Fat emulsion phantom capable of being used for ultrasonic and MRI-PDFF detection

Abstract

The invention discloses a fat emulsion phantom capable of being used for ultrasonic and MRI-PDFF detection. The fat emulsion phantom comprises the following steps: preparing an aqueous solution; preparing an oil solution; the water solution and the oil solution are poured into a beaker, the beaker is sealed with a preservative film, the beaker is heated to the solution temperature of 80-85 DEG C, stirring is conducted for 15-25 min till the solution is evenly milky white and no layering line exists in the solution, a hot plate is closed, the speed of 500 r / min is maintained, and stirring continues till the solution is cooled to 45-50 DEG C; thirdly, slowly injecting the stirred solution into a simulation container by using a glass rod, and oscillating the container to discharge bubbles in the solution; and finally, feeding the phantom container into a refrigerator at 4 DEG C, and freezing for more than 10 hours until the phantom is completely solidified, so as to obtain the fat emulsion phantom. The fat emulsion phantom has a relatively large volume, and can simultaneously meet the measurement of ultrasound and MRI-PDFF.

Description

Technical Field

[0001] The invention relates to the technical field of fat emulsion phantoms, in particular to a fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection. Background Art

[0002] In 2023, fatty liver has replaced chronic hepatitis B as the most common chronic liver disease in my country. The current gold standard for detecting fatty liver is histopathological examination, but it is invasive and has differences and repeatability between observers, which limit its clinical application. Magnetic resonance proton density fat fraction (MRI-PDFF) is currently the most commonly used imaging method for detecting fatty liver, but it has certain limitations due to personnel and equipment limitations, as well as differences in image processing between different machines.

[0003] Ultrasonic liver fat quantification technology is based on the principle that when ultrasound waves propagate in tissues, they will produce a greater degree of attenuation in fatty livers. It can image and quantify the degree of acoustic attenuation and is a new ultrasound detection technology for fatty liver. It is non-invasive, easy to use, and does not require additional ultrasound capabilities compared to conventional ultrasound imaging. It has a high application value in the early screening and diagnosis of fatty liver. However, there is currently no unified conclusion on the diagnosis and grading standards of fatty liver using ultrasonic attenuation coefficients: different manufacturers use different units to measure ultrasonic attenuation coefficients, such as the Siemens UDFF system uses percentages, while the Canon ATI system uses dB / cm / MHz; different acoustic attenuation measurement systems have inconsistent thresholds for the diagnosis and grading of fatty liver, and the degree of differentiation is low, such as the ATI diagnostic threshold for fatty liver is 0.64-0.72dB / cm / MHz for mild fatty liver, 0.72-0.79dB / cm / MHz for moderate fatty liver, and >0.79dB / cm / MHz for severe fatty liver, which has low differentiation in clinical use; there is currently a lack of research on how to correspond the ultrasonic attenuation coefficient to MRI-PDFF, which results in a lack of corresponding controls and reference standards for the detection of fatty liver using ultrasonic attenuation coefficients, thus limiting its clinical application. Therefore, it is particularly important to construct a phantom that can be prepared with different fat ratios and can perform MRI-PDFF and ultrasound fat quantitative detection simultaneously, to unify the ultrasound attenuation measurement values ​​of different machine manufacturers, and to standardize and compare the ultrasound parameters with the fat concentration and MRI-PDFF measurements.

[0004] The existing phantoms are difficult to make and have a small size. For example, the Chinese invention with publication number CN117192456A discloses a "magnetic resonance model for detecting fat content and its construction method, verification method and application". Through ultrasonic emulsification, in vitro fat correction models with different contents are obtained under specific emulsification parameters. However, the ultrasonic emulsification method has equipment and technical limitations, and the model dedicated to magnetic resonance is small in size and cannot meet the needs of ultrasonic scanning. Therefore, the present invention intends to improve the production of a fat emulsion phantom to meet the requirements of ultrasonic scanning and MRI-PDFF. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection to solve the above-mentioned traditional technical problems.

[0006] The present invention is implemented by the following technical solutions:

[0007] A fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection includes the following construction steps:

[0008] S1. Preparation of aqueous solution: Weigh agar powder and potassium sorbate respectively, add agar powder and potassium sorbate into a reaction container, add cold water while stirring, and then seal with plastic wrap to prevent water evaporation during microwave heating, then put it into a microwave oven, first heat it at high heat for 1.5 min-3 min, take it out and stir it for 25 s-35 s after heating, repeat the high heat heating process at least 2 times until the powder is dissolved, then heat it at medium heat until the solution boils, turn off the heat and cool it until there are no boiling bubbles, then heat it again, and repeat the medium heat heating process at least 2 times; wherein agar powder accounts for 3wt% of the total amount of the aqueous solution, and potassium sorbate accounts for 1wt% of the total amount of the aqueous solution;

[0009] S2. Preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 85°C-95°C, the rotation speed to 500r / min, the preset temperature of the first solution to 25°C-35°C, and then heat the oil to the preset temperature of the first solution; extract the emulsifier with a syringe and slowly inject it at 0.8cm-1.2cm above the liquid surface; then adjust the setting temperature of the heating plate to 140°C-160°C, the rotation speed to 750r / min, the stirring, the preset temperature of the second solution to 45°C-55°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil;

[0010] S3. Preparation of fat emulsion mimetic: first use a pipette to accurately determine the volume, pour the aqueous solution and the oil solution into a beaker according to the required ratio, seal it with plastic wrap to prevent water evaporation in the subsequent reaction, then set the hot plate temperature to 130°C-170°C and the speed to 500r / min, then heat the beaker to the solution temperature of 80°C-85°C, stir for 15min-25min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain a speed of 500r / min, and continue stirring until the solution cools to 45°C-50°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to expel the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

[0011] Furthermore, in step S1, the cold water is pure water.

[0012] Furthermore, in step S1, the high-fire heating temperature is 90°C-110°C.

[0013] Furthermore, in step S1, the temperature of medium-heat heating is 60°C-70°C.

[0014] Further, in step S1, heating is performed on high heat until the agar powder is dissolved.

[0015] Further, in step S1, the solution is heated at medium heat until it boils.

[0016] Furthermore, in step S2, the oil is peanut oil.

[0017] Further, in step S2, the emulsifier is OP-7 emulsifier.

[0018] Further, in step S3, the beaker includes a 1000 ml wide-bottom beaker and a medium-sized rotor, and the medium-sized rotor is placed in the beaker.

[0019] Furthermore, in step S3, the ratio of the aqueous solution to the oil solution is adjusted according to the required fat ratio of the fat emulsion mimetic of 0wt%-100wt%.

[0020] Furthermore, the fat emulsion phantoms that can be used for ultrasound and MRI-PDFF detection can be used for ultrasound in vitro fat phantoms with different fat contents.

[0021] Furthermore, the ultrasonic in vitro fat phantoms with different fat contents include ultrasonic in vitro fat phantoms with a fat content of 0-100wt%.

[0022] Furthermore, the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection has the following detection parameters in MRI-PDFF detection: GE HealthCare DiscoveryMR750 FatFrac sequence, measured at 3.0T, flip angle 3, and the following parameter settings are used to obtain the axial breath-hold IDEAL-IQ sequence: TR=6.1ms, TE=2.8ms, section thickness=5.0mm, bandwidth=125kHz, FOV=37cm×46cm, matrix=256×256, flip angle=3°, NEX=1.00, and the largest possible ROI is placed on 5 different levels (avoiding the edge of the container and impurities, covering more than 80% of the cross-section) to obtain 5 MRI-PDFF values, and finally the median is taken.

[0023] Further, the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection was tested in ATI (attenuation imaging) with the following detection parameters: Canon Aplio i900, after activating the ATI mode during grayscale US, a large sector-shaped color-coded sampling box automatically appeared, and when the color seemed uniform and the R2 value was equal to or greater than 0.8, a smaller sector-shaped ROI of approximately 2×4 cm in size was placed to include sufficient phantom area, and the measurement was repeated 5 times, and the median was taken.

[0024] Furthermore, the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection was tested in USAT (ultrasound attenuation imaging technology) with the following detection parameters: Canon Mindray Resona R9 Pro, USAT measurement first obtained the B-mode signal with the best image quality and no artifacts for measurement, USAT provided two regions of interest (ROI), a color-coded fixed ROI to sample a larger area of ​​the phantom to improve measurement accuracy, and a smaller mobile local ROI (3×3 cm) for quantitative measurement, 5 USAT measurements were performed and the median was recorded, the manufacturer's motion stability (M-STB) index and reliability map (RLB MAP) were used to evaluate the accuracy and stability of the measurement, M-STB helped monitor the real-time motion stability of the study area, M-STB was measured with at least four stars and a green area, indicating high reliability, and images with an RLB index >85% were used for measurement.

[0025] Furthermore, the test parameters of the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection in UGAP (ultrasound-guided attenuation parameters) detection are: GE LOGIQ, activate UGAP mode, place ROI on the phantom, select as large a range as possible to include more phantoms, repeat the measurement 5 times, and take the median.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The fat emulsion phantom of the present invention has a large volume and can simultaneously meet the measurement requirements of ultrasound and MRI-PDFF.

[0028] 2. The in vitro fat emulsion mimetic prepared by the present invention is emulsified by a heating and stirring method, so the materials are easier to obtain and the preparation is simpler.

[0029] 3. The in vitro fat emulsion phantom produced by the present invention has been tested by MRI-PDFF and three ultrasonic attenuation technologies, namely ATI, UGAP and USAT, and the results are more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the MRI-PDFF measurement diagram of the fat emulsion phantom of Example 1 of the present invention;

[0031] Figure 2 This is an ATI measurement diagram of the fat emulsion phantom of Example 1 of the present invention;

[0032] Figure 3 This is a USAT measurement diagram of the fat emulsion phantom of Example 1 of the present invention;

[0033] Figure 4 This is a UGAP measurement diagram of the fat emulsion phantom according to Example 1 of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0035] Example 1

[0036] A fat emulsion mimetic comprises the following construction steps:

[0037] S1. Preparation of aqueous solution: using an analytical balance to weigh agar powder and potassium sorbate respectively, adding the agar powder and potassium sorbate into a reaction container, adding cold water while stirring, and then sealing with plastic wrap to prevent water evaporation during microwave heating, then putting it into a microwave oven, first heating it at high heat for 2 minutes, taking it out after heating and stirring it for 30 seconds, repeating the high heat heating process 5 times until the powder is dissolved, then heating it at medium heat until the solution boils, turning off the heat and cooling it until there are no boiling bubbles, then heating it again, and repeating the medium heat heating process 5 times; wherein the agar powder accounts for 3wt% of the total amount of the aqueous solution, and the potassium sorbate accounts for 1wt% of the total amount of the aqueous solution;

[0038] S2, preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 90°C, the rotation speed to 500r / min, the preset temperature of the first solution to 30°C, and then heat the peanut oil to the preset temperature of the first solution; draw OP-7 emulsifier with a syringe and slowly inject it 1cm above the liquid surface; then adjust the setting temperature of the heating plate to 150°C, the rotation speed to 750r / min, the stirring, the preset temperature of the second solution to 50°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil;

[0039] S3. Preparation of fat emulsion mimetic: Select a 1000ml wide-bottom beaker and a medium-sized rotor, place the rotor in the beaker, first use a pipette to accurately determine the volume, pour the ratio of aqueous solution to oil solution into the beaker according to the fat ratio of the required fat emulsion mimetic of 2wt%, seal it with plastic wrap to prevent water evaporation, then set the hot plate temperature to 150°C and the speed to 500r / min, then heat the beaker to a solution temperature of 80°C-85°C, stir for 20min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain a speed of 500r / min, and continue stirring until the solution cools to 48°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to discharge the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

[0040] like Figure 1-Figure 4 As shown, after the detection of MRI-PDFF and three ultrasonic attenuation technologies, ATI, UGAP, and USAT, it is proved that the fat emulsion phantom of this embodiment 1 can be detected by MRI-PDFF and three ultrasonic attenuation technologies, ATI, UGAP, and USAT at the same time.

[0041] Among them, the detection parameters in MRI-PDFF detection are: GE HealthCare Discovery MR750FatFrac sequence, measured at 3.0T, flip angle 3, and the following parameter settings are used to obtain the axial breath-hold IDEAL-IQ sequence: TR=6.1ms, TE=2.8ms, section thickness=5.0mm, bandwidth=125kHz, FOV=37cm×46cm, matrix=256×256, flip angle=3°, NEX=1.00. Place as large a ROI as possible on 5 different levels (avoiding the edge of the container and impurities, covering more than 80% of the cross section) to obtain 5 MRI-PDFF values, and finally take the median.

[0042] The test parameters in ATI (attenuation imaging) examination were: Canon Aplio i900, after activating ATI mode during grayscale US, a large sector-shaped color-coded sampling box automatically appeared, and when the color seemed uniform and the R2 value was equal to or greater than 0.8, a smaller sector-shaped ROI of approximately 2×4 cm in size was placed to include sufficient phantom area, and the measurement was repeated 5 times, and the median was taken.

[0043] The test parameters in USAT (ultrasound attenuation imaging technology) detection were: Canon Mindray Resona R9 Pro. USAT measurement first obtained the B-mode signal with the best image quality and no artifacts for measurement. USAT provided two regions of interest (ROI), a color-coded fixed ROI to sample a larger area of ​​the phantom to improve measurement accuracy, and a smaller mobile local ROI (3×3 cm) for quantitative measurement. Five USAT measurements were performed and the median was recorded. The manufacturer's motion stability (M-STB) index and reliability map (RLB MAP) were used to evaluate the accuracy and stability of the measurement. M-STB helps to monitor the real-time motion stability of the study area. M-STB was measured with at least four stars and green areas, indicating high reliability, and images with RLB index >85% were used for measurement.

[0044] The test parameters in UGAP (ultrasound-guided attenuation parameters) detection are: GE LOGIQ, activate UGAP mode, place ROI on the phantom, select as large a range as possible to include more phantoms, repeat the measurement 5 times, and take the median.

[0045] Example 2

[0046] A fat emulsion mimetic comprises the following construction steps:

[0047] S1. Preparation of aqueous solution: using an analytical balance to weigh agar powder and potassium sorbate respectively, adding the agar powder and potassium sorbate into a reaction container, adding cold water while stirring, and then sealing with plastic wrap to prevent water evaporation during microwave heating, then putting it into a microwave oven, first heating it at high heat for 2 minutes, taking it out after heating and stirring it for 35 seconds, repeating the high heat heating process 3 times until the powder is dissolved, then heating it at medium heat until the solution boils, turning off the heat and cooling it until there are no boiling bubbles, then heating it again, and repeating the medium heat heating process 5 times; wherein the agar powder accounts for 3wt% of the total amount of the aqueous solution, and the potassium sorbate accounts for 1wt% of the total amount of the aqueous solution;

[0048] S2, preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 90°C, the rotation speed to 500r / min, the preset temperature of the first solution to 30°C, and then heat the peanut oil to the preset temperature of the first solution; draw OP-7 emulsifier with a syringe and slowly inject it 1cm above the liquid surface; then adjust the setting temperature of the heating plate to 150°C, the rotation speed to 750r / min, the stirring, the preset temperature of the second solution to 50°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil;

[0049] S3. Preparation of fat emulsion mimetic: Select a 1000ml wide-bottom beaker and a medium-sized rotor, place the rotor in the beaker, first use a pipette to accurately determine the volume, pour the ratio of aqueous solution to oil solution into the beaker according to the fat ratio of the required fat emulsion mimetic of 10wt%, seal it with plastic wrap to prevent water evaporation, then set the hot plate temperature to 150°C and the speed to 500r / min, then heat the beaker to a solution temperature of 80°C-85°C, stir for 20min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain a speed of 500r / min, and continue stirring until the solution cools to 48°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to discharge the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

[0050] After being tested by MRI-PDFF and three ultrasonic attenuation technologies, namely ATI, UGAP and USAT, it is proved that the fat emulsion phantom of Example 2 can be tested by MRI-PDFF and three ultrasonic attenuation technologies, namely ATI, UGAP and USAT.

[0051] Example 3

[0052] A fat emulsion mimetic comprises the following construction steps:

[0053] S1. Preparation of aqueous solution: weighing agar powder and potassium sorbate respectively with an analytical balance, adding the agar powder and potassium sorbate into a reaction container, adding cold water while stirring, and then sealing with plastic wrap to prevent water evaporation during microwave heating, then putting it into a microwave oven, first heating it at high heat for 3 minutes, taking it out after heating and stirring it for 25 seconds, repeating the high-heat heating process 4 times until the powder is dissolved, then heating it at medium heat until the solution boils, turning off the heat and cooling it until there are no boiling bubbles, then heating it again, and repeating the medium-heat heating process 5 times; wherein the agar powder accounts for 3wt% of the total amount of the aqueous solution, and the potassium sorbate accounts for 1wt% of the total amount of the aqueous solution;

[0054] S2, preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 90°C, the rotation speed to 500r / min, the preset temperature of the first solution to 30°C, and then heat the peanut oil to the preset temperature of the first solution; draw OP-7 emulsifier with a syringe and slowly inject it 1cm above the liquid surface; then adjust the setting temperature of the heating plate to 150°C, the rotation speed to 750r / min, the stirring, the preset temperature of the second solution to 50°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil;

[0055] S3. Preparation of fat emulsion mimetic: Select a 1000ml wide-bottom beaker and a medium-sized rotor, place the rotor in the beaker, first use a pipette to accurately determine the volume, pour the ratio of aqueous solution to oil solution into the beaker according to the fat ratio of the required fat emulsion mimetic of 50wt%, seal it with plastic wrap to prevent water evaporation, then set the hot plate temperature to 150°C and the speed to 500r / min, then heat the beaker to a solution temperature of 80°C-85°C, stir for 20min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain a speed of 500r / min, and continue stirring until the solution cools to 48°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to discharge the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

[0056] After being tested by MRI-PDFF and three ultrasonic attenuation technologies, namely ATI, UGAP and USAT, it is proved that the fat emulsion phantom of Example 3 can be tested by MRI-PDFF and three ultrasonic attenuation technologies, namely ATI, UGAP and USAT.

[0057] Example 4

[0058] A fat emulsion mimetic comprises the following construction steps:

[0059] S1. Preparation of aqueous solution: using an analytical balance to weigh agar powder and potassium sorbate respectively, adding the agar powder and potassium sorbate into a reaction container, adding cold water while stirring, and then sealing with plastic wrap to prevent water evaporation during microwave heating, then putting it into a microwave oven, first heating it at high heat for 1.5 min, taking it out after heating and stirring it for 30 s, repeating the high heat heating process 5 times until the powder is dissolved, then heating it at medium heat until the solution boils, turning off the heat and cooling it until there are no boiling bubbles, then heating it again, and repeating the medium heat heating process 5 times; wherein the agar powder accounts for 3wt% of the total amount of the aqueous solution, and the potassium sorbate accounts for 1wt% of the total amount of the aqueous solution;

[0060] S2, preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 90°C, the rotation speed to 500r / min, the preset temperature of the first solution to 30°C, and then heat the peanut oil to the preset temperature of the first solution; draw OP-7 emulsifier with a syringe and slowly inject it at 1.2cm above the liquid surface; then adjust the setting temperature of the heating plate to 150°C, the rotation speed to 750r / min, the stirring, the preset temperature of the second solution to 50°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil;

[0061] S3. Preparation of fat emulsion mimetic: Select a 1000ml wide-bottom beaker and a medium-sized rotor, place the rotor in the beaker, first use a pipette to accurately determine the volume, pour the ratio of aqueous solution to oil solution into the beaker according to the fat ratio of the required fat emulsion mimetic of 100wt%, seal it with plastic wrap to prevent water evaporation, then set the hot plate temperature to 150°C and the speed to 500r / min, then heat the beaker to a solution temperature of 80°C-85°C, stir for 20min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain a speed of 500r / min, and continue stirring until the solution cools to 48°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to discharge the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

[0062] After being tested by MRI-PDFF and three ultrasonic acoustic attenuation technologies, namely ATI, UGAP and USAT, it is proved that the fat emulsion phantom of Example 4 can be tested by MRI-PDFF and three ultrasonic acoustic attenuation technologies, namely ATI, UGAP and USAT.

[0063] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection, characterized in that: The build steps include: S1. Preparation of aqueous solution: Weigh agar powder and potassium sorbate respectively, add agar powder and potassium sorbate into a reaction container, add cold water while stirring, seal with plastic wrap, then put into a microwave oven, heat at high heat for 1.5 min-3 min, take out and stir for 25 s-35 s after heating, repeat the high heat heating process at least 2 times until the powder is dissolved, heat at medium heat until the solution boils, turn off the heat and cool until there are no boiling bubbles, then heat again, repeat the medium heat heating process at least 2 times; wherein agar powder accounts for 3wt% of the total amount of the aqueous solution, and potassium sorbate accounts for 1wt% of the total amount of the aqueous solution; S2. Preparation of oil solution: using a heating plate, first set the temperature of the heating plate to 85°C-95°C, the rotation speed to 500r / min, the preset temperature of the first solution to 25°C-35°C, and then heat the oil to the preset temperature of the first solution; extract the emulsifier with a syringe and slowly inject it at 0.8cm-1.2cm above the liquid surface; then adjust the setting temperature of the heating plate to 140°C-160°C, the rotation speed to 750r / min, the preset temperature of the second solution to 45°C-55°C, and then heat the above solution to the preset temperature of the second solution; wherein the emulsifier accounts for 2wt% of the total amount of the oil; S3. Preparation of fat emulsion mimetic: first use a pipette to accurately determine the volume, pour the aqueous solution and the oil solution into a beaker according to the required ratio, seal it with plastic wrap, and then set the hot plate temperature to 130°C-170°C and the rotation speed to 500r / min. Then, heat the beaker to a solution temperature of 80°C-85°C, stir for 15min-25min, stir until the solution is uniformly milky white and there is no stratification line in the solution, then turn off the hot plate, maintain 500r / min, and continue stirring until the solution cools to 45°C-50°C; then, use a glass rod to slowly inject the stirred solution into the mimetic container, shake the container to expel the bubbles in the solution; finally, send the mimetic container to a 4°C refrigerator and freeze it for more than 10 hours until the mimetic is completely solidified to obtain a fat emulsion mimetic.

2. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: In step S1, the temperature of high-fire heating is 90°C-110°C; the temperature of medium-fire heating is 60°C-70°C.

3. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: In step S2, the oil is peanut oil, and the emulsifier is OP-7 emulsifier.

4. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: In step S3, the ratio of the aqueous solution to the oil solution is adjusted according to the required fat ratio of the fat emulsion mimetic of 0wt%-100wt%.

5. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: The detection parameters of the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection in MRI-PDFF detection are: GE HealthCare Discovery MR750 FatFrac sequence, measured at 3.0T, flip angle 3, and the following parameter settings are used to obtain the axial breath-hold IDEAL-IQ sequence: TR=6.1ms, TE=2.8ms, section thickness=5.0mm, bandwidth=125kHz, FOV=37cm×46cm, matrix=256×256, flip angle=3°, NEX=1.00, and ROIs as large as possible are placed on 5 different levels to obtain 5 MRI-PDFF values, and the median is finally taken.

6. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: The detection parameters of the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection in ATI detection are as follows: Canon Aplio i900, after activating the ATI mode during grayscale US, a large sector-shaped color-coded sampling box automatically appears, and when the color appears to be uniform and the R2 value is equal to or greater than 0.8, a smaller sector-shaped ROI of approximately 2×4 cm is placed to include sufficient phantom area, and the measurement is repeated 5 times, and the median is taken.

7. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: The detection parameters of the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection in USAT detection are: Canon Mindray Resona R9Pro, USAT measurement first obtains B-type signals with the best image quality and no artifacts for measurement, USAT provides two regions of interest, color-coded fixed ROI, sampling a larger area of ​​the phantom to improve measurement accuracy, and a smaller mobile local ROI (3×3 cm) for quantitative measurement, 5 USAT measurements are performed and the median is recorded.

8. The fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection according to claim 1, characterized in that: The detection parameters of the fat emulsion phantom that can be used for ultrasound and MRI-PDFF detection in UGAP detection are: GE LOGIQ, activating UGAP mode, placing ROI on the phantom, selecting as large a range as possible to include more phantoms, repeating the measurement 5 times, and taking the median.

Images