A CT scanner front collimator and its manufacturing method

Abstract

This invention discloses a CT scanner front collimator and its manufacturing method, relating to the field of medical device technology. The CT scanner front collimator includes a filtering device, a slicing device, and a housing. The filtering device includes a filtering assembly and a filtering guide rail, with the filtering assembly slidably connected to the filtering guide rail. The slicing device includes a first slicing assembly, a second slicing assembly, and a slicing guide rail, with the slicing assembly slidably connected to the slicing guide rail, forming an adjustable slicing opening between the slicing assemblies. The housing includes two side plates and a detachable bottom plate. The two side plates are arranged opposite each other and connected by two crossbeams. The two filtering guide rails are respectively fixed to the upper planes of the two crossbeams, and the two slicing guide rails are respectively fixed to the lower planes of the two crossbeams. The bottom plate has a bottom plate opening. This invention achieves miniaturization and structural optimization of the collimator, reduces radiation dose by combining tungsten steel plate shielding, supports a compact layout for multi-source CT scanners, and meets the requirements of larger scanning aperture, lighter rotating body weight, and higher rotation speed for CT scanners.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a CT machine front collimator and a manufacturing method thereof. BACKGROUND

[0002] Unlike single-source CT machines that usually only pursue reducing the size of the front collimator in the Y direction to obtain a larger scanning aperture size, multi-source CT machines have multiple groups of light paths, and there are more requirements for the compact design of the multiple groups of light paths. For example, a three-source CT machine includes three groups of x-ray light paths, each of which is arranged with an x-ray source, a front collimator, and a detector. Each group of x-ray light paths needs to cover a common central scanning area (FOV), and the diameter of the FOV needs to be large enough to cover the scanning parts of most patients. However, the expansion of the FOV leads to an increase in the arc length occupied by the detector on the ring-shaped gantry, making the spatial arrangement of the three groups of x-ray sources, front collimators, and detectors challenging. To address this issue, one common approach is to increase the distance (SDD) between the focal point of the x-ray source and the detector or to reduce the space occupied by the x-ray source and the front collimator. However, the increase in SDD reduces the CT image resolution, and due to the attenuation characteristics of x-rays, a larger SDD requires a larger radiation dose to maintain the signal-to-noise ratio, resulting in an increase in the amount of radiation received by the patient. The other approach is to arrange the front collimator in the narrow triangular area formed by the edges of the three groups of light paths, thereby reducing the size of the front collimator in the X and Y directions and reducing its occupation of the intersection area of the three groups of light paths, which is a key balance between spatial constraints and performance that avoids light path obstruction without sacrificing SDD or increasing radiation dose.

[0003] In the prior art, the collimator is mostly a box structure with four closed sides, only the upper and lower two sides are open for collimating rays and mounting internal parts. Cast aluminum or cast steel is used as the box material, and a lead shielding layer is attached inside. This structure has high processing precision requirements, and the closed box around the four sides makes it very inconvenient to disassemble and assemble the internal parts. Moreover, the structure is complex, large in size and weight, and there are technical bottlenecks in the complexity of the structure, size and weight, maintenance convenience, and adaptability to multi-source CT machines. There is an urgent need for a small, lightweight, and multi-source CT machine compatible collimator design. SUMMARY

[0004] In view of the above-mentioned defects or shortcomings in the prior art, the present application provides a CT machine front collimator and a manufacturing method thereof. Through the open box frame and shared beam design, the structure size of the front collimator is optimized, realizing the miniaturization, lightweight, and high precision of the CT machine front collimator, and meeting the compact layout requirements of multi-source CT machines.

[0005] In one aspect of the present application, a CT machine front collimator is provided, comprising:

[0006] Filtering device, slicing device and box

[0007] The filtering device comprises a filtering assembly and two filtering rails, and the filtering assembly is slidably connected with the two filtering rails arranged in parallel at both ends.

[0008] The slicing device comprises a first slicing assembly, a second slicing assembly and two slicing rails arranged in parallel, and the two ends of the first slicing assembly and the second slicing assembly are slidably connected with the two slicing rails respectively, and the first slicing assembly and the second slicing assembly form a slicing opening with adjustable opening size between them.

[0009] The box comprises two side plates and a detachable bottom plate, the two side plates are oppositely arranged and connected through two cross beams, the two filtering rails are fixed on the upper planes of the two cross beams respectively, the two slicing rails are fixed on the lower planes of the two cross beams respectively, and the bottom plate is provided with a bottom plate opening.

[0010] Further, the filtering assembly comprises a plurality of filters, a filter fixing seat, a filtering motor and two filtering sliders, the plurality of filters are fixed on the filter fixing seat in parallel, the filter fixing seat is fixed with the filtering sliders at both ends respectively, the filtering sliders are slidably connected with the filtering rails, and the filtering motor is connected with the filter fixing seat and drives the filter fixing seat to slide along the filtering rails through the two filtering sliders, so as to switch different filters.

[0011] Further, the first slicing assembly comprises a first slice, a first slice fixing seat, a first slice motor and two first slice sliders, the first slice is fixed on the first slice fixing seat, the first slice fixing seat is connected with the first slice sliders at both ends respectively, the first slice sliders are slidably connected with the slicing rails, and the first slice motor is connected with the first slice fixing seat and drives the first slice fixing seat to slide along the slicing rails through the first slice sliders, so as to drive the first slice to move axially along the slicing rails.

[0012] The second slicing assembly comprises a second slice, a second slice fixing seat, a second slice motor and two second slice sliders, the second slice is fixed on the second slice fixing seat, the second slice fixing seat is connected with the second slice sliders at both ends respectively, the second slice sliders are slidably connected with the slicing rails, and the second slice motor is connected with the second slice fixing seat and drives the second slice fixing seat to slide along the slicing rails through the second slice sliders, so as to drive the second slice to move axially along the slicing rails.

[0013] The first slice and the second slice move axially relatively or oppositely along the slicing rails.

[0014] Further, the two side edges of the bottom plate on the same side of the cross beam are provided with folded edges.

[0015] Further, the filter comprises a flat filter and an arc-shaped filter.

[0016] Further, the first slice and the second slice shield x-rays outside the slice opening to adjust the x-ray layer thickness, and the bottom plate shields x-rays outside the bottom plate opening to limit the x-ray width.

[0017] Further, the surface of the cross beam of the box is covered with a detachable cover plate, and the top of the box is covered with a detachable cover plate comprising an optical path entrance to shield x-ray scattering lines.

[0018] Further, the cover plate, the first slice, the second slice and the bottom plate are made of tungsten steel plate.

[0019] Further, the first slice and the second slice are arranged in an arc shape with the focus of x-rays as the center.

[0020] Another aspect of the present application provides a manufacturing method of the CT machine front collimator as described above, comprising:

[0021] Two tangent lines are drawn from the focus of x-rays to the central scanning area, and the distance between the two intersection points of the tangent lines and the plane of the bottom plate of the front collimator is the opening size of the bottom plate opening along the radial direction of the slice guide rail.

[0022] The two arc-shaped edges of the detector are connected with the focus of x-rays, and the distance between the two intersection points of the two connecting lines and the plane of the lowest points of the first slice and the second slice is the maximum opening size of the slice opening along the axial direction of the slice guide rail, wherein the opening size of the bottom plate opening of the front collimator along the axial direction of the slice guide rail is not less than the maximum opening size of the slice opening along the axial direction of the slice guide rail.

[0023] The CT machine front collimator and the manufacturing method thereof provided by the present application adopt an open box frame and a shared cross beam design, which facilitates the disassembly and maintenance of the internal parts of the collimator, simplifies the fixing method, and effectively shields x-ray scattering radiation by combining the tungsten steel plate covering and the bottom plate folding process, thereby reducing the radiation dose, effectively reducing the size of the collimator in the X direction and the Y direction, and reducing the overall weight. It provides key technical support for the compact layout requirements of multiple x-ray optical paths of multi-source CT machines, and can meet the requirements of larger scanning aperture, lighter rotating body weight and higher rotating speed of CT machines. BRIEF DESCRIPTION OF DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings:

[0025] Figure 1 is a structural schematic diagram of a CT machine front collimator provided by an embodiment of the present application;

[0026] Figure 2 is a slice device structural schematic diagram of a CT machine front collimator provided by an embodiment of the present application;

[0027] Figure 3 is a bottom view of a CT machine front collimator without a bottom plate provided by an embodiment of the present application;

[0028] Figure 4 is a right view of a CT machine front collimator provided by an embodiment of the present application;

[0029] Figure 5 is a first view angle diagram of a bottom plate of a CT machine front collimator provided by an embodiment of the present application;

[0030] Figure 6 is a second view angle diagram of a bottom plate of a CT machine front collimator provided by an embodiment of the present application;

[0031] Figure 7 is a structural schematic diagram of a three-source CT machine provided by an embodiment of the present application.

[0032] 1-front collimator; 2-x-ray source; 3-detector; 11-filtering device; 12-slice device; 13-box; 111-filtering assembly; 1111-filter; 1112-filter fixing seat; 1113-filter motor; 1114-filter sliding block; 112-filter guide rail; 121-first slice assembly; 1211-first slice; 1212-first slice fixing seat; 1213-first slice motor; 1214-first slice guide rail; 122-second slice assembly; 1221-second slice; 1222-second slice fixing seat; 1223-second slice motor; 1224-second slice sliding block; 123-slice guide rail; 124-slice opening; 131-side plate; 132-bottom plate; 133-cross beam; 134-bottom plate opening; 135-folded edge. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting thereof. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0035] It should be understood that although the terms first, second, third, etc. can be employed in describing the acquisition module in the embodiments of the application, these acquisition modules should not be limited by these terms. These terms are only used to distinguish one acquisition module from another.

[0036] Depending on the context, the word "if" can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting", as used herein. Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the stated condition or event]" or "in response to detecting [the stated condition or event]", depending on the context.

[0037] It should be noted that the terms "upper", "lower", "left", "right", and the like as used herein are described based on the angle shown in the drawings, and should not be construed as limiting the embodiments of the application. In addition, in the context, it should also be understood that when referring to an element formed "on" or "under" another element, it can be directly formed "on" or "under" another element, or indirectly formed "on" or "under" another element through an intermediate element.

[0038] With reference to Figures 1-6 The CT machine pre-collimator 1 provided by the embodiments of the application comprises:

[0039] The filtering device 11, the slicing device 12 and the box body 13;

[0040] The filtering device 11 comprises a filtering assembly 111 and two filtering guide rails 112, and the filtering assembly 111 is slidably connected with the two filtering guide rails 112 arranged in parallel at both ends;

[0041] Specifically, referring to Figure 1The filtering assembly 111 comprises a plurality of filters 1111, a filter fixing seat 1112, a filter motor 1113 and two filter sliding blocks 1114. The plurality of filters 1111 are fixed in parallel on the filter fixing seat 1112. The filter fixing seat 1112 is fixed with the two filter sliding blocks 1114 at two ends respectively. The filter sliding blocks 1114 are in sliding connection with the filtering guide rail 112. The filter motor 1113 is connected with the filter fixing seat 1112 and drives the filter fixing seat 1112 to slide along the filtering guide rail 112 through the two filter sliding blocks 1114, so as to switch different filters 1111. Optionally, the plurality of filters 1111 comprise filters of different materials and different thicknesses, such as flat filters and arc-shaped filters, which are used to switch different filters for selectively filtering x-rays according to different scanning requirements, remove low-energy x-rays, and optimize imaging quality and reduce radiation dose.

[0042] Referring to Figure 2 The slicing device 12 comprises a first slicing assembly 121, a second slicing assembly 122 and two parallel slicing guide rails 123. The two ends of the first slicing assembly 121 and the second slicing assembly 122 are in sliding connection with the two slicing guide rails 123 respectively. The first slicing assembly 121 and the second slicing assembly 122 form a slicing opening 124 with an adjustable opening size therebetween.

[0043] Specifically, the first slicing assembly 121 comprises a first slice 1211, a first slice fixing seat 1212, a first slice motor 1213 and two first slice sliding blocks 1214. The first slice 1211 is fixed on the first slice fixing seat 1212. The first slice fixing seat 1212 is connected with one first slice sliding block 1214 at two ends respectively. The first slice sliding block 1214 is in sliding connection with the slicing guide rail 123. The first slice motor 1213 is connected with the first slice fixing seat 1212 and drives the first slice fixing seat 1212 to slide along the slicing guide rail 123 through the first slice sliding block 1214, thereby driving the first slice 1211 to move axially along the slicing guide rail 123.

[0044] The second slicing assembly 122 comprises a second slice 1221, a second slice fixing seat 1222, a second slice motor 1223 and two second slice sliding blocks 1224. The second slice 1221 is fixed on the second slice fixing seat 1222. The second slice fixing seat 1222 is connected with one second slice sliding block 1224 at two ends respectively. The second slice sliding block 1224 is in sliding connection with the slicing guide rail 123. The second slice motor 1223 is connected with the second slice fixing seat 1222 and drives the second slice fixing seat 1222 to slide along the slicing guide rail 123 through the second slice sliding block 1224, thereby driving the second slice 1221 to move axially along the slicing guide rail 123.

[0045] Furthermore, the first slice 1211 and the second slice 1221 are configured as arcs centered on the focal point of the X-ray. They move relative to or opposite to each other along the axial direction of the slice guide rail 123 to form a slice opening 124. The first slice 1211 and the second slice 1221 are made of shielding material to shield the X-rays outside the slice opening 124. Preferably, the first slice 1211 and the second slice 1221 are made of tungsten steel plate. By adjusting the opening width of the slice opening 124 in the long axis direction of the human body, i.e., the Z direction, the thickness of the X-ray layer passing through the slice opening 124 can be adjusted, thereby limiting the scanning imaging range of X-rays in the Z direction and reducing the radiation dose. The smaller the X-ray layer thickness, the higher the resolution of the CT image.

[0046] See Figure 1 , 3 The housing 13 includes two side plates 131 and a detachable bottom plate 132. The two side plates 131 are arranged opposite each other and connected by two crossbeams 133. Two filter guide rails 112 are respectively fixed on the upper plane of the two crossbeams 133, and two slicing guide rails 123 are respectively fixed on the lower plane of the two crossbeams 133. The open structure of the two sides of the housing in the X direction reduces the size of the collimator in the X direction and facilitates the disassembly and maintenance of the internal components of the collimator. The upper and lower functional areas of the filter layer and the slicing layer are fixed and connected by a common crossbeam, which simplifies the fixing method, saves the size of the collimator in the Y direction, and optimizes the space utilization of the collimator.

[0047] See Figure 3 , 4 The filter motor 1113, the first slice motor 1213, and the second slice motor 1223 are fixed to the outer walls of the two side plates;

[0048] See Figure 5 , 6 The base plate 132 has a rectangular base plate opening 134, directly below the slice opening 124. X-rays, starting from the X-ray source focal point, pass sequentially through the filter 1111, the slice opening 124, and the base plate opening 134 to reach the detector. Preferably, the base plate 132 and the crossbeam 133 have folded edges 135 on their two sides. For example, the CT scanner collimator provided in this embodiment can be applied to a three-source CT scanner. (See reference...) Figure 7 The illustrated three-source CT scanner includes three sets of X-ray beam paths. Each set of X-ray beam paths is equipped with an X-ray source 2, a front collimator 1, and a detector 3. Each set of X-ray beam paths needs to cover a common central scanning area (FOV). The two sides of the collimator base plate in one set of X-ray beam paths can be set as parallel folded edges according to the edge path direction of the other two sets of X-ray beam paths. The angle and length of the folded edges can also be changed according to the X-ray beam paths and space requirements. By making full use of the triangular area, the internal space of the collimator can be increased, or the required space can be made up for other components of the CT scanner.

[0049] Optionally, the open surface of the crossbeam 133 of the box 13 is covered by a detachable cover plate, and the upper open surface of the box 13 is covered by a detachable cover plate including the light path entrance, which can shield x-ray scattering lines, preferably, the cover plate (not shown in the figure) of the embodiment is made of tungsten steel plate, which has higher hardness and better ray shielding effect, can reduce the lead shielding layer required in the traditional collimator box, further reduce the size of the box, the tungsten steel bottom plate 132 shields the x-rays outside the bottom plate opening 134 to limit the x-ray width, that is, the range of x-rays in the X direction, and reduce the radiation dose.

[0050] The CT machine front collimator provided by the embodiment of the present application adopts an open box frame and a shared crossbeam design, which facilitates the disassembly and maintenance of the internal parts of the collimator, simplifies the fixing mode, effectively shields x-ray scattering radiation by combining the tungsten plate covering and the bottom plate folding process, reduces the radiation dose, effectively reduces the size of the collimator in the X direction and the Y direction, and reduces the overall weight, thereby providing key technical support for the compact layout requirements of multiple x-ray light paths of a multi-source CT machine, and meeting the requirements of a larger scanning aperture, a lighter rotating body weight and a higher rotating speed of the CT machine. In addition, the CT machine front collimator provided by the embodiment can also be applied to a single-source CT machine.

[0051] Another embodiment of the present application provides a manufacturing method of the CT machine front collimator as described above, comprising:

[0052] Two tangent lines are drawn from the focus of the x-ray to the central scanning area, and the distance between the two intersection points of the two tangent lines and the plane of the bottom plate 132 of the front collimator is the opening size of the bottom plate opening 134 in the radial direction of the slice guide rail 123;

[0053] The two arc-shaped edges of the detector 3 are connected with the focus of the x-ray, and the distance between the two intersection points of the two connecting lines and the plane of the lowest points of the first slice 1211 and the second slice 1221 is the maximum opening size of the slice opening 124 in the axial direction of the slice guide rail 123, wherein the opening size of the bottom plate opening 134 of the front collimator in the axial direction of the slice guide rail 123 is not less than the maximum opening size of the slice opening 124 in the axial direction of the slice guide rail 123.

[0054] When applied to the three-source CT machine as shown in Figure 7 The edge rays of the other two groups of x-ray light paths distributed on both sides of the front collimator 1 in a group of x-ray light paths are the limit position size of the front collimator 1 in the X direction, and the radial distance between the position of the three light paths and the x-ray source is not affected, which is the limit position size of the front collimator 1 in the Y direction;

[0055] In the three-source CT machine, the three groups of x-ray light paths have common FOV and same SDD size, each group of x-ray source can work alone or three groups work simultaneously, each group of light path is equivalent to a single-source CT machine, according to different design requirements, the FOV and SDD of the three groups of x-ray light paths can be designed as different sizes, and the size of the front collimator 1 changes accordingly.

[0056] The above description is merely the preferred embodiments of the present application. It should be understood by those skilled in the art that the disclosed scope of the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by any combinations of the above technical features or equivalent features without departing from the disclosed concept. For example, the above features are replaced with the technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. A CT machine pre-collimator, characterized by, A filter device, a slicing device and a box body are provided for a multi-source CT machine. The filter device comprises a filter assembly and two filter rails, and the filter assembly is slidably connected to the two filter rails. The slicing device comprises a first slicing assembly, a second slicing assembly and two parallel slicing rails, and the first slicing assembly and the second slicing assembly are slidably connected to the two slicing rails. The box body comprises two side plates and a detachable bottom plate, and the two side plates are oppositely arranged and connected by two cross beams. The two filter rails are fixed to the upper planes of the two cross beams, and the two slicing rails are fixed to the lower planes of the two cross beams. The two side edges of the bottom plate on the same side of the cross beam are provided with folded edges.

2. A CT machine pre-collimator according to claim 1, characterized in that, The filter assembly comprises a plurality of filters, a filter fixing seat, a filter motor and two filter sliding blocks, and the filters are fixed on the filter fixing seat.

3. A CT machine pre-collimator according to claim 1, wherein, The filter fixing seat is fixed with the filter sliding blocks at both ends, and the filter sliding blocks are slidably connected to the filter rails. The filter motor is connected to the filter fixing seat and drives the filter fixing seat to slide along the filter rails through the two filter sliding blocks, so as to switch different filters. The first slicing assembly comprises a first slicing, a first slicing fixing seat, a first slicing motor and two first slicing sliding blocks.

4. A CT machine pre-collimator according to claim 2, wherein, The first slicing is fixed on the first slicing fixing seat, and the first slicing fixing seat is connected with the first slicing sliding blocks at both ends.

5. A CT machine pre-collimator according to claim 3, wherein, The first slicing motor is connected to the first slicing fixing seat and drives the first slicing fixing seat to slide along the slicing rails through the first slicing sliding blocks, so as to drive the first slicing to move axially along the slicing rails.

6. A CT machine pre-collimator according to claim 5, wherein, The second slicing assembly comprises a second slicing, a second slicing fixing seat, a second slicing motor and two second slicing sliding blocks.

7. A CT machine pre-collimator according to claim 6, wherein, The second slicing is fixed on the second slicing fixing seat, and the second slicing fixing seat is connected with the second slicing sliding blocks at both ends. The second slicing motor is connected to the second slicing fixing seat and drives the second slicing fixing seat to slide along the slicing rails through the second slicing sliding blocks, so as to drive the second slicing to move axially along the slicing rails. The first slicing and the second slicing move axially and oppositely along the slicing rails. The first slicing and the second slicing shield x-rays outside the slicing opening to adjust the x-ray layer thickness, and the bottom plate shields x-rays outside the bottom plate opening to limit the width of x-rays. The surface of the cross beam of the box body is covered with a detachable cover plate, and the top of the box body is covered with a detachable cover plate comprising a light path inlet to shield x-ray scattering lines. The cover plate, the first slicing, the second slicing and the bottom plate are made of tungsten steel plate.

8. A CT machine pre-collimator according to claim 3, wherein, The first slice and the second slice are arranged in an arc shape with the focus of the x-rays as the center.

9. A method of manufacturing a CT pre-collimator according to any one of claims 1-8, characterized by, Comprise: Two tangent lines are drawn from the focus of the x-rays to the center of the scanning area, and the distance between the two intersection points of the two tangent lines and the plane of the bottom plate of the front collimator is the opening size of the bottom plate opening along the radial direction of the slice guide rail; The two arc edges of the detector are connected with the focus of the x-rays, and the distance between the two intersection points of the two connecting lines and the plane of the lowest points of the first slice and the second slice is taken as the maximum opening size of the slice opening along the axial direction of the slice guide rail, wherein the opening size of the bottom plate opening of the front collimator along the axial direction of the slice guide rail is not less than the maximum opening size of the slice opening along the axial direction of the slice guide rail.

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