CN111281406A

CN111281406A - Scintillator pixel array, detector submodule, module, detector and CT device

Info

Publication number: CN111281406A
Application number: CN202010075490.7A
Authority: CN
Inventors: 李双学; 楼珊珊; 于军; 王凤晨
Original assignee: Neusoft Medical Systems Co Ltd
Current assignee: Neusoft Medical Systems Co Ltd
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2020-06-16

Abstract

The application discloses a scintillator pixel array, a detector submodule, a module, a detector and a CT device. The scintillator pixel array is used for receiving rays emitted by an X-ray source of a CT host computer and attenuated by a scanned object, and comprises a plurality of scintillator pixels. Each scintillator pixel is a polyhedron made up of a top surface, a bottom surface opposite the top surface, and side surfaces connecting the top and bottom surfaces. The corresponding side surfaces of the adjacent scintillator pixels form a gap, the side surfaces forming the gap are overlapped with the X-rays passing through the surfaces of the adjacent scintillator pixels, so that all the rays in the ray beams irradiating to the gap pass through the gap, and thus the rays of the ray beams do not intersect with the side surfaces forming the gap, and therefore the rays cannot pass through the scintillator pixels and enter another scintillator pixel adjacent to the scintillator pixels, the problem of parallax crosstalk signals caused by ray crosstalk between the adjacent scintillator pixels is avoided, image noise and artifacts are not generated, and the image quality is improved.

Description

Scintillator pixel array, detector submodule, module, detector and CT device

Technical Field

The present application relates to the field of medical technology, and more particularly, to scintillator pixel arrays, detector sub-modules, detectors, and CT devices.

Background

An electronic Computed Tomography (CT) apparatus includes an X-ray source and a detector (also called detector). The X-ray source emits X-rays which pass through the body to be attenuated. And the detector receives and processes the attenuated X-rays to obtain a tomographic image of the human body. Wherein the detector comprises a plurality of detector modules, each detector module comprising a plurality of detector sub-modules, each detector sub-module comprising an array of scintillator pixels for converting X-rays for further processing. Based on the imaging mechanism, in order to ensure that each position information on the obtained human body tomographic image is clear and accurate, the imaging system requires that each scintillator pixel is not interfered by the surrounding environment and the adjacent scintillator pixels as much as possible in the whole imaging process. During the conversion of X-rays by the scintillator, this interference is actually present as interference of X-rays leaking from adjacent scintillator pixels.

Based on this, there is a need in the art for a technique that avoids interference between adjacent scintillator pixels of a scintillator.

Disclosure of Invention

To overcome some or all of the problems of the related art, the present application provides a scintillator pixel array. The array is used for receiving rays emitted by an X-ray source of a CT host computer after being attenuated by a scanned object and comprises a plurality of scintillator pixels, each scintillator pixel is a polyhedron formed by a top surface, a bottom surface opposite to the top surface and side surfaces connected with the corresponding top surface and the bottom surface, corresponding side surfaces of adjacent scintillator pixels form a space, and the side surfaces forming the space are overlapped with the X-rays passing through the surfaces of the side surfaces, so that all the rays in a ray beam which are emitted to the space pass through the space.

Optionally, each of the spaces is filled with a material that reflects and absorbs visible light.

Optionally, in the array, the angles formed by the side surfaces of the scintillator pixels located on the same side of the same row or column and the corresponding bottom surfaces are equal, the planes in which the side surfaces of different columns are located intersect with the same straight line, and the straight line passes through the focus center of the X-ray source; the planes of the side surfaces of different rows intersect on the same straight line, and the straight line passes through the focus center of the X-ray source.

Optionally, the rows and columns of the array are arranged according to a first row-column characteristic, or according to a first row-column characteristic and a second row-column characteristic, where the first row-column characteristic is: the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different rows on the same row or different rows on the same column gradually approaches 90 degrees from the two side edges of the row or column to the middle position of the row or column according to the angle of the spaced ray beams passing through the side surface; the second row and column characteristics are: the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different columns on the same row or different rows on the same column gradually increases or decreases from one side edge of the row or column to the other side edge of the row or column according to the angle of the spaced ray beams passing through the side surface.

In another aspect, the present application further discloses a detector sub-module comprising a scintillator pixel array, a top surface of the scintillator pixel array forming a top surface of the detector sub-module, rows and columns of the pixel array being arranged in the first row-column characteristic in a Z-direction and an X-direction of the CT rotation system, the array forming the detector sub-module as a first detector sub-module; or the scintillator pixel array is arranged according to the second row-column characteristic in the Z direction of the CT rotating system and is arranged according to the first row-column characteristic in the X direction, and the detector sub-module formed by the array is used as a second detector sub-module.

In another aspect, the present application also discloses another detector module. The detector module includes a support and a plurality of detector sub-modules mounted to the support, the top surfaces of the plurality of detector sub-modules arranged along a Z-arc of a CT rotational system of the CT mainframe and including at least one of the first detector sub-modules.

In another aspect, the present application also discloses another detector module. The detector module includes a support and a plurality of detector sub-modules mounted to the support, a top surface of the plurality of detector sub-modules being aligned along a Z-direction of a CT rotational system of the CT mainframe and including at most one of the first detector sub-modules and at least one of the second detector sub-modules.

In another aspect, the present application also discloses another detector module. The detector module comprises a support and a plurality of detector sub-modules mounted to the support, the plurality of detector sub-modules including a middle detector sub-module located within a predetermined distance of the focal reference plane and an edge detector sub-module located outside the middle detector sub-module, a top surface of the middle detector sub-module being aligned along the Z-direction and comprising at most one of the first detector sub-modules and at least one of the second detector sub-modules; the top surfaces of the edge detector sub-modules are arranged along a Z-direction arc of the CT rotating system and comprise at least one first detector sub-module, wherein the focus reference plane passes through the focus center of the X-ray source and is parallel to an XY plane of the CT rotating system.

Optionally, in any of the above detector modules, top surfaces of a plurality of the detector sub-modules mounted to the support form a receiving field corresponding to an irradiation field of the X-ray source in a YZ plane of the CT rotation system, the receiving field being asymmetric with respect to a focal reference plane of the X-ray source. Optionally, in the case of the Z-direction arc arrangement of the CT rotating system along the CT mainframe, the top surfaces of the detector sub-modules in the arc arrangement are distributed on arcs of target circles with unequal radii centered on the focal center of the X-ray source.

Optionally, a sum of widths of top surfaces of detector sub-modules on one side of the focus reference plane in the Z-direction is greater than a sum of widths of top surfaces of detector sub-modules on the other side of the focus reference plane in the Z-direction such that the receiving field is asymmetric with respect to the focus reference plane of the X-ray source. In another aspect, the present application discloses a detector including a housing and a plurality of any one of the detector modules, each detector module arranged in the housing along an arc in an X-direction of the CT rotational system.

In another aspect, the present application discloses a CT apparatus comprising a gantry, an X-ray source, and a detector of any of the foregoing, wherein the gantry comprises an opening for receiving a scan object; the X-ray source is used for emitting rays to the scanning object; the detector is disposed on an opposite side of the opening from the X-ray source for receiving radiation attenuated by the scanned object and converting the radiation into an electrical signal.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects:

1. the side surfaces corresponding to the adjacent scintillator pixels form a gap, and the side surfaces forming the gap are overlapped with the X-rays passing through the surfaces of the side surfaces, so that all the rays in the ray beams irradiating to the gap pass through the gap, therefore, for the adjacent scintillator pixels, the rays of the ray beams do not intersect with the side surfaces forming the gap, and therefore, the rays do not pass through the scintillator pixel and enter another scintillator pixel adjacent to the scintillator pixel, thereby avoiding the problem of parallax crosstalk signals caused by X-ray crosstalk between the adjacent scintillator pixels, generating no image noise and artifacts, and improving the image quality.

2. As each interval is filled with the material which reflects and absorbs visible light, the loss of light energy converted by the scintillator can be reduced, the optical crosstalk between adjacent scintillator pixels can be avoided, and the image quality is further improved.

3. Because the top surfaces of the plurality of detector sub-modules are arranged in a straight line along the Z direction of the CT rotating system of the CT host and comprise at most one first detector sub-module and at least one second detector sub-module, the straight line can reduce the processing difficulty of the detector module bracket and the assembling difficulty of the detector module as a whole, and the first detector sub-module and the second detector sub-module can avoid the crosstalk of rays and improve the image quality.

4. Because the top surfaces of the plurality of detector sub-modules are arranged along the Z-direction arc of the CT rotating system of the CT host and comprise at least one first detector sub-module, the types of the scintillator pixel array can be reduced under the condition that all the detector modules are the first detector sub-modules, the material management in production is easy, and the image quality can be improved because at least one first detector sub-module is comprised.

5. Since the manufacturing cost of the detector sub-modules along the straight line is much lower than that of the detector sub-modules along the arc, the top surface of the middle detector sub-modules is arranged in a straight line, and the top surface of the edge detector sub-modules is arranged in an arc, compared with the mode that the detector sub-modules are all arranged in an arc, the manufacturing difficulty of the detector module is lower, the manufacturing cost is lower, the scheme can be applied to the detector with large coverage range (such as 512 layers) in the Z direction, in addition, the middle detector sub-module comprises at most one first detector sub-module and at least one second detector sub-module, and/or the edge detector sub-module comprises at least one first detector sub-module, and the image quality can be improved.

6. Because a plurality of detector sub-modules form a receiving domain corresponding to the irradiation domain of the X-ray source on a YZ plane of the CT rotating system, the receiving domain is asymmetric relative to the focus reference plane, the distribution of the top surfaces of the detector sub-modules better conforms to the irradiation characteristics of the X-ray source so as to fully utilize the rays of the X-ray source, and the requirements on the performance parameters of the X-ray source (such as an X-ray bulb tube) and the manufacturing difficulty and cost of CT equipment (such as Z-direction large-coverage CT equipment) are reduced.

7. Since the top surfaces of the detector sub-modules arranged in an arc shape are distributed on the arc of the target circle with unequal radius and the focal point of the X-ray source as the center, the X-direction gaps of the adjacent detector modules at different positions in the Z direction can be equal or have the deviation value as small as possible, thereby obtaining better image quality, preferably, the top surfaces of the detector modules form a receiving area, under the condition that the Z direction is asymmetric relative to the focal point reference plane, the X-direction gaps between the adjacent modules at different positions in the Z direction are more uneven and have the deviation larger than under the condition that the Z direction is symmetric, the scheme that the top surfaces of the detector sub-modules are distributed on the arc of the target circle with unequal radius and the focal point of the X-ray source as the center can solve the problem, and the cost of the X-ray source is reduced, ensuring or even optimizing image quality.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

FIG. 1 is a diagram of the position of an X-ray beam with respect to a scintillator pixel;

FIG. 2 is a schematic diagram of a CT apparatus;

FIG. 3 is a schematic diagram of a detector configuration;

FIG. 4 is a schematic diagram of a scintillator pixel array;

FIG. 5 is a cross-sectional view of the scintillator pixel array shown in FIG. 4 along line A-A;

fig. 6 is a partially enlarged view of a portion a in fig. 5;

FIG. 7 is a cross-sectional view of the scintillator pixel array shown in FIG. 4 taken along line B-B;

fig. 8 is a partially enlarged view of a portion B in fig. 7;

FIG. 9 is a schematic diagram of another scintillator pixel array configuration;

FIG. 10 is a cross-sectional view of the scintillator pixel array shown in FIG. 9 along the line C-C;

FIG. 11 is a schematic structural diagram of a third scintillator pixel array;

FIG. 12 is a cross-sectional view of the scintillator pixel array shown in FIG. 11 taken along line D-D;

FIG. 13 is a schematic view of a first detector module configuration;

FIG. 14 is a projection view of the detector module of FIG. 13 in the YZ plane of a CT rotational system;

FIG. 15 is a schematic diagram of a second detector module configuration;

FIG. 16 is a projection view of the detector module of FIG. 15 in the YZ plane of a CT rotational system;

FIG. 17 is a schematic diagram of a third detector module;

FIG. 18 is a projection view of the detector module shown in FIG. 17 in the YZ plane of the CT rotational system;

FIG. 19 is a schematic diagram of a fourth detector module;

FIG. 20 is a projection view of the detector module shown in FIG. 19 in the YZ plane of the CT rotational system;

FIG. 21 is a schematic view of the corresponding fan angle of a detector sub-module with the top surface of the detector sub-module asymmetrically distributed with respect to the focus reference plane.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this 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.

It should be understood that the terms "first," "second," and the like as used in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Similarly, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one; "plurality" means two or more than two. Unless otherwise indicated, "front", "rear", "lower" and/or "upper" and the like are for convenience of description and are not limited to one position or one spatial orientation. The word "comprising" or "comprises", and the like, means that the element or item listed as preceding "comprising" or "includes" covers the element or item listed as following "comprising" or "includes" and its equivalents, and does not exclude other elements or items.

Exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following embodiments, features of the embodiments can be supplemented with each other or combined with each other without conflict.

Referring to fig. 1, the inventors of the present application found that: the X-ray source (including an X-ray tube, alternatively referred to as a bulb) typically emits X-rays in a cone shape. Currently, a single detector sub-module includes a scintillator formed by arranging scintillator pixels in an array, the scintillator pixels 101a are rectangular solids, and a GAP (GAP)102a is formed between adjacent scintillator pixels 101 a. The scintillator pixel array is also arranged by the scintillator pixels 101a in a rectangular parallelepiped, which causes most of the X-ray beams 103 received by the scintillator pixels 101a to pass through the scintillator pixels obliquely and enter the scintillator pixels adjacent to the GAP (GAP)102a through the GAP (GAP)102a between the adjacent scintillator pixels, i.e. the rays of the ray beams intersect the side surfaces of the adjacent scintillator pixels, which causes parallax crosstalk signals, which generates image noise and artifacts, and reduces the image quality.

Referring to fig. 2 in conjunction with fig. 5 to 12, in order to at least solve the problem of parallax crosstalk signals caused by X-rays obliquely passing through a scintillator pixel and a GAP (GAP) between the adjacent scintillator pixels entering the scintillator pixel adjacent to the scintillator pixel, the present application discloses a scintillator pixel array, a detector sub-module, a detector and a CT apparatus. To facilitate understanding of the present application, a CT apparatus is first introduced as follows:

the CT device shown in fig. 2 is a medical device, however, the skilled person will understand that the CT device also comprises a device for security check, such as a security check machine. Since these apparatuses include a detector, the CT apparatus for medical treatment is described as an example only and is configured as follows: the CT apparatus includes a gantry 10, an X-ray source 20, a detector 30, and a gantry 40. The coordinate system shown in fig. 2 is that of a rotatable CT rotation system relative to the gantry 10. The CT rotational system includes at least the X-ray source 20 and the detector 30. As shown, the coordinate system includes X, Y, and Z axes that are perpendicular to each other. The Z-axis is the rotation axis of the CT rotation system, and is parallel to the coronal plane of the scanned object 50 (patient in the medical field), defining the slice direction of the CT apparatus. The X-axis and the Y-axis define a plane perpendicular to the Z-axis. The X-axis is generally along the channel direction of the detector 30. The X-ray source 20 and the detector 30 rotate circumferentially about the Z-axis as a group. The gantry 10 is formed with an opening 11 for receiving the scan object 50. A scanning object 50 (a patient in the medical field) is placed on the carrier table 40 and together with the carrier table 40 can be located within the opening 11. In the field of security screening, the scanning object is baggage or other object that can be transported by a conveyor to pass through the opening 11. The X-ray source 20 and the detector 30 are arranged on opposite sides of the opening 11. The X-ray source 20 is used to emit a fan-shaped or cone-shaped beam of radiation toward the scanned object 50. As in fig. 6, each ray bundle 103 comprises a number of

rays

103a, 103b and 103 c; alternatively, as shown in FIG. 8,

several rays

103d, 103e, and 103f are included. The illustration of figures 5-10 is merely for convenience of illustrating the radiation beams, for example, the number of radiation beams illustrated in figures 5-10 does not represent the actual number of radiation beams.

Referring to fig. 3 in conjunction with fig. 13 to 20, the detector 30 is used for detecting the attenuated radiation passing through the scanned object 50 and converting the optical signal of the received radiation into an electrical signal, and includes a plurality of detector modules 3 (one detector module 3 is shown in a dashed line box in fig. 3) and a housing 302. A plurality of detector modules 3 are arranged in an arc along the X-direction (along the X-axis direction, and then the same) of the CT rotating system in the housing 302. In embodiments of the present application, the arc arrangement refers to the top surface of the detector sub-modules being tangent to the arc of a target circle centered at the focal center. Each detector module 3 comprises a support 301 and a detector submodule, such as 100a1, 100b1 or 100c1, mounted to the support 301. The arrangement of the plurality of detector sub-modules is described subsequently.

Referring to fig. 13-20 in conjunction with fig. 2-12, each detector sub-module 100a1, 100b1, or 100c1 includes a scintillator pixel array, a photodiode, a substrate, and an AD conversion circuit, or each detector sub-module 100a1, 100b1, or 100c1 includes a scintillator pixel array, a photodiode, and a substrate, in which case the detector sub-module needs to be connected to the AD conversion circuit by a connector.

Referring to fig. 4 to 12, the

scintillator pixel array

100a, 100b or 100c is used for receiving attenuated radiation of a scanned object from a detection X-ray source of a CT host, and includes a plurality of scintillator pixels 101. The plurality of scintillator pixels 101 are arranged in an array, and a GAP (GAP)102 is formed between adjacent scintillator pixels 101. As shown in fig. 4 to 7, each scintillator pixel 101 is a polyhedron constituted by a top surface 1011a, a bottom surface 1012a opposite to the top surface 1011a, and a left side surface 1013a, a right side surface 1014a, a front side surface 1015a, and a back side surface 1016a connected to the respective top surface 1011a and bottom surface 1012 a. In fig. 9 and 10, the top surface is labeled 1011b, the bottom surface is labeled 1012b, the left side surface is labeled 1013b, the right side surface is labeled 1014b, the front side surface is labeled 1015b, and the back side surface is labeled 1016 b. In fig. 11 and 12, the top surface is labeled 1011c, the bottom surface is labeled 1012c, the left side surface is labeled 1013c, the right side surface is labeled 1014c, the front side surface is labeled 1015c, and the back side surface is labeled 1016 c. In the above embodiments, the scintillator pixel 101 has four side surfaces in total, and the skilled person will appreciate that in other embodiments, the number of side surfaces of the scintillator pixel 101 may be other numbers, for example, more than 4. The top surfaces of all scintillator pixels 101 constitute the top surfaces of the detector sub-modules that receive the X-rays. The lateral surfaces constituting the interspace 102 coincide with the X-rays passing through the surface thereof, so that the rays of the bundle of rays directed towards the interspace 102 all pass through the respective interspace 102.

In the above embodiment, since all the rays of the ray bundle that are directed to the space 102 pass through the corresponding space 102, and the side surface that forms the space 102 coincides with the X-rays that pass through the surface, all the rays of the ray bundle that are directed to the space 102 pass through the corresponding space 102, and therefore, the ray bundle 103 does not pass through one scintillator pixel 101 and then enters another scintillator pixel 101 that is adjacent to the scintillator pixel 101 through the space 102, which effectively avoids the problem of parallax crosstalk signals caused by X-ray crosstalk between adjacent scintillator pixels, does not generate image noise and artifacts, and improves image quality.

Referring to fig. 4 in conjunction with fig. 5 to 12, in the

pixel arrays

100a, 100b and 100c, the angles between the side surfaces and the corresponding bottom surfaces of the scintillator pixels located on the same side of the same row or column are equal. Planes of the side surfaces of different columns intersect on the same straight line, the straight line passes through the focal center of the X-ray source, planes of the side surfaces of different rows intersect on the same straight line, and the straight line passes through the focal center of the X-ray source. More detailed description is as follows:

with reference to fig. 4 and 7, taking as an example that one side surface (front side surface), the row of a line a-a and the column of a line B-B are on the same plane, the front side surface 1015a and the bottom surface 1012a of the scintillator pixel in the first row and the first column form an angle θ 1, the front side surface 1015a and the bottom surface 1012a of the scintillator pixel in the first column and the first row and the second column form an angle θ 2, the front side surface 1015a and the bottom surface 1012a of the scintillator pixel in the first column and the first row form an angle θ 3, and so on, the front side surface 1015a and the bottom surface 1012a of the scintillator pixel in the first row and the N column form an angle θ N, then θ 1 is θ 2 … … — N, and for example, the front side surface 1013a and the bottom surface 1015a of the scintillator pixel in the first column and the N column form an angle θ 3, and so on, the front side surface 1015a and the bottom surface 1015a of the scintillator pixel in the first row and the N column form an angle θ N, then θ 2 … … is 1013N — 3, and the bottom surface 1013a 3 of the scintillator pixel in the left side surface 1013a and the bottom surface 383, and the bottom surface 1013a 3 of the pixel in the column and the bottom surface of the scintillator pixel in the bottom surface 1013N column and the bottom surface of the scintillator pixel in the bottom surface of the left column and the scintillator pixel in the bottom surface of the bottom column and the scintillator pixel in the bottom surface of the bottom surface.

Planes of the side surfaces of different columns intersect on the same straight line, the straight line passes through the focal center of the X-ray source, planes of the side surfaces of different rows intersect on the same straight line, and the straight line passes through the focal center of the X-ray source. For example, in fig. 4, still taking the row of the line a-a in fig. 4 as the first row, the column of the line B-B as the first column and three columns as an example, the plane of the left surface 1013a of the scintillator pixel in the first column and the plane of the right surface 1014a, the plane of the left surface 1013a of the scintillator pixel in the second column and the plane of the right surface 1014a, and the plane of the left surface 1013a of the scintillator pixel in the third column and the plane of the right surface 1014a intersect with a same straight line passing through the focal center of the X-ray source. Taking three rows as an example, a plane in which the front side surface 1015a of the scintillator pixel in the first row and a plane in which the back side surface 1016a are located, a plane in which the front side surface 1015a of the scintillator pixel in the second row and a plane in which the back side surface 1016a are located, and a plane in which the front side surface 1015a of the scintillator pixel in the third row and a plane in which the back side surface 1016a are located intersect with each other on the same straight line, and the straight line passes through the focal center of the X-ray source.

With continued reference to FIG. 5 in conjunction with FIG. 4, in one embodiment, as shown in pixel array 100a, the angle between the side and bottom surfaces of the same side of the scintillator pixels in different columns (columns in the line B-B direction) in the same row (rows in the line A-A direction) gradually approaches 90 degrees from the two side edges of the row to the middle position M of the row depending on the angle of the beam of radiation passing through the spacing.

Referring to fig. 7 and 4 in conjunction with fig. 5, 9 and 11, the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different rows on the same column gradually approaches 90 degrees from the two side edges of the column to the middle M of the column according to the angle of the beam of rays passing through the interval formed by the side surfaces. As shown in fig. 7 in conjunction with fig. 4, the side surfaces of the column are a front side surface 1015a and a back side surface 1016a, respectively. Although fig. 7 is a cross-sectional view of a column of fig. 4, reference can also be made to fig. 7 for a cross-sectional view of a column of the scintillator pixel array shown in fig. 9 and 11. The left side surface (i.e., front side surface 1015a) of each scintillator pixel makes an angle, labeled θ, with the corresponding bottom surface 1012 a. The included angle θ between the front side surface 1015a and the corresponding bottom surface 1012a gradually increases and approaches 90 degrees from the edge of the row toward the middle position M of the row. The back side surface 1016a and the corresponding bottom surface 1012a form an angle Φ that decreases from the edge of the row toward the row middle position M and approaches 90 degrees.

With continued reference to fig. 9-12, in

pixel arrays

100b and 100c, the included angle between the side surface and the bottom surface of the same side of the scintillator pixels in different rows gradually increases or decreases from one side edge of the row to the other side edge of the row according to the angle of the radiation beam passing through the side surface to form the interval, as shown in fig. 10, the left side surface 1013b forms an included angle α with the bottom surface 1012b, the right side surface 1014b forms an included angle β with the bottom surface 1012b, the included angle α gradually increases from left to right, correspondingly, the included angle β gradually decreases from left to right, in fig. 12, the left side surface 1013c forms an included angle α with the bottom surface 1012b, and the right side surface 1014c and the bottom surface 1012c form an included angle β, the included angle α gradually increases from left to right, and the included angle β gradually decreases from left to right.

With continuing reference to fig. 9-12, in the array shown in fig. 9-12, the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixel in different rows on the same row gradually increases or decreases from one side edge of the row or column to the other side edge of the row or column according to the angle of the spaced ray bundle passing through the side surface, and the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixel in different rows on the same column gradually approaches 90 degrees from the two side edges of the column to the middle of the column according to the angle of the spaced ray bundle passing through the side surface. Skilled persons will appreciate that in a pixel array, the rows and columns can be interchanged, and thus, there is also a gradual increase or decrease in the angle formed by the side and bottom surfaces of the same side of scintillator pixels in different rows on the same column, depending on the angle of the beam of radiation passing through the space formed by the side surfaces, from one side edge of the column to the other side edge of the row or column.

In summary, one row or column feature of the scintillator pixel array as a whole from the scintillator pixel array is (for convenience of description, referred to as the first row and column feature): the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different columns on the same row or different rows on the same column gradually approaches 90 degrees from the two side edges of the row to the middle position of the row according to the angle of the ray beam which passes through the side surface to form an interval. Another row or column feature of the scintillator pixel array is (for ease of description, referred to as the second row-column feature): the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different columns on the same row or different rows on the same column is gradually increased or decreased from one side edge of the row to the other side edge of the row according to the angle of the ray beam passing through the side surface to form the interval. The rows and columns of the scintillator pixel array shown in fig. 4 are arranged according to the first row-column characteristic, respectively. In the scintillator pixel arrays shown in fig. 9 and 11, the rows thereof are arranged according to the second row-column characteristic, and the columns thereof are arranged according to the first row-column characteristic.

The skilled person will understand that: although the rows and columns of the pixel array are combined according to the first row and column features, or the first row and column features and the second row and column features can make the angles of the included angles formed by the side surfaces of the scintillator pixels located on the same side of the same row or the same column and the corresponding bottom surfaces equal, and the planes of the side surfaces of different columns intersect on the same straight line, and the straight line passes through the focal center of the X-ray source, and the planes of the side surfaces of different rows intersect on the same straight line, and the straight line passes through the focal center of the X-ray source, it can also be realized by other ways that the angles of the included angles formed by the side surfaces of the scintillator pixels located on the same side of the same row or the same column and the planes of the side surfaces of different columns intersect on the same straight line, and the straight line passes through the focal center of the X-ray source, and planes in which the side surfaces of different rows are located intersect on the same straight line, and the straight line passes through the focal center of the X-ray source. How the included angle formed by the side surface and the bottom surface of each scintillator pixel array is gradually increased or decreased is determined by the radiation characteristics of rays, and the condition that adjacent scintillator pixels do not generate ray crosstalk is taken as the standard.

With continuing reference to fig. 6 and 8 in combination with fig. 5, 7, 9, 10, 11 and 12, in one embodiment, each of the spaces 102 is filled with a material that reflects and absorbs visible light, thereby reducing the loss of light energy converted by the scintillator and avoiding crosstalk between adjacent scintillator pixels 101, thereby further improving the image quality.

Any of the foregoing arrangements of the scintillator pixel arrays can be achieved by conventional scintillator cutting processes or by casting of scintillator material.

When the aforementioned scintillator pixel array is applied to a detector sub-module, the top surface of each scintillator pixel of the scintillator pixel array constitutes the top surface of the detector sub-module. Based on the first and second row-column characteristics, two types of detector sub-modules can be generated, namely a first detector sub-module and a second detector sub-module, wherein the scintillator pixel arrays of the first detector sub-module are arranged according to the first row-column characteristics in the Z direction (Z-axis direction, which is then the same) and the X direction (X-axis direction, which is then the same) of the CT rotation system, and the scintillator pixel arrays of the second detector sub-module are arranged according to the second row-column characteristics in the Z direction of the CT rotation system and according to the first row-column characteristics in the X direction.

The following describes how the first and second detector sub-modules constitute a detector module, wherein the detector sub-module made up of the scintillator pixel array 100a shown in fig. 4 serves as a first detector sub-module 100a1, the detector sub-module made up of the scintillator pixel array 100b shown in fig. 9 serves as a second detector sub-module 100b1, and the detector sub-module made up of the scintillator pixel array 100c shown in fig. 11 serves as a second detector sub-module 100c 1.

The side surfaces and bottom surfaces of the scintillator pixel array generally form an angle that gradually approaches 90 degrees from the two side edges of the row or column toward the middle of the row or column, in combination with the irradiation characteristics of X-rays, generally a position in the middle of the top surface of a scintillator pixel array (e.g., 100a) of this type is disposed perpendicular to an X-ray beam, the top surface of a detector sub-module formed by this type of scintillator pixel array is perpendicular to the X-ray beam, and may be arranged in an arc in the Z-direction of the CT rotation system or in a straight line and placed in the vicinity of the focal point reference plane L (the focal point reference plane L is illustrated in fig. 10 for the purpose of illustrating this positional relationship), in the embodiments of the present application, the straight line arrangement means that the top surfaces of the detector sub-modules are coplanar or the top surfaces of the detector sub-modules on the support are respectively located in several different planes, which are parallel to each other, and which form a stepped arrangement viewed from the side of the planes, as shown in fig. 10, the side surfaces and bottom surfaces of the scintillator pixel array are generally formed with an angle that gradually increases from the left side surface of the scintillator pixel array and to the X-ray source, and may be placed perpendicular to the X-ray detector sub-module, and may be placed in a position of the X-ray detector sub-module such as viewed from the X-ray source, and the detector sub-module, such as a straight line, and the scintillator pixel array is placed perpendicular to the X-ray radiation system, and the detector sub-module is placed perpendicular to the X-detector sub-module, and placed perpendicular to the X-detector sub-module is placed in the X-detector sub-module, and the X-detector sub-module is placed in.

Based on the arrangement of the detector sub-modules formed by the scintillator pixel array, several detector modules are illustrated in fig. 13 to 20. The skilled person will appreciate that other types of detector sub-modules, such as known detector sub-modules, may also be included in the detector module.

Referring to fig. 13 and 14, in one embodiment, the detector module includes a support and a plurality of detector sub-modules mounted to the support, top surfaces of the plurality of detector sub-modules being aligned along a Z-direction of a CT rotational system of a CT mainframe and including at most one first detector sub-module 100a1 and at least one second detector sub-module 100b1 and 100c 1. The skilled person will appreciate that said at most includes embodiments without said first detector sub-module 100a1 in addition to the above described embodiment including one said first detector sub-module 100a 1. The linear arrangement can reduce the processing difficulty of the detector module bracket and the assembly difficulty of the whole detector module. In a further scheme, the alignment can also be realized by aligning the detector sub-modules in the Z direction integrally.

Referring to fig. 15 and 16, in one embodiment, the detector module includes a support and a plurality of detector sub-modules mounted to the support, the plurality of detector sub-modules having top surfaces arranged along a Z-arc of a CT rotational system of the CT mainframe and including at least a first detector sub-module, one first detector sub-module 100a1 being illustrated in fig. 15 and 16. In an embodiment of the application, the arc arrangement is that the top surface of the detector sub-modules is tangent to the arc of a target circle centered at the focal center. In a further aspect, the arcuate arrangement may also be implemented by the first detector sub-modules as a whole being arranged in an arc along the Z-direction. The top surfaces 311 of the plurality of first detector sub-modules are arranged along the Z-direction arc, so that the variety of the scintillator pixel array can be reduced, and the material management in production is easy.

Referring to fig. 17 and 18 in conjunction with fig. 12-14, in one embodiment, referring to the focal reference plane of the X-ray source as a reference, the plurality of detector sub-modules on the support includes a middle detector sub-module located within a predetermined distance of the focal reference plane and an edge detector sub-module located outside the predetermined distance, the top surface of the middle detector sub-module being aligned along the Z-direction and including at most one of the first detector sub-module and at least one of the second detector sub-module (e.g., 100b1 and 100c 1); and/or the top surfaces of the edge detector sub-modules are arranged along the Z-direction arc of the CT rotating system and comprise at least one first detector sub-module (such as 100a 1). In fig. 17 and 18, three detector sub-modules are arranged linearly and two detector sub-modules are arranged in an arc shape on the left and right sides. The preset distance is determined according to specific situations, and as shown in fig. 17 and 18, the preset distance is 1 detector submodule, so that three detector submodules are linearly arranged. The skilled person will appreciate that in one embodiment it is possible that the edge detector sub-modules are arranged entirely in an arc along the Z-direction and the middle detector sub-modules are arranged entirely in a line along the Z-direction, whereby the top surfaces of the edge detector sub-modules are arranged in an arc along the Z-direction of the CT rotation system and the top surfaces of the middle detector sub-modules are arranged in a line along the Z-direction. In one embodiment, a distance between a top surface of the middle detector sub-module and the center of focus is less than a distance between a top surface of the edge detector sub-module and the center of focus.

Because the manufacturing cost of the detector sub-modules spliced along the straight line is far lower than that of the detector sub-modules spliced along the circular arc, the straight line arrangement of the middle detector sub-modules and the arc arrangement of the edge detector sub-modules are compared with the mode that all the detector sub-modules are spliced in the arc shape, the manufacturing difficulty of the detector modules is reduced, and further the manufacturing cost is reduced, and the scheme can be applied to detectors with large coverage ranges (such as 512 layers).

Referring to fig. 19 and 20, in the embodiment shown in fig. 15 to 16, the top surfaces of all the detector sub-modules are distributed on the arc of the same target circle with the center of the focus of the X-ray source as the center, and the skilled person will understand that in another embodiment, in the case of an arc arrangement, the top surfaces 311 of a plurality of detector sub-modules in the arc arrangement are distributed on the arc of the target circle with unequal radii and the center of the focus of the X-ray source (i.e. the arc arrangement). Fig. 19 and 20 illustrate two radii R1 and R2, the top surfaces 311 of the first through third detector sub-modules and the top surfaces 311 of the seventh and eight detector sub-modules are distributed on and tangent to an arc of a target circle of radius R2, the top surfaces 311 of the fourth through sixth detector sub-modules are distributed on and tangent to an arc of a target circle of radius R1, and R1< R2.

When designing and manufacturing a detector with a large Z-direction coverage range, the X-direction gaps between adjacent modules at different Z-direction positions are more uneven and have larger deviation in a receiving domain formed by the top surfaces of the detector sub-modules in a Z-direction asymmetric state than in a Z-direction symmetric state, and the X-direction gaps of the adjacent detector modules at different Z-direction positions are ensured to be equal or have the smallest deviation value as possible by distributing the top surfaces of a plurality of first detector sub-modules on target circles with different radiuses, so that the cost of an X-ray source is reduced, and the image quality is ensured and even optimized, and better image quality is obtained. The skilled person will appreciate that although the example is given for a receive field formed by the top surface of the detector sub-module which is asymmetric with respect to the focus reference plane, this approach may also be applied to a situation in which the receive field formed by the top surface of the detector sub-module is symmetric with respect to the focus reference plane.

Referring to fig. 21 in conjunction with fig. 15, 16, 19 and 20, in one embodiment, a plurality of detector sub-modules mounted on a support form a receiving field corresponding to an irradiation field of the X-ray source in a YZ plane of a CT rotational system, the receiving field being asymmetric with respect to a focal reference plane of the X-ray source. As shown in fig. 21, the X-ray source 20 includes a target disk 1. The receiving field 32 includes a left receiving field 321 and a right receiving field 322 with reference to the focus reference plane L. The left and right receiving

fields

321 and 322 are asymmetrical with respect to the focus reference plane L. By making the receiving field 32 asymmetric with respect to the focus reference plane L, this has at least the following advantages: the ray of the X-ray source is fully utilized through the asymmetric design, and the performance parameter requirement of the X-ray source (such as an X-ray bulb tube) and the manufacturing difficulty and cost of the CT equipment with the large Z-direction coverage range are reduced. Specifically, referring to fig. 21, 15, 16, 19 and 20, the left receiving area is larger than the right receiving area, and the left receiving area is located at a side away from the target disc, and the right receiving area is located at a side of the target disc.

With continuing reference to fig. 15, 16, 19 and 20, the top surface of each first detector sub-module has an equal width in the Z-direction of the rotational system, such that the number of detector sub-modules on the left side (e.g., 4 shown in the figure) is greater than the number of detector sub-modules on the right side (e.g., 3 shown in the figure) at the focus reference plane L. In fig. 16, to illustrate the asymmetry, focus reference plane L is extended to first detector sub-module 100a 1. By such a design, the sum of the widths of the detector sub-modules on one side of the focus reference plane L in the Z direction is larger than the sum of the widths of the detector sub-modules on the other side of the focus reference plane in the Z direction, so that the receiving field is asymmetrical with respect to the focus reference plane L of the X-ray source.

Although the above-mentioned embodiments shown in fig. 15 and 16 are described by taking the top surfaces 311 of the detector sub-modules as the example, the widths in the Z direction are equal, and it can be understood by the skilled person that the above-mentioned asymmetric design can also be realized when the widths in the Z direction of the top surfaces 311 of the detector sub-modules are not equal, in which case, the lengths of the receiving fields formed by the top surfaces on one side of the focus reference plane L are made to be greater than the lengths of the receiving fields on the other side by arc-splicing the detector sub-modules in the Z direction.

Referring to fig. 13, 14, 17 and 18, in one embodiment, a plurality of detector sub-modules form a receiving field corresponding to an irradiation field of the X-ray source in a YZ plane of the CT rotation system, and the receiving field is symmetrical with respect to a focus reference plane of the X-ray source. In the case that the widths of the top surfaces 311 of the detector sub-modules in the Z direction are equal, the number of detector sub-modules on the left side of the focus reference plane L and the number of detector sub-modules on the right side of the focus reference plane L are equal, and of course, in the case that the widths of the top surfaces 311 of the detector sub-modules in the Z direction are not equal, the symmetrical arrangement may be achieved as long as the total length of the top surfaces 311 of the detector sub-modules on the left side of the focus reference plane L in the Z direction is equal to the total length of the top surfaces 311 of the detector sub-modules on the right side of the. In both the symmetric design and the asymmetric design, the widths of the detector sub-modules in the X direction may be equal or unequal.

With continued reference to fig. 11-18, the artisan will appreciate that fig. 13 and 14 illustrate a symmetrical design in the case of a straight alignment, and fig. 15 and 16 and fig. 19 and 20 illustrate an asymmetrical design in the case of an arcuate alignment, but the artisan will appreciate that an asymmetrical design may also be employed in the case of a top surface of a detector sub-module aligned along the Z-direction; a symmetrical design may be used where the top surfaces of the detector sub-modules are arranged along a Z-arc. For the case that the top surfaces of the middle detector sub-modules are arranged in a straight line and the top surfaces of the edge detector sub-modules are arranged in an arc, the receiving domains formed by the top surfaces of the detector sub-modules may be symmetrical or asymmetrical with respect to the focus reference plane, in the case of asymmetry, the top surfaces of the edge detector sub-modules are distributed on target circles with unequal radii around the center of the focus of the X-ray source, and further, the distance between the top surface of the middle detector sub-module and the center of the focus is smaller than the distance between the top surface of the edge detector sub-module and the center of the focus.

Although the above description has been given by way of example of a scintillator pixel array featuring rows and columns each being a first row and column feature or featuring rows and columns being said first row and column feature and a second row and column feature, the skilled person will understand that a detector sub-module with a scintillator pixel array of this type may also constitute a detector module, with the detector sub-module being constituted by an array, the top surface of each scintillator pixel of the scintillator pixel array constituting the top surface of the detector sub-module. The scintillator pixel array includes a plurality of scintillator pixels, each of which is a polyhedron constituted by a top surface, a bottom surface opposite to the top surface, and side surfaces connected to the respective top and bottom surfaces, the respective side surfaces of adjacent scintillator pixels constituting a space through which all rays in a ray bundle directed to the space pass. In one embodiment, each of the spaces is filled with a material that reflects and absorbs visible light.

The present application further discloses a detector comprising a housing and a plurality of detector modules as described in any of the previous paragraphs, the plurality of detector modules arranged on the housing along an arc in an X-direction of a CT rotational system.

The detector is not only suitable for an imaging device which converts a ray (such as an X-ray) into a material such as GOS (gold oxide) of visible light particles and then obtains an image through photoelectric conversion and the like, but also suitable for an imaging device which directly converts the X-ray into a material such as cadmium zinc telluride (CdZnTe, CZT) of an electric signal and then obtains an image through data processing. Based on this, the present application further discloses a CT apparatus comprising a gantry, an X-ray source and any of the aforementioned detectors, wherein the gantry comprises an opening for receiving a scanned object. The X-ray source is used for emitting rays to the scanning object. The detector is disposed on an opposite side of the opening from the X-ray source for receiving radiation attenuated by the scanned object and converting the radiation into an electrical signal.

Although the present application has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application, and all changes, substitutions and alterations that fall within the spirit and scope of the application are to be understood as being covered by the following claims.

Claims

1. A scintillator pixel array for receiving attenuated radiation from an X-ray source of a CT mainframe that has been scanned, wherein the array comprises a plurality of scintillator pixels, each scintillator pixel being a polyhedron formed by a top surface, a bottom surface opposite the top surface, and side surfaces connecting the respective top and bottom surfaces, wherein the respective side surfaces of adjacent scintillator pixels form a space, and the side surfaces forming the space coincide with X-rays passing through their surfaces such that all of the rays in a beam that strike the space pass through the space.

2. The scintillator pixel array of claim 1, wherein each of said spaces is filled with a material that reflects and absorbs visible light.

3. The scintillator pixel array according to claim 1 or 2, wherein in the array, the side surfaces on the same side of the scintillator pixels in the same row or column form an equal angle with the corresponding bottom surface, the planes of the side surfaces in different columns intersect on the same straight line, and the straight line passes through the focal center of the X-ray source; the planes of the side surfaces of different rows intersect on the same straight line, and the straight line passes through the focus center of the X-ray source.

4. The scintillator pixel array of claim 3, wherein the rows and columns of the array are arranged in accordance with a first row-column characteristic, or a first row-column characteristic and a second row-column characteristic, wherein,

the first row is characterized by: the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different rows on the same row or different rows on the same column gradually approaches 90 degrees from the two side edges of the row or column to the middle position of the row or column according to the angle of the spaced ray beams passing through the side surface;

the second row and column characteristics are: the included angle formed by the side surface and the bottom surface of the same side of the scintillator pixels in different columns on the same row or different rows on the same column gradually increases or decreases from one side edge of the row or column to the other side edge of the row or column according to the angle of the spaced ray beams passing through the side surface.

5. A detector sub-module comprising a scintillator pixel array having a top surface forming a top surface of the detector sub-module, rows and columns of the pixel array being arranged in accordance with the first row and column features of claim 4 in a Z-direction and an X-direction of a CT rotation system, the array forming the detector sub-module as a first detector sub-module;

alternatively, the scintillator pixel array is arranged in the Z-direction of the CT rotation system according to the second row-column feature of claim 4 and in the X-direction according to the first row-column feature of claim 4, and the detector sub-module formed by the array serves as the second detector sub-module.

6. A detector module comprising a support and a plurality of detector sub-modules mounted to the support, the plurality of detector sub-modules having top surfaces arranged along a Z-arc of a CT rotation system of a CT mainframe and comprising at least a first detector sub-module of claim 5;

alternatively, the detector module comprises a support and a plurality of detector sub-modules mounted to the support, top surfaces of the plurality of detector sub-modules being aligned along a Z-direction of a CT rotation system of a CT mainframe and comprising at most one first detector sub-module of claim 5 and at least one second detector sub-module of claim 5;

alternatively, the detector module comprises a support and a plurality of detector sub-modules mounted to the support, the plurality of detector sub-modules comprising a middle detector sub-module located within a predetermined distance of a focus reference plane and an edge detector sub-module outside the range, a top surface of the middle detector sub-module being aligned along the Z-direction and comprising at most one first detector sub-module of claim 5 and at least one second detector sub-module of claim 5; and/or a top surface of the edge detector sub-modules arranged along a Z-direction arc of the CT rotational system and comprising at least one first detector sub-module of claim 5, wherein the focal reference plane passes through a focal center of the X-ray source and is parallel to an XY plane of the CT rotational system.

7. The detector module of claim 6, wherein top surfaces of the plurality of detector sub-modules mounted to the support form a receiving field corresponding to an illumination field of the X-ray source at a YZ-plane of the CT rotational system, the receiving field being asymmetric with respect to the focal reference plane.

8. The detector module of claim 6 or 7, wherein in the case of the Z-direction arc arrangement along the CT rotational system of the CT mainframe, the top surfaces of the arc arrangement of detector sub-modules are distributed on an arc of a target circle of unequal radius centered on the center of the focal spot of the X-ray source.

9. The detector module of claim 7, wherein a sum of widths in the Z-direction of top surfaces of detector sub-modules on one side of the focus reference plane is greater than a sum of widths in the Z-direction of top surfaces of detector sub-modules on the other side of the focus reference plane such that the receive field is asymmetric with respect to the focus reference plane.

10. A detector comprising a housing and a plurality of detector modules according to any of claims 6 to 9, each detector module being arranged in the housing along an arc in the X-direction of the CT rotation system.

11. A CT apparatus comprising a gantry, an X-ray source, and a detector according to claim 10, wherein,

the gantry includes an opening for receiving a scan subject;

the X-ray source is used for emitting rays to the scanning object;

the detector is disposed on an opposite side of the opening from the X-ray source for receiving radiation attenuated by the scanned object and converting the radiation into an electrical signal.