CN218075022U - Anti-scatter grid and imaging system - Google Patents
Anti-scatter grid and imaging system Download PDFInfo
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- CN218075022U CN218075022U CN202122639557.8U CN202122639557U CN218075022U CN 218075022 U CN218075022 U CN 218075022U CN 202122639557 U CN202122639557 U CN 202122639557U CN 218075022 U CN218075022 U CN 218075022U
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Abstract
The utility model provides an anti-scattering grid and an imaging system, wherein the anti-scattering grid comprises a plurality of grid pieces arranged at intervals, and the extension lines of the grid pieces are converged at an intersection point; the grid sheets comprise a plurality of first grid sheets arranged along a first direction and a plurality of second grid sheets arranged along a second direction, and an included angle between the first direction and the second direction is greater than 0 degree and smaller than or equal to 90 degrees. The utility model ensures the receiving efficiency of the anti-scattering grid to the large cone angle transmitting ray by setting the extension lines of the grid pieces to be converged at an intersection point when the anti-scattering grid of the utility model is applied to an imaging system; meanwhile, the projection area of the grid plate along the emission direction of the emitted rays can be reduced, the shielding of the grid plate on a pixel area of the ray receiving unit is reduced, the imaging performance is improved, and the anti-scattering in the two-dimensional direction can be realized by arranging the grid plate along the two directions.
Description
Technical Field
The utility model relates to an imaging technology field, concretely relates to anti-scatter grid and imaging system.
Background
During imaging, emitted radiation is directed from a radiation source toward an object to be imaged. When an image of an object to be imaged is created using the emission rays, a part of the emission rays directly pass through the object to be imaged and are incident to the ray receiving unit to generate an image; another portion of the emitted radiation is scattered at the object to be imaged and generates scattered radiation which reaches the radiation receiving unit at an angle which deviates significantly from the original path of the emitted radiation. The incidence of scattered radiation on the radiation receiving unit causes artifacts, thereby reducing the contrast of the image.
The influence of scattered radiation on the image is reduced by using an anti-scatter grid in the prior art. As shown in fig. 1, the scattered radiation is absorbed by the grid sheet 1' in the anti-scatter grid 1 to eliminate the scattered radiation.
The anti-scatter grid 1 in the prior art has the following problems: (1) The grid pieces 1 'of the anti-scatter grid 1 are parallel to each other, and along the extending direction of the emitted ray, the projection of the grid pieces 1' on the ray receiving unit can occupy the pixel area of the ray receiving unit, so that the available pixel area of the ray receiving unit is reduced, and the imaging performance of the ray receiving unit is further influenced; (2) Due to the shielding of the adjacent grid pieces 1', the transmitted rays cannot penetrate through the two ends of the anti-scattering grid 1 to reach the ray receiving unit, so that the transmission efficiency of the anti-scattering grid on the large cone angle transmitted rays is low, and the imaging performance of the ray receiving unit is further influenced; and (3) the anti-scattering in one dimension can be realized.
SUMMERY OF THE UTILITY MODEL
In view of the above, there is a need to provide an anti-scatter grid and an imaging system, so as to solve the technical problems in the prior art that the available pixel area of a radiation receiving unit is reduced due to a grid sheet, the transmission efficiency of the anti-scatter grid to a large cone angle emitted radiation is low, and the anti-scatter in a two-dimensional direction cannot be realized, so that the imaging performance of the radiation receiving unit is poor.
On one hand, the utility model provides an anti-scattering grid, the anti-scattering grid includes a plurality of grid pieces that set up at interval, the extension lines of a plurality of grid pieces assemble in an intersection point;
the grid sheets comprise a plurality of first grid sheets arranged along a first direction and a plurality of second grid sheets arranged along a second direction, and an included angle between the first direction and the second direction is greater than 0 degree and smaller than or equal to 90 degrees.
In some possible implementations, each of the plurality of grid sheets includes a first side and a second side that are disposed opposite each other, and a minimum spacing between the first side and the second side is greater than or equal to 100 micrometers.
In some possible implementations, the grid sheet includes a top surface and a bottom surface that are disposed opposite to each other, both ends of the top surface and the bottom surface are respectively connected to the first side surface and the second side surface, the grid sheet includes an upper grid sheet close to the top surface and a lower grid sheet close to the bottom surface, and a distance between the first side surface and the second side surface at least at a portion of the lower grid sheet is greater than a distance between the first side surface and the second side surface at the upper grid sheet.
In some possible implementations, the grid sheet is made of a first material having an atomic number greater than or equal to 74, and the content of the first material is greater than or equal to 90%.
In some possible implementations, the angle between the bottom surface centerline of the first grid sheet and the bottom surface centerline of the second grid sheet is 90 °.
In some possible implementations, a plurality of the first grid sheets are arranged in a staggered manner along the second direction, and/or a plurality of the second grid sheets are arranged in a staggered manner along the first direction.
The utility model also provides an imaging system, which comprises a ray source, a ray receiving unit and an anti-scattering grid; the ray source is used for emitting emission rays; the ray receiving unit is used for receiving the emitted rays; the anti-scatter grid is arranged between the ray receiving unit and the ray source;
wherein the anti-scatter grid is the anti-scatter grid described in any one of the above possible implementation manners.
In some possible implementations, each of the grid plates is arranged along an emission direction of the emission ray corresponding to the grid plate.
In some possible implementations, the ray receiving unit includes a plurality of ray receiving sub-units and a plurality of splicing gaps formed by the plurality of ray receiving sub-units, and along the emission direction of the emitted ray, the projection of the grid sheet on the ray receiving unit at least partially coincides with the splicing gap corresponding to the grid sheet.
In some possible implementations, along the emission direction of the emitted ray, a center line of a projection of the grid sheet on the ray receiving unit coincides with a center line of the stitching slit corresponding to the grid sheet.
The beneficial effects of adopting the embodiment are as follows: the utility model provides an anti-scatter grid assembles in an nodical through the extension line that sets up a plurality of grid pieces that the interval set up, compares a plurality of grid pieces that the parallel interval set up among the prior art, will the utility model provides an anti-scatter grid is when being applied to imaging system, has improved the transmission ray of transmission ray incidence to the interval between a plurality of grid pieces, and greatly reduced is by the transmission ray that the grid piece sheltered from, effectively guarantees anti-scatter grid to big cone angle transmission ray's receiving efficiency. Furthermore, by arranging the extension lines of the grid pieces arranged at intervals to converge at an intersection point, the projection area of the grid pieces along the emission direction of the emitted rays can be reduced, so that the situation that the projection of the grid pieces occupies the effective area of a ray receiving unit in an imaging system when the anti-scattering grid is applied to the imaging system is avoided, and the imaging performance of the imaging system is improved.
Furthermore, the grid pieces comprise a plurality of first grid pieces arranged along the first direction and a plurality of second grid pieces arranged along the second direction, and an included angle between the first direction and the second direction is larger than 0 degree and smaller than or equal to 90 degrees, so that two-dimensional anti-scattering in the first direction and the second direction can be realized, and the anti-scattering capability of the anti-scattering grid is further improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a schematic diagram of a prior art imaging system;
fig. 2 is a schematic two-dimensional structure diagram of an anti-scattering grid according to an embodiment of the present invention;
fig. 3 is a schematic three-dimensional structure diagram of an anti-scatter grid according to an embodiment of the present invention;
fig. 4 is a schematic two-dimensional structure diagram of a grid sheet provided by an embodiment of the present invention;
fig. 5 is another schematic three-dimensional structure diagram of an anti-scatter grid according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an imaging system according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of grid plate redundancy according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a first arrangement position of the anti-scatter grid and the radiation receiving unit according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of a second arrangement position of the anti-scatter grid and the radiation receiving unit according to an embodiment of the present invention;
fig. 10 is another schematic structural diagram of an anti-scatter grid according to an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by the skilled in the art without creative work belong to the protection scope of the present invention.
In the description of the embodiments of the present invention, "a plurality" means two or more unless otherwise specified. The terms "comprises" and/or "comprising" mean the presence of means, acts, steps, elements, operations, and/or components, but do not preclude the presence or addition of one or more other means, acts, steps, elements, operations, components, and/or groups thereof.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.
The utility model provides an anti-scatter grid and imaging system explains below respectively.
As shown in fig. 2 and 3, an anti-scatter grid 100 provided by an embodiment of the present invention includes a plurality of grid pieces 110 arranged at intervals, and extension lines of the plurality of grid pieces 110 converge at an intersection point;
the plurality of grid sheets 110 includes a plurality of first grid sheets 1101 arranged along a first direction a and a plurality of second grid sheets 1102 arranged along a second direction B, an angle between the first direction a and the second direction B is greater than 0 ° and less than or equal to 90 °.
Compared with the prior art a plurality of grid pieces that parallel interval set up, the embodiment of the utility model provides an anti-scatter grid 100 assembles in an nodical through the extension line that sets up a plurality of grid pieces 110 that the interval set up, realizes will the utility model discloses when anti-scatter grid 100 that provides in real time is applied to the ray receiving unit, improve the transmission ray incident to the spaced transmission ray between a plurality of grid pieces 110, greatly reduced is by the transmission ray that grid piece 110 sheltered from, effectively guarantees anti-scatter grid 100 to the receiving efficiency of big cone angle transmission ray. Furthermore, by arranging that the extension lines of the grid pieces 110 arranged at intervals are converged at an intersection point, the projection area of the grid pieces 110 along the emission direction of the emitted rays can be reduced, so that when the anti-scatter grid is applied to an imaging system, the projection of the grid pieces 110 occupies the effective area of a ray receiving unit in the imaging system, and the imaging performance of the imaging system is improved.
By arranging the plurality of first grid sheets 1101 along the first direction a and the plurality of second grid sheets 1102 along the second direction B, scattered rays along the first direction a and the second direction B can be eliminated at the same time, the anti-scatter capability of the anti-scatter grid 100 is improved, the purity of the emitted rays 200 passing through the anti-scatter grid 100 is further improved, and artifacts and other phenomena caused by the scattered rays 300 are avoided.
In an embodiment of the present invention, as shown in fig. 2, during the emitting radiation 200 is emitted to the anti-scatter grid 100, a part of the emitting radiation 200 is incident to the anti-scatter grid 100 along its original emitting path; another portion of the emitted radiation 200 scatters during transmission and generates scattered radiation 300 to the anti-scatter grid 100, the emission path of the scattered radiation 300 being significantly offset from the original emission path of the emitted radiation. At this time, the scattered ray 300 is absorbed by the grid plate 110.
In fig. 2 and 3, the dotted line is the emission ray 200, and the solid line with arrows is the scattered ray 300.
In a specific embodiment of the present invention, the emission ray 200 is a cone beam ray, namely: each of the emitted rays 200 are non-parallel and each of the emitted rays 200 has an intersection.
In a preferred embodiment of the present invention, as shown in fig. 4, the grid sheet 110 includes a first side 111 and a second side 112, and since the absorption of the scattered ray 300 by the grid sheet 110 is proportional to the thickness of the grid sheet 110, in order to avoid the scattered ray 300 affecting the imaging, in some embodiments of the present invention, the minimum distance between the first side 111 and the second side 112 is greater than or equal to 100 micrometers. Namely: the thickness of each location of the grid sheet 110 is greater than or equal to 100 microns.
By setting the thickness of each position of the grid sheet 110 to be greater than or equal to 100 micrometers, the absorption of the grid sheet 110 to the scattered ray 300 can be ensured, the scattered ray 300 is prevented from penetrating through the grid sheet 110 to affect imaging, and the imaging contrast is improved.
In some embodiments of the present invention, as shown in fig. 4, the grid sheet 110 includes a top surface 113 and a bottom surface 114 disposed opposite to each other, both ends of the top surface 113 and the bottom surface 114 are connected to the first side surface 111 and the second side surface 112 respectively, the grid sheet 110 includes an upper grid sheet near the top surface 113 and a lower grid sheet near the bottom surface 114, and a distance between at least a portion of the first side surface 111 and the second side surface 112 of the lower grid sheet is greater than a distance between the first side surface 111 and the second side surface 112 of the upper grid sheet.
Wherein, in one particular embodiment, the upper grid sheet is part of the top surface 113 to the centerline between the top surface 113 and the bottom surface 114; the lower grid sheet is part of the bottom surface 114 to the centerline between the top surface 113 and the bottom surface 114.
When the shot ray 200 is a cone beam ray, the shot ray 200 gradually diverges in a direction from the top surface 113 to the bottom surface 114, and thus, by setting the interval between the first side surface 111 and the second side surface 112 at the lower grid plate to be larger than the interval between the first side surface 111 and the second side surface 112 at the upper grid plate, the ability of the lower grid plate to absorb the scattered ray 300 can be improved.
In some embodiments of the present invention, as shown in fig. 3, the distance between the first side surface 111 and the second side surface 112 gradually increases in a direction from the top surface 113 to the bottom surface 114.
In order to reduce the machining precision and facilitate the machining of the grid sheet 110, in some embodiments of the present invention, the spacing between the first side 111 and the second side 112 is equal.
It should be noted that: since the grid plate 110 is used for absorbing the scattered ray 300, in order to improve the absorption capacity of the grid plate 110 for the scattered ray 300, in some embodiments of the present invention, the material for manufacturing the grid plate 110 includes a first material with an atomic number greater than or equal to 74, and the content of the first material is greater than or equal to 90%.
This is because the larger the atomic number of the first material in the manufacturing materials of the grid plate 110 is, and the higher the content of the first material is, the stronger the absorption capability of the grid plate 110 for the scattered ray 300 is, and therefore, by setting that the manufacturing materials of the grid plate 110 include the first material with the atomic number greater than or equal to 74, and the content of the first material is greater than or equal to 90%, the absorption capability of the grid plate 110 for the scattered ray 300 can be further improved.
In the embodiment of the present invention, the first material may be any one of tungsten, lead, uranium, gold, and the like.
It should be noted that: when the atomic number of the material of which grid sheet 110 is made is greater than 74, the spacing between first side 111 and second side 112 may be less than 100 microns, due to: a material with an atomic number greater than 74 may have a higher absorption of scattered radiation 300, which may suitably reduce the separation between the first side 111 and the second side 112.
In some embodiments of the present invention, in order to improve convenience in installation and positioning of the grid sheet 110, the anti-scatter grid 100 further includes a connection plate, and the grid sheet 110 is connected to the connection plate.
It should be understood that: in order to avoid additional scattered radiation due to the connection plate, the connection plate should be arranged at a position that does not affect the emitted radiation, and the specific arrangement position thereof is not limited herein.
In a specific embodiment of the present invention, the angle between the centerline of the bottom surface of the first grid sheet 1101 and the centerline of the bottom surface of the second grid sheet 1102 is 90 °.
In some embodiments of the present invention, as shown in fig. 3, along the second direction B, the plurality of first grid sheets 1101 are staggered, that is: along the second direction B, the plurality of first grid sheets 1101 are not located on the same straight line.
In some embodiments of the present invention, as shown in fig. 5, along the second direction B, the plurality of first grid sheets 1101 are located on the same straight line.
By arranging along the second direction B, the plurality of first grid pieces 1101 may be arranged in a staggered manner or may not be arranged in a staggered manner (the plurality of first grid pieces 1101 are located on the same straight line), so that the diversity of the arrangement manner of the plurality of first grid pieces 1101 can be increased, and the applicability of the anti-scatter grid 100 can be improved.
It should be noted that: in some embodiments of the present invention, along the first direction a, the plurality of second grid sheets 1102 may also be disposed in a staggered manner or disposed in a non-staggered manner, which is not described herein again.
The embodiment of the present invention further provides an imaging system, as shown in fig. 6, the imaging system 10 includes a ray source 20, a ray receiving unit 40, and an anti-scatter grid 100; the radiation source 20 is used for emitting emission rays 200; the ray receiving unit 40 is used for receiving the emitted ray 200; the anti-scatter grid 100 is disposed between the radiation receiving unit 40 and the radiation source 20;
the anti-scatter grid 100 is the anti-scatter grid 100 described in any one of the above-mentioned embodiments of the anti-scatter grid.
In a specific embodiment of the present invention, as shown in fig. 6, the radiation source 20 emits the emission radiation 200, and after the emission radiation 200 reaches the object 30 to be imaged, a part of the emission radiation 200 directly passes through the interval between the object 30 to be imaged and the grid plate 110 along the original emission path and then enters the radiation receiving unit 40 to generate an image; another portion of the emitted radiation 200 is scattered at the object 30 to be imaged and generates scattered radiation 300 reaching the anti-scatter grid 100, the emission path of the scattered radiation 300 deviating significantly from the original emission path of the emitted radiation 200. At this time, the scattered ray 300 is absorbed by the grid plate 110.
It should be noted that: the object to be imaged 30 may be any one of a substance, a tissue, an organ, an object, a specimen, a body, and the like. In some embodiments, the object 30 to be imaged may be any one of the head, chest, lung, pleura, mediastinum, abdomen, large intestine, small intestine, bladder, gall bladder, pelvic cavity, diaphysis, blood vessels, and the like.
It should also be noted that: the emitted radiation 200 emitted by the radiation source 20 may be any one of particle radiation or photon radiation. The particle beam includes any one of a seed, an atom, and a heavy ion. The photon ray includes any one of X ray, gamma ray, alpha ray and beta ray.
In one embodiment of the present invention, the emitted radiation 200 emitted by the radiation source 20 is X-rays.
In particular, as the resolution requirement of the radiation receiving unit 40 increases, a small-pixel radiation receiving unit, which refers to the radiation receiving unit 40 formed by combining a plurality of pixel regions having a small size (a pixel size less than 0.2 mm), is developed. Thus, it can be seen that: the small-pixel ray receiving unit may cause a significant reduction in the available pixel area due to the projection occlusion of the grid plate 110, and even cause the small-pixel ray receiving unit to fail to receive the emitted ray 200, resulting in failure to image effectively. The embodiment of the utility model provides an anti-scatter grid 100 assembles in an nodical through the extension line that sets up a plurality of grid pieces 110, can reduce the projection area of grid piece 110 on ray receiving unit 40 the least to it is applicable to little pixel ray receiving unit to make it.
In order to minimize the projected area of the grid plate 110 on the radiation receiving unit 40, in some embodiments of the present invention, each grid plate 110 is arranged along the emission direction of the corresponding emission ray 200 of the grid plate 110.
The embodiment of the utility model provides a through setting up every grid piece and all arranging along the emission direction of emission ray 200 that grid piece 110 corresponds, realize along emission ray 200's emission direction, grid piece 110's projected area is minimum, and then makes it be applicable to little pixel ray receiving element more.
It should be understood that: the grid sheet 110 may be of any suitable shape and/or size. For example: the cross-sectional shape of the grid sheet 110 may be triangular, rectangular, square, trapezoidal, fan-shaped, or other irregular shape.
In a specific embodiment of the utility model, ray receiving element 40 is concatenation ray receiving element, as shown in fig. 5, and ray receiving element 40 is formed by the concatenation of a plurality of ray receiving subunit 41, and it has a large amount of small-size pixels to distribute on each ray receiving subunit 41, and a large amount of small-size pixels form the pixel region for formation of image, two adjacent ray receiving subunit 41 form a concatenation gap 42.
In order to avoid the technical problem of not being able to effectively image when the splicing gap 42 and the grid plate 110 occupy the pixel area of the radiation receiving unit 40 at the same time, in some embodiments of the present invention, as shown in fig. 6, along the emitting direction of the emitted radiation 200, the projection of the grid plate 110 on the radiation receiving unit 40 and the splicing gap 42 at least partially coincide.
By arranging that the projection of the grid sheet 110 on the ray receiving unit 40 is at least partially overlapped with the splicing gap 42, the overlapped part does not occupy the pixel area of the ray receiving unit 40, that is, the occupied area of the projection of the grid sheet 110 on the ray receiving unit 40 on the pixel area of the ray receiving unit 40 along the emitting direction of the emitted ray 200 can be reduced, so that the influence on the pixel area of the ray receiving unit 40 can be reduced, the pixel area available for the ray receiving unit 40 can be improved, and the technical effect of improving the imaging performance of the ray receiving unit 40 can be realized.
In a preferred embodiment of the present invention, the plurality of splicing slits 42 and the plurality of grid sheets 110 correspond one to one, that is: along the emission direction of the emitted ray 200, the projection of each grid plate 110 on the ray receiving unit 40 at least partially coincides with its corresponding splicing slit 42.
By arranging that the projection of each grid plate 110 on the ray receiving unit 40 is at least partially overlapped with the corresponding splicing slit 42 along the emission direction of the emitted ray 200, the occupied area of the projection of the grid plate 110 on the ray receiving unit 40 can be further reduced, the influence of the grid plate 110 on the pixel area of the ray receiving unit 40 can be further reduced, and the available pixel area of the ray receiving unit 40 can be further improved.
Since the thickness of the splicing slit 42 is related to factors such as the manufacturing process and the application scenario of the radiation receiving unit 40, when the factors such as the manufacturing process and the application scenario of the radiation receiving unit 40 are different, the width of the splicing slit 42 may be smaller than, equal to, or larger than the thickness of the grid sheet 110. When the width of the splicing gap 42 is smaller than, equal to, or larger than the thickness of the grid plate 110, the splicing gap 42 and the grid plate 110 are arranged differently.
Therefore, in some embodiments of the present invention, when the thickness of the grid sheet 110 is greater than or equal to the width of the splicing gap 42, the splicing gap 42 corresponding to the grid sheet 110 is completely covered by the projection of the grid sheet 110 on the ray receiving unit 40 along the emitting direction of the emitted ray 200.
It should be noted that: when the thickness of the grating sheet 110 is different at each position, the thickness of the grating sheet 110 in the above-described embodiment refers to the minimum thickness of the grating sheet 110.
When the thickness of the grid plate 110 is greater than or equal to the width of the splicing gap 42, by setting that the projection of the grid plate 110 on the radiation receiving unit 40 along the emission direction of the emission ray 200 completely covers the splicing gap 42 corresponding to the grid plate 110, the projection of the grid plate 110 on the radiation receiving unit 40 can be minimized when the thickness of the grid plate 110 is greater than or equal to the width of the splicing gap 42, so that the area occupying the available pixel area of the radiation receiving unit 40 can be minimized, thereby further improving the imaging efficiency.
In a preferred embodiment of the present invention, along the emitting direction of the emitted radiation 200, the center line of the projection of the grid plate 110 on the radiation receiving unit 40 coincides with the center line of the splicing gap 42 corresponding to the grid plate 110.
By arranging that the center line of the projection of the grid plate 110 on the ray receiving unit 40 coincides with the center line of the splicing gap 42 corresponding to the grid plate 110 along the emission direction of the emitted ray 200, the pixel area failure of one 41 of the ray receiving sub-units on the ray receiving unit 40 caused by the projection of the grid plate 110 on the ray receiving unit 40 due to the fact that the center line of the projection of the grid plate 110 on the ray receiving unit 40 does not coincide with the center line of the splicing gap 42 corresponding to the grid plate 110 and the grid plate 110 is offset can be avoided, the symmetry of the projection of the grid plate 110 on the ray receiving unit 40 on two adjacent pixel areas is realized, the failure of one pixel area is avoided, and the imaging effectiveness of the ray receiving unit 40 is further improved.
In some other embodiments of the present invention, when the thickness of the grid sheet 110 is smaller than the width of the splicing gap 42, along the emitting direction of the emitted ray 200, the projection of the grid sheet 110 on the ray receiving unit 40 is located in the splicing gap 42 corresponding to the grid sheet 110.
Similarly, when the thickness of each position of the grid plate 110 is different, the thickness of the grid plate 110 refers to the minimum thickness of the grid plate 110.
When the thickness of the grid sheet 110 is smaller than the width of the splicing gap 42, the projection of the grid sheet 110 on the ray receiving unit 40 is located in the splicing gap 42 corresponding to the grid sheet 110 by setting the emission direction along the emission ray 200, so that the projection of the grid sheet 110 on the ray receiving unit 40 does not affect the pixel area of the ray receiving unit 40, and the imaging effectiveness is improved. And also provides some redundancy for the arrangement of the grid sheet 110.
It should be noted that: when the thickness of the grid plate 110 is much smaller than the width of the splicing gap 42 (for example, the thickness of the grid plate 110 is 1/4 of the width of the splicing gap 42), two grid plates 110 may be disposed at the splicing gap 42, and a material identical to the material of the grid plate is filled between the two grid plates 110, so as to avoid an excessively large difference between the thickness of the grid plate 110 and the width of the splicing gap 42, and further avoid the splicing gap 42 from receiving a large amount of the emission rays 200, thereby improving the imaging effect.
In an embodiment of the present invention, as shown in fig. 7, when the inclination design error or the machining error occurs during the design or machining of the grid plate 110, the error grid plate 115 and the error grid plate 11 occur5 may include a first error grid slice 1151 and a second error grid slice 1152 that are symmetric to grid slice 110 when no errors are present. The first and second error grid plates 1151 and 1152 may cause an additional projection area l along the emission direction of the emission ray 200 1 ，l 1 The values of (A) are:
where L is the length of the grid sheet 110,
is the angle between the transmitted ray 200 at the grid plate 110 and the ray receiving unit 40; θ is the angle between the first error grid plate 1151 or the second error grid plate 1152 and the grid plate 110.
Taking L as 10mm for example, when θ =1 °,
the time can cause 181 um's extra projection region, and when concatenation gap 42 was 1000um, and grid sheet 110 thickness was 100um, can provide 450 um's extra projection scope respectively in the both sides of concatenation gap 42 central line, from this can know, theta can enlarge to 2.5, promptly: a certain redundancy is provided for the processing and mounting of the grid plate 110, achieving that even if errors occur in the processing and mounting of the grid plate 110, the pixel area of the radiation receiving unit 40 is not obstructed.
From the above description it follows that: the larger the width of the stitching slit 42, the greater the redundancy it provides to the grid sheet 110, i.e.: the larger the width of the stitching slit 42, the less the grid plate 110 may completely coincide with the emission ray 200 emitted by the radiation source 20, and it is also ensured that the pixel area of the radiation receiving unit 40 is not affected. Further, the larger the width of the splicing slit 42 is, the more the center line of the projection of the grid plate 110 on the radiation receiving unit 40 and the center line of the splicing slit 42 corresponding to the grid plate 110 are shifted from each other in the emission direction of the emission radiation 200, the pixel area of the radiation receiving unit 40 is not affected.
In the preferred embodiment of the present invention, when the thickness of the grid plate 110 is equal to the width of the splicing gap 42, the projection of the grid plate 110 on the ray receiving unit 40 and the splicing gap 42 corresponding to the grid plate 110 completely coincide along the emitting direction of the emitted ray 200.
By setting the thickness of the grid plate 110 equal to the width of the splicing slit 42, it may be achieved that the projection of the grid plate 110 on the radiation receiving unit 40 and the splicing slit 42 corresponding to the grid plate 110 completely coincide along the emission direction of the emitted radiation 200. The thickness of the grid plate 110 can be maximized while ensuring that the grid plate 110 does not affect the pixel area of the radiation receiving unit 40, thereby improving the absorption capacity of scattered radiation and ensuring the contrast of imaging.
It should be noted that: in some embodiments of the present invention, along the second direction B, each splicing gap 42 is staggered, in some other embodiments of the present invention, along the second direction B, each splicing gap 42 can also be located on the same straight line.
It should be understood that: the distance between the bottom surface 114 of the grid plate 110 and the radiation receiving unit 40 can be adjusted according to actual conditions, and in some embodiments of the present invention, as shown in fig. 8, the distance between the bottom surface 114 of the grid plate 110 and the radiation receiving unit 40 is very close, for example: when the distance between the bottom surface 114 of the grid plate 110 and the ray receiving unit 40 is less than 1mm, the distance between two adjacent grid plates 110 is equal to the width of the ray receiving subunit 41 along the extending direction of the bottom surface 114, that is:
W 1 ＝W 0
in the formula, W 1 Is the distance between two adjacent grid sheets 110 in the direction of extension of the bottom surfaces 114 of the grid sheets 110; w 0 Is the width of the ray receiving subunit 42.
It should be noted that: as shown in fig. 8, two adjacent grid sheets 110 include a first sub-grid sheet 116 and a second sub-grid sheet 117, and a distance between two adjacent grid sheets 110 refers to: the distance between the sidewall of the first sub-grid piece 116 adjacent to the second sub-grid piece 117 and the sidewall of the second sub-grid piece 117 adjacent to the first sub-grid piece 116.
In some embodiments of the present invention, as shown in fig. 9, the distance between the bottom surface 114 of the grid plate 110 and the ray receiving unit 40 is greater than 1mm, and then the distance between two adjacent grid plates 110 at this time is:
W 2 ＝(L 2 -L 3 )*W 0 /L 2
in the formula, W 2 Is the distance between two adjacent grid plates 110; l is 2 The vertical distance from the radiation source 20 to the radiation receiving unit 40; l is a radical of an alcohol 3 The vertical distance from the bottom surface 114 of the grid sheet 110 to the ray-receiving unit 40; w is a group of 0 The width of the ray receiving subunit 41.
Likewise, as shown in fig. 9, two adjacent grid sheets 110 include a third sub-grid sheet 118 and a fourth sub-grid sheet 119, and the distance between two adjacent grid sheets 110 refers to: the distance between the sidewall of the third sub-grid 118 near the fourth sub-grid 119 and the sidewall of the fourth sub-grid 119 near the third sub-grid 118.
As shown in fig. 9, the angle between the third sub-grid 118 and the ray receiving unit 40 is:
arctan(L 2 /L 1 )
in the formula, L 1 Is the vertical distance between the end of the radiation receiving subunit 41 remote from the radiation source 20 and the radiation source 20.
The included angle between the fourth sub-grid 119 and the ray receiving unit 40 is:
arctan(L 2 /(L 1 -W 0 ))
it should be understood that: the included angle between the first sub-grid sheet 116 and the ray receiving unit 40 is equal to the included angle between the third sub-grid sheet 118 and the ray receiving unit 40; the angle between the second sub-grid sheet 117 and the radiation receiving unit 40 is equal to the angle between the fourth sub-grid sheet 119 and the radiation receiving unit 40.
It should be noted that: in order to facilitate the assembly of the anti-scatter grid 100 with the radiation receiving unit 40 and to improve the compactness of the anti-scatter grid 100 and the radiation receiving unit 40, the shape of the bottom surface 114 should be adapted to the shape of the radiation receiving unit 40. Specifically, the method comprises the following steps: as shown in FIG. 6, when the radiation receiving unit 40 is a flat-panel radiation receiving unit, the bottom surface 114 of the grid sheet 110 is also flat, and the bottom surface 114 of the grid sheet 110 is parallel to the radiation receiving unit 40. As shown in fig. 10, when the radiation receiving unit 40 is a curved-surface radiation receiving unit, the bottom surface 114 of the grid sheet 110 is also a curved plate, and the bottom surface 114 of the grid sheet 110 and the radiation receiving unit 40 are concentric arcs.
It should also be understood that: the imaging system in the embodiment of the present invention can alternatively implement more components. For example, if in one embodiment the imaging system is to include other components, such as a processor, in addition to the components shown, the imaging system may also include a processor in addition to the components described above.
It should be noted that: the imaging system in the embodiments of the present invention may be applied to a plurality of fields, for example, the healthcare industry (e.g., medical applications), security applications, industrial applications, and the like. For example, the imaging system may be at least one of a Computed Tomography (CT) system, a Digital Radiography (DR) system, a Positron Emission Tomography (PET) system, a Single-Photon Emission Computed Tomography (SPECT) system, and the like. In some embodiments, the imaging system may also be used for internal inspection of the assembly, for example: at least one of a crack detection system, a security scanning system, a fault analysis system, a wall thickness analysis system, and the like.
It should be understood that: when the imaging system is a CT system, the radiation receiving unit may be an imaging detector or a part of an imaging detector, and is not particularly limited herein.
To sum up, the utility model provides an anti-scatter grid and imaging system arranges through the direction of transmission that sets up every grid piece and all follow its transmission ray that corresponds the position, has improved the transmission ray and has incided the quantity of interval between a plurality of grid pieces, and greatly reduced is by the quantity of the transmission ray that the grid piece sheltered from, effectively guarantees anti-scatter grid to big cone angle transmission ray's receiving efficiency, and then has improved transmission ray's imaging performance. Furthermore, each grid sheet is arranged along the emission direction of the emission ray at the corresponding position, so that the projection area of the grid sheet is the minimum along the emission direction of the emission ray, the shielding of the grid sheet on the pixel area of the ray receiving unit can be reduced, and the imaging performance can be further improved.
Further, the utility model discloses a set up projection and the coincidence seam at least part coincidence of grid plate on ray receiving element, the pixel region of ray receiving element will not be occupied to the part of coincidence, can reduce along the transmitting direction of transmission ray, the area occupied of projection to ray receiving element pixel region of grid plate on ray receiving element, and then can reduce the regional influence of pixel to ray receiving element, realize improving the usable pixel region of ray receiving element, improve the formation of image performance of ray receiving element.
The anti-scatter grid and the imaging system provided by the present invention are introduced in detail, and a specific example is applied to explain the principle and the implementation of the present invention, and the description of the above embodiment is only used to help understand the method and the core idea of the present invention; meanwhile, for those skilled in the art, according to the idea of the present invention, there may be some changes in the specific implementation and application scope, and to sum up, the content of the present specification should not be understood as a limitation to the present invention.
Claims (10)
1. An anti-scatter grid is characterized by comprising a plurality of grid pieces which are arranged at intervals, wherein extension lines of the grid pieces are converged at an intersection point;
the grid sheets comprise a plurality of first grid sheets arranged along a first direction and a plurality of second grid sheets arranged along a second direction, and an included angle between the first direction and the second direction is greater than 0 degree and smaller than or equal to 90 degrees.
2. The anti-scatter grid according to claim 1, wherein each grid sheet of the plurality of grid sheets comprises a first side surface and a second side surface that are oppositely disposed, and a minimum spacing between the first side surface and the second side surface is greater than or equal to 100 microns.
3. The anti-scatter grid according to claim 2, wherein the grid sheet includes a top surface and a bottom surface disposed opposite each other, the top surface and the bottom surface having opposite ends connected to the first side surface and the second side surface, respectively, the grid sheet including an upper grid sheet adjacent to the top surface and a lower grid sheet adjacent to the bottom surface, a spacing between the first side surface and the second side surface at least partially of the lower grid sheet being greater than a spacing between the first side surface and the second side surface at the upper grid sheet.
4. The anti-scatter grid according to claim 1, wherein the grid sheet is made of a first material having an atomic number greater than or equal to 74, and the content of the first material is greater than or equal to 90%.
5. The anti-scatter grid according to claim 3, wherein an angle between a bottom surface centerline of the first grid sheet and a bottom surface centerline of the second grid sheet is 90 °.
6. The anti-scatter grid according to claim 1, wherein a plurality of said first grid segments are staggered along said second direction and/or a plurality of said second grid segments are staggered along said first direction.
7. An imaging system, comprising a radiation source, a radiation receiving unit and an anti-scatter grid; the ray source is used for emitting emission rays; the ray receiving unit is used for receiving the emitted rays; the anti-scatter grid is arranged between the ray receiving unit and the ray source;
wherein the anti-scatter grid is the anti-scatter grid of any one of claims 1-6.
8. The imaging system of claim 7, wherein each of the grid slices is arranged along an emission direction of the emission ray corresponding to the grid slice.
9. The imaging system of claim 7, wherein the ray receiving unit comprises a plurality of ray receiving subunits and a plurality of splicing gaps formed by splicing the plurality of ray receiving subunits, and the grid sheet is arranged corresponding to the splicing gaps; along the emission direction of the emitted ray, the projection of the grid sheet on the ray receiving unit is at least partially overlapped with the splicing gap corresponding to the grid sheet.
10. The imaging system of claim 9, wherein, along the direction of emission of the emitted radiation, a center line of a projection of the grid sheet on the radiation receiving unit coincides with a center line of the stitching slit corresponding to the grid sheet.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117064422A (en) * | 2023-09-13 | 2023-11-17 | 北京富通康影科技有限公司 | Anti-scattering grid of CT detector |
| CN117064422B (en) * | 2023-09-13 | 2024-11-12 | 北京富通康影科技有限公司 | Anti-scattering grid of CT detector |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117064422A (en) * | 2023-09-13 | 2023-11-17 | 北京富通康影科技有限公司 | Anti-scattering grid of CT detector |
| CN117064422B (en) * | 2023-09-13 | 2024-11-12 | 北京富通康影科技有限公司 | Anti-scattering grid of CT detector |
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