Integrated die body for CBCT geometric parameter calculation and performance evaluation

Abstract

The invention relates to an integrated die body for CBCT geometric parameter calculation and performance evaluation. The integrated die body comprises a shell, a geometric parameter calculation module and a performance evaluation module. The geometric parameter calculation module comprises a first mounting plate, and a plurality of metal balls are arranged in the first mounting plate; the performance evaluation module comprises a spatial resolution module, a contrast module, a uniformity module and a spatial accuracy module; the spatial resolution module comprises a second mounting plate fixedly provided with a first metal wire target extending in the horizontal direction and a third mounting plate fixedly provided with a second metal wire target extending in the vertical direction. The contrast ratio module comprises a fourth mounting plate, and a plurality of annular insertion blocks with different X-ray absorption coefficients and different diameters are arranged in the fourth mounting plate; the uniformity module comprises a fifth mounting plate; the space accuracy module comprises a sixth mounting plate, and a plurality of regular shapes are machined on the sixth mounting plate. The device is small in size and high in integration degree, geometric parameters and image quality indexes can be calculated through single scanning, and the testing efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of medical image quality control and inspection, and in particular to an integrated phantom for calculating geometric parameters and evaluating the performance of CBCT. Background Technology

[0002] Currently, CBCT (cone-beam computed tomography) equipment is widely used in dentistry, oral and maxillofacial surgery, orthopedics, and industrial non-destructive testing. Evaluating its geometric accuracy and image quality (such as spatial resolution, contrast, and uniformity) is a crucial step in product development, registration and certification, and clinical application.

[0003] However, existing CBCT phantoms have the following problems:

[0004] 1. Most phantoms have complex structures and large volumes, making them unsuitable for use in small and medium-sized CBCTs;

[0005] 2. Multiple tests require testing on multiple different phantoms (such as MTF phantoms, contrast phantoms, geometric correction phantoms, etc.), resulting in low testing efficiency;

[0006] 3. A single scan often yields only a single performance metric, making it difficult to simultaneously complete the calculation of geometric parameters and the full set of performance evaluations within the same dataset.

[0007] Therefore, there is an urgent need for an integrated phantom design scheme that is compact, highly integrated, and capable of completing multiple CBCT performance tests in a single scan. Summary of the Invention

[0008] This invention provides an integrated phantom for calculating CBCT geometric parameters and evaluating performance, in order to solve the above-mentioned technical problems.

[0009] To address the aforementioned technical problems, this invention provides an integrated phantom for CBCT geometric parameter calculation and performance evaluation, comprising an outer shell and a geometric parameter calculation module and a performance evaluation module integrated within the outer shell;

[0010] The geometric parameter calculation module includes a first mounting plate, which contains a plurality of metal spheres with different vertical heights.

[0011] The performance evaluation module includes a layered stacked spatial resolution module, a contrast module, a uniformity module, and a spatial accuracy module.

[0012] The spatial resolution module includes a second mounting plate and a third mounting plate. A first metal wire target extending horizontally is fixed on the second mounting plate, and a second metal wire target extending vertically is fixed on the third mounting plate.

[0013] The contrast module includes a fourth mounting plate, which contains a plurality of annular inserts. The annular inserts are made of materials with different X-ray absorption coefficients, and each material is processed into a variety of different diameters.

[0014] The uniformity module includes a fifth mounting plate, which is made of a uniform material.

[0015] The spatial accuracy module includes a sixth mounting plate, on which multiple regular shapes are machined;

[0016] The first mounting plate, the second mounting plate, the third mounting plate, the fourth mounting plate, the fifth mounting plate, and the sixth mounting plate have the same outer diameter and match the inner diameter of the outer shell.

[0017] Preferably, the upper and lower parts of the inner wall of the outer casing are respectively provided with cushioning pads.

[0018] Preferably, the outer casing is made of an X-ray low-absorption material.

[0019] Preferably, the outer shell is made of carbon fiber, polymethyl methacrylate, polymethacrylamide, or polycarbonate.

[0020] Preferably, the first mounting plate has four longitudinally extending positioning posts, and each positioning post has at least one tungsten ball of different heights.

[0021] Preferably, the diameter of the tungsten ball is 0.5 mm to 3 mm.

[0022] Preferably, the first metal wire target is made of aluminum wire with a diameter of 0.3 mm; the second metal wire target is made of steel wire with a diameter of 0.2 mm.

[0023] Preferably, the annular insert includes a PTFE column, a polyoxymethylene column, an LDPE column, and an air cavity.

[0024] Preferably, the PTFE column, polyoxymethylene column, LDPE column, and air cavity all include at least four specifications with diameters of 1.0 mm, 2.0 mm, 3.0 mm, and 4.0 mm.

[0025] Preferably, the regular shapes processed on the sixth mounting plate include at least cylinders, cubes, and triangular prisms.

[0026] Compared with existing technologies, the integrated phantom for CBCT geometric parameter calculation and performance evaluation provided by this invention has the following advantages:

[0027] 1. This invention has a high degree of integration; a single integrated phantom can complete multiple CBCT performance tests.

[0028] 2. The present invention has a compact overall structure, making it suitable for dental and animal CBCT systems with limited field of view (FOV);

[0029] 3. This invention can calculate geometric parameters and image quality indicators with a single scan, which greatly improves testing efficiency;

[0030] 4. This invention can be used for unified evaluation in equipment research and development, production quality control and regulatory certification, thereby achieving standardization. Attached Figure Description

[0031] Figure 1 This is an exploded three-dimensional view of an integrated phantom for CBCT geometric parameter calculation and performance evaluation in a specific embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the geometric parameter calculation module in a specific embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the spatial resolution module in a specific embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the contrast module in a specific embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the uniformity module in a specific embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the spatial accuracy module in a specific embodiment of the present invention.

[0037] In the diagram: 100-Outer shell, 110-Buffer pad, 120-Connecting ring, 200-Geometric parameter calculation module, 210-First mounting plate, 220-Positioning post, 230-Tungsten ball, 300-Performance evaluation module, 310-Spatial resolution module, 311-Second mounting plate, 312-First wire target, 313-Third mounting plate, 314-Second wire target, 315-Cover plate, 316-Mounting block, 320-Contrast module, 321-Fourth mounting plate, 322-Mounting ring, 323-PTFE column, 324-Polyoxymethylene column, 325-LDPE column, 326-Air cavity, 330-Uniformity module, 331-Fifth mounting plate, 340-Spatial accuracy module, 341-Sixth mounting plate, 342-Cylindrical cavity, 343-Cube cavity, 344-Triangular cavity. Detailed Implementation

[0038] To illustrate the technical solutions of the invention in more detail, specific embodiments are listed below to demonstrate the technical effects; it should be emphasized that these embodiments are used to illustrate the invention and not to limit the scope of the invention.

[0039] The integrated phantom for CBCT geometric parameter calculation and performance evaluation provided by this invention, such as Figure 1 As shown, it includes a housing 100 and a geometric parameter calculation module 200 and a performance evaluation module 300 integrated within the housing 100, wherein:

[0040] The geometric parameter calculation module 200 includes a first mounting plate 210, which contains a plurality of metal balls with different vertical heights. Geometric parameters are calculated using the plurality of metal balls whose positions are precisely known.

[0041] The performance evaluation module 300 includes a spatial resolution module 310, a contrast module 320, a uniformity module 330, and a spatial accuracy module 340 arranged in a layered stack. Multiple modules are stacked and integrated within the housing 100, which can comprehensively evaluate the imaging performance of the CBCT system.

[0042] The spatial resolution module 310 includes a second mounting plate 311 and a third mounting plate 313. A first wire target 312 extending horizontally is fixed on the second mounting plate 311, and a second wire target 314 extending vertically is fixed on the third mounting plate 313. In the CT reconstruction image, the spatial resolution (MTF) can be calculated by the point (or edge) diffusion function of the wire.

[0043] The contrast module 320 includes a fourth mounting plate 321, which has multiple annular inserts. The annular inserts are made of materials with different X-ray absorption coefficients, and each material is processed into multiple different diameters. In the CT reconstruction image, the contrast information of the system can be determined by identifying the type of material and its corresponding diameter.

[0044] The uniformity module 330 includes a fifth mounting plate 331, which is made of a uniform material. In the CT reconstruction image, the uniformity information of the system is calculated by selecting the gray values ​​of several different regions.

[0045] The spatial accuracy module 340 includes a sixth mounting plate 341, on which multiple regular shapes are machined. The distances and angles between these regular shapes are determined and known. The corresponding regular shapes are identified in the CT reconstruction image, and the distances and angles are calculated to determine the spatial accuracy of the reconstruction.

[0046] The first mounting plate 210, the second mounting plate 311, the third mounting plate 313, the fourth mounting plate 321, the fifth mounting plate 331 and the sixth mounting plate 341 have the same outer diameter and match the inner diameter of the outer shell 100. The whole structure is compact, highly integrated and suitable for dental and animal CBCT and other limited field of view (FOV) systems.

[0047] This invention can calculate geometric parameters and multiple image quality indicators in a single scan, which greatly improves testing efficiency and can be used for unified evaluation in equipment research and development, production quality control and regulatory certification, thus achieving standardization.

[0048] In some embodiments, please refer to Figure 1 The upper and lower parts of the inner wall of the outer shell 100 are respectively provided with buffer pads 110, which can be made of PMI (polymethacrylimide) material to protect the components inside the outer shell 100.

[0049] In some embodiments, please refer to Figure 1 The outer shell 100 may be made of a low-absorption X-ray material, such as carbon fiber (CF), polymethyl methacrylate (PMMA), polymethacrylimide (PMI), or polycarbonate (PC).

[0050] In some embodiments, please refer to the following: Figure 2 The first mounting plate 210 is provided with four longitudinally extending positioning posts 220. Each positioning post 220 is provided with at least one tungsten ball 230 of different heights. The diameter of the tungsten ball is 0.5mm to 3mm. The positioning height of the tungsten ball 230 is set by the positioning posts 220 to obtain a uniformly distributed tungsten ball 230 dot matrix, and then the geometric parameters are calculated.

[0051] In some embodiments, please refer to the following: Figure 3 The first wire target 312 uses aluminum wire with a diameter of 0.3 mm; the second wire target 314 uses steel wire with a diameter of 0.2 mm. The MTF curve is calculated by embedding the tilted wire targets. Specifically, the second mounting plate 311 and the third mounting plate 313 are provided with detachable mounting blocks 316, in which the wire targets are installed to facilitate the loading, unloading and replacement of the wire targets; a cover plate 315 is provided at the opening of the mounting block 316 to protect the internal wire targets.

[0052] In some embodiments, please refer to the following: Figure 4Multiple annular inserts are fixedly mounted within the fourth mounting plate 321 via mounting rings 322. In this embodiment, the annular inserts include PTFE (polytetrafluoroethylene) pillars 323, Delrin (polyoxymethylene) pillars 324, LDPE (low-density polyethylene) pillars 325, and air cavities 326. Alternatively, materials such as aluminum or PMMA can be used, depending on the required density. In this embodiment, the PTFE pillars 323, Delrin pillars 324, LDPE pillars 325, and air cavities 326 each include at least four specifications with diameters of 1.0 mm, 2.0 mm, 3.0 mm, and 4.0 mm. Using the material position information, samples are taken separately for each material in different directions, and the required contrast information is calculated.

[0053] In some embodiments, please refer to the following: Figure 5 The fifth mounting plate 331 is made of PMMA material, with a diameter of 160mm and a thickness of 10mm. It serves as the central pure material area, and the uniformity module 330 is used to calculate the uniformity.

[0054] In some embodiments, please refer to the following: Figure 6 The regular shapes machined on the sixth mounting plate 341 include at least cylinders, cubes, and triangular prisms, specifically corresponding to... Figure 6 The cylindrical cavity 342, cubic cavity 343, and triangular cavity 344 are used to measure distance and volume error.

[0055] In summary, the integrated phantom for CBCT geometric parameter calculation and performance evaluation provided by the present invention includes a shell 100 and a geometric parameter calculation module 200 and a performance evaluation module 300 integrated within the shell 100. The geometric parameter calculation module 200 includes a first mounting plate 210, which contains a plurality of metal spheres with different vertical heights. The performance evaluation module 300 includes a spatial resolution module 310, a contrast module 320, a uniformity module 330, and a spatial accuracy module 340 arranged in a layered stack. The spatial resolution module 310 includes a second mounting plate 311 and a third mounting plate 313. A first metal wire target 312 extending horizontally is fixed on the second mounting plate 311, and a second metal wire target 314 extending vertically is fixed on the third mounting plate 313. The contrast module 320 includes a fourth mounting plate 321, which contains multiple annular inserts made of materials with different X-ray absorption coefficients, each material being processed into multiple different diameters. The uniformity module 330 includes a fifth mounting plate 331, which is made of a uniform material. The spatial accuracy module 340 includes a sixth mounting plate 341, which has multiple regular shapes processed on it. The outer diameters of the first mounting plate 210, second mounting plate 311, third mounting plate 313, fourth mounting plate 321, fifth mounting plate 331, and sixth mounting plate 341 are the same and match the inner diameter of the outer shell 100. The entire structure is compact, highly integrated, and suitable for finite field-of-view (FOV) systems such as dental and animal CBCT. This invention can calculate geometric parameters and multiple image quality indicators in a single scan, significantly improving testing efficiency. It can be used for unified evaluation in equipment development, production quality control, and regulatory certification, achieving standardization.

[0056] Obviously, those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. An integrated phantom for CBCT geometric parameter calculation and performance evaluation, characterized in that, Includes a housing and a geometric parameter calculation module and a performance evaluation module integrated within the housing; The geometric parameter calculation module includes a first mounting plate, which contains a plurality of metal spheres with different vertical heights. The performance evaluation module includes a layered stacked spatial resolution module, a contrast module, a uniformity module, and a spatial accuracy module. The spatial resolution module includes a second mounting plate and a third mounting plate. A first metal wire target extending horizontally is fixed on the second mounting plate, and a second metal wire target extending vertically is fixed on the third mounting plate. The contrast module includes a fourth mounting plate, which has multiple annular inserts. The annular inserts are made of materials with different X-ray absorption coefficients, and each material is processed into multiple different diameters. The uniformity module includes a fifth mounting plate, which is made of a uniform material. The spatial accuracy module includes a sixth mounting plate, on which multiple regular shapes are machined; The first mounting plate, the second mounting plate, the third mounting plate, the fourth mounting plate, the fifth mounting plate, and the sixth mounting plate have the same outer diameter and match the inner diameter of the outer shell.

2. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The upper and lower parts of the inner wall of the outer shell are respectively provided with cushioning pads.

3. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The outer shell is made of a low-absorption X-ray material.

4. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 2, characterized in that, The outer shell is made of carbon fiber, polymethyl methacrylate, polymethacrylamide, or polycarbonate.

5. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The first mounting plate has four longitudinally extending positioning posts, and each positioning post has at least one tungsten ball of different heights.

6. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 5, characterized in that, The diameter of the tungsten ball is 0.5 mm to 3 mm.

7. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The first metal wire target uses aluminum wire with a diameter of 0.3 mm; the second metal wire target uses steel wire with a diameter of 0.2 mm.

8. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The annular insert includes a PTFE column, a polyoxymethylene column, an LDPE column, and an air cavity.

9. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 8, characterized in that, The PTFE column, polyoxymethylene column, LDPE column, and air cavity all include at least four specifications with diameters of 1.0 mm, 2.0 mm, 3.0 mm, and 4.0 mm.

10. The integrated phantom for CBCT geometric parameter calculation and performance evaluation as described in claim 1, characterized in that, The regular shapes processed on the sixth mounting plate include at least cylinders, cubes, and triangular prisms.

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