge of a second adjacent plate; and means for moving each individual plate.

[0009] WO 2013 132 387 A2 describes an X-ray system comprising an X-ray source, a single substantially circular collimator, a camera, a detector and a monitor, means for moving the collimator in a plane generally parallel to the plane of the collimator; and the collimator comprises a central opening which transmits all radiation, an outer ring which reduces the transmitted radiation by an amount which depends on the material and the thickness of the material, and an inner ring between the central opening and the outer ring, the thickness varying as a function of the distance from the center, starting at zero thickness on the side of the central opening and ending at the thickness of the outer annulus on the side of the outer annulus.

[0010] A challenge with the use of such conventional ROI filter modules is that the filter disk with the filter cutout cannot only remain stationary in the beam path containing the X-rays, but must also be dynamically movable on a regular basis. Preferably, an ROI filter module can be moved in two spatial directions within a single plane of motion.

[0011] The inventor of the present invention is aware of the use of a kinematic guide device that moves the filter disk within the plane of movement. For this purpose, the kinematic guide device typically has two linear rails arranged at right angles to one another. In particular, the linear rail of the second direction of movement is coupled to the carriage of the linear rail of the first direction of movement. The filter disk is preferably mounted on the carriage of the linear rail of the second direction of movement. The kinematic guide device has, in particular, drive means for moving the filter disk. In particular, for reasons of available installation space and / or to reduce the moving masses, the drive means are arranged stationary on a base plate of the ROI filter module, with the filter disk being moved by means of a complex belt guide through the drive means.

[0012] The invention is based on the object of specifying an ROI filter module, a depth stop, an X-ray tube and an imaging modality with reduced installation space requirements.

[0013] The problem is solved by the features of the independent claims. Advantageous embodiments are described in the subclaims.

[0014] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0015] The ROI filter module according to the invention has - a filter unit and - a kinematic guide device for moving the filter unit within a plane of movement, - wherein the filter unit has a holding device and a filter disc connected to the holding device with at least one cylindrical filter cutout, characterized in that - that the kinematic guide device has a first pivot joint and a second pivot joint, - wherein a rotation axis of the first rotary joint and a rotation axis of the second rotary joint are spaced apart from each other and aligned parallel and are perpendicular to the plane of movement, - wherein the second pivot joint is rotatably mounted around the axis of rotation of the first pivot joint and - wherein the filter unit is mounted so as to be rotatable about the axis of rotation of the second rotary joint.

[0016] The ROI filter module according to the invention is particularly advantageous because, compared to the conventional design with linear rails, the swivel joints require significantly less installation space, while at the same time, the functional scope of the ROI filter module typically remains the same. Thus, the ROI filter module can advantageously be used even when the available installation space is limited. Alternatively or additionally, the saved installation space can be used for additional functions and / or modules. Overall, a base plate, which is essential for the conventional design with linear rails, can preferably be omitted or made smaller.

[0017] A further advantage of the ROI filter module is its reduced complexity due to the reduced number of components. Furthermore, the total mass moved by the rotary joints is preferably reduced, which allows the drive units to be smaller and / or less powerful. In return, the travel speed within the movement plane can be increased.

[0018] Another advantage is that eliminating the linear rails typically results in significant cost savings. The swivel joints and / or the ball bearings required for them are often significantly cheaper than the linear rails.

[0019] The ROI filter module is particularly designed to reduce X-rays from an X-ray source in an examination region to a maximum extent. In other words, at least the cylindrical filter section of the filter disk remains free for the X-rays. The ROI filter module is particularly suitable for reducing X-rays from an X-ray source in an examination region to a level other than zero. The ROI filter module can advantageously allow the X-rays to pass unhindered in a region of interest (ROI), while partially or completely reducing the X-rays in an adjacent region. The ROI filter module is particularly designed to reduce X-rays with a photon energy of up to 200 keV.

[0020] The ROI filter module corresponds in particular to an ROI assembly. The ROI filter module or ROI assembly is typically suitable for being combined with at least one further module or assembly. The ROI filter module is in particular a device.

[0021] The ROI filter module comprises the filter unit and the kinematic guide device. The filter unit is movable, in particular, by means of the kinematic guide device. The kinematic guide device has, in particular, a fixed point relative to which the filter unit is movable. The kinematic guide device is, in particular, configured to move the filter unit within or parallel to the plane of movement. The filter unit can be movable, in particular, in two spatial directions by means of the kinematic guide device. The plane of movement is, in particular, defined by the two spatial directions.

[0022] The kinematic guide device is particularly designed for dynamic movement of the filter unit. In particular, the filter unit can be moved multiple times using the kinematic guide device. Between movement processes using the kinematic guide device, the filter unit is stationary, in particular for a limited period of time.

[0023] Moving the filter unit comprises, in particular, moving and / or deflecting the filter unit. Moving the filter unit may comprise changing the current relative position and / or setting a new relative position of the filter unit relative to the fixed point of the kinematic guide device.

[0024] When moving the filter unit, the holding device and the filter disc, in particular, are moved together due to their connection. The holding device and the filter disc are in particular fixedly and / or detachably connected to one another. The filter disc is in particular attached to the holding device. The holding device is in particular designed to hold the filter disc. The holding device is typically attached to the kinematic guide device. The filter disc is in particular arranged parallel to or in the plane of movement.

[0025] The filter disc is preferably made of an X-ray-opaque material. The X-ray-opaque material can, in particular, be tungsten and / or lead.

[0026] The filter disc can be a filter plate. The surface area of ​​the filter disc is typically several times larger than the thickness of the filter disc. The thickness of the filter disc can be less than 50 mm, in particular less than 10 mm. The thickness can be, for example, 0.1 mm.

[0027] The filter cutout is preferably a through-hole. In this case, the through-hole typically forms a hollow cylinder. Alternatively, it is conceivable to form the filter cutout as a recess. Advantageously, the cross-section of the filter cutout is round.

[0028] The filter cutout is typically located centrally on the filter disc. In any case, the filter cutout is preferably not located at the edge of the filter disc. The filter cutout is advantageously spaced from an edge of the filter disc such that the X-rays cannot propagate simultaneously through the filter cutout and past the edge of the filter disc.

[0029] The filter disk can have multiple filter sections. The multiple filter sections are typically spaced apart from one another such that the X-rays can only propagate through one of the multiple filter sections. At least two of the multiple filter sections typically have different cross-sectional areas.

[0030] The first rotary joint and the second rotary joint, in particular, have independent axes of rotation. In other words, the axis of rotation of the first rotary joint and the axis of rotation of the second rotary joint lie next to one another and not on top of one another. When the axes of rotation lie next to one another, they are in particular spaced apart from one another and advantageously aligned parallel such that they are perpendicular to the plane of movement. The axis of rotation of the first rotary joint and the axis of rotation of the second rotary joint, in particular, each define the plane of movement. Since the axis of rotation of the first rotary joint and the axis of rotation of the second rotary joint are aligned parallel to one another, the respectively defined planes of movement are identical or at least parallel to one another. In the latter case, the two parallel planes of movement define the plane of movement in or parallel to which the kinematic guide device can move the filter unit.

[0031] Each rotary joint can comprise two rotating parts that can be rotated relative to one another around the rotation axis. A rotating part can be designed as a lever arm, for example as a rotor, or alternatively as a fixed point, for example as a stator. A fixed point can be, for example, a base plate to which the kinematic guide device is fixedly mounted. In this case, the filter unit can be moved around the fixed point of the base plate by means of the kinematic guide device. The base plate can be configured, in particular, for fastening a drive means of the ROI filter module and / or for fastening the ROI filter module to another module, in particular a collimator module.

[0032] Depending on the reference system, it is conceivable that a rotating part forms a rotor for one rotary joint and a stator for another. Depending on the reference system, one rotating part may be stationary, while the other rotating part may rotate relative to the stationary rotating part.

[0033] For example, the second pivot joint can be arranged on a rotating part of the first pivot joint. In this case, the second pivot joint is mounted so that it can rotate around the axis of rotation of the first pivot joint. The rotating part of the first pivot joint can form the stationary part of the second pivot joint, and vice versa. In this case, the first pivot joint and the second pivot joint are connected to each other, in particular, via a lever arm.

[0034] In particular, the holding device of the filter unit can form the rotating part of the second pivot joint. Alternatively, the second pivot joint can have a lever arm as a rotating part, to which the holding device is attached.

[0035] One embodiment provides that the holding device has a first carrier plate and that the filter disc is arranged stationary relative to the first carrier plate. This embodiment is particularly advantageous because the first carrier plate can protect the filter disc from mechanical damage and / or contamination. Alternatively or additionally, the filter unit is advantageously stiffer due to surface contact between the first carrier plate and the filter disc. Typically, the structure with the first carrier plate is less complex and / or more cost-effective than the conventional design with a steel frame. The first carrier plate and the filter disc preferably overlap to a maximum extent. The first carrier plate and the filter disc are preferably arranged one above the other.

[0036] One embodiment provides that the first carrier plate is made of an X-ray transparent material. This embodiment is particularly advantageous because, compared to the filter disk, the first carrier plate's contribution to reducing X-ray radiation is comparatively small or non-existent. In particular, when the first carrier plate has a larger area than the filter disk, this embodiment is advantageous because a section of the first carrier plate projecting beyond the filter disk can be placed in the X-ray beams without attenuating the X-rays at all or significantly. Thus, compared to the conventional design with the steel frame, this embodiment advantageously allows an edge region of the filter unit, in particular the holding device, to be arranged in the beam path of the X-rays, whereas conventionally the steel frame reduces the X-rays.

[0037] One embodiment provides that the X-ray-transparent material is a plastic. This embodiment is particularly advantageous because plastic typically has comparatively low X-ray absorption and / or sufficient strength to hold the filter disc.

[0038] One embodiment provides for the plastic to be fiber-reinforced. The fibers of the fiber-reinforced plastic can, in particular, comprise carbon. One advantage of this embodiment relates to increased strength of the first carrier plate.

[0039] One embodiment provides that the holding device further comprises a second support plate, wherein the filter disc is arranged in a sandwich construction between the first support plate and the second support plate. The first support plate and the second support plate can, in principle, be substantially identical and / or structurally identical. Typically, the first support plate and the second support plate are constructed symmetrically and / or congruently. The sandwich construction means that the filter unit has a layered structure consisting of the first support plate, the filter disc, and the second support plate.

[0040] One embodiment provides that the filter disc is fastened to the first carrier plate and / or to the second carrier plate by means of a fastening means. Alternatively or additionally, the first carrier plate and the second carrier plate can be fastened to one another by means of a fastening means. In the latter case, for example, the filter disc can be clamped between the first carrier plate and the second carrier plate, in particular without any fastening means. The fastening means can in particular be at least one screw, one rivet, one adhesive, and / or one welded connection. The fastening means can comprise a plurality of such connections.

[0041] One embodiment provides that at least a portion of the first support plate and / or the second support plate protrudes beyond the filter disc. The first support plate and the second support plate can, in particular, be dimensioned such that they form a frame around the filter disc. This embodiment is particularly advantageous in order to enable the protruding portion for fastening the first support plate and / or the second support plate to the kinematic guide device. For example, the fastening means can be arranged in the protruding portion.

[0042] One embodiment provides that the kinematic guide device has a first drive means for rotating the second rotary joint about the first rotary joint and a second drive means for rotating the filter unit about the second rotary joint. The first drive means has, for example, a motor and a power transmitter. The second drive means has, for example, a motor and a power transmitter. The power transmitter is particularly suitable for transmitting the power provided by the motor. The power transmitter can, in particular, be a chain transmitter or a belt transmitter. In particular, the motor can provide a force which is transmitted to a rotary joint by means of the power transmitter in order to rotate the rotary joint about its axis of rotation. This embodiment is particularly advantageous because the kinematic guide device can advantageously move the filter unit using motor power.

[0043] One embodiment provides that the first rotary joint has a deflection pulley and that the second drive means can be deflected by means of the deflection pulley of the first rotary joint. The deflection pulley can have a transmission ratio equal to or unequal to 1. In particular, the power transmitter of the second drive means can be deflected by means of the deflection pulley. This embodiment advantageously enables the motor of the second drive means to be arranged stationary with respect to the first rotary joint and the second rotary joint. The fact that the first rotary joint has a deflection pulley means in particular that an axis of rotation of the deflection pulley lies on the axis of rotation of the first rotary joint. The axis of rotation of the deflection pulley and the axis of rotation of the first rotary joint are in particular decoupled from one another, so that rotation of the deflection pulley occurs independently of the first rotary joint and vice versa.

[0044] An alternative embodiment to the previous embodiment provides that the second drive means comprises a rotary motor and that the first rotary joint comprises the rotary motor of the second drive means. This embodiment advantageously enables the rotary motor to be moved together with the first rotary joint. The rotary motor is, in particular, designed to be movable. The fact that the first rotary joint comprises the rotary motor means, in particular, that an axis of rotation of the rotary motor lies on the axis of rotation of the first rotary joint. The axis of rotation of the rotary motor and the axis of rotation of the first rotary joint are, in particular, decoupled from one another, so that rotation of the rotary motor occurs independently of the first rotary joint and vice versa.

[0045] A depth stop according to the invention has - an ROI filter module and - a collimator module for limiting a useful radiation section, wherein the at least one cylindrical filter section of the filter disc can be pivoted in by means of the kinematic guide device such that the cylindrical filter section and the useful radiation section overlap along a direction perpendicular to the plane of movement.

[0046] The depth stop is particularly suitable for consecutively reducing and / or limiting X-rays using multiple modules, in particular the ROI filter module and the collimator module. In other words, the depth stop enables the shaping of the X-rays that propagate through the depth stop, in particular through the ROI filter module and the collimator module. The X-rays typically propagate perpendicular to the plane of movement, in particular parallel to the direction perpendicular to the plane of movement or along the direction perpendicular to the plane of movement.

[0047] The collimator module is typically configured to change the size of the useful radiation section. The useful radiation section typically has a rectangular shape. To limit the useful radiation section, the collimator module can have multiple lead lamellae. Alternatively or additionally, the useful radiation section can be limited by means of circular segment diaphragms that can be rotated relative to one another. Limiting the useful radiation section means, in particular, that the X-rays can propagate through the useful radiation section unhindered and / or unfiltered, while the X-rays outside the useful radiation section are preferably completely reduced or absorbed. The area of ​​the useful radiation section is typically at least a factor of 1.5, preferably 2 or 4, larger than the area of ​​the filter section of the filter disk.

[0048] The ROI filter module can be arranged above the collimator module. Alternatively, the ROI filter module can be arranged below the collimator module. In other words, the ROI filter module can be arranged between an X-ray source and the collimator module. Alternatively, the collimator module can be arranged between the X-ray source and the ROI filter module.

[0049] The fact that the at least one cylindrical filter section can be pivoted in means, in particular, that the at least one cylindrical filter section can also be pivoted out. The pivoting in and / or out takes place, in particular, by means of the kinematic guide device.

[0050] Swiveling in involves, in particular, inserting the filter unit into the X-ray beam path. Swiveling out involves, in particular, removing the filter unit from the beam path.

[0051] Swinging the filter cutout in activates the filter unit. Swinging the filter cutout out deactivates the filter unit.

[0052] In particular, after pivoting in, the pivoted-in filter section and the useful radiation section typically overlap along the direction perpendicular to the plane of movement. In particular, after pivoting out, the pivoted-out filter section and the useful radiation section generally do not overlap along the direction perpendicular to the plane of movement. It is conceivable that, particularly after pivoting out, an area of ​​the pivoted-out filter disk outside the filter section and the useful radiation section overlap along the direction perpendicular to the plane of movement. Alternatively, the filter disk can be pivoted out in such a way that the filter disk and the useful radiation section do not overlap along the direction perpendicular to the plane of movement.

[0053] If the filter section is pivoted in such a way that the cylindrical filter section and the useful radiation section overlap in the direction perpendicular to the plane of movement, X-rays can typically propagate along this direction through the filter section and the useful radiation section. Overall, the free area for the unobstructed passage of X-rays is typically limited to the area of ​​the filter section. Typically, X-rays that are not absorbed by a region of the filter disk outside the filter section can propagate through the useful radiation section, provided this region overlaps with the useful radiation section.

[0054] If the filter section of the filter disc, in particular the filter disc itself, is positioned so as not to overlap with the useful radiation section, i.e., in particular, is not pivoted in but preferably pivoted out, X-rays can typically propagate through the entire useful radiation section. The free area for the unhindered passage of the X-rays typically corresponds to the area of ​​the useful radiation section, provided that no area of ​​the filter disc outside the filter section overlaps with the useful radiation section.

[0055] To pivot the filter section in and / or out, the kinematic guide device moves, in particular, the filter unit. The fact that the at least one cylindrical filter section of the filter disc can be pivoted in and / or out by means of the kinematic guide device means, in particular, that the at least one cylindrical filter section of the filter disc can be moved from a starting position to a target position within the plane of movement by means of the kinematic guide device in such a way that, after the movement, the filter section and the useful radiation section can overlap or no longer overlap.

[0056] An X-ray source according to the invention has - a depth of field and - an X-ray source which is aligned with the useful radiation section of the collimator module.

[0057] The X-ray source is typically an X-ray tube with an evacuated housing in which electrons are accelerated from a cathode to an anode. X-rays are typically generated by the interaction of the accelerated electrons on the anode. To accelerate the electrons, the X-ray source typically has an acceleration unit that can accelerate the electrons using a high voltage of up to 200 kV.

[0058] The X-ray source is particularly aligned with the useful radiation section in such a way that the X-rays can generally propagate through the useful radiation section. In particular, the X-ray source is aligned such that the X-rays are perpendicular to the plane of movement of the ROI filter module. The X-rays run, in particular, parallel to the axis of rotation of the first rotary joint and / or the axis of rotation of the second rotary joint.

[0059] The evacuated housing can, for example, have an X-ray exit window around which a flange is arranged. For example, the depth stop can be attached to the flange. It is conceivable for the flange to additionally comprise a lead window. Alternatively or additionally, a pre-filter module with a copper filter can be arranged between the evacuated housing and the depth stop. Typically, the depth stop is aligned relative to the X-ray source such that the ROI filter module is arranged between the evacuated housing and the collimator module.

[0060] An imaging modality according to the invention has - an X-ray tube, - an X-ray detector and - an examination area arranged between the X-ray source and the X-ray detector, whereby X-rays from the X-ray source in the examination area can be reduced to a maximum of some extent by means of the ROI filter module.

[0061] The imaging modality is particularly suitable for diagnostic imaging. Diagnostic imaging is, in particular, angiography, radiography, mammography, and / or computed tomography. Alternatively or additionally, the imaging modality may be suitable for materials testing and / or safety inspection.

[0062] The X-rays emitted by the X-ray tube illuminate the examination area before striking the X-ray detector. The X-ray detector records attenuation profiles that characterize an object located in the examination area. These attenuation profiles can advantageously be used to reconstruct an image of the object.

[0063] The examination area is typically located between the X-ray tube and the X-ray detector. The subject being examined is positioned, for example, on a patient couch in the examination area. The subject being examined, or rather the examination area, is primarily illuminated by the X-rays.

[0064] The ROI filter module is designed to use the filter disk to reduce those X-rays from the X-ray source that penetrate the examination area. Due to the at least one filter section, the ROI filter module cannot usually completely reduce the X-rays in the examination area, but only partially. "Partially at most" means, in particular, to a level other than zero or less than 100%. The ROI filter module is particularly unsuitable for completely reducing the X-rays in the examination area. In contrast, the collimator module can typically completely reduce the X-rays in the examination area.

[0065] The invention is described and explained in more detail below with reference to the exemplary embodiments illustrated in the figures. In the following description of the figures, essentially identical structures and units are designated by the same reference numerals as when the respective structure or unit first appeared.

[0066] They show: Fig. 1 an ROI filter module according to the invention, Fig. 2 a first embodiment of the filter unit, Fig. 3 a second embodiment of the filter unit, Fig. 4 a first embodiment of the ROI filter module, Fig. 5 a second embodiment of the ROI filter module and Fig. 6 an imaging modality according to the invention.

[0067] Fig. 1 shows a schematic view of the ROI filter module 10 according to the invention from a bird's eye view with a viewing direction perpendicular to the plane of movement E.

[0068] The ROI filter module 10 has a filter unit 11 and a kinematic guide device 12 for moving the filter unit 11 within a movement plane E. The filter unit 11 has a holding device 13 and a filter disk 14 connected to the holding device 13 with at least one cylindrical filter cutout 15.

[0069] The kinematic guide device 12 has a first pivot joint 16 and a second pivot joint 17. A rotation axis of the first pivot joint 16 and a rotation axis of the second pivot joint 17 are spaced apart from each other, aligned parallel, and perpendicular to the plane of movement E. The second pivot joint 17 is rotatably mounted about the rotation axis of the first pivot joint 16. The filter unit 11 is rotatably mounted about the rotation axis of the second pivot joint 17.

[0070] Fig. 2 shows a first embodiment of the filter unit 11 in a perspective exploded view.

[0071] The holding device 13 has a first support plate 18. The filter disk 14 is arranged in a fixed position relative to the first support plate 18. The first support plate 18 is made of an X-ray transparent material, wherein the X-ray transparent material is a plastic. Optionally, the Fiber-reinforced plastic. At least a portion of the first carrier plate 18 extends beyond the filter disc 14.

[0072] Fig. 3 shows a second embodiment of the filter unit 11 in a perspective exploded view.

[0073] The holding device 13 further comprises a second carrier plate 19. The filter disc 14 is arranged in a sandwich construction between the first carrier plate 18 and the second carrier plate 19. The filter disc 14 has Fig. 3 has a plurality of filter cutouts 15. At least one section of the first support plate 18 and the second support plate 19 protrudes beyond the filter disc 14.

[0074] The first support plate 18 and the second support plate 19 are fastened to each other by means of a fastening means. Alternatively or additionally, but not in Fig. 3, the filter disc can be attached to the first carrier plate and / or to the second carrier plate by means of a fastening means.

[0075] The fastening means of the embodiment in Fig. 3 includes, for example, a riveted connection. Alternative designs include a screw, an adhesive, and / or a welded connection.

[0076] Fig. 4 shows a first embodiment of the ROI filter module 10 from a bird's eye view.

[0077] The kinematic guide device 12 has a first drive means 20 for rotating the second rotary joint 17 about the first rotary joint 16 and a second drive means 21 for rotating the filter unit 11 about the second rotary joint 16. The first rotary joint 16 has a deflection pulley 22. The second drive means 21 can be deflected by means of the deflection pulley 22 of the first rotary joint 16. The gear ratio of the deflection pulley 22 is not equal to 1. The first drive means 20 and the second drive means 21 can each have a rotary motor.

[0078] Fig. Figure 5 shows a second embodiment of the ROI filter module 10 in a perspective view. Compared to the design in Fig. 4, the first rotary joint 16 has the rotary motor of the second drive means 21 instead of the deflection pulley 22.

[0079] Fig. Figure 6 shows an imaging modality 40 according to the invention in a section along the X-ray beam path R. The image plane of the Fig. 5 is perpendicular to the plane of movement E.

[0080] A depth stop 23 according to the invention has an ROI filter module 10 and a collimator module 24 for limiting a useful radiation section 25. The collimator module 24 forms, in particular, the useful radiation section 25. By means of the Fig. 6, the at least one cylindrical filter section 15 of the filter disc 14 can be pivoted in such a way that the cylindrical filter section 15 and the useful radiation section 25 overlap along a direction perpendicular to the plane of movement E. In Fig. 5, the filter cutout 15 is pivoted in and thus positioned overlapping with the useful radiation cutout 25.

[0081] An X-ray source 30 according to the invention comprises a depth stop 23 and an X-ray source 26. The X-ray source 26 is aligned with the useful radiation aperture 25 of the collimator module. The X-rays generated at the anode of the X-ray source 26 propagate along the X-ray beam path R. The X-ray beam path R is perpendicular to the plane of motion E.

[0082] The imaging modality 40 comprises the X-ray source 30, an X-ray detector 41, and an examination region 42 arranged between the X-ray source 31 and the X-ray detector 41. Using the ROI filter module 10, X-rays from the X-ray source 26 can be reduced to a maximum of some extent in the examination region 42. An examination object can be arranged in the examination region 42. The examination object can be, in particular, a patient, a material, or another object. The X-rays from the X-ray source 26 typically have a maximum photon energy of 200 keV, typically more than 20 keV and / or less than 150 keV.

[0083] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is nevertheless not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 5 278 887 A

[0004] US 2012 187 312 A1

[0005] US 2016 192 892 A1

[0006] US 2016 211 045 A1

[0007] US 2016 317 104 A1

[0008] WO 2013 132 387 A2

[0009]

Claims

[1] ROI filter module (10), comprising - a filter unit (11) and - a kinematic guide device (12) for moving the filter unit (11) within a plane of movement (E), - wherein the filter unit (11) has a holding device (13) and a filter disc (14) connected to the holding device (13) with at least one cylindrical filter cutout (15), characterized by , - that the kinematic guide device (12) has a first rotary joint (16) and a second rotary joint (17), - wherein an axis of rotation of the first pivot joint (16) and an axis of rotation of the second pivot joint (17) are spaced apart from one another and aligned parallel and are perpendicular to the plane of movement (E), - wherein the second pivot joint (17) is rotatably mounted around the axis of rotation of the first pivot joint (16) and - wherein the filter unit (11) is rotatably mounted around the axis of rotation of the second rotary joint (17). [2] ROI filter module (10) according to claim 1, wherein the holding device (13) has a first carrier plate (18) and wherein the filter disc (14) is arranged in a fixed position relative to the first carrier plate (18). [3] ROI filter module (10) according to claim 2, wherein the first carrier plate (18) is formed from an X-ray transparent material. [4] ROI filter module (10) according to claim 3, wherein the X-ray transparent material is a plastic. [5] ROI filter module (10) according to claim 4, wherein the plastic is fiber-reinforced. [6] ROI filter module (10) according to one of claims 2 to 5, wherein the holding device (13) further comprises a second carrier plate (19), wherein the filter disc (14) is arranged in a sandwich construction between the first carrier plate (18) and the second carrier plate (19). [7] ROI filter module (10) according to one of claims 2 to 6, wherein the filter disc (14) is fastened to the first carrier plate (18) and / or to the second carrier plate (19) by means of a fastening means. [8] ROI filter module (10) according to one of claims 6 to 7, wherein the first carrier plate (18) and the second carrier plate (19) are fastened to one another by means of a fastening means. [9] ROI filter module (10) according to one of claims 7 or 8, wherein the fastening means comprises a screw, a rivet, an adhesive and / or a welded connection. [10] ROI filter module (10) according to one of claims 2 to 9, wherein at least a portion of the first carrier plate (18) and / or the second carrier plate (19) projects beyond the filter disc (14). [11] ROI filter module (10) according to one of the preceding claims, wherein the kinematic guide device (12) comprises a first drive means (20) for rotating the second rotary joint (17) about the first rotary joint (16) and a second drive means (21) for rotating the filter unit (11) about the second rotary joint (16). [12] ROI filter module (10) according to claim 11, wherein the first rotary joint (16) has a deflection roller (22) and wherein the second drive means (21) can be deflected by means of the deflection roller (22) of the first rotary joint (16). [13] ROI filter module (10) according to claim 11, wherein the second drive means (21) comprises a rotary motor and wherein the first rotary joint (16) comprises the rotary motor of the second drive means (21). [14] Depth stop (23), comprising - an ROI filter module (10) according to one of the preceding claims and - a collimator module (24) for delimiting a useful radiation section (25), wherein the at least one cylindrical filter section (15) of the filter disk (14) can be pivoted in by means of the kinematic guide device (12) such that the cylindrical filter section (15) and the useful radiation section (25) overlap along a direction perpendicular to the plane of movement (E). [15] X-ray source (30), comprising - a depth stop (23) according to claim 14 and - an X-ray source (26) which is aligned with the useful radiation section (25) of the collimator module (25). [16] Imaging modality (40), comprising - an X-ray source (30) according to claim 15, - an X-ray detector (41) and - an examination area (42) arranged between the X-ray source (30) and the X-ray detector (41), wherein X-rays from the X-ray source (26) in the examination area (42) can be reduced to a maximum of some extent by means of the ROI filter module (10).

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