Method and apparatus for establishing dosimetry with a fine breast phantom

Abstract

This application relates to a method and apparatus for establishing a dosimetric fine breast physical phantom. The method includes: designing equivalent material formulations for two types of breast tissue, adipose tissue and fibroglandular tissue, according to mixing ratios and printing parameters; obtaining a series of fine breast digital models with different glandular percentages and compression thicknesses based on representative parameters of the female breast; enabling a fused deposition modeling (FDM) 3D printer to support voxel model 3D printing, and generating nozzle paths based on the voxel models to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology. This solves the problems of related technologies failing to obtain accurate three-dimensional dose distribution, difficulty in accurately assessing radiation health risks, poor variability of breast parameters in existing phantoms, low representativeness and realism of phantom parameters, and unscientific placement of dose measurement units.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a method and apparatus for establishing a dosimetric fine breast physical phantom. Background Technology

[0002] Currently, breast cancer is one of the most common cancers, causing more than 600,000 deaths annually. As one of the most effective methods for detecting and diagnosing breast cancer, mammography (MG) offers advantages such as rapid screening and low equipment cost, and is widely used in breast cancer screening. However, breast tissue is one of the most sensitive tissues to radiation-induced carcinogenesis. The radiation weighting factor for breast tissue has been adjusted from 0.05 to 0.12, meaning that while mammography diagnoses cancer, it also carries a potential risk of radiation-induced carcinogenesis. To accurately assess the radiation risks associated with mammography and optimize radiation protection, it is necessary to accurately measure the dose to breast tissue. To simulate the non-uniform structure within breast tissue, breast physical phantoms have undergone a series of developments, evolving from simple homogeneous phantoms to non-uniform structural phantoms composed of different materials. The rapid development of 3D printing technology in recent years has provided an opportunity to manufacture breast physical phantoms with intricate structures. Based on high-resolution dual-material additive 3D printing technology, two 3D printing materials can be used to characterize the adipose tissue and fibroglandular tissue within the breast, thereby creating breast physical phantoms that can simulate the anatomical structure of the human breast. Some research institutions abroad have created some detailed physical phantoms of the breast based on the dual-material 3D printing method, including the Duke phantom and the Federico phantom. These phantoms can reproduce the detailed structure of the actual human breast, but there are still many limitations. The realism of the digital breast models used in the printing of existing physical phantoms still needs to be improved.

[0003] In related technologies, current international quality assurance (QA) protocols primarily use simple physical phantoms made of homogeneous materials to simulate human breasts of specific thickness and glandular content in order to measure the average glandular dose caused by mammography. Related technologies can stack PMMA homogeneous phantoms and PA homogeneous phantoms to simulate breast tissue of equal thickness, or use ACR phantoms composed of PMMA material and wax fillers as physical phantoms for dosimetry.

[0004] However, in the relevant technologies, the breast digital models required to establish fine breast physical phantoms are all based on the clinical data of the subjects. It is difficult to adjust the breast parameters to establish a series of fine breast physical phantoms with different glandular percentages and compression thicknesses. Moreover, the digital models used for printing are often generated based on the clinical data of a single patient. The measured average glandular dose and dose distribution are not convincing. The actual dose distribution caused by MG is extremely uneven, making it difficult to accurately reflect the three-dimensional spatial distribution of radiation dose. Furthermore, the radiation tissue equivalence of the 3D printing materials used is poor, which leads to the loss of some model information. These issues urgently need to be improved. Summary of the Invention

[0005] This application provides a method and apparatus for constructing a detailed physical phantom of the breast for dosimetry, in order to solve the problems of related technologies that mainly use simple physical phantoms made of homogeneous materials to measure the average glandular dose caused by mammography, resulting in inaccurate dose measurement results, inability to simulate the exposure parameters of the imaging equipment in AEC mode, inability to obtain accurate three-dimensional dose distribution, difficulty in accurately assessing radiation health risks, poor variability of breast parameters in existing phantoms, low representativeness and realism of phantom parameters, unscientific placement of dose measurement units, poor radiation tissue equivalence of the 3D printing materials used, and easy loss of some model information.

[0006] The first aspect of this application provides a method for establishing a precise physical phantom of the breast for dosimetry, comprising the following steps: measuring the elemental composition and physical density of various fused deposition modeling (FDM) 3D printing materials and additives; adjusting the mixing ratio and printing parameters of the materials according to the elemental composition and physical density; designing equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, according to the mixing ratio and printing parameters, such that the mass decay coefficient and physical density of the formulation materials are close to the two types of breast tissues under preset conditions to obtain screened tissue equivalent materials; and establishing the number of normal female breast tissues with different glandular percentages based on representative parameters of female breasts. Based on the mathematical model of normal female breast and the series of breast compression voxel models, a series of detailed breast digital models with different glandular percentages and compression thicknesses are obtained; and a communication protocol for a fused deposition modeling 3D printer is generated based on the selected tissue equivalent material and the series of detailed breast digital models, so that the fused deposition modeling 3D printer supports voxel model 3D printing and generates nozzle paths according to the voxel models, so as to obtain a dosimetric detailed breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology.

[0007] Optionally, in one embodiment of this application, the step of adjusting the mixing ratio and printing parameters of the materials according to the elemental composition and physical density, and designing equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, according to the mixing ratio and printing parameters, so that the mass decay coefficient and physical density of the formulation materials reach a preset proximity condition with the two types of breast tissues to obtain screened tissue equivalent materials, includes: calculating the effective atomic number after mixing the various fused deposition modeling 3D printing materials and additives at a preset mixing ratio, so that the effective atomic number reaches the preset proximity condition with the effective atomic number of the two types of breast tissues to determine the material mixing formulation; obtaining the mixed material according to the material mixing formulation, and 3D printing the mixed material at a preset extrusion rate or filling rate, so that the physical density reaches the preset proximity condition with the physical density of the two types of breast tissues; measuring the mass decay coefficient and physical density of the material based on the 3D printing, and comparing the mass decay coefficient and physical density with the measurement results of the adipose tissue and fibroglandular tissue sections to obtain comparison results; verifying the radiation tissue equivalence of the material based on the comparison results to obtain the tissue equivalent material.

[0008] Optionally, in one embodiment of this application, the formula for calculating the effective atomic number is:

[0009]

[0010] Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

[0011] Optionally, in one embodiment of this application, the step of establishing a mathematical model of normal female breast with different glandular percentages and a series of breast compression voxel models with different compression thicknesses based on representative parameters of female breasts includes: acquiring clinical images of the subject; analyzing the breast anatomy of the subject based on the clinical images to obtain at least one of the representative parameters of female breasts, including breast morphology parameters, refined structural shape and distribution; and modeling the female breast morphology based on the representative parameters of female breasts to obtain a mathematical model of normal female breast with different glandular percentages; determining the voxelization range of the mathematical model of normal female breasts; and performing voxelization on the female breast within the voxelization range. A voxelization operation was performed on a normal breast mathematical model. Different voxel values ​​were set for voxels containing only adipose tissue and voxels containing only fibroglandular tissue. For voxels containing both types of breast tissue at the boundary between adipose tissue and fibroglandular tissue, corresponding voxel values ​​were set using a linear interpolation method based on the glandular percentage of the voxel. The voxel values ​​were used to characterize the transition region between adipose tissue, fibroglandular tissue, and the boundary between the two types of breast tissue. Based on the biomechanical characteristics of adipose tissue, fibroglandular tissue, and skin tissue, the compression process of a refined normal breast voxel model was simulated to obtain a series of breast compression voxel models with different compression thicknesses.

[0012] Optionally, in one embodiment of this application, before generating the communication protocol for the fused deposition modeling 3D printer based on the selected tissue equivalent material and the series of fine breast digital models, the method further includes: simulating the process of the series of fine breast digital models undergoing mammography, obtaining simulation results of the dose three-dimensional spatial distribution during the imaging process, determining a dose measurement scheme based on the simulation results; selecting the placement position of the dose measurement unit based on the dose measurement scheme, layering the series of fine breast digital models under the thickness of the dose measurement unit, and setting the voxel information of the placement position to obtain a cavity that can accommodate the dose measurement element based on the voxel information.

[0013] Optionally, in one embodiment of this application, the step of having the fused deposition modeling 3D printer generate a nozzle path based on the voxel model to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology includes: printing adipose tissue voxel blocks using a first tissue equivalent material and printing glandular tissue voxel blocks using a second tissue equivalent material based on the nozzle path; extruding the two printing materials at a preset ratio onto the voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue; printing the voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue using the two printing materials; and simulating the transition boundary between the adipose tissue and the fibroglandular tissue and between the adipose tissue and the fibroglandular tissue to obtain the dosimetric fine breast physical phantom.

[0014] A second aspect of this application provides an apparatus for establishing a precise physical phantom of the breast for dosimetry, comprising: a measurement module for measuring the elemental composition and physical density of various fused deposition modeling (FDM) 3D printing materials and additives, adjusting the mixing ratio and printing parameters of the materials according to the elemental composition and physical density, and designing equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, according to the mixing ratio and printing parameters, such that the mass decay coefficient and physical density of the formulation materials are close to preset conditions for the two types of breast tissues, namely adipose tissue and fibroglandular tissue, to obtain screened tissue equivalent materials; and a phantom module for establishing phantoms of different glandular percentages based on representative parameters of the female breast. A mathematical model of normal female breast and a series of breast compression voxel models with different compression thicknesses are used to obtain a series of detailed breast digital models with different glandular percentages and compression thicknesses based on the mathematical model of normal female breast and the series of breast compression voxel models; and a generation module is used to generate a communication protocol for a fused deposition modeling 3D printer based on the selected tissue equivalent material and the series of detailed breast digital models, so that the fused deposition modeling 3D printer supports 3D printing of voxel models and generates nozzle paths based on voxel models, so as to obtain a dosimetric detailed breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology.

[0015] Optionally, in one embodiment of this application, the measurement module includes: a calculation unit, used to calculate the effective atomic number of the various fused deposition modeling 3D printing materials and additives mixed in a preset mixing ratio, so that the effective atomic number reaches a preset proximity condition with the effective atomic number of the two types of breast tissue, thereby determining the material mixing formula; a first printing unit, used to obtain the mixed material according to the material mixing formula, and to 3D print the mixed material at a preset extrusion rate or filling rate, so that the physical density reaches the preset proximity condition with the physical density of the two types of breast tissue; a comparison unit, used to measure the mass decay coefficient and physical density of the material based on the 3D printing, and to compare the mass decay coefficient and physical density with the measurement results of the adipose tissue and the fibroglandular tissue sections to obtain a comparison result; and a first generation unit, used to verify the radiation tissue equivalence of the material based on the comparison result, thereby obtaining the tissue equivalent material.

[0016] Optionally, in one embodiment of this application, the formula for calculating the effective atomic number is:

[0017]

[0018] Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

[0019] Optionally, in one embodiment of this application, the establishment module includes: a first establishment unit, used to acquire clinical images of the subject, analyze the breast anatomy of the subject based on the clinical images, obtain at least one of the representative parameters of the female breast, including breast morphology parameters, refined structural shape and distribution, and model the female breast morphology based on the representative parameters of the female breast to obtain a mathematical model of normal female breast with different glandular percentages; a second establishment unit, used to determine the voxelization range of the mathematical model of normal female breast, perform voxelization operation on the mathematical model of normal female breast within the voxelization range, set different voxel values ​​for voxels that only include adipose tissue and voxels that only include fibroglandular tissue, and set corresponding voxel values ​​for voxels containing the two types of breast tissue at the boundary between adipose tissue and fibroglandular tissue using a linear interpolation method based on the glandular percentage of the voxel;

[0020] The simulation unit is used to characterize the transition region at the junction of the adipose tissue, the fibroglandular tissue, and the two types of breast tissue according to the voxel values, and to simulate the compression process of a fine normal breast voxel model according to the biomechanical properties of the adipose tissue, the fibroglandular tissue, and the skin tissue, so as to obtain a series of breast compression voxel models with different compression thicknesses.

[0021] Optionally, in one embodiment of this application, it further includes: a simulation module, used to simulate the process of the series of fine breast digital models undergoing mammography before generating the communication protocol of the fused deposition modeling 3D printer based on the screened tissue equivalent material and the series of fine breast digital models, to obtain the simulation results of the dose three-dimensional spatial distribution during the imaging process, and to determine the dose measurement scheme based on the simulation results; and a selection module, used to select the placement position of the dose measurement unit based on the dose measurement scheme, to layer the series of fine breast digital models under the thickness of the dose measurement unit, and to set the voxel information of the placement position, so as to obtain a cavity that can accommodate the dose measurement element based on the voxel information.

[0022] Optionally, in one embodiment of this application, the generation module includes: a second printing unit, configured to print adipose tissue voxel blocks using a first tissue equivalent material and glandular tissue voxel blocks using a second tissue equivalent material based on the nozzle path, and to extrude the two printing materials at a preset ratio to the voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue; and a second generation unit, configured to print voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue according to the two printing materials, and to simulate the transition boundary between the adipose tissue and the fibroglandular tissue and between the adipose tissue and the fibroglandular tissue, so as to obtain the dosimetric fine breast physical phantom.

[0023] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for establishing a dosimetric fine breast physical phantom as described in the above embodiments.

[0024] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for establishing a dosimetric fine breast physical phantom.

[0025] This application's embodiments can establish a series of detailed digital breast models representing typical female breast parameters based on mathematical methods, design a printing material formulation with strong tissue equivalence, optimize the FDM dual-material printing method, and fabricate a series of detailed breast physical phantoms that can accurately measure the three-dimensional dose distribution during mammography. Based on Monte Carlo simulation results, a dose measurement scheme is set up, providing an advanced tool for mammography diagnostic dose measurement, accurately assessing radiation health risks, and playing a significant role in guiding clinical practice and reducing public radiation health risks. This solves the problems in related technologies where homogeneous physical phantoms greatly simplify the internal structure of the breast, failing to represent the anatomical structure of the breast. Simple physical phantoms can only be used to roughly assess the average glandular dose and cannot obtain an accurate three-dimensional dose distribution. Dosimetric physical phantoms are often used for selecting exposure parameters in the Automatic Exposure Control (AEC) mode of MG systems, but because homogeneous phantoms cannot represent the fine internal structure of the breast, the exposure parameters obtained from their simulations are inaccurate. Therefore, the measurement results obtained from existing simple physical phantoms are difficult to accurately evaluate the glandular dose caused by breast imaging.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a flowchart illustrating a method for establishing a dosimetric fine breast physical phantom according to an embodiment of this application;

[0029] Figure 2 This is a flowchart of a method for establishing a dosimetric fine breast physical phantom according to an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of a device for establishing a dosimetric fine breast physical phantom according to an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0032] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0033] The method and apparatus for establishing a precise physical phantom of the breast for dosimetry according to embodiments of this application are described below with reference to the accompanying drawings. The aforementioned background technologies primarily use simple physical phantoms made of homogeneous materials to measure the average glandular dose caused by mammography, resulting in inaccurate dose measurement results. Furthermore, these technologies cannot simulate the exposure parameters of the imaging equipment in AEC mode, failing to obtain accurate three-dimensional dose distribution and making it difficult to accurately assess radiation health risks. Additionally, existing phantoms exhibit poor variability in breast parameters, low representativeness and realism, unscientific placement of dose measurement units, and poor radiation tissue equivalence of the 3D printing materials used, easily leading to missing model information. This application provides a method for establishing a refined breast physical phantom for dosimetry. This method uses mathematical methods to establish a series of refined breast digital models characterizing typical female breast parameters, designs a printing material formulation with strong tissue equivalence, optimizes the FDM dual-material printing method, and fabricates a series of refined breast physical phantoms capable of accurately measuring the three-dimensional dose distribution during mammography. A dose measurement scheme is set based on Monte Carlo simulation results, providing an advanced tool for mammography dose measurement and accurately assessing radiation health risks. This is of great significance for guiding clinical practice and reducing public radiation health risks. This solves the problems that the spatial distribution characteristics of fibrous glands in the detailed digital breast models established by related technologies still differ from the actual situation, that existing 3D printing materials cannot meet the requirements of tissue equivalent materials and cannot be used to make physical phantoms for dosimetry, and that the 3D printing process can also lead to the loss of some model information, affecting the accuracy of measurement results.

[0034] Specifically, Figure 1 This is a flowchart illustrating a method for establishing a dosimetric fine breast physical phantom provided in an embodiment of this application.

[0035] like Figure 1 As shown, the method for establishing a dosimetric fine breast physical phantom includes the following steps:

[0036] In step S101, the elemental composition and physical density of various fused deposition modeling 3D printing materials and additives are measured. The mixing ratio and printing parameters of the materials are adjusted according to the elemental composition and physical density. Based on the mixing ratio and printing parameters, equivalent material formulations for two types of breast tissue, namely adipose tissue and fibroglandular tissue, are designed respectively. The mass decay coefficient and physical density of the formulation materials are made to be close to the preset conditions of the two types of breast tissue, so as to obtain the screened tissue equivalent materials.

[0037] It is understood that the preset proximity condition in this application embodiment can be that the mass attenuation coefficient and physical density of the formulation material are as close as possible to the two types of breast tissue; in order to accurately simulate the interaction between X-rays and breast tissue, the mass attenuation coefficient, mass energy absorption coefficient, and physical density of the printing material are required to be equal to those of breast tissue. For human adipose tissue and fibroglandular tissue, the densities are 0.95 g / cm³, respectively. 3 and 1.02 g / cm 3 The physical density range of the relevant 3D materials is 1.1-1.3 g / cm³. 3 Furthermore, its mass attenuation coefficient and mass-energy absorption coefficient differ somewhat from those of breast tissue, making it unsuitable for fabricating physical phantoms for dosimetry. Therefore, embodiments of this application can design new printing material formulations and select suitable printing parameters to ensure the radiation tissue equivalence of the printing material.

[0038] In actual implementation, the embodiments of this application can measure the elemental composition and physical density of various fused deposition modeling 3D printing materials and additives. Using the mass decay coefficient and physical density of tissue equivalent materials as the equivalence basis, the mixing ratio and printing parameters of the materials are adjusted according to the elemental composition and physical density. Based on the mixing ratio and printing parameters, equivalent material formulations for adipose tissue and fibroglandular tissue are designed respectively, so that the mass decay coefficient and physical density of the formulation materials are close to the two types of breast tissue, namely adipose tissue and fibroglandular tissue, to obtain the screened tissue equivalent materials. In the embodiments of this application, the mass decay coefficient is proportional to the effective atomic number, both of which represent the decay property of the material. The effective atomic number is used in the material design stage, and the mass decay coefficient is used in the material verification stage.

[0039] The embodiments of this application can design equivalent material formulations for adipose tissue and fibroglandular tissue according to the mixing ratio and printing parameters to obtain screened tissue equivalent materials. This provides support for the subsequent fabrication of dosimetric fine breast physical phantoms that can measure mammographic dose distribution, optimizes the FDM (Fused Deposition Modeling) dual-material printing method, and provides an advanced tool for mammographic X-ray diagnostic dose measurement, thereby improving the accuracy of assessing radiation health risks.

[0040] It should be noted that the preset proximity conditions can be set by those skilled in the art according to the actual situation, and no specific restrictions are imposed here.

[0041] Optionally, in one embodiment of this application, the effective atomic number and printing parameters of the material are adjusted according to at least one elemental composition and physical density, and equivalent material formulations for adipose tissue and fibroglandular tissue are designed according to the effective atomic number and printing parameters to obtain screened tissue equivalent materials. This includes: calculating the effective atomic number of various fused deposition modeling 3D printing materials and additives after mixing them in a preset mixing ratio, so that the effective atomic number reaches a preset proximity condition with the effective atomic number of the two types of breast tissue, to determine the material mixing formulation; obtaining the mixed material according to the material mixing formulation, and 3D printing the mixed material at a preset extrusion rate or filling rate, so that the physical density reaches a preset proximity condition with the physical density of the two types of breast tissue; measuring the mass decay coefficient and physical density of the material based on 3D printing, and comparing the mass decay coefficient and physical density with the measurement results of adipose tissue and fibroglandular tissue sections to obtain comparison results; verifying the radiation tissue equivalence of the material based on the comparison results to obtain tissue equivalent materials.

[0042] It is understood that the materials in the embodiments of this application can be sample materials; the preset mixing ratio in the embodiments of this application can be different mixing ratios; the preset proximity condition in the embodiments of this application can be that the effective atomic number after mixing with different mixing ratios and the effective atomic number of the two types of breast tissue are as close as possible; the preset extrusion rate in the embodiments of this application can be different extrusion rates.

[0043] In practical implementation, this application embodiment can screen various commercially available fused deposition modeling 3D printing materials and additives, measure their physical density and elemental composition, calculate the effective atomic number of various printing materials and additives after mixing in different mixing ratios, so that the effective atomic number is as close as possible to the effective atomic number of the two types of breast tissue, in order to determine the material mixing formula; this application embodiment can obtain a mixed material according to the material mixing formula, and 3D print the mixed material at different extrusion rates or filling rates, measure the density of each sample material, and select the printing parameters of the sample material with the density closest to that of breast tissue as the parameters used for the actual nozzle; this application embodiment can use a digital mammography (DM) system to measure the mass decay coefficient and physical density of the selected sample material based on 3D printing, and compare the mass decay coefficient and physical density with the measurement results of CIRS sections of adipose tissue and fibroglandular tissue to obtain comparison results, and verify the radiation tissue equivalence of the material based on the comparison results to obtain tissue equivalent materials.

[0044] The embodiments of this application can compare the mass attenuation coefficient with the measurement results of adipose tissue and fibroglandular tissue sections to obtain comparison results. Based on the comparison results, the radiation tissue equivalence of the material can be verified to obtain tissue equivalent materials. This further provides support for the subsequent fabrication of a dosimetric fine breast physical phantom that can measure the dose distribution of mammography, thereby providing an advanced tool for mammography dose measurement.

[0045] It should be noted that the preset mixing ratio, preset proximity conditions, and preset extrusion rate can be set by those skilled in the art according to the actual situation, and no specific restrictions are imposed here.

[0046] Optionally, in one embodiment of this application, the formula for calculating the effective atomic number is:

[0047]

[0048] Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

[0049] In actual implementation, the effective atomic number Z in the embodiments of this application eff It is proportional to the mass decay coefficient, and its calculation formula is:

[0050]

[0051] Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number. The specific value of X is obtained by fitting the interaction between materials with different atomic numbers and the X-rays emitted by the clinical X-ray machine through Monte Carlo simulation.

[0052] The embodiments of this application improve the accuracy of calculations through formulas, accurately obtain the effective atomic number, thereby ensuring the detailed structure of the simulated human body and further accurately assessing radiation health risks.

[0053] In step S102, based on representative parameters of the female breast, a mathematical model of normal female breast with different glandular percentages and a series of breast compression voxel models with different compression thicknesses are established. Based on the mathematical model of normal female breast and the series of breast compression voxel models, a series of refined breast digital models with different glandular percentages and compression thicknesses are obtained.

[0054] Understandably, current digital breast models are often based on clinical data from individual patients, making it difficult to adjust their parameters to create a series of phantoms with different glandular percentages and compression thicknesses. Furthermore, the physical phantom parameters created using this method only represent individual patients, and the measured average glandular dose and dose distribution cannot be used to evaluate the test results of a population.

[0055] Therefore, as a possible implementation method, embodiments of this application can establish mathematical models of normal female breasts with different glandular percentages and a series of breast compression voxel models with different compression thicknesses based on representative parameters of female breasts. Based on the mathematical models of normal female breasts and the series of breast compression voxel models, a series of refined breast digital models with different glandular percentages and compression thicknesses can be obtained, thereby improving the representativeness and realism of the phantom parameters.

[0056] Optionally, in one embodiment of this application, based on representative parameters of the female breast, a mathematical model of normal female breast with different glandular percentages and a series of breast compression voxel models with different compression thicknesses are established, including: acquiring clinical images of the subject; analyzing the anatomical structure of the subject's breast based on the clinical images to obtain at least one representative parameter of the female breast among breast morphology parameters, refined structural shape and distribution; modeling the female breast morphology based on the representative parameters of the female breast to obtain a mathematical model of normal female breast with different glandular percentages; determining the voxelization range of the mathematical model of normal female breast; performing voxelization operation on the mathematical model of normal female breast within the voxelization range; setting different voxel values ​​for voxels that only include adipose tissue and voxels that only include fibroglandular tissue; and setting corresponding voxel values ​​for voxels containing both types of breast tissue at the boundary between adipose tissue and fibroglandular tissue using a linear interpolation method based on the glandular percentage of the voxel.

[0057] It is understood that the representative parameters of the female breast in the embodiments of this application can be representative parameters of the female breast in Chinese women.

[0058] In actual implementation, this application embodiment can collect clinical images of the examinee, analyze the anatomical structure of the examinee's breast based on the clinical images, statistically summarize representative parameters of the female breast, obtain representative parameters of the female breast such as breast shape parameters, refined structural shape and distribution, statistically analyze the spatial distribution characteristics of fibroglandular tissue in the coronal, sagittal and vertical axes of the breast, and analyze the anatomical structure of fibroglandular tissue. This application embodiment can model the shape of the female breast based on the representative parameters of the female breast, carry out refined structural growth in different areas of the breast according to statistical laws, and establish a mathematical model of the female breast in normal (uncompressed state) with different glandular percentages.

[0059] Furthermore, in this embodiment, a fine structure localization algorithm can be used to determine the voxelization range of the female normal breast mathematical model. Within the voxelization range, the female normal breast mathematical model is voxelized in order from the outer layer to the inner layer. Different voxel values ​​are set for voxels that include only adipose tissue and voxels that include only fibroglandular tissue. For voxels containing both types of breast tissue at the boundary between adipose tissue and fibroglandular tissue, the corresponding voxel value is set using a linear interpolation method based on the glandular percentage of the voxel. The voxel values ​​characterize the transition area at the junction of adipose tissue, fibroglandular tissue, and the two types of breast tissue. Based on the biomechanical characteristics of adipose tissue, fibroglandular tissue, and skin tissue, the compression process of the fine normal breast voxel model in the MG system is simulated to obtain a series of breast compression voxel models with different compression thicknesses.

[0060] This application embodiment can model the shape of a woman's breast based on representative parameters of the woman's breast, obtain mathematical models of normal breasts with different glandular percentages, and simulate the compression process of a fine normal breast voxel model based on the biomechanical characteristics of adipose tissue, fibroglandular tissue and skin tissue, to obtain a series of breast compression voxel models with different compression thicknesses, thereby effectively producing a series of fine breast digital models with different glandular percentages and compression thicknesses.

[0061] In step S103, a communication protocol for the fused deposition modeling (FDM) 3D printer is generated based on the selected tissue equivalent materials and a series of fine breast digital models, so that the FDM 3D printer can support voxel models for 3D printing and generate nozzle paths based on voxel models, so as to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive FDM 3D printing technology.

[0062] Specifically, in this embodiment, the communication protocol controlling the fused deposition modeling (FDM) 3D printer can be modified based on the selected tissue equivalent materials and a series of detailed breast digital models. This enables the FDM 3D printer to support voxel models for 3D printing, achieving a mapping from digital models to physical models. By importing voxel models, the FDM 3D printer can automatically plan the nozzle path based on the voxel models. This ensures that based on a series of detailed breast digital models (with different glandular percentages and different compression thicknesses), a dosimetric detailed breast physical phantom can be obtained using high-resolution dual-material additive FDM 3D printing technology. The material can then be extruded and 3D printed according to the designed material formulation and corresponding parameters to characterize two types of breast tissue.

[0063] This application embodiment can obtain a dosimetric fine breast physical phantom based on high-resolution dual-material additive fused deposition modeling 3D printing technology, thereby establishing a fine breast digital model based on typical female breast parameters, optimizing the fused deposition modeling (FDM) dual-material 3D printing method, and thus producing a dosimetric fine breast physical phantom that can measure the dose distribution of mammography.

[0064] Optionally, in one embodiment of this application, before generating the communication protocol of the fused deposition modeling 3D printer based on the selected tissue equivalent material and a series of fine breast digital models, the method further includes: simulating the process of the series of fine breast digital models undergoing mammography, obtaining the simulation results of the dose three-dimensional spatial distribution during the imaging process, determining the dose measurement scheme based on the simulation results; selecting the placement position of the dose measurement unit based on the dose measurement scheme, layering the series of fine breast digital models under the thickness of the dose measurement unit, and setting the voxel information of the placement position to obtain a cavity that can accommodate the dose measurement element based on the voxel information.

[0065] It is understood that the breast physical phantom in this application embodiment is a necessary tool for conducting mammography dose assessment. Since the actual structure of the human breast is very complex, including delicate structures such as skin, fat, lactiferous ducts, lobules, and Cooper's ligaments, according to Monte Carlo calculation results, the glandular dose obtained based on a simple phantom can differ from the actual patient's radiation dose by up to 43%. Related Monte Carlo simulation studies have shown that the dose distribution caused by mammography is extremely uneven, and the radiation risk is closely related to local high doses. Using a single average glandular dose cannot accurately assess the radiation risk.

[0066] Therefore, in actual implementation, the embodiments of this application can simulate the process of a series of fine breast digital models undergoing mammography based on the Monte Carlo method, obtain the simulation results of the three-dimensional spatial distribution of dose during the imaging process, and determine the dose measurement scheme based on the simulation results. The embodiments of this application can select several locations with larger dose values ​​or faster dose decay rates as the placement positions of the dose measurement unit based on the dose measurement scheme, layer the series of fine breast digital models under this thickness, and set the voxel information at this position as air, so as to obtain a cavity that can accommodate the dose measurement element based on the voxel information.

[0067] This application embodiment can simulate the process of a series of detailed digital breast models undergoing mammography, obtain simulation results of the three-dimensional spatial distribution of dose during actual mammography, select the placement position of the dose measurement unit to place the dose measurement element in the cavity of the detailed breast physical phantom, and thus set up a dose measurement scheme based on the Monte Carlo simulation results, providing an advanced tool for mammography dose measurement. It can ensure that the readout results of the dose measurement unit can reflect the actual spatial distribution of breast dose and accurately assess radiation health risks. This phantom can be used as a powerful tool for dose measurement, and can also be used for the calibration, inspection and optimization of actual X-ray imaging equipment.

[0068] It should be noted that, in this embodiment, the phantom can be placed on a mammography platform and irradiated in AEC mode. Since this dosimetric fine breast physical phantom can characterize the anatomical structure and radiation attenuation characteristics of the female breast, the exposure parameters at this time are the same as those of a phantom with the same breast parameters when actually receiving imaging. Furthermore, the dose measurement unit readouts at each location can represent the three-dimensional dose spatial distribution. By replacing the physical phantom with different breast parameters (different glandular percentages, different compression thicknesses) and repeating the above operation, the corresponding exposure parameters and three-dimensional dose distribution can be obtained.

[0069] Optionally, in one embodiment of this application, a fused deposition modeling 3D printer generates a nozzle path based on a voxel model to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology. This includes: printing adipose tissue voxel blocks using a first tissue equivalent material and glandular tissue voxel blocks using a second tissue equivalent material based on the nozzle path; extruding the two printing materials at a preset ratio onto the voxel blocks at the boundary between adipose tissue and fibroglandular tissue; printing voxel blocks at the boundary between adipose tissue and fibroglandular tissue using the two printing materials; and simulating the transition boundary between adipose tissue and fibroglandular tissue and between adipose tissue and fibroglandular tissue to obtain a dosimetric fine breast physical phantom.

[0070] It is understood that the adipose tissue block in the embodiments of this application is a voxel block containing only adipose tissue, that is, a voxel block of pure adipose tissue, and the fibroglandular tissue block is a voxel block containing only fibroglandular tissue, that is, a voxel block of pure fibroglandular tissue. The voxel block containing only adipose tissue is printed by the first tissue equivalent material, and the voxel block containing only fibroglandular tissue is printed by the second tissue equivalent material. The voxel block at the boundary between adipose tissue and fibroglandular tissue is extruded with the two printing materials in the corresponding proportions according to the glandular percentage represented by the voxel value.

[0071] The current FDM 3D printing process involves first converting a voxel model into a surface model, then performing geometric repairs on the surface model, and finally 3D printing. This results in the loss of some information from the voxel model due to the model conversion. Furthermore, current detailed breast physical phantoms do not have a transition zone between the two types of materials with attenuation properties. This simplification is inconsistent with reality and will affect the accuracy of measurement results.

[0072] Therefore, in actual implementation, the embodiments of this application can use a first tissue equivalent material to print voxel blocks representing adipose tissue, and a second tissue equivalent material to print voxel blocks representing fibroglandular tissue, based on the nozzle path. In the embodiments of this application, for voxel blocks at the boundary between adipose tissue and fibroglandular tissue, the printing materials are extruded sequentially using two nozzles in a corresponding proportion according to the percentage of glandular content represented by the voxel value, to simulate the transition boundary between adipose tissue and fibroglandular tissue and between adipose tissue and fibroglandular tissue, so as to obtain a fine physical phantom of breast tissue for dosimetry.

[0073] The embodiments of this application can simulate adipose tissue and fibroglandular tissue, as well as the transition boundary between adipose tissue and fibroglandular tissue, to obtain a dosimetric fine breast physical phantom. This creates a transition zone between the two types of materials with attenuation properties between them, thereby improving the accuracy of measurement results. A series of dosimetric fine breast physical phantoms with adjustable parameters can be produced, which can accurately obtain the three-dimensional dose distribution within the breast. This can provide a powerful tool for dose assessment and optimization in mammography, equipment development, etc., and is of great significance for guiding clinical practice and reducing public radiation health risks.

[0074] It should be noted that the preset ratio can be elaborated in detail by those skilled in the art based on the actual situation, and no specific restrictions are imposed here.

[0075] Specifically, it can be combined with Figure 2 As shown, the working principle of the method for establishing a dosimetric fine breast physical phantom in this application is explained in detail with a specific embodiment.

[0076] like Figure 2 As shown, the embodiments of this application include the following steps:

[0077] Step S201: Measure the elemental composition and physical density of various FDM 3D printing materials. Based on the mass decay coefficient and physical density of tissue equivalent materials, adjust the effective atomic number and printing parameters of the materials to design equivalent material formulations for adipose tissue and fibrous gland tissue respectively.

[0078] Step S202: Establish a series of detailed digital models of the breast based on representative parameters of the female breast, with different glandular percentages and compression thicknesses.

[0079] Step S203: Based on the screened tissue equivalent materials and the established series of fine breast digital models, optimize the FDM dual-material printing method to produce a fine breast physical phantom for dosimetry.

[0080] It should be noted that this application demonstrates a method for fabricating a detailed breast physical phantom under compression, which can be used for dose assessment in digital mammography (DM) and digital breast tomosynthesis (DBT) systems. In fact, the method proposed in this application is also applicable to the fabrication of normal breast physical phantoms. For the established detailed breast voxel normal model, if 3D printing is performed directly without performing compression simulation, a normal physical phantom can be fabricated for measuring the three-dimensional dose spatial distribution of three-dimensional breast imaging systems such as cone-beam computed tomography (CBCT) systems.

[0081] The method for establishing a detailed breast physical phantom for dosimetry, as proposed in the embodiments of this application, can establish a series of detailed breast digital models representing typical female breast parameters based on mathematical methods. It designs a printing material formulation with strong tissue equivalence, optimizes the FDM dual-material printing method, and fabricates a series of detailed breast physical phantoms capable of accurately measuring the three-dimensional dose distribution during mammography. Based on Monte Carlo simulation results, a dose measurement scheme is set up, providing an advanced tool for mammography dose measurement and accurately assessing radiation health risks. This is of great significance for guiding clinical practice and reducing public radiation health risks. This solves the problems of related technologies that mainly use simple physical phantoms made of homogeneous materials to measure the average glandular dose caused by mammography, resulting in inaccurate dose measurement results. Furthermore, these technologies cannot simulate the exposure parameters of the imaging equipment in AEC mode, cannot obtain accurate three-dimensional dose distribution, and are difficult to accurately assess radiation health risks. Additionally, existing phantoms have poor breast parameter variability, low parameter representativeness and realism, unscientific placement of dose measurement units, and poor radiation tissue equivalence of the 3D printing materials used, easily leading to missing model information.

[0082] Next, with reference to the accompanying drawings, a method and apparatus for establishing a dosimetric fine breast physical phantom according to an embodiment of this application are described.

[0083] Figure 3 This is a schematic diagram of the apparatus for establishing a fine physical phantom of the mammary gland for dosimetry, according to an embodiment of this application.

[0084] like Figure 3 As shown, the apparatus 10 for establishing a fine breast physical phantom for dosimetry includes: a measurement module 100, an establishment module 200, and a generation module 300.

[0085] Specifically, the measurement module 100 is used to measure the elemental composition and physical density of various fused deposition modeling 3D printing materials and additives, adjust the mixing ratio and printing parameters of the materials according to the elemental composition and physical density, and design equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, according to the mixing ratio and printing parameters, so that the mass decay coefficient and physical density of the formulation materials are close to the preset conditions of the two types of breast tissues, so as to obtain the screened tissue equivalent materials.

[0086] Module 200 is established to create mathematical models of normal female breasts with different glandular percentages and a series of breast compression voxel models with different compression thicknesses based on representative parameters of female breasts. Based on the mathematical models of normal female breasts and the series of breast compression voxel models, a series of refined breast digital models with different glandular percentages and compression thicknesses are obtained.

[0087] The generation module 300 is used to generate a communication protocol for the fused deposition modeling 3D printer based on the selected tissue equivalent materials and a series of fine breast digital models, so that the fused deposition modeling 3D printer can support voxel models for 3D printing and generate nozzle paths based on voxel models to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology.

[0088] Optionally, in one embodiment of this application, the measurement module 100 includes: a calculation unit, a first printing unit, a comparison unit, and a first generation unit.

[0089] The calculation unit is used to calculate the effective atomic number of various fused deposition modeling 3D printing materials and additives after mixing them in a preset mixing ratio, so that the effective atomic number is close to the effective atomic number of two types of breast tissue, in order to determine the material mixing formula.

[0090] The first printing unit is used to obtain a mixed material according to the material mixing formula, and to 3D print the mixed material at a preset extrusion rate or filling rate so that the physical density is close to the physical density of the two types of breast tissue.

[0091] The comparison unit is used to measure the mass decay coefficient and physical density of materials based on 3D printing, and compares the measurement results of the mass decay coefficient and physical density with those of adipose tissue and fibrogland tissue sections to obtain comparison results.

[0092] The first generation unit is used to verify the radiation tissue equivalence of the material based on the comparison results, so as to obtain tissue-equivalent material.

[0093] Optionally, in one embodiment of this application, the formula for calculating the effective atomic number is:

[0094]

[0095] Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

[0096] Optionally, in one embodiment of this application, the establishment module 200 includes: a first establishment unit and a second establishment unit.

[0097] The first unit is used to acquire clinical images of the subject, analyze the anatomical structure of the subject's breast based on the clinical images, obtain at least one representative parameter of the female breast from the breast morphology parameters, refined structural shape and distribution, and model the female breast morphology based on the representative parameter of the female breast to obtain a mathematical model of normal female breast with different glandular percentages.

[0098] The second unit is used to determine the voxelization range of the female normal breast mathematical model. Within the voxelization range, the female normal breast mathematical model is voxelized. Different voxel values ​​are set for voxels that include only adipose tissue and voxels that include only fibroglandular tissue. For voxels that contain both types of breast tissue at the boundary between adipose tissue and fibroglandular tissue, the corresponding voxel values ​​are set using a linear interpolation method based on the glandular percentage of the voxel.

[0099] The simulation unit is used to characterize the transition area between adipose tissue and fibroglandular tissue and the junction of the two types of breast tissue according to voxel values, and to simulate the compression process of a fine normal breast voxel model according to the biomechanical properties of adipose tissue, fibroglandular tissue and skin tissue, so as to obtain a series of breast compression voxel models with different compression thicknesses.

[0100] Optionally, in one embodiment of this application, the apparatus 10 for establishing a dosimetric fine breast physical phantom further includes a simulation module and a selection module.

[0101] The simulation module is used to simulate the process of a series of fine breast digital models undergoing mammography before generating the communication protocol of the fused deposition modeling 3D printer based on the selected tissue equivalent materials and a series of fine breast digital models. It obtains the simulation results of the three-dimensional spatial distribution of dose during the imaging process and determines the dose measurement scheme based on the simulation results.

[0102] The selection module is used to select the placement position of the dose measurement unit based on the dose measurement scheme, layer the fine breast digital model under the thickness of the dose measurement unit, and set the voxel information of the placement position so as to obtain a cavity that can accommodate the dose measurement element according to the voxel information.

[0103] Optionally, in one embodiment of this application, the generation module 300 includes: a second printing unit and a second generation unit.

[0104] The second printing unit is used to print adipose tissue voxel blocks using a first tissue equivalent material and glandular tissue voxel blocks using a second tissue equivalent material based on the nozzle path, and to extrude the two printing materials at a preset ratio to the voxel blocks at the boundary between adipose tissue and fibroglandular tissue.

[0105] The second generation unit is used to print voxel blocks at the boundary between adipose tissue and fibroglandular tissue according to two printing materials, and to simulate the transition boundary between adipose tissue and fibroglandular tissue and between adipose tissue and fibroglandular tissue, so as to obtain a fine breast physical phantom for dosimetry.

[0106] It should be noted that the foregoing explanation of the method embodiment for establishing a dosimetric fine breast physical phantom also applies to the apparatus for establishing a dosimetric fine breast physical phantom in this embodiment, and will not be repeated here.

[0107] The apparatus for establishing a detailed breast physical phantom for dosimetry, as proposed in the embodiments of this application, can establish a series of detailed breast digital models characterizing typical female breast parameters based on mathematical methods. It designs a printing material formulation with strong tissue equivalence, optimizes the FDM dual-material printing method, and fabricates a series of detailed breast physical phantoms capable of accurately measuring the three-dimensional dose distribution during mammography. Based on Monte Carlo simulation results, it sets up a dose measurement scheme, providing an advanced tool for mammography dose measurement and accurately assessing radiation health risks. This is of great significance for guiding clinical practice and reducing public radiation health risks. Therefore, it solves the problems of related technologies that mainly use simple physical phantoms made of homogeneous materials to measure the average glandular dose caused by mammography, resulting in inaccurate dose measurement results. Furthermore, these technologies cannot simulate the exposure parameters of the imaging equipment in AEC mode, cannot obtain accurate three-dimensional dose distribution, and are difficult to accurately assess radiation health risks. Additionally, existing phantoms have poor breast parameter variability, low parameter representativeness and realism, unscientific placement of dose measurement units, and poor radiation tissue equivalence of the 3D printing materials used, easily leading to missing model information.

[0108] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0109] The memory 401, the processor 402, and the computer program stored on the memory 401 and capable of running on the processor 402.

[0110] When the processor 402 executes the program, it implements the method for establishing a dosimetric fine breast physical phantom provided in the above embodiments.

[0111] Furthermore, electronic devices also include:

[0112] Communication interface 403 is used for communication between memory 401 and processor 402.

[0113] The memory 401 is used to store computer programs that can run on the processor 402.

[0114] The memory 401 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0115] If the memory 401, processor 402, and communication interface 403 are implemented independently, then the communication interface 403, memory 401, and processor 402 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized into address buses, data buses, control buses, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0116] Optionally, in a specific implementation, if the memory 401, processor 402, and communication interface 403 are integrated on a single chip, then the memory 401, processor 402, and communication interface 403 can communicate with each other through an internal interface.

[0117] Processor 402 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0118] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for establishing a dosimetric fine breast physical phantom.

[0119] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0120] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0121] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0122] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0123] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0124] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0125] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0126] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method of creating a dosimetric fine breast phantom, characterized in that, Includes the following steps: The elemental composition and physical density of various fused deposition modeling 3D printing materials and additives were measured. The mixing ratio and printing parameters of the materials were adjusted according to the elemental composition and physical density. Equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, were designed according to the mixing ratio and printing parameters. The mass decay coefficient and physical density of the formulation materials were made to be close to the preset conditions of the two types of breast tissues, so as to obtain the screened tissue equivalent materials. Based on representative parameters of the female breast, mathematical models of normal female breasts with different glandular percentages and a series of breast compression voxel models with different compression thicknesses were established. Based on the mathematical models of normal female breasts and the series of breast compression voxel models, a series of refined breast digital models with different glandular percentages and compression thicknesses were obtained. The communication protocol for the fused deposition modeling 3D printer is generated based on the selected tissue equivalent materials and the series of fine breast digital models, so that the fused deposition modeling 3D printer supports voxel model 3D printing and generates nozzle paths according to the voxel models, so as to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology.

2. The method of claim 1, wherein, The process involves adjusting the mixing ratio and printing parameters of the material based on the elemental composition and physical density, and designing equivalent material formulations for two types of breast tissue—adipose tissue and fibroglandular tissue—based on the mixing ratio and printing parameters. This ensures that the mass decay coefficient and physical density of the formulated material are close to the preset conditions of the two types of breast tissue, thereby obtaining screened tissue equivalent materials, including: The effective atomic number of the various fused deposition modeling 3D printing materials and additives is calculated after being mixed in a preset mixing ratio, so that the effective atomic number is close to the effective atomic number of the two types of breast tissue, in order to determine the material mixing formula. According to the material mixing formula, a mixed material is obtained, and the mixed material is 3D printed at a preset extrusion rate or filling rate so that the physical density is close to the physical density of the two types of breast tissue. Based on the 3D printing, the mass decay coefficient and physical density of the material are measured, and the measurement results of the mass decay coefficient and physical density are compared with those of the adipose tissue and the fibrogland tissue sections to obtain comparison results; The radiation tissue equivalence of the material is verified based on the comparison results to obtain the tissue-equivalent material.

3. The method of claim 2, wherein, The formula for calculating the effective atomic number is: Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

4. The method of claim 1, wherein, The aforementioned mathematical models of normal female breasts with different glandular percentages and a series of breast compression voxel models with different compression thicknesses, based on representative parameters of female breasts, include: Acquire clinical images of the subject, analyze the breast anatomy of the subject based on the clinical images, obtain at least one of the representative parameters of the female breast, including breast morphology parameters, refined structural shape and distribution, and model the female breast morphology based on the representative parameters of the female breast to obtain a mathematical model of normal female breast with different glandular percentages. The voxelization range of the mathematical model of normal female breast tissue is determined, and the voxelization operation is performed on the mathematical model of normal female breast tissue within the voxelization range. Different voxel values ​​are set for voxels that only include adipose tissue and voxels that only include fibroglandular tissue. For voxels that contain the two types of breast tissue at the boundary between adipose tissue and fibroglandular tissue, the corresponding voxel values ​​are set using a linear interpolation method according to the glandular percentage of the voxel. The voxel values ​​characterize the transition region at the junction of the adipose tissue, the fibroglandular tissue, and the two types of breast tissue. Based on the biomechanical properties of the adipose tissue, the fibroglandular tissue, and the skin tissue, the compression process of a fine normal breast voxel model is simulated to obtain a series of breast compression voxel models with different compression thicknesses.

5. The method of claim 1, wherein, Before generating the communication protocol for the fused deposition modeling 3D printer based on the selected tissue equivalent materials and the series of detailed breast digital models, the following steps are also included: The process of the series of detailed digital breast models undergoing mammography is simulated to obtain the simulation results of the three-dimensional spatial distribution of dose during the imaging process, and the dose measurement scheme is determined based on the simulation results; Based on the aforementioned dose measurement scheme, the placement position of the dose measurement unit is selected, the series of detailed breast digital models are layered under the thickness of the dose measurement unit, and the voxel information of the placement position is set so as to obtain a cavity that can accommodate the dose measurement element according to the voxel information.

6. The method of claim 1, wherein, The process of generating a nozzle path for the fused deposition modeling 3D printer based on the voxel model to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology includes: Based on the nozzle path, adipose tissue voxel blocks are printed using a first tissue equivalent material, glandular tissue voxel blocks are printed using a second tissue equivalent material, and the two printing materials are extruded at a preset ratio onto the voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue. Voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue are printed using the two printing materials, and the transition boundary between the adipose tissue and the fibroglandular tissue, as well as between the adipose tissue and the fibroglandular tissue, is simulated to obtain the dosimetric fine breast physical phantom.

7. An apparatus for creating a fine breast physics phantom for dosimetry, characterized by, include: The measurement module is used to measure the elemental composition and physical density of various fused deposition modeling 3D printing materials and additives. Based on the elemental composition and physical density, the mixing ratio and printing parameters of the materials are adjusted. Based on the mixing ratio and printing parameters, equivalent material formulations for two types of breast tissues, namely adipose tissue and fibroglandular tissue, are designed respectively. The mass decay coefficient and physical density of the formulation materials are made to be close to the preset conditions of the two types of breast tissues, so as to obtain the screened tissue equivalent materials. A module is established to create mathematical models of normal female breasts with different glandular percentages and a series of breast compression voxel models with different compression thicknesses based on representative parameters of female breasts. Based on the mathematical models of normal female breasts and the series of breast compression voxel models, a series of refined breast digital models with different glandular percentages and compression thicknesses are obtained. The generation module is used to generate a communication protocol for the fused deposition modeling 3D printer based on the selected tissue equivalent materials and the series of fine breast digital models, so that the fused deposition modeling 3D printer can support voxel models for 3D printing, and generate nozzle paths based on the voxel models, so as to obtain a dosimetric fine breast physical phantom using high-resolution dual-material additive fused deposition modeling 3D printing technology.

8. The apparatus of claim 7, wherein, The measurement module includes: The calculation unit is used to calculate the effective atomic number of the various fused deposition modeling 3D printing materials and additives after mixing them in a preset mixing ratio, so that the effective atomic number and the effective atomic number of the two types of breast tissue reach the preset close condition, so as to determine the material mixing formula. The first printing unit is used to obtain a mixed material according to the material mixing formula, and to 3D print the mixed material at a preset extrusion rate or filling rate, so that the physical density is close to the physical density of the two types of breast tissue. A comparison unit is used to measure the mass decay coefficient and physical density of the material based on the 3D printing, and to compare the measurement results of the mass decay coefficient and physical density with those of the adipose tissue and the fibrogland tissue sections to obtain comparison results; The first generation unit is used to verify the radiation tissue equivalence of the material based on the comparison results, so as to obtain the tissue-equivalent material.

9. The apparatus of claim 8, wherein, The formula for calculating the effective atomic number is: Where, α i Z represents the proportion of electrons in the total number of elements of the i-th element. i Let X be the atomic number of the i-th element. The exponent X is related to the photon energy and reflects the variation of the reaction cross section between X-rays and matter with the atomic number.

10. The apparatus according to claim 7, characterized in that, The establishment module includes: The first establishment unit is used to acquire clinical images of the subject, analyze the anatomical structure of the subject's breast based on the clinical images, obtain at least one of the representative parameters of the female breast, including breast morphology parameters, refined structural shape and distribution, and model the female breast morphology based on the representative parameters of the female breast to obtain a mathematical model of normal female breast with different glandular percentages. The second establishment unit is used to determine the voxelization range of the female normal breast mathematical model, perform voxelization operation on the female normal breast mathematical model within the voxelization range, set different voxel values ​​for voxels that only include adipose tissue and voxels that only include fibroglandular tissue, and set corresponding voxel values ​​for voxels containing the two types of breast tissue at the boundary between adipose tissue and fibroglandular tissue using a linear interpolation method according to the glandular percentage content of the voxel. The simulation unit is used to characterize the transition region at the junction of the adipose tissue, the fibroglandular tissue, and the two types of breast tissue according to the voxel values, and to simulate the compression process of a fine normal breast voxel model according to the biomechanical properties of the adipose tissue, the fibroglandular tissue, and the skin tissue, so as to obtain a series of breast compression voxel models with different compression thicknesses.

11. The apparatus of claim 7, wherein, Also includes: The simulation module is used to simulate the process of the series of fine breast digital models undergoing mammography before generating the communication protocol of the fused deposition modeling 3D printer based on the screened tissue equivalent materials and the series of fine breast digital models, to obtain the simulation results of the three-dimensional spatial distribution of dose during the imaging process, and to determine the dose measurement scheme based on the simulation results. The selection module is used to select the placement position of the dose measurement unit based on the dose measurement scheme, layer the series of fine breast digital models under the thickness of the dose measurement unit, and set the voxel information of the placement position so as to obtain a cavity that can accommodate the dose measurement element according to the voxel information.

12. The apparatus of claim 7, wherein, The generation module includes: The second printing unit is used to print adipose tissue voxel blocks using a first tissue equivalent material and glandular tissue voxel blocks using a second tissue equivalent material based on the nozzle path, and to extrude the two printing materials at a preset ratio to the voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue. The second generation unit is used to print voxel blocks at the boundary between the adipose tissue and the fibroglandular tissue according to the two printing materials, and to simulate the transition boundary between the adipose tissue and the fibroglandular tissue and between the adipose tissue and the fibroglandular tissue, so as to obtain the dosimetric fine breast physical phantom.

13. An electronic device, comprising: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for establishing a dosimetric fine breast physical phantom as described in any one of claims 1-6.

14. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by a processor to implement the method for establishing a dosimetric fine breast physical phantom as described in any one of claims 1-6.

Images