Ultrasonic attenuation coefficient and MRI-PDFF conversion method and system

Abstract

The invention discloses an ultrasonic attenuation coefficient and MRI-PDFF conversion method and system, relates to the field of medical treatment and public health, is applied to evaluation of the ultrasonic attenuation coefficient on fatty liver grading, and comprises the following steps: measuring an ultrasonic attenuation parameter and a magnetic resonance proton density fat fraction MRI-PDFF, and analyzing a linear relationship between the ultrasonic attenuation parameter and the MRI-PDFF; based on the linear relation, regression analysis is carried out on the ultrasonic attenuation parameters and the MRI-PDFF to obtain a conversion formula between the ultrasonic attenuation coefficient and the MRI-PDFF, and the conversion formula is used for evaluating the severity of the fatty liver through the ultrasonic attenuation coefficient. According to the method, the ultrasonic attenuation coefficient corresponds to the MRI-PDFF measured value, and a reference is provided for evaluating the severity of the fatty liver by using the ultrasonic attenuation coefficient clinically.

Description

Technical Field

[0001] The present invention relates to the field of medical care, and in particular to a method and system for converting an ultrasonic attenuation coefficient and an MRI-PDFF. Background Art

[0002] Fatty liver has replaced chronic hepatitis B as the most common chronic liver disease. 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.

[0004] However, there is currently no unified standard for how to use the ultrasonic attenuation index to grade fatty liver, and there is also a lack of relevant research on how to correspond the ultrasonic attenuation coefficient to MRI-PDFF. As a result, the detection of fatty liver using the ultrasonic attenuation coefficient lacks corresponding control and reference standards, limiting its clinical application. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a conversion technology of ultrasonic attenuation coefficient and MRI-PDFF for preliminary detection of fatty liver staging by ultrasound, aiming to analyze whether the measured values ​​of ultrasonic attenuation coefficient and MRI-PDFF for different fat volume fractions have a linear relationship, and use relevant regression research to fit the measured values ​​of ultrasonic attenuation coefficient and MRI-PDFF to obtain the regression formula of the two, so as to facilitate the clinical combination of the two to evaluate the severity of fatty liver in patients and achieve early and comprehensive detection of fatty liver.

[0006] In order to achieve the above technical objectives, the present application provides a method for converting ultrasound attenuation coefficient and MRI-PDFF, which is applied to preliminary detection of fatty liver staging by ultrasound, comprising the following steps:

[0007] Ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF were measured, and the linear relationship between ultrasound attenuation parameters and MRI-PDFF was analyzed;

[0008] Based on the linear relationship, the conversion of ultrasound attenuation parameters and MRI-PDFF was completed by regression analysis of ultrasound attenuation parameters and MRI-PDFF, which was used to evaluate the severity of fatty liver by ultrasound attenuation coefficient.

[0009] Preferably, in the process of obtaining the magnetic resonance proton density fat fraction MRI-PDFF, ROIs are placed on 5 different levels, avoiding the edge of the container and impurities, and covering more than 80% of the cross section, and 5 MRI-PDFF values ​​are obtained, and the median is taken as MRI-PDFF.

[0010] Preferably, in the process of acquiring the ultrasound attenuation parameters, attenuation imaging ATI, ultrasound-guided attenuation parameters UGAP and ultrasound attenuation imaging technology USAT are used as ultrasound attenuation parameters.

[0011] Preferably, in the process of obtaining ATI, when the color appears to be uniform and the R2 value is equal to or greater than 0.8, a sector ROI of 2×4 cm size is placed to include a sufficient area of ​​the phantom; the measurement is repeated 5 times, the median is taken, and the ATI is obtained.

[0012] Preferably, in the process of acquiring UGAP, a ROI is placed on the phantom, a range as large as possible is selected to include more phantoms, the measurement is repeated 5 times, the median is taken, and the UGAP is acquired.

[0013] Preferably, in the process of acquiring USAT, the USAT is measured by first obtaining the B-type signal with the best image quality and no artifacts, and 5 USAT measurements are performed and the median is recorded to acquire USAT, wherein USAT provides two regions of interest ROIs: sampling of a large area of ​​the phantom through a color-coded fixed ROI, and quantitative measurement of a small moving local ROI.

[0014] Preferably, in the process of acquiring the linear relationship, the linear relationship between the ultrasound attenuation parameter and the MRI-PDFF is acquired according to the linear relationship between ATI, UGAP and USAT and MRI-PDFF respectively.

[0015] The present invention discloses a conversion system of an ultrasonic attenuation coefficient and an MRI-PDFF, and the system is used to implement the above-mentioned conversion method of an ultrasonic attenuation coefficient and an MRI-PDFF. The system comprises:

[0016] An analysis module is used to measure ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF, and analyze the linear relationship between ultrasound attenuation parameters and MRI-PDFF;

[0017] The conversion module is used to obtain a conversion formula between the ultrasound attenuation coefficient and MRI-PDFF by performing regression analysis on the ultrasound attenuation parameter and MRI-PDFF based on a linear relationship, and is used to evaluate the severity of fatty liver through the ultrasound attenuation coefficient.

[0018] The present invention discloses the following technical effects:

[0019] The regression formula obtained in the present invention is limited to the case where only the influence of fat fraction on ultrasonic attenuation coefficient is considered, which corresponds to the principle of MRI-PDFF for measuring fat signal ratio.

[0020] The regression formula obtained by the present invention can preliminarily correspond the ultrasonic attenuation coefficient with the MRI-PDFF measurement value, providing a reference for clinical use of the ultrasonic attenuation coefficient to assess the severity of fatty liver. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is the linear regression analysis of the MRI-PDFF and ATI-5MHz groups described in the present invention;

[0023] Figure 2 is the linear regression analysis of the MRI-PDFF and ATI-4MHz groups described in the present invention;

[0024] Figure 3 is the linear regression analysis of the MRI-PDFF and UGAP groups described in the present invention;

[0025] Figure 4 is the linear regression analysis of the MRI-PDFF and USAT groups described in the present invention;

[0026] Figure 5 It is a schematic diagram of the method flow of the present invention. DETAILED DESCRIPTION

[0027] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0028] The present invention provides a method for converting an ultrasonic attenuation coefficient and MRI-PDFF, which is applied to preliminary ultrasonic detection of fatty liver staging, and comprises the following steps:

[0029] Ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF were measured, and the linear relationship between ultrasound attenuation parameters and MRI-PDFF was analyzed;

[0030] Based on the linear relationship, the conversion formula between ultrasound attenuation coefficient and MRI-PDFF was obtained by regression analysis of ultrasound attenuation parameters and MRI-PDFF, which was used to evaluate the severity of fatty liver by ultrasound attenuation coefficient.

[0031] Further preferably, in the method for converting an ultrasonic attenuation coefficient and MRI-PDFF provided by the present invention, in the process of obtaining the magnetic resonance proton density fat fraction MRI-PDFF, ROIs are placed on 5 different levels, avoiding the edge of the container and impurities, and covering more than 80% of the cross-section, and 5 MRI-PDFF values ​​are obtained, and the median is taken as the MRI-PDFF.

[0032] Further preferably, in a method for converting an ultrasonic attenuation coefficient and MRI-PDFF provided by the present invention, in the process of obtaining ultrasonic attenuation parameters, attenuation imaging ATI, ultrasound-guided attenuation parameter UGAP and ultrasonic attenuation imaging technology USAT are used as ultrasonic attenuation parameters.

[0033] Further preferably, in the method for converting an ultrasonic attenuation coefficient to an MRI-PDFF provided by the present invention, in the process of obtaining ATI, when the color appears to be uniform and the R2 value is equal to or greater than 0.8, a sector ROI of 2×4 cm is placed to include a sufficient phantom area; the measurement is repeated 5 times, the median is taken, and the ATI is obtained.

[0034] Further preferably, in the method for converting ultrasonic attenuation coefficient and MRI-PDFF provided by the present invention, in the process of obtaining UGAP, ROI is placed on the phantom, and as large a range as possible is selected to include more phantoms, the measurement is repeated 5 times, and the median is taken to obtain UGAP.

[0035] Further preferably, in the method for converting an ultrasonic attenuation coefficient and MRI-PDFF provided by the present invention, in the process of acquiring USAT, the USAT is measured, and the B-type signal with the best image quality and no artifacts is first measured, and 5 USAT measurements are performed and the median is recorded to acquire the USAT, wherein the USAT provides two regions of interest ROIs: sampling of a large area of ​​the phantom through a color-coded fixed ROI, and quantitative measurement of a small moving local ROI.

[0036] Further preferably, in the process of obtaining the linear relationship, the method for converting the ultrasonic attenuation coefficient and MRI-PDFF provided by the present invention obtains the linear relationship between the ultrasonic attenuation parameter and MRI-PDFF according to the linear relationship between ATI, UGAP and USAT and MRI-PDFF respectively.

[0037] The present invention discloses a conversion system of an ultrasonic attenuation coefficient and an MRI-PDFF, and the system is used to implement the above-mentioned conversion method of an ultrasonic attenuation coefficient and an MRI-PDFF. The system comprises:

[0038] An analysis module is used to measure ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF, and analyze the linear relationship between ultrasound attenuation parameters and MRI-PDFF;

[0039] The conversion module is used to obtain a conversion formula between the ultrasound attenuation coefficient and MRI-PDFF by performing regression analysis on the ultrasound attenuation parameter and MRI-PDFF based on a linear relationship, and is used to evaluate the severity of fatty liver through the ultrasound attenuation coefficient.

[0040] Example: Figure 1-5 As shown, the present invention provides a method for converting ultrasound attenuation coefficient and MRI-PDFF in a fat emulsion phantom, which specifically includes the following contents:

[0041] 1. Preparation of in vitro fat emulsion phantoms: prepare in vitro fat emulsion phantoms with 12 fat concentrations of 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, and 100%, and the phantoms can be used for ultrasound and MRI-PDFF measurements.

[0042] 2. Measurement of Ultrasound Attenuation Parameters and MRI-PDFF:

[0043] (1) MRI-PDFF detection: Equipment: GE HealthCare Discovery MR750FatFrac sequence, measured at 3.0T, flip angle 3, placing the largest possible ROI 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 taking the median.

[0044] (2) ATI (Attenuation Imaging): Equipment: Canon Aplioi900. After activating the ATI mode during grayscale US, a large sector-shaped color-coded sampling box automatically appears. Adjust the frequency to 4 MHz and 5 MHz, respectively. When the color appears uniform and the R2 value is equal to or greater than 0.8, place a smaller sector-shaped ROI of approximately 2 × 4 cm in size to include sufficient phantom area. Repeat the measurement 5 times and take the median.

[0045] (3) UGAP (ultrasound-guided attenuation parameter): Equipment: 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.

[0046] (4) USAT (Ultrasound Attenuation Imaging Technology): Equipment: Canon Mindray Resona R9 Pro. USAT measurement first obtains the B-mode signal with the best image quality and no artifacts for measurement. USAT provides two regions of interest (ROI), a color-coded fixed ROI that samples 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 (RLBMAP) were used to evaluate the accuracy and stability of the measurement. M-STB helps monitor the real-time motion stability of the study area. M-STB is measured with at least four stars and a green area, indicating high reliability, and images with an RLB index of >85% are used for measurement.

[0047] 3. Linear correlation analysis between ultrasound attenuation parameters and MRI-PDFF:

[0048] Using spss24.0 software, ultrasound attenuation parameters and MRI-PDFF data were input, and linear correlation analysis was performed between ATI, USAT, and UGAP data and MRI-PDFF data, respectively. The results showed that r = 0.966 for the ATI (5MHz) group, R 2 =0.933 (p < 0.001), ATI (4MHz) group r = 0.969, R 2 =0.940 (p < 0.001), UGAP group r = 0.978, R 2 =0.956 (p<0.001), USAT group r=0.884, R 2 =0.782 (p<0.05). The linear analysis r values ​​of the four groups of ultrasound attenuation parameters and MRI-PDFF were all greater than 0.8, p<0.05, among which the r values ​​of the ATI group, ATI group and UGAP group were greater than 0.9, indicating that the ultrasound attenuation coefficients of the four groups and the measured values ​​of MRI-PDFF all showed a good linear relationship.

[0049] IV. Regression analysis of ultrasound attenuation parameters and MRI-PDFF:

[0050] Using spss24.0 software, ultrasound attenuation parameters and MRI-PDFF data were input, and ATI, USAT, and UGAP data were regressed with MRI-PDFF data, respectively, and the regression equation was obtained: ATI (5MHz) group α = -8.460, β = 75.727 (p < 0.001), ATI (4MHz) group α = -8.639, β = 77.756 (p < 0.001), UGAP group α = -19.562, β = 103.519 (p < 0.001), USAT group α = -10.073, β = 80.948 (p < 0.001).

[0051] 5. Derivation and verification of regression formula

[0052] Based on the linear correlation coefficient r value, the UGAP group had the strongest linear correlation with MRI-PDFF among the four groups. Therefore, the regression formula of the UGAP group and MRI-PDFF, i.e., y=-10.073+80.948x, was taken as the conversion formula between the ultrasonic attenuation coefficient and MRI-PDFF. The original data of the ATI (5MHz) group, ATI (4MHz) group, and USAT group were substituted into the y value using spss24.0 software to calculate the theoretical values ​​of MRI-PDFF in each group. The Bland-Altman analysis was performed on the theoretical values ​​of MRI-PDFF in each group with the original values ​​using SPSSAU software. The scattered points were all within the 95% confidence interval, indicating that the formula can be applied to the ultrasonic attenuation coefficient measurement of each manufacturer, and the ultrasonic attenuation coefficient and MRI-PDFF were converted accordingly, which can be used to evaluate the severity of fatty liver by the ultrasonic attenuation coefficient.

[0053] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0054] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for converting ultrasonic attenuation coefficient and MRI-PDFF, characterized in that: The ultrasonic attenuation coefficient is applied to the evaluation of fatty liver grading, including the following steps: Measuring ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF, and analyzing the linear relationship between the ultrasound attenuation parameters and MRI-PDFF; Based on the linear relationship, a conversion formula between the ultrasonic attenuation coefficient and MRI-PDFF is obtained by performing regression analysis on the ultrasonic attenuation parameter and MRI-PDFF, which is used to evaluate the severity of fatty liver through the ultrasonic attenuation coefficient.

2. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 1, characterized in that: In the process of obtaining the magnetic resonance proton density fat fraction MRI-PDFF, ROIs were placed on 5 different levels, avoiding the edge of the container and impurities and covering more than 80% of the cross section. Five MRI-PDFF values ​​were obtained, and the median was taken as the MRI-PDFF.

3. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 2, characterized in that: In the process of acquiring ultrasound attenuation parameters, attenuation imaging ATI, ultrasound-guided attenuation parameter UGAP and ultrasound attenuation imaging technology USAT are used as the ultrasound attenuation parameters.

4. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 3, characterized in that: In the process of obtaining ATI, when the color seems uniform and R 2 When the value was equal to or greater than 0.8, a sector-shaped ROI of 2 × 4 cm was placed to include sufficient phantom area; the measurement was repeated 5 times, and the median was taken to obtain the ATI.

5. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 4, characterized in that: In the process of obtaining UGAP, ROI was placed on the phantom, and the largest possible range was selected to include more phantoms. The measurement was repeated 5 times, and the median was taken to obtain UGAP.

6. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 5, characterized in that: In the process of acquiring USAT, the B-mode signal with the best image quality and no artifacts was first measured for USAT measurement. Five USAT measurements were performed and the median was recorded to acquire USAT, where USAT provides two regions of interest (ROIs): a color-coded fixed ROI for sampling a large area of ​​the phantom, and a small moving local ROI for quantitative measurement.

7. The method for converting ultrasonic attenuation coefficient and MRI-PDFF according to claim 6, characterized in that: In the process of obtaining the linear relationship, the linear relationship between the ultrasound attenuation parameter and the MRI-PDFF is obtained according to the linear relationship between ATI, UGAP and USAT and MRI-PDFF respectively.

8. A conversion system for ultrasound attenuation coefficient and MRI-PDFF, characterized in that: The system is used to implement a method for converting an ultrasonic attenuation coefficient and an MRI-PDFF as described in any one of claims 1 to 7, and the system comprises: An analysis module, used to measure ultrasound attenuation parameters and magnetic resonance proton density fat fraction MRI-PDFF, and analyze the linear relationship between the ultrasound attenuation parameters and MRI-PDFF; A conversion module is used to complete the conversion of the ultrasonic attenuation parameter and MRI-PDFF by performing regression analysis on the ultrasonic attenuation parameter and MRI-PDFF based on the linear relationship, so as to evaluate the severity of fatty liver through the ultrasonic attenuation coefficient.

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