A brain tissue equivalent material for medical imaging and its preparation method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHAOYANG BIOTECH
- Filing Date
- 2026-04-10
- Publication Date
- 2026-06-30
Smart Images
Figure CN122302501A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of tissue equivalent materials technology, and in particular to a brain tissue equivalent material for use in medical imaging equipment and its preparation method. Background Technology
[0002] The use of ionizing radiation is linked to an increased risk of cancer, thus requiring adherence to stringent safety standards. The International Atomic Energy Agency (IAEA) emphasizes the importance of optimizing radiation protection to minimize patient exposure while still achieving desired diagnostic or interventional outcomes. Radiology plays a vital role in healthcare, offering significant benefits in diagnosis, treatment, and monitoring. However, there is an urgent need to optimize imaging protocols to reduce radiation exposure while maintaining high diagnostic image quality. The potential for cancer induction due to radiation exposure from medical imaging is a significant concern in clinical practice.
[0003] To accurately simulate a patient's exposure to ionizing radiation, a range of materials known as tissue equivalence materials are used to replicate the characteristics of human tissues and organs. For these substitutes to provide reliable results, they must exhibit absorption properties very similar to actual human tissue. Acrylic acid, also known as polymethyl methacrylate (PMMA), has become the most commonly used tissue equivalence material in diagnostic radiodosimetry due to its ease of handling.
[0004] Epoxy resins are the preferred choice for medical imaging applications due to their superior performance. They are non-toxic, chemically inert, and provide very strong adhesion to a wide range of materials, including metals, ceramics, and plastics. The high mechanical and chemical properties of epoxy resins make them suitable for demanding medical applications. Their dimensional stability and minimal shrinkage upon curing make them suitable for use in aqueous and chemically demanding environments. Furthermore, their repeatability and customizable formulations contribute to their widespread use as biomimetic materials for medical imaging and testing purposes.
[0005] In recent years, with the continuous advancement of medical technology, the treatment methods for acute ischemic stroke have become increasingly diverse and comprehensive. Although these treatments have greatly improved patient prognosis, the latest data shows that the mortality rate for acute ischemic stroke patients remains high. However, traditional CT scans have limitations in the early detection of ischemic stroke, especially within 6 hours of onset, where their detection rate is significantly lower than that of magnetic resonance diffusion-weighted imaging. This diagnostic gap has spurred the demand for highly realistic tissue equivalent materials to achieve standardized equipment calibration and quality control.
[0006] The CT values of normal brain tissue fall within a defined range: 37–45 HU for gray matter and 25–32 HU for white matter. Therefore, providing a novel tissue equivalent material based on epoxy resin matrix with added composite fillers to better simulate the radiological properties of human brain tissue and more accurately mimic its heterogeneous structural characteristics is of significant value. Summary of the Invention
[0007] The purpose of this invention is to provide a brain tissue equivalent material for use in medical imaging equipment and its preparation method, which provides a highly accurate and stable tissue equivalent material for the calibration, performance verification, development of new imaging technologies, and medical teaching models of medical imaging equipment, thereby promoting the improvement of imaging diagnostic quality.
[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a brain tissue equivalent material for use in medical imaging equipment, the brain tissue equivalent material comprising the following raw materials by mass fraction: Bisphenol A epoxy resin 20-35%, octyl glycidyl ether 10-15%, urea 1-5%, calcium carbonate 1-5%, sodium dihydrogen phosphate 1-5%, dipotassium hydrogen phosphate 1-5%, polyethylene 15-35%, methyl methacrylate 15-25%, trimethylhexanediamine 5-15%.
[0009] The present invention also provides a method for preparing the brain tissue equivalent material used in medical imaging equipment, comprising the following steps: 1) Bisphenol A epoxy resin, octyl glycidyl ether, urea, calcium carbonate, sodium dihydrogen phosphate and dipotassium hydrogen phosphate are mixed to obtain an epoxy resin mixture; 2) The epoxy resin mixture is subjected to ultrasonic vibration to obtain an ultrasonic product. The ultrasonic product, polyethylene, methyl methacrylate and trimethylhexanediamine are mixed to obtain a mixture. 3) The mixture is subjected to vacuum degassing, initial curing and drying in sequence to obtain brain tissue equivalent material.
[0010] Preferably, the mixing in step 1) is a first mixing of bisphenol A epoxy resin and octyl glycidyl ether, a second mixing of the first mixture and urea, a third mixing of the second mixture and calcium carbonate, and a fourth mixing of the third mixture, sodium dihydrogen phosphate and dipotassium hydrogen phosphate to obtain an epoxy resin mixture.
[0011] Preferably, step 2) involves mixing the ultrasonic product and polyethylene in a first mixing process, mixing the first mixture with methyl methacrylate in a second mixing process, and mixing the second mixture with trimethylhexanediamine in a third mixing process to obtain a mixture.
[0012] Preferably, the frequency of the ultrasonic oscillation in step 2) is 17~23kHz, and the duration of the ultrasonic oscillation is 25~35min.
[0013] Preferably, the vacuum degassing time in step 3) is 25~35 min, and the vacuum degree of vacuum degassing is -0.015~-0.005 MPa.
[0014] Preferably, the initial curing temperature in step 3) is 25~35℃, and the initial curing time is 8~15h; the drying temperature is 50~80℃, and the drying time is 2~6h.
[0015] The beneficial effects of this invention are: The brain tissue equivalent material of the present invention is a novel tissue equivalent material based on adding composite fillers to an epoxy resin matrix. By selecting the type of filler and controlling its concentration, a composite material that better simulates the radiological properties of human brain tissue can be obtained, so as to more accurately simulate the heterogeneous structural characteristics of brain tissue.
[0016] The key advantage of the brain tissue equivalent material of the present invention lies in its excellent stability and highly adjustable physical properties; by precisely controlling the proportion of each component in the equivalent material, the X-ray attenuation characteristics of different brain tissues can be effectively simulated, thereby achieving targeted matching of CT values of specific brain tissues.
[0017] The CT value of the brain tissue equivalent material of this invention is highly consistent with that of real brain tissue, successfully covering the typical range of gray matter and white matter. The brain tissue equivalent material has excellent wide-spectrum attenuation characteristics: within the energy range of 60~200keV commonly used in clinical CT equipment, the deviation of the X-ray attenuation coefficient from the target brain tissue material is always controlled within 5%, showing excellent spectral stability and simulation accuracy. Attached Figure Description
[0018] Figure 1 The images show physical representations of brain tissue equivalent materials prepared in Example 1 and Comparative Example 1, where A represents Example 1 and B represents Comparative Example 1. Figure 2 X-ray attenuation curves of brain tissue equivalent materials prepared in Example 1 and their corresponding gray matter attenuation curves; Figure 3 X-ray attenuation curves of brain tissue equivalent materials prepared in Example 1 and their corresponding brain white matter attenuation curves; Figure 4 The relative deviation of the linear attenuation coefficient of the brain tissue equivalent material prepared in Example 1 relative to the gray matter; Figure 5 The linear attenuation coefficient of the brain tissue equivalent material prepared in Example 1 is relative to the deviation of the brain white matter. Detailed Implementation
[0019] This invention provides a brain tissue equivalent material for use in medical imaging equipment, the brain tissue equivalent material comprising the following raw materials by mass fraction: Bisphenol A epoxy resin 20-35%, octyl glycidyl ether 10-15%, urea 1-5%, calcium carbonate 1-5%, sodium dihydrogen phosphate 1-5%, dipotassium hydrogen phosphate 1-5%, polyethylene 15-35%, methyl methacrylate 15-25%, trimethylhexanediamine 5-15%.
[0020] The brain tissue equivalent material of the present invention comprises the following raw materials in the following mass fractions: 20-35% bisphenol A epoxy resin, preferably 23-30%, more preferably 25-28%; 10-15% octyl glycidyl ether, preferably 11-14%, more preferably 12-13%; 1-5% urea, preferably 2-4%, more preferably 3%; 1-5% calcium carbonate, preferably 2-4%, more preferably 3%; 1-5% sodium dihydrogen phosphate, preferably 2-4%, more preferably 3%; 1-5% dipotassium hydrogen phosphate, preferably 2-4%, more preferably 3%; 15-35% polyethylene, preferably 20-30%, more preferably 25-27%; 15-25% methyl methacrylate, preferably 17-23%, more preferably 20%; and 5-15% trimethylhexanediamine, preferably 8-12%, more preferably 10%.
[0021] The present invention also provides a method for preparing the brain tissue equivalent material used in medical imaging equipment, comprising the following steps: 1) Bisphenol A epoxy resin, octyl glycidyl ether, urea, calcium carbonate, sodium dihydrogen phosphate and dipotassium hydrogen phosphate are mixed to obtain an epoxy resin mixture; 2) The epoxy resin mixture is subjected to ultrasonic vibration to obtain an ultrasonic product. The ultrasonic product, polyethylene, methyl methacrylate and trimethylhexanediamine are mixed to obtain a mixture. 3) The mixture is subjected to vacuum degassing, initial curing and drying in sequence to obtain brain tissue equivalent material.
[0022] In this invention, the mixing in step 1) is preferably a first mixing of bisphenol A epoxy resin and octyl glycidyl ether, a second mixing of the first mixture and urea, a third mixing of the second mixture and calcium carbonate, and a fourth mixing of the third mixture, sodium dihydrogen phosphate and dipotassium hydrogen phosphate to obtain an epoxy resin mixture.
[0023] In this invention, the time for the first mixing, the second mixing and the fourth mixing in step 1) is preferably 7 to 13 minutes, more preferably 10 minutes; the time for the third mixing is preferably 15 to 25 minutes, more preferably 20 minutes.
[0024] In this invention, step 2) preferably involves a first mixing of the ultrasonic product and polyethylene, a second mixing of the first mixture and methyl methacrylate, and a third mixing of the second mixture and trimethylhexanediamine to obtain a mixture.
[0025] In this invention, the mixing time for the first mixing step 2) is preferably 15-25 min, more preferably 20 min; the mixing times for the second and third mixing steps are independently preferably 8-17 min, more preferably 10-15 min.
[0026] In this invention, the frequency of the ultrasonic oscillation in step 2) is preferably 17~23kHz, more preferably 18~21kHz, and even more preferably 19~20kHz. The duration of the ultrasonic oscillation is preferably 25~35min, more preferably 27~32min, and even more preferably 30min.
[0027] In this invention, the vacuum degassing time in step 3) is preferably 25~35 min, more preferably 27~32 min, and even more preferably 30 min. The vacuum degree of vacuum degassing is preferably -0.015~-0.005 MPa, more preferably -0.012~-0.007 MPa, and even more preferably -0.01~-0.008 MPa.
[0028] In this invention, the initial curing temperature in step 3) is preferably 25~35℃, more preferably 27~33℃, and even more preferably 30℃; the initial curing time is preferably 8~15h, more preferably 10~12h; the drying temperature is preferably 50~80℃, more preferably 60~70℃, and even more preferably 65℃; the drying time is preferably 2~6h, more preferably 3~5h, and even more preferably 4h.
[0029] When the brain tissue equivalent material of the present invention is applied to medical imaging equipment such as CT, it achieves parameter values consistent with the brain tissue detection values.
[0030] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0031] In the examples, the molecular weight of polyethylene is 1.5 million to 6 million, and stirring is performed at a uniform speed.
[0032] Example 1
[0033] Mix 100.01g of bisphenol A epoxy resin with 29.98g of octyl glycidyl ether and stir mechanically for 10 minutes; add 6.7g of urea and continue stirring for 10 minutes; then add 10.24g of calcium carbonate and stir for 20 minutes; then add 5.51g of sodium dihydrogen phosphate and 4.03g of dipotassium hydrogen phosphate and stir for 10 minutes to obtain an epoxy resin mixture.
[0034] The epoxy resin mixture was ultrasonically vibrated at 20 kHz for 30 min; 90.02 g of polyethylene was added to the ultrasonic product and stirred for 20 min; then 80.23 g of methyl methacrylate was added and stirred for 15 min; finally, 32.23 g of trimethylhexanediamine was added and stirred for 10 min to obtain the mixture.
[0035] The mixture was evacuated to -0.01 MPa and vacuum degassed for 30 minutes. The degassed product was poured into a sealed mold and placed at 25°C for 12 hours for initial curing. The initially cured product was placed in a 60°C constant temperature oven for 4 hours. Finally, the power to the constant temperature oven was turned off, and the product was allowed to cool naturally to 25°C before being removed and demolded to obtain brain tissue equivalent material.
[0036] Example 2
[0037] Mix 100.71g of bisphenol A epoxy resin with 30.48g of octyl glycidyl ether and stir mechanically for 10 minutes; add 6.63g of urea and continue stirring for 10 minutes; then add 10.24g of calcium carbonate and stir for 20 minutes; finally add 4.17g of sodium dihydrogen phosphate and 3.83g of dipotassium hydrogen phosphate and stir for 10 minutes to obtain an epoxy resin mixture.
[0038] The epoxy resin mixture was ultrasonically vibrated at 22 kHz for 28 min; 100.73 g of polyethylene was added to the ultrasonic product and stirred for 20 min; then 86.65 g of methyl methacrylate was added and stirred for 15 min; finally, 32.63 g of trimethylhexanediamine was added and stirred for 10 min to obtain the mixture.
[0039] The mixture was evacuated to -0.01 MPa and vacuum degassed for 30 minutes. The degassed product was poured into a sealed mold and pre-cured at 30°C for 12 hours. The pre-cured product was placed in a constant temperature oven at 60°C for 4 hours. Finally, the constant temperature oven was turned off and allowed to cool naturally to 25°C. The product was then removed and demolded to obtain brain tissue equivalent material.
[0040] Example 3
[0041] Mix 100g of bisphenol A epoxy resin with 35g of octyl glycidyl ether and stir mechanically for 12 minutes; add 5.5g of urea and continue stirring for 12 minutes; then add 8g of calcium carbonate and stir for 18 minutes; finally add 6g of sodium dihydrogen phosphate and 5.2g of dipotassium hydrogen phosphate and stir for 12 minutes to obtain an epoxy resin mixture.
[0042] The epoxy resin mixture was ultrasonically vibrated at 18 kHz for 33 min; 105 g of polyethylene was added to the ultrasonic product and stirred for 20 min; then 78 g of methyl methacrylate was added and stirred for 15 min; finally, 30 g of trimethylhexanediamine was added and stirred for 10 min to obtain the mixture.
[0043] The mixture was evacuated to -0.009 MPa and vacuum degassed for 30 minutes. The degassed product was poured into a sealed mold and placed at 25°C for 10 hours for initial curing. The initially cured product was placed in a 70°C constant temperature oven for 3 hours. Finally, the power to the constant temperature oven was turned off, and the product was allowed to cool naturally to 25°C before being removed and demolded to obtain brain tissue equivalent material.
[0044] Comparative Example 1
[0045] The step of ultrasonically vibrating the epoxy resin mixture at 20 kHz for 30 min in Example 1 is omitted. Instead, 90.02 g of polyethylene is directly added to the epoxy resin mixture and stirred for 20 min. Other process conditions are the same as in Example 1.
[0046] Comparative Example 2
[0047] Mix 100.03g of bisphenol A epoxy resin with 29.99g of octyl glycidyl ether and stir mechanically for 10 minutes; add 6.76g of urea and continue stirring for 10 minutes; then add 5.53g of sodium dihydrogen phosphate and 4.03g of dipotassium hydrogen phosphate and stir for 10 minutes to obtain an epoxy resin mixture.
[0048] The epoxy resin mixture was ultrasonically vibrated at 20 kHz for 30 min; 90.12 g of polyethylene was added to the ultrasonic product and stirred for 20 min; then 80.26 g of methyl methacrylate was added and stirred for 15 min; finally, 32.29 g of trimethylhexanediamine was added and stirred for 10 min to obtain the mixture.
[0049] The mixture was evacuated to -0.01 MPa for 30 minutes for degassing. The degassed product was poured into a sealed mold and placed at 25°C for 12 hours for initial curing. The initially cured product was placed in a 60°C constant temperature oven for 4 hours. Finally, the constant temperature oven was turned off and allowed to cool naturally to about 25°C. The product was then removed and demolded to obtain brain tissue equivalent material.
[0050] The typical CT value of real brain gray matter is 35-45 HU, and the typical CT value of real brain white matter is 25-35 HU. Testing showed that the CT value of the brain tissue equivalent material prepared in Example 1 was 45 HU, consistent with real brain gray matter data; the CT value of the brain tissue equivalent material prepared in Example 2 was 27 HU, consistent with real brain white matter data; the CT value of the brain tissue equivalent material prepared in Comparative Example 2 was -13 HU, significantly different from the actual brain tissue data. Compared to Examples 1 and 2, Comparative Example 2 did not add calcium carbonate; while the difference between Example 2 and Example 1 was an increased proportion of polyethylene.
[0051] Physical images of the brain tissue equivalent materials prepared in Example 1 and Comparative Example 1 are shown below. Figure 1 As shown, A is Example 1, and B is Comparative Example 1. Figure 1 It can be seen that the epoxy resin mixture in Example 1 was subjected to ultrasonic vibration treatment before other fillers were added, and a smooth and uniform composite material was finally obtained. In contrast, Comparative Example 1 was not subjected to ultrasonic vibration, and a large amount of precipitation appeared in the composite material.
[0052] The brain tissue equivalent material of the present invention achieves parameter values consistent with those of brain tissue when applied to medical imaging equipment such as CT scans. The X-ray attenuation curve of the brain tissue equivalent material prepared in Example 1 and its corresponding gray matter attenuation curve are shown below. Figure 2 As shown, the X-ray attenuation curve of the brain tissue equivalent material prepared in Example 1 and its corresponding brain white matter attenuation curve are as follows. Figure 3 As shown. The relative deviation of the linear attenuation coefficient of the brain tissue equivalent material prepared in Example 1 relative to the gray matter is as follows. Figure 4 As shown. The relative deviation of the linear attenuation coefficient of the brain tissue equivalent material prepared in Example 1 relative to the brain white matter is shown in Figure 1. Figure 5 As shown in the figure. Analysis shows that, within the energy range of 60~200keV commonly used in clinical CT equipment, the deviation between the simulated X-ray attenuation coefficient and the respective target brain tissue material in Example 1 is controlled within 5%, demonstrating excellent energy response consistency.
[0053] The brain tissue equivalent material of the present invention provides an ideal solution for accurately simulating brain tissue due to its adjustable component ratio, stable performance, and high similarity to real brain tissue in terms of CT value and broad energy spectrum attenuation characteristics.
[0054] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A brain tissue equivalent material for use in medical imaging equipment, characterized in that, The brain tissue equivalent material comprises the following raw materials by mass fraction: Bisphenol A epoxy resin 20-35%, octyl glycidyl ether 10-15%, urea 1-5%, calcium carbonate 1-5%, sodium dihydrogen phosphate 1-5%, dipotassium hydrogen phosphate 1-5%, polyethylene 15-35%, methyl methacrylate 15-25%, trimethylhexanediamine 5-15%.
2. The method for preparing brain tissue equivalent material for detection in medical imaging equipment as described in claim 1, characterized in that, It includes the following steps: 1) Bisphenol A epoxy resin, octyl glycidyl ether, urea, calcium carbonate, sodium dihydrogen phosphate and dipotassium hydrogen phosphate are mixed to obtain an epoxy resin mixture; 2) The epoxy resin mixture is subjected to ultrasonic vibration to obtain an ultrasonic product. The ultrasonic product, polyethylene, methyl methacrylate and trimethylhexanediamine are mixed to obtain a mixture. 3) The mixture is subjected to vacuum degassing, initial curing and drying in sequence to obtain brain tissue equivalent material.
3. The preparation method according to claim 2, characterized in that, Step 1) The mixing is carried out by first mixing bisphenol A epoxy resin and octyl glycidyl ether, second mixing the first mixture with urea, third mixing the second mixture with calcium carbonate, and fourth mixing the third mixture with sodium dihydrogen phosphate and dipotassium hydrogen phosphate to obtain an epoxy resin mixture.
4. The preparation method according to claim 2 or 3, characterized in that, Step 2) The mixing involves a first mixing of the ultrasonic product and polyethylene, a second mixing of the first mixture and methyl methacrylate, and a third mixing of the second mixture and trimethylhexanediamine to obtain a mixture.
5. The preparation method according to claim 4, characterized in that, Step 2) The frequency of the ultrasonic oscillation is 17~23kHz, and the duration of the ultrasonic oscillation is 25~35min.
6. The preparation method according to claim 5, characterized in that, Step 3) The vacuum degassing time is 25~35 min, and the vacuum degree of vacuum degassing is -0.015~-0.005 MPa.
7. The preparation method according to claim 6, characterized in that, Step 3) The initial curing temperature is 25~35℃ and the initial curing time is 8~15h; the drying temperature is 50~80℃ and the drying time is 2~6h.