System and apparatus for pre-collimation of radiation beam

Abstract

The invention relates to a system and apparatus for pre-collimation of a radiation beam. The apparatus includes a pre-collimator and a shape filter. The shape filter is located at least in a first portion of the first component of the pre-collimator.

Description

Technical Field

[0001] The present disclosure relates to systems and apparatus for pre-collimation of radiation beams. Background Art

[0002] In medical imaging, such as computed tomography (CT), filters may be used to modify the intensity and / or change the shape of a radiation beam. Summary of the invention

[0003] In at least one example embodiment, the present disclosure provides an apparatus comprising a pre-collimator and a shape filter located at least in a first portion of a first component of the pre-collimator.

[0004] In at least one example embodiment, the first part of the pre-collimator is configured to move between a first position in which the first portion is aligned with a central beam axis of the radiation beam and a second position in which the first portion is outside the radiation beam.

[0005] In at least one example embodiment, the pre-collimator includes a second component of the pre-collimator.The second component of the pre-collimator is aligned with the central beam axis.

[0006] In at least one example embodiment, the second component of the pre-collimator is fixed relative to the radiation beam.

[0007] In at least one example embodiment, the first component of the pre-collimator includes a second portion. The second portion is similar to the first portion of the pre-collimator.

[0008] In at least one example embodiment, when the first component is in the second position, the second portion is aligned with a central beam axis of the radiation beam and the first portion is outside the radiation beam. When the first component is in the first position, the second portion is outside the radiation beam and the first portion is aligned with a central beam axis of the radiation beam.

[0009] In at least one example embodiment, the apparatus further comprises a support configured to hold the first portion and the second portion of the pre-collimator.

[0010] In at least one example embodiment, the support is configured to move between a first position and a second position. When the support is in the first position, the first portion of the pre-collimator is aligned with the central beam axis. When the support is in the second position, the second portion of the pre-collimator is aligned with the central beam axis.

[0011] In at least one example embodiment, the apparatus further comprises a first beam hardening filter and a second beam hardening filter, wherein the first beam hardening filter is coupled to the bracket adjacent to the first portion of the pre-collimator, and the second beam hardening filter is coupled to the bracket adjacent to the second portion of the pre-collimator.

[0012] In at least one example embodiment, the second component of the pre-collimator is closer to the radiation source than the first component of the pre-collimator.

[0013] In at least one example embodiment, the shape filter includes a first surface and a second surface opposite to the first surface. The first surface includes a curved surface configured to face toward a radiation source, and the second surface includes a flat surface.

[0014] In at least one example embodiment, the present disclosure provides a system. The system includes a radiation source configured to emit a radiation beam and includes a filtering assembly. The filtering assembly includes a pre-collimator and includes a shape filter located at least in a first portion of a first component of the pre-collimator.

[0015] In at least one example embodiment, the first part of the pre-collimator is configured to move between a first position in which the first portion is aligned with a central beam axis of the radiation beam and a second position in which the first portion is outside the radiation beam.

[0016] In at least one example embodiment, the pre-collimator includes a second component of the pre-collimator.The second component of the pre-collimator is aligned with the central beam axis.

[0017] In at least one example embodiment, the second component of the pre-collimator is fixed relative to the radiation beam.

[0018] In at least one example embodiment, the first component of the pre-collimator includes a second portion. The second portion is similar to the first portion of the pre-collimator.

[0019] In at least one example embodiment, when the first component is in the second position, the second portion is aligned with a central beam axis of the radiation beam and the first portion is outside the radiation beam. When the first component is in the first position, the second portion is outside the radiation beam and the first portion is aligned with a central beam axis of the radiation beam.

[0020] In at least one example embodiment, the system further includes a support configured to hold the first portion and the second portion of the pre-collimator.

[0021] In at least one example embodiment, the support is configured to move between a first position and a second position. When the support is in the first position, the first portion of the pre-collimator is aligned with the central beam axis. When the support is in the second position, the second portion of the pre-collimator is aligned with the central beam axis.

[0022] In at least one example embodiment, the system further comprises a first beam hardening filter and a second beam hardening filter, wherein the first beam hardening filter is coupled to the bracket adjacent to the first portion of the pre-collimator, and the second beam hardening filter is coupled to the bracket adjacent to the second portion of the pre-collimator.

[0023] In at least one example embodiment, the second component of the pre-collimator is closer to the radiation source than the first component of the pre-collimator.

[0024] In at least one example embodiment, the shape filter includes a first surface and a second surface opposite to the first surface. The first surface includes a curved surface configured to face toward a radiation source, and the second surface includes a flat surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The various features and advantages of the non-limiting embodiments herein may become more apparent upon reviewing the detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and should not be construed as limiting the scope of the claims. Unless expressly stated otherwise, the accompanying drawings should not be considered to be drawn to scale. For the sake of clarity, the various dimensions of the accompanying drawings may have been exaggerated.

[0026] Figure 1 is a front view of an imaging system according to at least one example embodiment.

[0027] Figure 2A According to at least one example embodiment Figure 1 A cross-sectional view of an imaging system wherein the pre-collimator is in a first position.

[0028] Figure 2B According to at least one example embodiment Figure 1 A cross-sectional view of an imaging system wherein the pre-collimator is located in a second position.

[0029] Figure 3 According to at least one example embodiment Figure 2A-2B Exploded view of the first component of the pre-collimator.

[0030] Figure 4 According to at least one example embodiment, Figure 1 A side cross-sectional view of an imaging device.

[0031] Figure 5A According to at least one example embodiment Figure 2A-Figure 4 Perspective view of the pre-collimator shape filter.

[0032] Figure 5B According to at least one example embodiment Figure 5A Side view of the shape filter.

[0033] Figure 5C According to at least one example embodiment Figure 5B Cross-sectional view of the shape filter. DETAILED DESCRIPTION

[0034] Some detailed example embodiments are disclosed herein. However, the specific structural and functional details disclosed herein are only for the representative purpose of describing some example embodiments. However, the example embodiments can be implemented in many alternative forms and should not be interpreted as being limited to the example embodiments set forth herein.

[0035] Therefore, although the example embodiments are capable of various modifications and alternative forms, the example embodiments thereof are shown in the drawings by way of example and will be described in detail herein. However, it should be understood that there is no intention to limit the example embodiments to the specific forms disclosed, but rather, the example embodiments should encompass all modifications, equivalents, and alternatives falling within the scope of the example embodiments. Throughout the description of the drawings, the same reference numerals refer to the same elements.

[0036] It should be understood that when an element or layer is referred to as being "on another element or layer," "connected to," "coupled to," or "overlying" another element or layer, it may be directly on, connected to, coupled to, or overlying another element or layer, or there may be intermediate elements or layers. In contrast, when an element is referred to as being "directly on another element or layer," "directly connected to," or "directly coupled to" another element or layer, there are no intermediate elements or layers. Throughout the specification, the same reference numerals refer to the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements, regions, layers and / or parts, these elements, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, region, layer or part from another region, layer or part. Therefore, the first element, region, layer or part discussed below may be referred to as the second element, region, layer or part without departing from the teachings of the exemplary embodiments.

[0038] For ease of description, spatially relative terms (e.g., "below," "below," "lower," "above," "upper," etc.) may be used herein to describe the relationship of one element or feature to another element or feature, as shown in the figures. It should be understood that, in addition to the orientation depicted in the figures, spatially relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as being "below" or "below" other elements or features will be oriented "above" the other elements or features. Therefore, the term "below" can cover both above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein can be interpreted accordingly.

[0039] The terms used herein are only used for the purpose of describing various example embodiments and are not intended to limit the example embodiments. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprises", "comprising", "having", and / or "containing" when used in this specification specify the presence of the features, integers, steps, operations, and / or elements, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0040] Example embodiments are described herein with reference to cross-sectional views, which are schematic diagrams of example embodiments. Therefore, shapes different from those shown can be expected. Therefore, example embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but should include deviations and variations in shape.

[0041] When the words "approximately" and "substantially" are used in conjunction with a numerical value in this specification, it is intended that the associated numerical value includes a tolerance of ±10% of the numerical value, unless otherwise explicitly defined. In addition, when the term "substantially" or "substantially" is used in conjunction with a geometric shape, it is intended that the accuracy of the geometric shape is not required, but the freedom of the shape is within the scope of the present disclosure. In addition, regardless of whether a numerical value or shape is modified as "approximately", "substantially" or "substantially", it should be understood that these values ​​and shapes should be interpreted as including manufacturing or operating tolerances (e.g., ±10%) of the numerical value or shape.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the example embodiments belong. It should also be understood that terms (including terms defined in commonly used dictionaries) should be interpreted as having a meaning consistent with that in the context of the relevant technology and should not be interpreted in an idealized or overly formal sense, unless so defined herein.

[0043] Figure 1 is a front view of an imaging system according to at least one example embodiment.

[0044] In at least one example embodiment, the imaging system 100 can be used for diagnosis and treatment. For example, the imaging system 100 can include a computed tomography (CT) system to scan an object and / or a human patient. In at least one example embodiment, the imaging system 100 includes a support 14 for an object or patient (such as subject 16) to be imaged or scanned and / or treated. For example, the support 14 can include a table or a bed.

[0045] In at least one example embodiment, the imaging system 100 includes a radiation source 20. The radiation source 20 may be coupled to the gantry 12 and positioned above the support 14 and / or the object 16. The gantry 12 may be configured to rotate about the support 14 and / or the object 16 and to move back and forth along the length of the support 14. The radiation source 20 is configured to direct a radiation beam toward a target, such as the object 16, and through the target to a detector 40. The detector 40 includes a plurality of sensors configured to detect or sense an intensity or energy level of the radiation beam passing through the object 16. In at least one example embodiment, the imaging system 100 also includes a control system 18 configured to control the operation of the gantry 12 and the radiation source 20. For example, the control system 18 may be configured to control the energy level of the radiation beam emitted from the radiation source 20.

[0046] In at least one example embodiment, the imaging system 100 includes a filter assembly 105. The filter assembly 105 may be positioned adjacent to the radiation source 20, as will be described below with respect to Figure 2A-2B discussed.

[0047] Figure 2A According to at least one example embodiment Figure 1 A cross-sectional view of an imaging system wherein the pre-collimator is in a first position. Figure 2B According to at least one example embodiment Figure 1 A cross-sectional view of an imaging system wherein the pre-collimator is located in a second position.

[0048] In at least one example embodiment, the filtering assembly 105 includes a pre-collimator 200 and a beam shaping filter, such as a shape filter 220. The pre-collimator 200 includes a movable component, such as a first component 201, and a fixed component, such as a second component 202. In at least one example embodiment, the second component 202 of the pre-collimator 200 is coupled to the radiation source 20, or is positioned adjacent to the radiation source 20. For example, the second component 202 of the pre-collimator 200 can be closer to the radiation source 20 than the first component 201. The second component 202 can be aligned with a central beam axis 225 of the radiation beam from the radiation source 20. For example, a vertical line extending through the z-axis and through the center of the first component 201 can be aligned with the central beam axis 225 of the radiation beam. As described above, the second component 202 can also be fixed relative to the radiation source 20 and the radiation beam.

[0049] In at least one example embodiment, the first component 201 includes a first portion 205 and a second portion 210. The first portion 205, the second portion 210 and the second component 202 may be the same or similar. In other example embodiments, the first portion 205 and the second portion 210 are the same or similar. For example, the second portion 210 may have a size and shape similar to the first portion 205. In at least one example embodiment, the pre-collimator 200 (including the first portion 205, the second portion 210 and the second component 202) includes lead, brass, or a combination thereof. The first portion 205, the second portion 210 and the second component 202 of the pre-collimator 200 may be configured to contain scatter emitted in a lateral direction. For example, the first portion 205, the second portion 210 and the second component 202 of the pre-collimator 200 may block: out-of-focus radiation; scatter generated in the front window of the tube of the radiation source; any penetration and scatter from the aperture of the radiation source; and / or one or more filters, beam shaping elements and blades associated with the imaging system 100.

[0050] In at least one example embodiment, the first portion 205 of the pre-collimator 200 includes a shape filter 220. For example, the shape filter 220 may be a bowtie filter. In other example embodiments, the shape filter 220 may include a triangular, trapezoidal, or wedge-shaped beam shaping filter. The shape filter 220 may be configured to reduce exposure of the radiation beam to the object 16 and improve the scattering behavior of the radiation beam delivered to the detector 40, as will be described below with respect to Figure 4 In at least one example embodiment, shape filter 220 includes aluminum, tantalum, lead, brass, a plastic material, or a combination thereof.

[0051] In at least one example embodiment, the first component 201 of the precollimator 200 (including the first portion 205 and the second portion 210) is configured to be movably coupled to the second component 202 of the precollimator 200. For example, the first portion 205 and the second portion 210 can be moved between a first position and a second position. In the first position, the first portion 205 is aligned with the central beam axis 225 of the radiation beam, and the third portion is outside the radiation beam such that the second portion 210 is not aligned with the central beam axis 225. For example, in the first position, a vertical line extending through the z-axis and passing through the center of the first portion 205 is aligned with the central beam axis 225, as shown in FIG. Figure 2A In the second position, the second portion 210 is aligned with the central beam axis 225, and the first portion 205 is outside the radiation beam, such that the first portion 205 is not aligned with the central beam axis 225. For example, in the second position, a vertical line extending through the z-axis and through the center of the second portion 210 is aligned with the central beam axis 225, as shown in FIG. Figure 2B The first portion 205 and the second portion 210 can slide between a first position and a second position to engage with the second portion 210 of the pre-collimator 200 .

[0052] In at least one example embodiment, an operator can manually slide the first portion 205 and the second portion 210 between the first position and the second position. Thus, the operator can choose whether to align the first portion 205 and the shape filter 220 with the central beam axis 225 or the second portion 210 with the central beam axis 225 based on the selected radiation program or to meet specific needs. In other example embodiments, the first portion 205, the second portion 210, and the shape filter 220 can be moved between the first position and the second position, such as by a linear actuator. The linear actuator and / or the first portion 205 and the second portion 210 can be communicatively coupled to the control system 18 to control the movement of the first portion 205 and the second portion 210 between the first position and the second position. For example, the control system 18 can control the movement of the first portion 205, the second portion 210, and the shape filter 220 based on the two-dimensional or three-dimensional image to be acquired.

[0053] Figure 3 According to at least one example embodiment Figure 2A-2B Exploded view of the first component of the pre-collimator.

[0054] In at least one example embodiment, the filter assembly 105 includes a support 300 configured to hold the first component 201 of the precollimator 200. For example, the support 300 may hold the first portion 205 and the second portion 210 of the first component 201 of the precollimator 200. The support 300 may include a base portion 320 defining a first opening 305 and a second opening 310, the first opening 305 being configured to receive at least a portion of the first portion 205 of the precollimator 200, and the second opening 310 being configured to receive at least a portion of the second portion 210 of the precollimator 200. The first opening 305 of the support 300 may also receive at least a portion of the shape filter 220. In at least one example embodiment, the support 300 is movably coupled to the second portion 210 of the precollimator 200 and is configured to move the first portion 205 (including the shape filter 220) and the second portion 210 between a first position and a second position, as described with respect to Figure 2A-2B discussed.

[0055] In at least one example embodiment, the bracket 300 includes a first side wall 325 and a second side wall 330. The first side wall 325 and the second side wall 330 may be positioned on opposite sides of the base portion 320. The first side wall 325 and the second side wall 330 may each extend along the length of the base portion 320 and have a height extending perpendicular to the base portion 320. The first side wall 325 and the second side wall 330 may be configured to support the first portion 205 and the second portion 210, and / or to secure the first portion 205 and the second portion 210 to the bracket 300.

[0056] In at least one example embodiment, the bracket 300 may include one or more attachment features 335. For example, the one or more attachment features 335 may include one or more brackets connected to one or both of the first side wall 325 and the second side wall 330. The one or more attachment features 335 may also be configured to couple the bracket 300 to at least a portion of the imaging system 100, such as the gantry 12 or the radiation source 20.

[0057] In at least one example embodiment, the filtering assembly 105 may include a plurality of fasteners 340 , such as bolts and / or screws, for connecting the first portion 205 , the second portion 210 , and the shape filter 220 to the bracket 300 .

[0058] In at least one example embodiment, the filter assembly 105 may include one or more additional filters coupled to the first portion 205, the second portion 210, and / or the bracket 300. For example, the filter assembly 105 may include a first filter 315 and a second filter 318, the first filter 315 being coupled to a side of the bracket 300 opposite the first portion 205, and the second filter 318 being coupled to a side of the bracket opposite the second portion 210. For example, the first filter 315 and the second filter 318 may be coupled to the bracket 300 via one or more of the fasteners 340. In at least one example embodiment, the first filter 315 may define an opening corresponding to the first opening 305 of the bracket 300, and the second filter 318 may define an opening corresponding to the second opening 310 of the bracket 300. In other example embodiments, the first filter 315 and the second filter 318 are configured to cover the first opening 305 and the second opening 310, respectively.

[0059] In at least one example embodiment, the first portion 205 and the second portion 210 may include additional filters, combinations of filters, or multiple filter sizes. For example, the first filter 315 and / or the second filter 318 may include a planar filter and / or a beam hardening filter. A beam hardening filter (such as a foil filter) may be used to change the energy spectrum of the radiation beam. For example, a beam hardening filter may be used to filter out lower energy X-rays, changing the X-ray spectrum to a "harder" beam with a larger proportion of high energy X-rays. Lower energy X-rays tend to be absorbed by the object 16 and therefore do not reach the detector 40 (and therefore do not contribute to the resulting image), thus only increasing the dose to the object 16. By hardening the beam, the dose to the object 16 can be reduced. For example, higher energy X-rays have a greater probability of penetrating the object 16 without reducing the dose delivered to the object 16. Therefore, higher energy X-rays have a greater probability of penetrating the object 16 and require less flux to obtain the desired signal on the detector 40. Without hardening the radiation beam before it reaches the subject 16, the low energy photons at least partially penetrate the subject 16 and provide a large dose of radiation.

[0060] In at least one example embodiment, the first filter 315 and the second filter 318 may include a foil of titanium, tin, copper, or a combination thereof. For example, the first filter 315 and / or the second filter 318 may include a copper foil having a thickness between about 0.2 mm and about 0.3 mm. In other example embodiments, the first filter 315 and / or the second filter 318 may include a high-Z material.

[0061] Figure 4 According to at least one example embodiment, a method of Figure 1A side cross-sectional view of an imaging device.

[0062] In at least one example embodiment, the shape filter 220 includes a first surface 400 and includes a second surface 405 opposite to the first surface 400. The first surface 400 includes a curved surface. The curved surface is configured to face toward the radiation source 20 so that the bottom of the curved surface is farther away from the radiation source 20, such as Figure 4 The second surface 405 of the shape filter 220 comprises a flat or planar surface configured to face the object 16. In other example embodiments, the first surface 400 (including a curved surface) may be configured to face the object 16, and the second surface 405 (including a planar surface) may be configured to face the radiation source 20.

[0063] In at least one example embodiment, the shape filter 220 is configured to shape the radiation beam so that the shape of the radiation beam can better fit the cylindrical geometry of the object 16 (such as a patient) to be imaged. The shape filter 220 is also configured to shape the radiation beam so that the lateral or side scatter of the radiation beam is reduced. For example, the shape filter 220 can focus the radiation beam to a position closer to the central beam axis 225 and can reduce the scattering of the radiation beam outside the object 16. Therefore, the scattering caused by the shape filter 220 has a smaller footprint.

[0064] The combination of the shape filter 220 in the pre-collimator 200 provides a more compact system and allows the shape filter 220 to be positioned closer to the radiation source 20, compared to when the shape filter is positioned further downstream of the radiation beam and further away from the radiation source 20, the shape filter must be larger in size. Placing the shape filter 220 closer to the radiation source 20 also allows the shape filter 220 to have a smaller size, which provides lighter weight and reduced manufacturing costs. Since only the first surface 400 of the shape filter 220 includes a curved surface, and the second surface 405 of the shape filter 220 is flat or planar, the manufacturing ease of the shape filter 220 can also be improved. Therefore, only one side of the shape filter 220 needs to be processed. In addition, a filter (such as the first filter 315 or the second filter 318) can be placed directly on the planar second surface 405 of the shape filter 220, which can reduce the overall footprint and complexity of the filter assembly 105.

[0065] Positioning the shape filter 220 close to the radiation source 20, reducing the size of the shape filter 220, and providing a flat or planar surface on the second surface 405 may also improve scatter modeling and image reconstruction. Since the shape filter 220 is close to the radiation source 20, the scattering of the radiation beam is less dependent on the blades of the collimator that may be positioned downstream of the shape filter 220 along the path of the radiation beam. Any residual scatter emitted laterally or sideways from the shape filter 220 may also be blocked by at least the first portion 205 of the pre-collimator 200.

[0066] Scatter modeling and image reconstruction are improved because, due to the shape of shape filter 220 and the location of shape filter 220 near radiation source 20, it can be assumed that any remaining scatter will be closer to the main beam of the radiation beam (such as, closer to central beam axis 225). This assumption simplifies the software correction steps because the scatter from shape filter 220 is spatially confined, produces less noise outside of object 16 and away from central beam axis 225, and can be corrected by software more quickly and easily, thereby producing a more accurate image.

[0067] Figure 5A According to at least one example embodiment Figure 2A-Figure 4 Perspective view of the pre-collimator shape filter. Figure 5B According to at least one example embodiment Figure 5A Side view of the shape filter. Figure 5C According to at least one example embodiment Figure 5B Cross-sectional view of the shape filter.

[0068] In at least one example embodiment, the shape filter 220 includes a first region 500, a second region 505, and a third region 510. The third region 510 includes a curved surface and may be between the first region 500 and the second region 505, such as Figure 5A-5C In at least one example embodiment, the first surface 400 of the first region 500 and the second region 505 includes a flat or planar surface. For example, at least a portion of the first surface 400 of the first region 500 and the second region 505 may be parallel to the second surface 405. In other example embodiments, at least a portion of the first surface 400 of the first region 500 and the second region 505 may be curved or rounded.

[0069] In at least one example embodiment, the shape filter 220 may include a flange portion 515. The flange portion 515 may extend around at least a portion of the perimeter of the shape filter 220. For example, the flange portion 515 may extend around the perimeter of the second surface 405 of the shape filter 220. In other example embodiments, the flange portion 515 may extend from an opposite end of the shape filter 220. For example, the flange portion 515 may extend from the second surface 405 adjacent to the first region 500 and / or the second surface 405 adjacent to the second region 505. The flange portion 515 may be configured to secure the shape filter 220 to the first portion 205 and / or the bracket 300. For example, as Figure 4 As shown in FIG. 1 , the flange portion 515 can be coupled to the end of the first portion 205. Additionally or alternatively, the flange portion 515 can be coupled to at least a portion of the inner surface of the base portion 320 of the bracket 300, such as Figure 3 For example, flange portion 515 may define one or more through holes 520 for receiving fasteners 340 and securing shape filter 220 to first portion 205 and / or bracket 300 .

[0070] refer to Figure 5C , the third region 510 of the shape filter 220 includes a curved surface. In at least one example embodiment, the base of the curved surface or the third region 510 may be defined by a circle having a radius 600 between about 0 cm and about 20 cm. In at least one example embodiment, the radius 600 may be about 0.5 cm. The radius 600 may be defined between an inner surface of the curved surface of the third region 510 and a vertical axis 610 extending through the center of the shape filter 220. In at least one example embodiment, the curved portions of the first region 500 and the second region 505 may taper outwardly from the third region 510 to a flat or planar surface of the first surface 400, such as Figure 5A-5C as shown in .

[0071] In at least one example embodiment, the shape filter 220 includes a distance 625 between a first inflection point 630 (where the slope of the base of the third region 510 changes toward the second region 505) and a second inflection point 635 (where the slope of the curved surface of the third region 510 changes toward the top of the second region 505). The distance 625 can be between about 0 cm and about 20 cm. The distance 625 can also vary based on the desired thickness or height of the shape filter 220, which will be described below. In at least one example embodiment, the distance 625 between the base of the third region 510 and the top of the first region 500 can be the same.

[0072] In at least one example embodiment, the slope of the first surface 400 between the third region 510 and the second region 505 and the slope between the third region 510 and the first region 500 gradually terminate at the base of the curved surface of the third region 510. The gradual inclination of the curved surface of the shape filter and the positioning facing the radiation source 20 allow the base of the curved surface to be as far away from the radiation source 20 as possible, which alleviates the sensitivity problem of focus stability while also allowing the size of the shape filter 220 to be reduced. In at least one example embodiment, the slope of the first surface 400 between the third region 510 and the second region 505 can be about 45° relative to a horizontal line extending perpendicular to the vertical axis 610 through the first inflection point 630. In other example embodiments, the slope can be greater or less than 45°. In some example embodiments, the slope of the first surface 400 between the third region 510 and the first region 500 can be the same as the slope between the third region 510 and the second region 505.

[0073] In at least one example embodiment, the first region 500 and the second region 505 are mirror images across the vertical axis 610 of the shape filter 220. For example, the shape filter 220 may include a length 640 between the vertical axis 610 and the second side 620. The length between the vertical axis 610 and the first side 615 of the shape filter may be the same as the length 640. The length 640 may be such that the entire radiation beam is covered by the shape filter 220. In at least one example embodiment, the length 640 is between about 0 cm and about 20 cm.

[0074] In at least one example embodiment, the shape filter 220 includes a first height 645 extending from the second surface 405 to the top of the first region 500 and the second region 505. The first height 645 of the shape filter can be between about 1 cm and about 20 cm. In at least one example embodiment, the shape filter 220 also includes a second height 650 between the second surface 405 and the base of the curved surface of the third region 510. For example, the second height 650 can be between about 0 mm and about 10 mm.

[0075] In at least one example embodiment, the above Figure 5C The geometry and size of the shape filter 220 discussed improves ease of manufacture. Since less material is required to produce the shape filter 220 and it is lighter in weight, the cost of manufacturing the shape filter 220 may also be reduced. In addition, the size and shape of the shape filter 220 may be modified based on the desired filtering effect. For example, the above description of Figure 5C The dimensions discussed, such as radius 600, length 640, first height 645, and second height 650, may be modified to suit specific needs.

[0076] Although example embodiments have been disclosed herein, it will be appreciated that other variations are possible. Such variations should not be regarded as departing from the spirit and scope of the present disclosure, and all such modifications as would be apparent to one skilled in the art are intended to be included within the scope of the appended claims.

Claims

1. A device comprising: Pre-collimator; as well as A shape filter is located at least in a first portion of the first component of the pre-collimator.

2. The device according to claim 1, wherein: The first component of the pre-collimator is configured to: move between a first position and a second position; In the first position, the first portion is aligned with a central beam axis of the radiation beam; and In the second position, the first portion is outside the radiation beam.

3. The device according to claim 2, wherein: The pre-collimator comprises a second component of the pre-collimator; and The second component of the pre-collimator is aligned with the central beam axis.

4. The apparatus of claim 3, wherein the second component of the pre-collimator is fixed relative to the radiation beam.

5. The apparatus of claim 3, wherein the first component of the pre-collimator comprises a second portion that is similar to the first portion of the pre-collimator.

6. The device according to claim 5, wherein: when the first member is in the second position, the second portion is aligned with the central beam axis of the radiation beam and the first portion is outside the radiation beam; and When the first component is in the first position, the second portion is outside the radiation beam and the first portion is aligned with the central beam axis of the radiation beam.

7. The apparatus according to claim 5, further comprising: A support is configured to hold the first portion and the second portion of the pre-collimator.

8. The device according to claim 7, wherein: The bracket is configured to move between the first position and the second position; When the support is in the first position, the first portion of the pre-collimator is aligned with the central beam axis; and When the support is in the second position, the second portion of the pre-collimator is aligned with the central beam axis.

9. The apparatus according to claim 7, further comprising: a first beam hardening filter coupled to the support adjacent the first portion of the pre-collimator; as well as A second beam hardening filter is coupled to the support adjacent the second portion of the pre-collimator.

10. The device according to claim 3, wherein: The second component of the pre-collimator is closer to a radiation source than the first component of the pre-collimator.

11. The device according to claim 1, wherein The shape filter comprises a first surface and a second surface opposite to the first surface, The first surface comprises a curved surface configured to face toward a radiation source, and The second surface includes a planar surface.

12. A system comprising: a radiation source configured to emit a radiation beam; as well as A filter component, the filter component comprising: Pre-collimator, and A shape filter is located at least in a first portion of the first component of the pre-collimator.

13. The system of claim 12, wherein: The first component of the pre-collimator is configured to: move between a first position and a second position; In the first position, the first portion is aligned with a central beam axis of the radiation beam; and In the second position, the first portion is outside the radiation beam.

14. The system of claim 13, wherein: The pre-collimator comprises a second component of the pre-collimator; and The second component of the pre-collimator is aligned with the central beam axis.

15. The system of claim 14, wherein the second component of the pre-collimator is fixed relative to the radiation beam.

16. The system of claim 14, wherein the first component of the pre-collimator includes a second portion that is similar to the first portion of the pre-collimator.

17. The system of claim 16, wherein: when the first member is in the second position, the second portion is aligned with the central beam axis of the radiation beam and the first portion is outside the radiation beam; and When the first component is in the first position, the second portion is outside the radiation beam and the first portion is aligned with the central beam axis of the radiation beam.

18. The system of claim 16, further comprising: A support is configured to hold the first portion and the second portion of the pre-collimator.

19. The system of claim 18, wherein: The bracket is configured to move between the first position and the second position; When the support is in the first position, the first portion of the pre-collimator is aligned with the central beam axis; and When the support is in the second position, the second portion of the pre-collimator is aligned with the central beam axis.

20. The system of claim 18, further comprising: a first beam hardening filter coupled to the support adjacent the first portion of the pre-collimator; as well as A second beam hardening filter is coupled to the support adjacent the second portion of the pre-collimator.

21. The system of claim 14, wherein: The second component of the pre-collimator is closer to the radiation source than the first component of the pre-collimator.

22. The system of claim 12, wherein The shape filter comprises a first surface and a second surface opposite to the first surface, The first surface comprises a curved surface configured to face toward the radiation source, and The second surface includes a planar surface.

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