Multi-modal imaging system registration precision correction equipment and preparation method thereof

Abstract

The invention provides a multi-modal imaging system registration precision correction device and a preparation method thereof. The correction equipment comprises a support, the support comprises at least four supporting rods, each supporting rod is provided with a point source containing part, the tops of the at least four supporting rods form a virtual three-dimensional structure, and each point source containing part is located at the position of one top; and the at least four point sources are respectively accommodated in the at least four point source accommodating parts, the point sources are made of high-density materials with solution adsorption capacity, and when the correction equipment is used for correcting the multi-mode imaging system, each point source absorbs the radioactive source solution. The correction equipment provided by the invention comprises the point source with solution adsorption capacity, the point source can fully absorb the radioactive source solution to form a radioactive point source, the point source can replace a contrast agent to perform imaging under CT scanning due to the high-density characteristic of the point source, a mixed solution of the radioactive source and the contrast agent does not need to be used any more, and the correction effect is very good.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular, to a calibration device for the registration accuracy of a multimodal imaging system and a preparation method thereof. Background Art

[0002] Multimodal imaging technology uses different imaging techniques to perform multi-dimensional and three-dimensional imaging on the same patient, obtaining more comprehensive and accurate medical image information. Common multimodal imaging techniques include PET-CT, SPECT-CT, etc.

[0003] In PET-CT and SPECT-CT technologies, CT provides anatomical structure imaging, and PET / SPECT provides functional imaging. Through CT images, the specific position of PET / SPECT images in the human body can be located, and CT images can also be used to perform attenuation correction on PET / SPECT images. This fusion technology can give play to the advantages of the two imaging examination techniques while making up for their respective deficiencies, greatly improving the amount of information obtained on the images, thereby improving the sensitivity, specificity, and accuracy of disease diagnosis, enabling early diagnosis and judgment of the curative effect of diseases, and achieving the effect of 1 + 1 > 2.

[0004] When PET-CT and SPECT-CT work, it is necessary to accurately fuse the CT image and the PET / SPECT image into one picture, so as to achieve accurate positioning and attenuation correction of the lesion site. In order to ensure the accuracy, stability, and consistency of the device during production, manufacturing, and use, and to ensure the accuracy of image fusion, it is necessary to regularly calibrate the registration accuracy of the device. Here, a calibration model is required to calibrate the registration accuracy of PET-CT and SPECT-CT.

[0005] In the prior art, the calibration model mainly mixes a Tc-99m solution and a high-density CT contrast agent in a certain proportion, and then injects the mixed solution into multiple containers. The solutions distributed in each container need to have equal volume, the same density, and the same radioactivity of the radiation source. Currently, the containers for holding the mixed solution are generally cylindrical tubes or inverted cones with a wider top and a narrower bottom, such as CN103584878A and CN104665857A.

[0006] However, these solutions have the following deficiencies in actual operation:

[0007] 1. When injecting the mixed solution into the container, it is difficult to ensure that the injection volume of each container is consistent, resulting in inconsistent radioactivity of the radiation sources at each point source, which in turn leads to deviations in the identification of the positions of each point source during the calibration process. Moreover, during the injection process, the side walls of the container are likely to be contaminated with the radiation source, resulting in a non-spherical point source distribution of the radiation source, which will also lead to deviations in the identification of the positions of each point source during the calibration process. Additionally, during the injection process, air bubbles are likely to appear, and the presence of air bubbles will also cause inaccurate positioning.

[0008] 2. The container is in the shape of a cylindrical tube or an inverted cone with a wider top and a narrower bottom. When the PET / SPECT and CT perform a 360° scan, the data collected in each direction has anisotropy due to the uneven distribution of the radiation source, which will lead to inaccurate positioning of the radiation source and the inability to determine the central coordinates of the radiation source.

[0009] 3. Since the radiation source is liquid, it is prone to leakage during the injection process, causing radioactive contamination to the environment, personnel, and equipment, presenting safety hazards. Moreover, during the movement of the model or during the acquisition process by the scanning device, the internal radiation source will shake, resulting in the side walls of the container being contaminated with the radiation source, bringing inaccurate positioning of the radiation source and increasing the leakage risk at the same time.

[0010] 4. Since the mixed solution has certain requirements for the ratio of the radiation source to the contrast agent, it is necessary to strictly control the ratio of the contrast agent to the radiation source. When the ratio is inaccurate, it will lead to unclear PET / SPECT images and CT images, affecting the accuracy of registration and calibration. However, in the actual operation process, due to the short decay time of the radiation source, it is very difficult to strictly control the ratio.

[0011] The content in the background art section is only the technology known to the inventor and does not necessarily represent the prior art in this field. Summary of the Invention

[0012] To solve at least one of the above technical problems, a calibration device for the registration accuracy of a multimodal imaging system according to the first aspect of the present application includes:

[0013] A bracket, the bracket includes at least four support rods, and a point source accommodating part is provided on each support rod. The tops of at least four support rods form a virtual three-dimensional structure, and each point source accommodating part is located at the position of one of the tops; and

[0014] At least four point sources, which are respectively accommodated in at least four point source accommodating parts. The point sources are made of a high-density material with the ability to adsorb solution. When using the calibration device to calibrate the multimodal imaging system, each point source absorbs a radiation source solution.

[0015] In some embodiments of the present application, the high-density material is a material with micropores dispersed in a matrix.

[0016] In some embodiments of the present application, the density of the point source is greater than or equal to 2 g / cm 3 , and the porosity of the point source is greater than or equal to 20%.

[0017] In some embodiments of the present application, the point source is made of at least one of medical stone, montmorillonite, kaolinite, illite, and synthetic molecular sieve.

[0018] In some embodiments of the present application, the point source is a sphere, and the volume of the sphere is less than or equal to 10 mm 3 .

[0019] In some embodiments of the present application, the volume difference between any two of the point sources is within a predetermined range.

[0020] In some embodiments of the present application, the bracket further includes a central support block, and at least four of the struts are fixed on the central support block according to the distribution of the virtual three-dimensional structure.

[0021] In some embodiments of the present application, the volume of the virtual three-dimensional structure is greater than or equal to 4 times the volume of the central support block.

[0022] In some embodiments of the present application, the virtual three-dimensional structure is a polyhedron, and the central support block is a sphere or a polyhedron with the same shape as the virtual three-dimensional structure.

[0023] In some embodiments of the present application, a threaded hole is provided at the connection part between the central support block and the strut, a first threaded post is provided at one end of the strut, and the strut is screwed to the central support block through the threaded hole and the first threaded post.

[0024] In some embodiments of the present application, the bracket includes eight struts, and the vertices of the eight struts form a virtual regular cube structure; the central support block is also a regular cube structure;

[0025] The side length of the central support block is not greater than 10 cm, and the side length of the virtual regular cube structure is 20 - 40 cm.

[0026] In some embodiments of the present application, the point source accommodating part includes an accommodating groove and a sealing head. The accommodating groove is used to place the point source, and the sealing head is used to seal the point source in the accommodating groove.

[0027] In some embodiments of the present application, the receiving groove has a groove body, an inlet portion connected to the open end of the groove body, and a threaded portion provided at one end of the inlet portion away from the groove body; both the inlet portion and the threaded portion are cylinders; a second threaded post is provided on the sealing head, and the second threaded post can be connected to the threaded portion to form a seal for the inlet portion and the groove body.

[0028] In some embodiments of the present application, the lateral dimension inside the open end is equal to or greater than the maximum lateral dimension of the outer contour of the point source, and the difference in dimension is within 2 mm; the lateral dimension inside the inlet portion is equal to the lateral dimension inside the open end; the lateral dimension inside the threaded portion is greater than the lateral dimension inside the open end.

[0029] In some embodiments of the present application, the sum of the longitudinal dimension inside the groove body and the longitudinal dimension inside the inlet portion is equal to or greater than the maximum longitudinal dimension of the outer contour of the point source, and the difference in dimension is within 2 mm.

[0030] In some embodiments of the present application, the point source is a sphere, and the inner side of the groove body is a cylinder or has a curved surface.

[0031] In some embodiments of the present application, the side surface of the sealing head is provided with embossed patterns.

[0032] In some embodiments of the present application, the bracket is made of a material having low absorption characteristics for γ-rays and X-rays.

[0033] In some embodiments of the present application, the bracket is made of acrylic and / or carbon fiber.

[0034] In some embodiments of the present application, the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution.

[0035] In some embodiments of the present application, the radioactive activity concentration of the radioactive source solution is not less than 40 mCi / mL.

[0036] The second aspect of the present application provides a method for preparing a calibration device for the registration accuracy of a multimodal imaging system, including:

[0037] Preparing a point source:

[0038] Soaking a point source made of a high-density material with solution adsorption ability in a radioactive source solution for a predetermined time;

[0039] Preparing a bracket:

[0040] Preparing at least four support rods, and a point source receiving portion matching the structure of the point source is prepared on each support rod; and

[0041] Assembly:

[0042] Load the point sources into the point source accommodating parts respectively;

[0043] Assemble the at least four struts such that the tops of the at least four struts form a virtual three-dimensional structure, and each of the point source accommodating parts is respectively located at the position of one of the tops.

[0044] In some embodiments of the present application, the radioactivity concentration of the radioactive source solution is not less than 40 mCi / mL.

[0045] In some embodiments of the present application, the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution.

[0046] The calibration device provided by the present application includes point sources with the ability to adsorb solution. The point sources can form radioactive point sources by fully absorbing the radioactive source solution, and the high-density characteristics of the point sources themselves can replace the contrast agent to be imaged under CT scanning, without the need to use a mixed solution of radioactive sources and contrast agents.

[0047] Moreover, the stent includes at least four struts, and the tops of the four struts form a virtual three-dimensional structure. The point sources are erected on the vertices of the virtual three-dimensional structure through the stent, which can better simulate the three-dimensional structure of the human body in space, fully reflect the three-dimensional effect in space, and greatly reduce the interference of structures such as the stent on the imaging of the point sources during tomographic scanning, enabling rapid positioning of the point sources, so as to use the point sources for calibration of image registration.

[0048] In addition, since the radioactive source solution is adsorbed onto the point sources, it will not contaminate the side walls of the calibration device, there are no air bubbles, so the calibration effect is more accurate, and it will not leak into the environment to cause radioactive contamination to personnel, the environment, and equipment, with high safety.

[0049] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0051] Figure 1 Schematic three-dimensional structure diagram of a calibration device for the registration accuracy of a multimodal imaging system provided by an embodiment of the present application.

[0052] Figure 2 For Figure 1 Partial enlarged view of the structure of the calibration device shown.

[0053] Figure 3 For Figure 1 Partial disassembly diagram of the calibration device shown

[0054] Figure 4 Schematic three-dimensional structure diagram of the calibration device for the registration accuracy of the multimodal imaging system provided in another embodiment of the present application

[0055] Figure 5 Schematic three-dimensional structure diagram of the calibration device for the registration accuracy of the multimodal imaging system provided in yet another embodiment of the present application

[0056] Figure 6 Schematic structure diagram of the tank body and the inlet part provided in an embodiment of the present application

[0057] Figure 7 Process flow chart of preparing the calibration device provided in an embodiment of the present application

[0058] Figure 8 Schematic diagram of applying the calibration device shown in FIGS. 1-3 to the SPECT-CT system provided in an embodiment of the present application

[0059] Figure 9 Image obtained after performing SPECT tomography acquisition on the calibration device using the SPECT-CT system provided in an embodiment of the present application

[0060] Figure 10 Image obtained after performing CT acquisition on the calibration device using the SPECT-CT system provided in an embodiment of the present application

[0061] Figure 11 SPECT-CT fusion image obtained after calibration using the calibration device provided in an embodiment of the present application Detailed implementation manners

[0062] In the following, only some exemplary embodiments are briefly described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive

[0063] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and installations of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between various embodiments and / or installations discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0064] It should be noted that, unless otherwise clearly stipulated and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection: it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific situations. In addition, in the drawings, in order to effectively describe the technical content, the thickness, proportion, and size of the components are exaggerated or reduced.

[0065] The following, in combination with the drawings and embodiments, further details the specific embodiments of the present application so as to better understand the solution of the present application and the advantages of its various aspects. However, the specific embodiments and examples described below are only for illustrative purposes and not for limiting the present application.

[0066] Figures 1 to 3 Shown is a calibration device 1 provided by an embodiment of the present application, including a bracket 10 and a point source 20.

[0067] Figures 1 to 3 In the shown embodiment, the bracket 10 includes eight struts 11. The vertices of the eight struts 11 form a virtual cube structure. Each strut 11 is provided with a point source accommodation part 111, and each point source accommodation part 111 is respectively located at the top of the strut 11 for accommodating the point source 20.

[0068] In other embodiments of the present application, the struts 11 only need to be greater than or equal to four. For example, the bracket 10 can include four, five, six, seven or other numbers of struts 11, and at least the tops of four struts 11 can form a virtual three-dimensional structure. Figure 4 Shown is a calibration device provided by another embodiment of the present application, which includes four struts 11, and the tops of the four struts 11 form a virtual three-dimensional structure.

[0069] The point source 20 is mounted on the vertex of the virtual three-dimensional structure through the support 10, which can well simulate the three-dimensional structure of the human body in space, fully reflecting the three-dimensional effect in space. Moreover, during tomographic scanning, the interference of structures such as the support 10 on the imaging of the point source 20 is greatly reduced, and the point source 20 can be quickly located, so as to use the point source 20 for the correction of image registration.

[0070] Figures 1 to 3 In the illustrated embodiment, the vertices of the eight struts 11 form a virtual cube structure, which can more accurately simulate the three-dimensional structure of the human body in space and fully reflect the three-dimensional effect in space. In addition, this structure also ensures that the heights of the point sources are consistent, which is more conducive to eliminating the deviation in the position recognition of each point source during the correction process.

[0071] The point source 20 is made of a high-density material with the ability to adsorb solution. When using the calibration device 1 to calibrate the multimodal imaging system, each point source 20 absorbs the radioactive source solution. In this application, the point source 20 can fully absorb the radioactive source solution to form a radioactive point source, and the high-density characteristic of the point source itself can be used to image under CT scanning instead of using a mixed solution of radioactive source and contrast agent. Moreover, since the point source 20 is fixed, the movement of the radioactive source will not be caused by the movement of the bed board, support, etc., thus ensuring the accuracy of the point source position. In addition, since the radioactive source solution is adsorbed onto the point source 20, there is no liquid, no bubbles, it will not contaminate the side wall of the calibration device, and will not leak into the environment to cause radioactive pollution to personnel, the environment and equipment.

[0072] Optionally, the high-density material is a material with micropores dispersed in the matrix. For example, the density of the point source 20 can be greater than or equal to 2 g / cm 3 , and the density is greater than that of the liquid, making the images collected by CT clearer, which is helpful for positioning and increases the convenience. Optionally, the porosity of the point source 20 can be greater than or equal to 20%, so as to ensure a strong adsorption capacity for the radioactive source solution. In this application, the porosity refers to the percentage of the pore volume in the total volume of the material. Further optionally, the point source 20 is made of at least one of zeolite, montmorillonite, kaolinite, illite, and synthetic molecular sieve, and these materials have a strong adsorption capacity for the radioactive source solution. Among them, each point source 20 can be made of one of zeolite, montmorillonite, kaolinite, illite, and synthetic molecular sieve, and the materials used for multiple point sources 20 can be the same or different.

[0073] Figures 1 to 3 In the illustrated embodiment, the point source 20 is a sphere, which is easy to manufacture and place, and the spherical structure is conducive to ensuring the uneven distribution of the radioactive source, thus eliminating the problem of anisotropy. Optionally, the volume of the sphere is less than or equal to 10 mm 3, the small volume of the sphere can reduce the overall weight of the calibration device. Optionally, the volume difference between any two point sources 20 is within a predetermined range, and the regular shape is beneficial to reducing the position recognition error caused by inconsistent distribution of radiation sources. In other embodiments of the present application, the point source 20 can also be a cube, a cuboid or other shapes, and the present application does not limit this.

[0074] Optionally, the bracket 10 is made of a material with low absorption characteristics for γ-rays and X-rays, and can be made of acrylic and / or carbon fiber, for example. The material with low absorption characteristics for γ-rays and X-rays reduces the interference of structures such as the bracket on the point source sphere imaging, so that the point can be quickly located during scanning.

[0075] Optionally, the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution. When the calibration device is used in a SPECT-CT system, the radioactive source solution corresponds to a Tc-99m radioactive source solution; when the calibration device is used in a PET-CT system, the radioactive source solution corresponds to an F-18 radioactive source solution. Optionally, the radioactive activity concentration of the radioactive source solution is not less than 40 mCi / mL, so as to ensure that it can be quickly located during scanning.

[0076] Figures 1 to 3 In the illustrated embodiment, the bracket 10 further includes a central support block 12, and the eight struts 11 are respectively located at the eight vertices of the central support block 12. The central support block 12 can better support the bracket 10, thus ensuring the stability of the calibration device 1. Figures 1 to 3 In the illustrated embodiment, the central support block 12 is also a regular cube structure. In other embodiments of the present application, the central support block 12 can also be other structures, and at least four struts 11 are fixed on the central support block according to the distribution of the virtual three-dimensional structure formed by their tops. The virtual three-dimensional structure is a polyhedron, and the relatively preferred structure of the central support block is a sphere or a polyhedron of the same shape as the virtual three-dimensional structure, which is beneficial to forming a stable structure. Figure 4 In the illustrated embodiment, the central support block 12 is spherical, and the tops of the four struts 11 form a virtual three-dimensional structure. Figure 5 Illustrates a calibration device provided by another embodiment of the present application, wherein the central support block 12 is also spherical, and the eight struts 11 are respectively located on the spherical central support block 12, and the eight struts 11 form a cube structure.

[0077] Optionally, the volume of the virtual three-dimensional structure formed by the tops of at least four struts 11 is greater than or equal to 4 times the volume of the central support block 12. The volume of the central support block 12 is relatively small, which can avoid deformation under the influence of the gravity of the struts 11 and reduce the scattering and attenuation caused by the ray passing through it. For Figures 1 to 3In the illustrated embodiment, the side length of the central support block 12 may not be greater than 10 cm, and the side length of the virtual cube structure may be 20 - 40 cm. When a person lies down, the width of the body is approximately 20 - 40 cm. Setting the side length of the virtual cube within this range is conducive to better simulating the three-dimensional structure of the human body in space.

[0078] As Figure 3 shown, in this embodiment, threaded holes 121 are provided at each vertex of the central support block 12. At the other end of the support rod 11 opposite to the point source accommodating portion 111, a first threaded post 112 is provided. The support rod 11 and the central support block 12 are screwed together through the threaded holes 121 and the first threaded post 112. The replacement is convenient through threaded connection.

[0079] As Figure 2 shown, the point source accommodating portion 111 includes a receiving groove 1111 and a sealing head 1112. The receiving groove 1111 is used to place the point source 20, and the sealing head 1112 is used to seal the point source 20 in the receiving groove 1111. Such a structure is conducive to taking and placing the point source, and after being fixed, the point source will not shake, and will not cause the movement of the radiation source due to the movement of the bed board, bracket, etc., thereby ensuring the accuracy of the point source position, also ensuring a good sealing effect, and improving safety.

[0080] The receiving groove 1111 has a groove body 1111a, an inlet portion 1111b connected to the open end of the groove body 1111a, and a threaded portion 1111c provided at one end of the inlet portion 1111b away from the groove body 1111a. Figure 2 In the illustrated embodiment, the groove body 1111a is hemispherical, and the inlet portion 1111b and the threaded portion 1111c are both cylindrical.

[0081] In this application, optionally, to ensure that the point source 20 can be smoothly placed and fixed in the receiving groove 1111, the lateral dimension of the inner side of the open end of the groove body 1111a is equal to or greater than the maximum lateral dimension of the outer contour of the point source 20, and the difference in dimension is within 2 mm. Optionally, the lateral dimension of the inner side of the inlet portion 1111b is equal to the lateral dimension of the inner side of the open end of the groove body 1111a, which is conducive to being fixed in the receiving groove 1111. Of course, the lateral dimension of the inner side of the inlet portion 1111b can also be greater than the lateral dimension of the inner side of the open end of the groove body 1111a, which will not prevent the point source 20 from being placed into the groove body 1111a. Optionally, the lateral dimension of the inner side of the threaded portion 1111c is greater than the lateral dimension of the inner side of the open end of the groove body 1111a. Since the threaded portion 1111c needs to be provided with an internal thread, if the inner dimension is smaller than the inner dimension of the open end, the point source is likely to be unable to be placed. In addition, it can ensure that the threaded portion 1111c completely covers the inlet portion 1111b, thereby achieving sealing. Optionally, the sum of the longitudinal dimension of the inner side of the groove body 1111a and the longitudinal dimension of the inner side of the inlet portion 1111b is equal to or greater than the maximum longitudinal dimension of the outer contour of the point source 20, and the difference in dimension is within 2 mm. This can ensure that when the point source 20 is placed in the receiving groove 1111, it is completely within the space formed by the groove body 1111a and the inlet portion 1111b, which will not prevent the combination between the threaded portion and the second threaded post on the sealing head, ensuring the sealing effect and fixing the point source 20 so that the point source 20 will not shake with movement.

[0082] For example, in Figures 1 to 3 the illustrated embodiment, the lateral dimension of the inner side of the open end of the groove body 1111a and the lateral dimension of the inner side of the inlet portion 1111b can be equal to or greater than the diameter of the point source 20, and the difference in dimension is within 2 mm. The longitudinal dimension of the inner side of the inlet portion 1111b can be greater than or equal to the longitudinal dimension of the inner side of the groove body 1111a. The sum of the longitudinal dimension of the inner side of the groove body 1111a and the longitudinal dimension of the inner side of the inlet portion 1111b can be equal to or greater than the diameter of the point source 20, and the difference in dimension is within 2 mm. The lateral dimension of the inner side of the threaded portion 1111c can be greater than the diameter of the point source 20.

[0083] Figure 6 shows the state when the point source 20 is placed in the space formed by the groove body 1111a and the inlet portion 1111b. Figure 6 In it, the groove body 1111a is represented by a dotted line, and the inlet portion 1111b is represented by a solid line. As Figure 6 shown, as long as the inner side of the inlet portion 1111b is a cylinder, such as a triangular prism, a quadrangular prism, etc. Of course, it is best when the shape of the inlet portion 1111b matches the shape of the point source 20. The same applies to the threaded portion 1111c. As long as it is a cylinder, it is best to match the shape of the point source 20. For example, Figures 1 to 3In the illustrated embodiment, the point source 20 is a sphere, and both the inlet portion 1111b and the threaded portion 1111c are cylinders.

[0084] Figure 6 The dotted line L in [reference] represents the possible shape of the bottom (inner side) of the groove body 1111a. When the point source 20 is a sphere, the inner side of the groove body 1111a can be a cylinder or have an arc surface. Preferably, the groove body 1111a is hemispherical, and the diameter of the arc surface of the bottom L is equal to or slightly larger than the diameter of the point source 20. After the point source 20 is placed, half of the spherical surface of the point source 20 abuts against the arc surface of the bottom L, and at this time, the fixation of the point source 20 is more secure. In other embodiments of the present application, the groove body 1111a can be a cylinder plus an arc, and the diameter of the arc surface of the bottom L is larger than the diameter of the point source 20. After the point source 20 is placed, a part of the arc surface of the point source 20 abuts against the arc surface of the bottom L. In other embodiments of the present application, the groove body 1111a can be a cylinder, and the bottom L is a plane. After the point source 20 is placed, the lowest point of the point source 20 abuts against the surface of the bottom L. In other embodiments of the present application, various changes can also be made according to the structure of the point source 20 as long as it can play a role in accommodating and fixing the point source 20.

[0085] Figures 1 to 3 In the illustrated embodiment, a second threaded post 1112a is provided on the sealing head 1112. The second threaded post 1112a can be connected to the threaded portion 1111c and form a seal for the inlet portion 1111b and the groove body 1111a. The sealing head and the receiving groove are conveniently replaced by threaded connection. The side surface of the sealing head 1112 is provided with a knurling 1112b, and the setting of the knurling is used to increase the friction force and facilitate the disassembly of the sealing head.

[0086] The calibration device provided by the present application includes a point source having a solution adsorption capacity. The point source can fully absorb the radioactive source solution to form a radioactive point source, and the high-density characteristic of the point source itself can replace the contrast agent to be imaged under CT scanning, eliminating the need to use a mixed solution of a radioactive source and a contrast agent. Moreover, the high density of the point source makes the images collected by CT clearer, which helps with positioning and increases convenience.

[0087] Moreover, the bracket includes at least four struts, and the tops of the four struts form a virtual three-dimensional structure. The point source is erected on the vertex of the virtual three-dimensional structure through the bracket, which can better simulate the three-dimensional structure of the human body in space, fully reflect the three-dimensional effect in space, and greatly reduce the interference of structures such as the bracket on the imaging of the point source during tomographic scanning. The point source can be quickly located without causing deviations in the position recognition of each point source during the calibration process, so as to perform calibration of image registration using the point source. The point source is fixed in the point source accommodating portion of the strut and will not move due to the movement of the bed board or the bracket, ensuring the accuracy of the position of the point source.

[0088] In addition, since the radioactive source solution is adsorbed onto the point source, it will not contaminate the side walls of the calibration device and there are no air bubbles. Therefore, the calibration effect is more accurate, and it will not leak into the environment to cause radioactive contamination to personnel, the environment, and equipment, ensuring high safety. Figure 7 FIG. Figure 7 shows a method for preparing the above calibration device provided by an embodiment of the present application, which includes the following steps S1 to S3.

[0089] S1: Prepare a point source.

[0090] In step S1, the point source made of a high-density material with the ability to adsorb solution is immersed in the radioactive source solution for a predetermined time.

[0091] After the point source is immersed in the radioactive source solution for a predetermined time, it can fully absorb the radioactive source solution. As mentioned above, the high-density material can be a material with micropores dispersed in the matrix. For example, the density of the point source can be greater than or equal to 2 g / cm 3 , and the porosity can be greater than or equal to 20%. The point source is made of a high-density material with a density greater than that of the liquid, making the images collected by CT clearer, which helps with positioning and does not require density control, increasing convenience. Further optionally, the point source is made of at least one of medical stone, montmorillonite, kaolinite, illite, and synthetic molecular sieve, and these materials have a strong adsorption ability for the radioactive source solution.

[0092] As mentioned above, when the calibration device is used in a SPECT-CT system, the radioactive source solution corresponds to a Tc-99m radioactive source solution; when the calibration device is used in a PET-CT system, the radioactive source solution corresponds to an F-18 radioactive source solution.

[0093] S2: Prepare a bracket.

[0094] In step S2, at least four support rods are prepared, and a point source receiving portion matching the structure of the point source is prepared on each support rod. The specific structure of the point source receiving portion is as described above and will not be elaborated here.

[0095] S3: Assemble.

[0096] In step S3, the point sources can be first loaded into the point source receiving portions respectively; then at least four support rods are assembled so that the tops of the at least four support rods form a virtual three-dimensional structure, and each point source receiving portion is located at the position of one top respectively.

[0097] The preparation method provided by this application is simple and easy to operate. The prepared calibration device includes a point source with the ability to adsorb solution. The point source can form a radioactive point source by fully absorbing the radioactive source solution, and the high-density characteristic of the point source itself can be used to image under CT scan instead of using a mixed solution of radioactive source and contrast agent, avoiding a series of influences caused by using the mixed solution. Moreover, the stent includes at least four struts, and the tops thereof form a virtual three-dimensional structure. The point source is erected on the vertex of the virtual three-dimensional structure through the stent, which can better simulate the three-dimensional structure of the human body in space, fully reflect the three-dimensional effect in space, and greatly reduce the interference of structures such as the stent on the imaging of the point source during tomographic scanning, enabling rapid positioning of the point source, so as to use the point source for calibration of image registration.

[0098] In an embodiment of this application, the method for preparing Figures 1 to 3 the calibration device 1 shown below is as follows:

[0099] Soak eight point sources 20 with a volume not greater than 10 mm 3 in a Tc-99m radioactive source solution or an F-18 radioactive source solution with a radioactive activity concentration not less than 40 mCi / mL for more than ten minutes to make them fully absorb the radioactive source solution. Then place these eight point sources 20 into the spaces formed by the hemispherical grooves 1111a and the cylindrical inlet parts 1111b of the eight struts 11 respectively, and then use eight sealing heads 1112 to seal the eight point sources 20 inside the eight struts 11. Then fix the eight struts 11 on the eight vertices of the central support block 12, and finally the production is completed.

[0100] This application further provides the application of the above calibration device in calibrating the registration accuracy of a multimodal imaging system. Optionally, the multimodal imaging system includes a SPECT-CT system or a PET-CT system.

[0101] Figure 8 Figure 1 shows the application of the calibration device 1 shown in FIGS. 1 to 3 to a SPECT-CT system provided by an embodiment of this application. Figure 8 The shown SPECT-CT system includes a SPECT unit 2, a CT unit 3, two gantry detectors 4, a support bedplate 5, and a bed 6.

[0102] During calibration, first place the calibration device 1 at five positions on the support bed plate 5 of the SPECT-CT system respectively. These five positions are equally spaced across the entire support bed plate. For each position placement, use the SPECT-CT system to scan the calibration device 1 to obtain five groups of first images obtained by the SPECT imaging system and five groups of second images obtained by the CT imaging system. Among them, before calibration, it is necessary to first adjust the height of the examination bed 6 so that the center of the calibration device 1 is on the rotation axis of the SPECT-CT system, and then extend the support bed plate 5 so that the center of the calibration device 1 coincides with the imaging field center of the SPECT detector 4. Figure 9 and Figure 10 are the images obtained by performing SPECT tomographic acquisition and CT acquisition at the position on the support bed plate 5 that is closest to the gantry detector 4 among the five positions of a certain point source of the calibration device 1.

[0103] Then, use filtered backprojection to perform three-dimensional reconstruction on each of the five groups of first images respectively, so as to obtain five groups of first three-dimensional image data corresponding to the five positions. Then, based on each group of first three-dimensional image data, determine the first pixel value contour line of each point source in each direction of the XYZ coordinate system respectively, and use the centroid method to calculate the first centroid of the first pixel value contour line in each direction. Then, determine the coordinate values of each first centroid on the XYZ coordinate system respectively, so as to obtain the first coordinates, and further obtain the first coordinate set. The first coordinate set includes 40 coordinates in each of the X, Y, and Z directions, for a total of 120 coordinates. Then, use the same method to obtain the second coordinate set. Similarly, the second coordinate set includes 40 coordinates in each of the X, Y, and Z directions, for a total of 120 coordinates.

[0104] The first coordinate set and the second coordinate set can be respectively expressed as:

[0105]

[0106] Among them, X Sij 、Y Sij 、Z Sij represent the coordinates of the i-th point source in the j-th position in the first imaging system, and X Cij 、Y Cij 、Z Cij represent the coordinates of the i-th point source in the j-th position in the second imaging system, where 1 ≤ i ≤ 8 and 1 ≤ j ≤ 5.

[0107] Then, according to the respective coordinates in the first coordinate set and the second coordinate set, obtain the spatial coordinate correction factors ΔX Sij 、ΔY Sij 、ΔZ Sij, or obtaining the spatial coordinate correction factors ΔX Cij , ΔY Cij , ΔZ Cij .

[0108] When collecting subsequent SPECT-CT images, the spatial coordinate correction factors ΔX Sij , ΔY Sij , ΔZ Sij are used to correct the images collected by the SPECT imaging system, or the spatial coordinate correction factors ΔX Cij , ΔY Cij , ΔZ Cij are used to correct the images collected by the CT imaging system, then the calibration is completed. The images collected after calibration can ensure that the deviation between the images collected by the SPECT imaging system and the CT imaging system is within 2 mm. Figure 11 FIG. shows the SPECT-CT fusion image obtained after calibration in an embodiment of the present application. After fusion, there is almost no deviation in the positions of the SPECT image and the CT image.

[0109] The above are only example embodiments of the present application and are not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0110] It can be understood from the description of the above embodiments that this specification includes the disclosure in the following manners.

[0111] [Appendix 1]

[0112] A calibration device for the registration accuracy of a multimodal imaging system, comprising:

[0113] A bracket, the bracket includes at least four support rods, and each of the support rods is provided with a point source accommodating portion. The tops of at least four of the support rods form a virtual three-dimensional structure, and each of the point source accommodating portions is located at the position of one of the tops; and

[0114] At least four point sources, which are respectively accommodated in at least four of the point source accommodating portions. The point sources are made of a high-density material with solution adsorption ability. When using the calibration device to calibrate the multimodal imaging system, each of the point sources absorbs a radioactive source solution.

[0115] [Appendix 2]

[0116] The calibration device according to Note 1, wherein the high-density material is a material with micropores dispersed in a matrix;

[0117] Optionally, the density of the point source is greater than or equal to 2 g / cm 3 , and the porosity of the point source is greater than or equal to 20%;

[0118] Optionally, the point source is made of at least one of medical stone, montmorillonite, kaolinite, illite, and synthetic molecular sieve.

[0119] [Note 3]

[0120] The calibration device according to Note 1, wherein the point source is a sphere, and the volume of the sphere is less than or equal to 10 mm 3 ;

[0121] Optionally, the volume difference between any two of the point sources is within a predetermined range.

[0122] [Note 4]

[0123] The calibration device according to Note 1 or 2, wherein the bracket further includes a central support block, and at least four of the struts are fixed on the central support block according to the distribution of the virtual three-dimensional structure;

[0124] Optionally, the volume of the virtual three-dimensional structure is greater than or equal to 4 times the volume of the central support block;

[0125] Optionally, the virtual three-dimensional structure is a polyhedron, and the central support block is a sphere or a polyhedron of the same shape as the virtual three-dimensional structure;

[0126] Optionally, a threaded hole is provided at the connection part between the central support block and the strut, a first threaded post is provided at one end of the strut, and the strut and the central support block are screwed together through the threaded hole and the first threaded post.

[0127] [Note 5]

[0128] The calibration device according to Note 4, wherein the bracket includes eight struts, and the vertices of the eight struts form a virtual regular cube structure; the central support block is also a regular cube structure;

[0129] The side length of the central support block is not greater than 10 cm, and the side length of the virtual regular cube structure is 20 - 40 cm.

[0130] [Note 6]

[0131] The calibration device according to Appendix 1 or 2, wherein the point source accommodating part includes an accommodating groove and a sealing head, the accommodating groove is used for placing the point source, and the sealing head is used for sealing the point source in the accommodating groove.

[0132] [Appendix 7]

[0133] The calibration device according to Appendix 6, wherein the accommodating groove has a groove body, an inlet part connected to the open end of the groove body, and a threaded part provided at one end of the inlet part away from the groove body; both the inlet part and the threaded part are cylinders; a second threaded post is provided on the sealing head, and the second threaded post can be connected to the threaded part to form a seal for the inlet part and the groove body;

[0134] Optionally, the lateral dimension inside the open end is equal to or greater than the maximum lateral dimension of the outer contour of the point source, and the difference in dimension is within 2 mm; the lateral dimension inside the inlet part is equal to the lateral dimension inside the open end; the lateral dimension inside the threaded part is greater than the lateral dimension inside the open end;

[0135] Optionally, the sum of the longitudinal dimension inside the groove body and the longitudinal dimension inside the inlet part is equal to or greater than the maximum longitudinal dimension of the outer contour of the point source, and the difference in dimension is within 2 mm;

[0136] Optionally, the point source is a sphere, and the inside of the groove body is a cylinder or has an arc surface

[0137] Optionally, the side surface of the sealing head is provided with embossed patterns.

[0138] [Appendix 8]

[0139] The calibration device according to Appendix 1 or 2, wherein the bracket is made of a material having low absorption characteristics for γ-rays and X-rays;

[0140] Optionally, the bracket is made of acrylic and / or carbon fiber.

[0141] [Appendix 9]

[0142] The calibration device according to Appendix 1 or 2, wherein the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution;

[0143] Optionally, the radioactive activity concentration of the radioactive source solution is not less than 40 mCi / mL.

[0144] [Appendix 10]

[0145] A method for preparing a calibration device for the registration accuracy of a multimodal imaging system, characterized by comprising:

[0146] Preparing a point source:

[0147] Immerse the point source made of a high-density material with solution adsorption capacity in a radioactive source solution for a predetermined time;

[0148] Preparing a support:

[0149] Prepare at least four support rods, and a point source accommodating portion matching the structure of the point source is prepared on each of the support rods; and

[0150] Assembly:

[0151] Respectively load the point sources into the point source accommodating portions;

[0152] Assemble the at least four support rods so that the tops of the at least four support rods form a virtual three-dimensional structure, and each of the point source accommodating portions is respectively located at the position of one of the tops.

[0153] [Appendix 11]

[0154] According to the preparation method described in Appendix 10, wherein the radioactivity concentration of the radioactive source solution is not less than 40 mCi / mL;

[0155] Optionally, the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution.

Claims

1. A calibration device for the registration accuracy of a multimodal imaging system, characterized in that, Comprising: A bracket, the bracket includes at least four struts, and a point source accommodating portion is provided on each strut. The tops of at least four struts form a virtual three-dimensional structure, and each point source accommodating portion is respectively located at the position of one of the tops; And At least four point sources, which are respectively accommodated in at least four point source accommodating portions. The point sources are made of a high-density material with solution adsorption ability. When using the calibration device to calibrate the multimodal imaging system, each point source absorbs a radioactive source solution.

2. The calibration device according to claim 1, characterized in that, The high-density material is a material with micropores dispersed in a matrix; Optionally, the density of the point source is greater than or equal to 2 g / cm 3 , and the porosity of the point source is greater than or equal to 20%; Optionally, the point source is made of at least one of zeolite, montmorillonite, kaolinite, illite, and synthetic molecular sieve.

3. The calibration device according to claim 1 or 2, characterized in that, The point source is a sphere, and the volume of the sphere is less than or equal to 10 mm 3 ; Optionally, the volume difference between any two point sources is within a predetermined range.

4. The calibration device according to claim 1 or 2, characterized in that, The bracket further includes a central support block, and at least four struts are fixed on the central support block according to the distribution of the virtual three-dimensional structure; Optionally, the volume of the virtual three-dimensional structure is greater than or equal to 4 times the volume of the central support block; Optionally, the virtual three-dimensional structure is a polyhedron, and the central support block is a sphere or a polyhedron with the same shape as the virtual three-dimensional structure; Optionally, a threaded hole is provided at the connection part between the central support block and the strut, a first threaded column is provided at one end of the strut, and the strut and the central support block are screwed together through the threaded hole and the first threaded column.

5. The calibration device according to claim 4, characterized in that, The bracket includes eight struts, and the vertices of the eight struts form a virtual regular cube structure; the central support block is also a regular cube structure; The side length of the central support block is not greater than 10 cm, and the side length of the virtual regular cube structure is 20 - 40 cm.

6. The calibration device according to claim 1 or 2, characterized in that The point source accommodating portion includes an accommodating groove and a sealing head. The accommodating groove is used to place the point source, and the sealing head is used to seal the point source in the accommodating groove.

7. The calibration device according to claim 6, wherein The accommodating groove has a groove body, an inlet portion connected to the open end of the groove body, and a threaded portion provided at the end of the inlet portion away from the groove body; both the inlet portion and the threaded portion are cylinders; a second threaded column is provided on the sealing head, and the second threaded column can be connected to the threaded portion to form a seal for the inlet portion and the groove body; Optionally, the lateral dimension inside the open end is equal to or greater than the maximum lateral dimension of the outer contour of the point source, and the difference in dimension is within 2 mm; the lateral dimension inside the inlet portion is equal to the lateral dimension inside the open end; the lateral dimension inside the threaded portion is greater than the lateral dimension inside the open end; Optionally, the sum of the longitudinal dimension inside the groove body and the longitudinal dimension inside the inlet portion is equal to or greater than the maximum longitudinal dimension of the outer contour of the point source, and the difference in dimension is within 2 mm; Optionally, the point source is a sphere, and the inside of the groove body is a cylinder or has an arc surface; Optionally, the side surface of the sealing head is provided with embossed patterns.

8. The calibration device according to claim 1 or 2, characterized in that, The bracket is made of a material with low absorption characteristics for γ-rays and X-rays; Optionally, the bracket is made of acrylic and / or carbon fiber.

9. The calibration device according to claim 1 or 2, characterized in that, The radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution; Optionally, the radioactive activity concentration of the radioactive source solution is not less than 40 mCi / mL.

10. A preparation method of a calibration device for the registration accuracy of a multimodal imaging system, characterized in that, Comprising: Preparing a point source: Immersing a point source made of a high-density material with solution adsorption capacity in the radioactive source solution for a predetermined time; Preparing a bracket: Preparing at least four support rods, and each of the support rods is provided with a point source accommodating part that matches the structure of the point source; and Assembling: Respectively loading the point sources into the point source accommodating parts; Assembling the at least four support rods such that the tops of the at least four support rods form a virtual three-dimensional structure, and each of the point source accommodating parts is respectively located at a position of one of the tops.

11. The preparation method according to claim 10, characterized in that, The radioactive activity concentration of the radioactive source solution is not less than 40 mCi / mL; Optionally, the radioactive source solution is a Tc-99m radioactive source solution or an F-18 radioactive source solution.

Images