Radiation detector and medical apparatus having the same

Abstract

This invention discloses a radiation detector and a medical device having the radiation detector. The radiation detector includes a photoelectric conversion layer and a scattering suppression grid. The photoelectric conversion layer includes a conversion layer body and pixel electrodes. The conversion layer body has a first side and a second side. The pixel electrodes are disposed on the second side and include multiple pixel electrode groups spaced apart. Each pixel electrode group includes multiple pixel electrode pieces of equal size spaced apart. The scattering suppression grid is disposed on the side of the photoelectric conversion layer near the first side and includes multiple scattering suppression channels corresponding to the pixel electrode groups. In the extension direction of the scattering suppression channels, the projection of any pixel electrode group on the second side is within the range of the projection of the scattering suppression channel on the second side. The radiation detector according to this invention achieves consistent pixel area for each pixel electrode group and reduces the impact of the scattering suppression grid on pixel consistency.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a radiation detector and a medical device having the radiation detector. Background Technology

[0002] In computed tomography (CT), angiography, or radiography, radiation (usually X-rays) passing through the human body is collected by a radiation detector to form scan data. The scan data is then used to generate diagnostic images through reconstruction algorithms. Since radiation is scattered during its journey from the radiation source to the radiation detector, a scatter suppression grid is placed between the photoelectric conversion layer of the radiation detector and the radiation source to reduce the impact of scattering. Typically, the scatter suppression grid is placed on the upper surface of the photoelectric conversion layer.

[0003] Because the thickness of the grid wall is greater than the gap between the pixel electrodes, the pixel electrodes facing the grid wall will be partially blocked. At the same time, due to manufacturing and installation errors in the anti-scattering grid, the pixel areas formed after the anti-scattering grid is installed are inconsistent, which will cause image artifacts. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, the present invention proposes a radiation detector to achieve consistent pixel area across individual pixel electrode sheets and reduce the impact of suppression scattering grids on pixel consistency.

[0005] The present invention also proposes a medical device having the above-mentioned radiation detector.

[0006] A radiation detector according to an embodiment of the present invention includes: a photoelectric conversion layer and a scattering suppression grid. The photoelectric conversion layer includes a conversion layer body and pixel electrodes. The conversion layer body has a first side and a second side disposed opposite to each other. The pixel electrodes are disposed on the second side and include a plurality of pixel electrode groups spaced apart. Each pixel electrode group includes a plurality of pixel electrode pieces of equal size spaced apart. The scattering suppression grid is disposed on the side of the photoelectric conversion layer near the first side and includes a plurality of scattering suppression channels corresponding to the pixel electrode groups. In the extending direction of the scattering suppression channels, the projection of any pixel electrode group on the second side is located within the range of the projection of the scattering suppression channel on the second side.

[0007] According to the radiation detector of the present invention, each pixel electrode group includes a plurality of pixel electrodes of equal size. In the incident direction of radiation, each pixel electrode group is aligned with a suppression scattering channel, and the pixel areas of the plurality of pixel electrode groups are equal, thereby achieving consistent pixel areas of each pixel electrode group and reducing the impact of the suppression scattering grid on pixel consistency.

[0008] According to some embodiments of the present invention, a high-voltage electrode gap is provided between two adjacent pixel electrode sheets in each pixel electrode sheet group, and a pixel electrode gap is provided between two adjacent pixel electrode sheet groups. In the direction of extension of the suppression scattering channel, the grid wall of the suppression scattering channel is aligned with the pixel electrode gap, and the wall thickness of the grid wall is not greater than the width of the pixel electrode gap.

[0009] According to some embodiments of the present invention, a grid electrode sheet is provided in the pixel electrode gap, and a third electrode gap is provided between the grid electrode sheet and the adjacent pixel electrode sheet. In the direction of extending the suppression scattering channel, the projection of the grid electrode sheet on the second side is located within the range of the projection of the grid wall on the second side.

[0010] According to some embodiments of the present invention, the grid electrode sheets between the plurality of pixel electrode sheet groups are electrically connected.

[0011] According to some embodiments of the present invention, at least one of the pixel electrode sheet groups located at the edge further includes a corner electrode sheet, the corner electrode sheet being located at the outer edge of the pixel electrode sheet group and spaced apart from the pixel electrode sheets within the group, the gap between the corner electrode sheet and the adjacent pixel electrode sheet being a high-voltage electrode gap, the gap between the corner electrode sheet and the grid electrode sheet being a fourth electrode gap, the width of the fourth electrode gap being greater than the width of the third electrode gap, an extension electrode sheet being disposed in the fourth electrode gap, the extension electrode sheet being connected to the adjacent grid electrode sheet.

[0012] According to some embodiments of the present invention, the extended electrode sheet and the grid electrode sheet are an integral structure.

[0013] According to some embodiments of the present invention, the gap between the extended electrode sheet and the corner electrode sheet is the high-voltage electrode gap.

[0014] According to some embodiments of the present invention, the voltage connected to the grid electrode sheet is different from the voltage connected to the pixel electrode sheet; or, the grid electrode sheet is grounded.

[0015] According to some embodiments of the present invention, the radiation detector further includes: a high-voltage electrode and a substrate, the high-voltage electrode being disposed between the scatter suppression grid and the conversion layer body; the substrate being disposed on the side of the pixel electrode facing away from the conversion layer body, the substrate having a pixel circuit and a grid circuit, each pixel electrode being connected to the pixel circuit through its corresponding connector, and the grid electrode being connected to the grid circuit through a connector.

[0016] A medical device according to another embodiment of the present invention includes the above-described radiation detector.

[0017] The radiation detector of the medical device achieves consistent pixel area for each pixel electrode and reduces the impact of the suppression scattering grid on pixel consistency.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a radiation detector according to an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 A magnified view of a section at point B in the middle;

[0021] Figure 3 This is a schematic diagram of a scattering suppression grid according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of a pixel electrode according to an embodiment of the present invention;

[0023] Figure 5 yes Figure 4 A magnified view of a section at point A in the middle;

[0024] Figure 6 yes Figure 4 A partially enlarged view of another embodiment at point A;

[0025] Figure 7 yes Figure 4 A partially enlarged view of another embodiment at point A in the middle.

[0026] Figure label:

[0027] Radiation detector 100, photoelectric conversion layer 10, conversion layer body 11, high voltage electrode 12, pixel electrode 13, welding ball 14, pixel electrode sheet group 15, pixel electrode sheet 16, first electrode gap a, second electrode gap b, third electrode gap c, grid electrode sheet 17, extended electrode sheet 18, corner electrode sheet 19, scatter suppression grid 20, scatter suppression channel 21, grid wall 22, substrate 30, integrated circuit 40. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] The following is combined with Figures 1-7 A radiation detector 100 according to an embodiment of the present invention will be described in detail.

[0033] Reference Figures 1-7As shown, the radiation detector 100 according to an embodiment of the present invention may include a photoelectric conversion layer 10 and a scattering suppression grid 20.

[0034] The photoelectric conversion layer 10 may include a conversion layer body 11 and a pixel electrode 13. The conversion layer body 11 has a first side and a second side, which are disposed opposite to each other. The pixel electrode 13 is disposed on the side of the conversion layer body 11 closer to the second side. In one example, the pixel electrode 13 is disposed on the second side. In another example, other layers may be disposed between the pixel electrode 13 and the conversion layer body 11. The pixel electrode 13 may be an anode.

[0035] The material selected for the conversion layer body 11 is capable of generating electrons when irradiated by radiation. Optionally, the conversion layer body 11 can be CZT (cadmium zinc telluride, CdZnTe), CdTe (cadmium telluride), CdZnTeSe (cadmium zinc selenide), CdTeSe (cadmium telluride selenide), Si (silicon), or other materials. The conversion layer body 11 can directly convert radiation (e.g., X-rays) into electrons without pixelation; instead, electrode plates are placed on the second side to divide the cells, forming a pixel-like acquisition effect. Based on the material characteristics of the conversion layer body 11, the radiation detector 100 is a photon detector that obtains the scan data of the subject by counting.

[0036] The photoelectric conversion layer 10 may further include a high-voltage electrode 12, which is disposed between the scattering suppression grid 20 and the conversion layer body 11. The high-voltage electrode 12 may be disposed on the first side or separated from the first side. The high-voltage electrode 12 may be referred to as the first electrode, and the pixel electrode 13 may be referred to as the second electrode. The high-voltage electrode 12 may also be referred to as the cathode. A voltage of 800 volts to 1000 volts is applied between the high-voltage electrode 12 and the pixel electrode 13.

[0037] Optionally, such as Figure 2 As shown, the high voltage electrode 12 is a high voltage electrode plate located on the upper side of the conversion layer body 11, and the pixel electrode 13 is a low voltage electrode plate located on the lower side of the conversion layer body 11. The potential difference between the high voltage electrode 12 and the pixel electrode 13 causes the electrons generated by the conversion layer body 11 to move toward the pixel electrode 13.

[0038] Combination Figures 4-6As shown, the pixel electrode 13 includes multiple pixel electrode groups 15, which are spaced apart. Each pixel electrode group 15 includes multiple pixel electrode pieces 16 of equal size that are spaced apart, so that the pixel area of ​​each pixel electrode group 15 is equal. Multiple pixel electrode groups 15 are provided on the underside of the conversion layer body 11, and the pixel electrode groups 15 achieve a pixelated acquisition effect similar to that of a pixelated scintillator.

[0039] The scattering suppression grid 20 is disposed on the side of the photoelectric conversion layer 10 near the first side. Specifically, the scattering suppression grid 20 is disposed on the side of the high-voltage electrode 12 facing away from the conversion layer body 11, such as... Figure 1 and Figure 2 As shown, the scattering suppression grid 20 is located above the high-voltage electrode 12. Combined with... Figure 3 The scattering suppression grid 20 includes multiple scattering suppression channels 21, which are correspondingly arranged with multiple pixel electrode groups 15. Optionally, the scattering suppression grid 20 has multiple grid walls 22, which are arranged in a grid structure, with each grid forming a scattering suppression channel 21. The grid walls 22 are typically made of a high-radiation-attenuation material such as tungsten or molybdenum with a thickness of about 0.1 mm. The grid walls 22 extend along the height direction and converge at a point, which is the focal point of the radiation source of the radiation detector 100. The radiation source is a cone beam or a fan beam. The radiation emitted by the radiation source is irradiated onto the corresponding pixel electrode group 15 through the corresponding scattering suppression channel 21. The scattering suppression channel 21 has the function of suppressing radiation scattering, enabling the photoelectric conversion layer 10 to better collect radiation.

[0040] In the direction of the suppression scattering channel 21, the projection of any pixel electrode group 15 onto the second side surface is within the range of the projection of the suppression scattering channel 21 onto the second side surface. The direction of the suppression scattering channel 21 is the incident direction of the radiation. In other words, in the incident direction of the radiation, each pixel electrode group 15 is aligned with one suppression scattering channel 21. In this way, by grouping the pixel electrodes, the pixel electrodes within the pixel electrode group can maintain a small gap, and the pixel areas of multiple pixel electrode groups 15 are equal. A larger gap can be set between the pixel electrode groups to correspond to the grid walls and avoid the grid walls from obscuring the pixel electrodes. This not only improves the spatial resolution of the image and helps to improve pixel detection efficiency, but also obtains an image with fewer artifacts.

[0041] According to an embodiment of the radiation detector 100 of the present invention, each pixel electrode group 15 includes a plurality of pixel electrode sheets 16 spaced apart and of equal size. This ensures that the pixel electrode sheets 16 have a uniform size, facilitating manufacturing and reducing the assembly difficulty of the pixel electrode sheets 16 on the second side of the conversion layer body 11, thereby improving the production efficiency of the radiation detector 100. In the extension direction of the suppression scattering channel 21, the projection of any pixel electrode group 15 onto the second side is within the range of the projection of the suppression scattering channel 21 onto the second side, achieving consistent pixel area for each pixel electrode group 15 and reducing the impact of the suppression scattering grid 20 on pixel consistency. In other words, the radiation detector 100 according to an embodiment of the present invention can ensure consistent pixel area for each pixel electrode group 15 while maintaining equal size for the pixel electrode sheets 16, making the radiation detector 100 of the present invention both simple in structure and effective in detecting radiation.

[0042] In some embodiments of the present invention, reference is made to... Figure 1 and Figure 2 As shown, the radiation detector 100 may further include a substrate 30 and an integrated circuit 40. The substrate 30 is disposed on the side of the pixel electrode 13 away from the conversion layer body 11, such as... Figure 1 and Figure 2 As shown, the substrate 30 is located below the pixel electrode 13. The substrate 30 contains a pixel circuit, and each pixel electrode 16 is connected to the pixel circuit via its corresponding connector. The pixel circuit is connected to the integrated circuit 40. Optionally, the pixel circuit is connected to the integrated circuit 40 via connecting wires or solder balls, etc. Figure 2 As shown, the pixel electrode 13 is soldered to the substrate 30 via solder balls 14. That is, each pixel electrode 16 is connected to the pixel circuit in the substrate 30 via its corresponding solder balls 14. The solder balls can be BGA balls (Ball Grid Array). The pixel circuit in the substrate 30 is connected to the integrated circuit 40 via connecting lines or solder balls, etc. The integrated circuit 40 processes the current collected by the pixel circuit.

[0043] In some embodiments of the present invention, reference is made to... Figures 1-2 and Figure 5As shown, each pixel electrode group 15 has a first electrode gap a between two adjacent pixel electrode patches 16, making the two adjacent pixel electrode patches 16 independent of each other. A second electrode gap b is also present between two adjacent pixel electrode groups 15. In the direction of extension of the suppression scattering channel 21, i.e., in the incident direction of the radiation, the grid wall 22 of the suppression scattering channel 21 is aligned with the second electrode gap b, and the wall thickness of the grid wall 22 is not greater than the width of the second electrode gap b. Thus, the grid wall 22 does not obstruct the pixel electrode patches 16, and the radiation within the suppression scattering channel 21 can fully illuminate the pixel electrode groups 15 surrounding the grid wall 22 of the suppression scattering channel 21, making the pixel areas of each pixel electrode group 15 equal and improving pixel detection efficiency and accuracy. In other words, in the incident direction of the radiation, the projection of the grid wall 22 on the second side surface is within the range of the projection of the second electrode gap b on the second side surface.

[0044] Optionally, the width of the second electrode gap b is greater than the width of the first electrode gap a, which can reduce the probability of the grid wall 22 obscuring the pixel electrode group 15.

[0045] In some embodiments of the present invention, reference is made to... Figures 1-2 and Figure 6 As shown, a grid electrode sheet 17 is provided within the second electrode gap b, and a third electrode gap c is provided between the grid electrode sheet 17 and the adjacent pixel electrode sheet 16. In the incident direction of the radiation, the grid wall 22 is aligned with the grid electrode sheet 17. Optionally, the wall thickness of the grid wall 22 is not less than the width of the grid electrode sheet 17. This ensures that the grid wall 22 completely blocks the grid electrode sheet 17, and the grid electrode sheet 17 does not affect the pixels at the pixel electrode sheet 16. The pixel size of each pixel electrode sheet 16 is consistent, and the pixel area of ​​each pixel electrode sheet group 15 is equal, resulting in the best radiation collection effect. In other words, in the extension direction of the suppression scattering channel 21, the projection of the grid electrode sheet 17 on the second side is located within the range of the projection of the grid wall 22 on the second side. In some examples, the wall thickness of the grid wall 22 can also be less than the width of the grid electrode sheet 17, and the width of the grid electrode sheet 17 is not greater than the width of the second electrode gap b. In this way, the wall thickness of the grid wall 22 is not greater than the width of the second electrode gap b, and the grid wall 22 does not block the pixel electrode sheet 16.

[0046] Optionally, the first electrode gap a is usually about 0.06 mm, and the wall thickness of the grid wall 22 is 0.2 mm. Then the width of the grid electrode piece 17 is at least greater than 0.2 mm minus the 0.06 mm of the first electrode gap a on both sides. The width of the grid electrode piece 17 is at least 0.08 mm. Taking into account the thickness deviation and position deviation of the grid wall 22, the width of the grid electrode piece 17 can be set to 0.12 mm.

[0047] In some embodiments of the present invention, the wall thickness of the grid wall 22 is W22, the width of the first electrode gap a is W1, and the width of the grid electrode piece 17 is W17. Then W1, W17, and W22 satisfy the following relationship: W22 - 2 × W1 ≤ W17 ≤ W22. When W22 = 0.2 mm and W1 = 0.06 mm, 0.08 mm ≤ W17 ≤ 0.2 mm.

[0048] In some embodiments of the present invention, reference is made to... Figure 2 As shown, the substrate 30 has a grid circuit, and the grid electrode sheet 17 is connected to the grid circuit via a connector. Optionally, as... Figure 2 As shown, the grid electrode 17 can also be connected to the grid circuit on the substrate 30 by means of welding balls 14 or the like.

[0049] In some embodiments of the present invention, the voltage connected to the grid electrode 17 is different from the voltage connected to the pixel electrode 16, which can reduce the generation of stray electrons and thereby reduce the influence of the area corresponding to the grid wall 22 of the suppression scattering grid 20 on normal pixel electrons.

[0050] In other embodiments of the present invention, the grid electrode sheet 17 may be grounded to divert stray electrons in the region corresponding to the grid wall 22 of the suppression scattering grid 20, thereby reducing the impact on normal pixel electrons.

[0051] In some embodiments of the present invention, the grid electrode sheets 17 between multiple pixel electrode sheet groups 15 are electrically connected, so that it is not necessary to provide a connector between each grid electrode sheet 17 and the grid circuit, which can save the number of connectors.

[0052] In some embodiments of the present invention, reference is made to... Figure 6 As shown, the grid electrode 17 between the multiple pixel electrode groups 15 is constructed as a single electrode, which facilitates the connection of the grid electrode 17 to the substrate 30 and the placement of the grid electrode 17 as a whole within the second electrode gap b.

[0053] In some embodiments not shown in the figures, the grid electrode 17 between any two adjacent pixel electrode groups 15 can be constructed as a separate electrode, and each grid electrode 17 is connected to the substrate 30 through its corresponding connector.

[0054] In some embodiments of the present invention, reference is made to... Figures 1-2 and Figure 7As shown, at least one of the pixel electrode groups 15 located at the edge also includes a corner electrode 19. The corner electrode 19 is located at the outer edge of the pixel electrode group 15 and is spaced apart from the pixel electrode 16 within the group. The gap between the corner electrode 19 and the adjacent pixel electrode 16 is a first electrode gap a, and the gap between the corner electrode 19 and the grid electrode 17 is a fourth electrode gap. The width of the fourth electrode gap is greater than the width of the third electrode gap c. An extension electrode 18 is disposed in the fourth electrode gap and is connected to the adjacent grid electrode 17. Thus, when the area of ​​the corner electrode 19 is smaller than the area of ​​the pixel electrode 16, the empty area of ​​the corner electrode 19 is filled with the extension electrode 18.

[0055] In some embodiments of the present invention, reference is made to... Figure 7 As shown, the extended electrode sheet 18 and the grid electrode sheet 17 are an integral structure, which makes the welding area of ​​the grid electrode sheet 17 large enough to facilitate welding and fixing of the grid electrode sheet 17.

[0056] In some embodiments of the present invention, reference is made to... Figure 7 As shown, the gap between the extended electrode plate 18 and the corner electrode plate 19 is the first electrode gap a, which can reduce the interference of the extended electrode plate 18 on the corner electrode plate 19.

[0057] In some embodiments of the present invention, reference is made to... Figures 4-7 As shown, the pixel electrodes 13 are in a matrix structure, and each pixel electrode group 15 includes n×n pixel electrode pieces 16, where n≥3 and n is an integer. Optionally, n=3, 4, 5, 6, 7, 8, 9, 10, etc. For example, each pixel electrode group 15 is a 3×3 matrix arrangement, that is, each pixel electrode group 15 has 9 pixel electrode pieces 16. The scattering suppression grid 20 is in a matrix structure, with each grid corresponding to one pixel electrode group, that is, each grid corresponds to 9 pixel electrode pieces 16, which helps to reduce the area of ​​the pixel electrodes 13 occupied by the grid wall 22 and improve the acquisition efficiency of the radiation detector 100.

[0058] Optionally, the radiation detector 100 is a counting-type direct conversion radiation detector.

[0059] A medical device according to another embodiment of the present invention includes the radiation detector 100 described above.

[0060] The radiation detector 100 of the medical device achieves consistent pixel area for each pixel electrode group 15 under the premise that the pixel electrode sheets 16 are all of equal size, and reduces the impact of the suppression scattering grid 20 on pixel consistency.

[0061] Alternatively, the medical device may be a computed tomography (CT) machine, an angiography machine, or a radiographic camera, etc.

[0062] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0063] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A radiation detector, characterized in that, include: A photoelectric conversion layer (10) is provided, comprising a conversion layer body (11) and a pixel electrode (13). The conversion layer body (11) has a first side and a second side disposed opposite to each other. The pixel electrode (13) is disposed on the second side. The pixel electrode (13) comprises a plurality of pixel electrode sheet groups (15) disposed at intervals. Each pixel electrode sheet group (15) comprises a plurality of pixel electrode sheets (16) of equal size disposed at intervals. Scattering suppression grid (20) is disposed on the side of the photoelectric conversion layer (10) near the first side. The scattering suppression grid (20) includes a plurality of scattering suppression channels (21) corresponding to the pixel electrode group (15). In the extending direction of the scattering suppression channel (21), the projection of any pixel electrode group (15) on the second side is located within the range of the projection of the scattering suppression channel (21) on the second side. Each pixel electrode sheet group (15) has a first electrode gap between two adjacent pixel electrode sheets (16) and a second electrode gap between two adjacent pixel electrode sheet groups (15); A grid electrode sheet (17) is provided in the second electrode gap, and a third electrode gap is provided between the grid electrode sheet (17) and the adjacent pixel electrode sheet (16). In the extension direction of the suppression scattering channel (21), the projection of the grid electrode sheet (17) on the second side is located within the range of the projection of the grid wall (22) on the second side. The voltage connected to the grid electrode (17) is different from the voltage connected to the pixel electrode (16); or, the grid electrode (17) is grounded.

2. The radiation detector according to claim 1, characterized in that, In the direction of extension of the suppression scattering channel (21), the grid wall (22) of the suppression scattering channel (21) is aligned with the second electrode gap, and the wall thickness of the grid wall (22) is not greater than the width of the second electrode gap.

3. The radiation detector according to claim 1, characterized in that, The grid electrode (17) is electrically connected between the plurality of pixel electrode groups (15).

4. The radiation detector according to claim 3, characterized in that, At least one of the pixel electrode sheet groups (15) located at the edge also includes a corner electrode sheet (19). The corner electrode sheet (19) is located at the outer edge of the pixel electrode sheet group (15) and is spaced apart from the pixel electrode sheets (16) in the group. The gap between the corner electrode sheet (19) and the adjacent pixel electrode sheet (16) is a first electrode gap. The gap between the corner electrode sheet (19) and the grid electrode sheet (17) is a fourth electrode gap. The width of the fourth electrode gap is greater than the width of the third electrode gap. An extension electrode sheet is provided in the fourth electrode gap. The extension electrode sheet is connected to the adjacent grid electrode sheet (17).

5. The radiation detector according to claim 4, characterized in that, The extended electrode sheet and the grid electrode sheet (17) are an integral structure.

6. The radiation detector according to claim 4, characterized in that, The gap between the extended electrode sheet and the corner electrode sheet (19) is the first electrode gap.

7. The radiation detector according to any one of claims 4-6, characterized in that, The radiation detector also includes: A high-voltage electrode (12) is disposed between the scattering suppression grid (20) and the conversion layer body (11); A substrate (30) is disposed on the side of the pixel electrode (13) away from the conversion layer body (11). The substrate (30) has a pixel circuit and a grid circuit. Each pixel electrode sheet (16) is connected to the pixel circuit through its corresponding connector, and the grid electrode sheet (17) is connected to the grid circuit through a connector.

8. A medical device, characterized in that, The radiation detector includes any one of claims 1-7.

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