A tissue property evaluation system based on magnetic resonance imaging

Abstract

The present invention belongs to the technical field of disease diagnostic devices and relates to a tissue property assessment system based on magnetic resonance imaging, comprising: a radio frequency transmitting module, a magnetic resonance imaging phantom, a radio frequency coil, a radio frequency receiving module, and a data processing module; the radio frequency transmitting module is used to transmit radio frequency signals; the magnetic resonance imaging phantom is placed below the subject's lumbar spine and is used to quantitatively detect T1WI and T2WI sequences; the radio frequency coil is disposed on the magnetic resonance imaging phantom and is used to transmit radio frequency signals passing through the magnetic resonance imaging phantom; the radio frequency receiving module is used to receive the radio frequency signals transmitted by the radio frequency coil; and the data processing module is used to analyze the signal-to-noise ratio of the radio frequency signals received by the radio frequency receiving module to obtain tissue property assessment results. By introducing the magnetic resonance imaging phantom in the present invention, signal differences caused by different types of instruments or different physical conditions of users can be resolved, providing a unified standard for magnetic resonance testing.

Description

Technical Field

[0001] The present invention relates to a tissue characteristic evaluation system based on magnetic resonance imaging, and belongs to the technical field of disease diagnosis devices, in particular to the technical field of bone density detection. Background Art

[0002] Osteoporosis is characterized by decreased bone strength and an increased risk of fractures. Its most serious consequence is fractures, with vertebral fractures being particularly common. Early and accurate assessment of fracture risk is key to identifying high-risk individuals and preventing osteoporotic fractures. Currently, clinical assessment of vertebral fracture risk primarily relies on quantitative computed tomography (QCT) bone mineral density measurements. However, QCT cannot fully reflect bone quality, such as strength and fracture resistance, and can be inaccurate, emitting a high dose of radiation.

[0003] Magnetic Resonance Imaging (MRI) is a commonly used medical imaging method with the advantage of being radiation-free. MRI can also obtain parameters such as the signal and signal-to-noise ratio of each vertebral tissue to calculate the M-score, which is used to assess bone quality. Currently, the M-score uses the tissue signals of the L1-L4 area of ​​the human body as a reference to quantitatively assess the risk of osteoporosis or fractures. However, due to differences in instruments, scanning parameters, and the varying content of various tissues in different human bodies, there is a lack of a standard reference when using the signal-to-noise ratio to characterize tissue characteristics and perform bone quality assessments. This lack of standardization makes the M-Score unreliable, limiting its practical application. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide a tissue property evaluation system based on magnetic resonance imaging, which can provide a standard reference for quantitative evaluation of tissue properties.

[0005] To achieve the above-mentioned objectives, the present invention proposes the following technical solutions: a tissue property assessment system based on magnetic resonance imaging, comprising: a radio frequency transmitting module, a magnetic resonance imaging phantom, a radio frequency coil, a radio frequency receiving module, and a data processing module; the radio frequency transmitting module is used to transmit radio frequency signals; the magnetic resonance imaging phantom is placed below the subject's lumbar spine and is used to perform quantitative detection of T1WI sequences and T2WI sequences; the radio frequency coil is set on the magnetic resonance imaging phantom and is used to transmit radio frequency signals passing through the magnetic resonance imaging phantom; the radio frequency receiving module is used to receive the radio frequency signals transmitted by the radio frequency coil; and the data processing module is used to analyze the signal-to-noise ratio of the radio frequency signals received by the radio frequency receiving module to obtain tissue property assessment results.

[0006] Furthermore, the magnetic resonance imaging phantom includes: a box, a plurality of tubular components and partitions, wherein the plurality of tubular components are arranged in the box, and the tubular components are filled with air, water, fat and bone mineral; and partitions are arranged between the tubular components.

[0007] Furthermore, the box body is triangular, and two corners corresponding to the bottom edge of the wedge body are rounded. The triangular box body is composed of a wedge body and wedge-shaped side panels, and the wedge-shaped side panels are bonded to the left and right sides of the wedge body.

[0008] Further, both ends of the tubular component are sealed with high-pressure glands, and suction foam material is arranged inside the high-pressure gland.

[0009] Furthermore, the number of the tubular components is 4, the first tubular component is filled with air, the second tubular component is filled with water, the third tubular component is filled with water and fat, and the fourth tubular component is filled with bone mineral.

[0010] Furthermore, tissue characteristics evaluation included bone density and bone fraction.

[0011] Furthermore, the bone density is calculated by calculating the average signal of each cone bone at the lumbar vertebrae and dividing it by the noise to obtain a first signal-to-noise ratio; dividing the signal of the bone mineral-filled tubular component by the noise to obtain a second signal-to-noise ratio; and dividing the first signal-to-noise ratio by the second signal-to-noise ratio to obtain a bone density signal.

[0012] Furthermore, the bone score is calculated by calculating the fat score and the water score; and subtracting the fat score and the water score from the full score to obtain the bone score in the vertebral bone.

[0013] Furthermore, the fat fraction is calculated by dividing the average signal of each cone bone at the lumbar vertebra by the signal of the tubular component filled with water to obtain the fat mass in the vertebral bone mass VBQ fat ; Fat fraction is equal to the fat mass in vertebral bone mass VBQ fat Divide by Q and multiply by 10; Q is equal to the signal filling the fat tubular component divided by the signal filling the water tubular component.

[0014] Furthermore, the water fraction is calculated by dividing the average signal of each cone bone at the lumbar vertebra by the signal of the fat-filled tubular component to obtain the water mass in the vertebral bone mass VBQ water ; Fat fraction is equal to the fat mass in vertebral bone mass VBQ water Divide by Y and multiply by 10; Y equals the signal filling the water tubular part divided by the signal filling the fat tubular part.

[0015] By adopting the above technical solution, the present invention has the following advantages: Utilizing the principle that different MRI sequences produce different signal intensities for water, oil, bone mineral, and air tubes, the MRI phantom of the present invention can simply, quickly, accurately, and quantitatively normalize the fat, water, and bone fractions in vertebral bones. This provides more accurate, optimized, and consistent results for bone quality testing, enabling quantitative assessment of bone quality and evaluation of bone quality or fracture risk. By introducing the MRI phantom, the present invention can address signal variations caused by different instrument types or varying user constitutions, providing a unified standard for MRI testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of a tissue characteristic evaluation system according to an embodiment of the present invention;

[0017] Figure 2 is a schematic structural diagram of a magnetic resonance imaging phantom according to an embodiment of the present invention;

[0018] Figure 3 is a side view of a magnetic resonance imaging phantom according to an embodiment of the present invention;

[0019] Figure 4 is a schematic structural diagram of a tubular component in one embodiment of the present invention;

[0020] Figure 5 is a diagram showing the placement of a magnetic resonance imaging phantom in one embodiment of the present invention;

[0021] Figure 6 is an image collected by a tissue characteristic evaluation system in one embodiment of the present invention, Figure 6 (a) is a T1-weighted image used to calculate fat fraction; Figure 6 (b) is a T2-weighted image used to calculate the water fraction.

[0022] Reference numerals:

[0023] 1- box body; 11- wedge-shaped body; 12- wedge-shaped side panel; 2- tubular component; 21- high-pressure gland; 22- suction foam material; 3- partition. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical direction of the present invention, the present invention will be described in detail through specific embodiments. However, it should be understood that the provision of specific embodiments is only for a better understanding of the present invention and they should not be construed as limitations of the present invention. In the description of the present invention, it should be understood that the terms used are for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "assembly," "disposition," and "connection" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0027] To address the bias in bone quality assessment results caused by inconsistent bone quality assessment standards in the prior art, the present invention introduces a magnetic resonance imaging (MRI) phantom. Its primary function is to analyze and correct MRI results. By filling different tubular components with different standard materials, the signal changes produced by hydrogen protons from these materials in the microenvironment synchronize with changes in the proton resonance frequency of molecules such as water, fat, and bone in tissue. Therefore, the signal-to-noise ratio of these standard materials can be used to correct and quantitatively assess the water, fat, and bone content in tissues, providing a standard reference for MRI results and preventing the impact of individual differences in subjects, differences in MRI equipment, and differences in scanning parameters on the phantom's assessment results. The tissue quality assessment system of the present invention determines the water and fat fractions in vertebral bone based on MRI signals, thereby obtaining the bone fraction in the vertebral bone. Bone tissue characteristics are then assessed based on the bone fraction. This system provides more accurate, optimized, and consistent results for bone quality assessment, enabling quantitative assessment of bone quality and osteoporotic fracture risk assessment. The present invention is described in detail below through examples.

[0028] Example

[0029] In this embodiment, the tissue characteristic evaluation system, such as Figure 1 As shown, it includes: a radio frequency transmitting module, a magnetic resonance imaging phantom, a radio frequency coil, a radio frequency receiving module and a data processing module;

[0030] A radio frequency transmitting module, used for transmitting radio frequency signals;

[0031] MRI phantoms, such as Figure 2 、 3 As shown, Figure 2 and Figure 3They are respectively a front structural diagram and a side structural diagram of a magnetic resonance imaging phantom according to an embodiment of the present invention. The magnetic resonance imaging phantom in this embodiment is as follows: Figure 1 and Figure 2 As shown, it includes: a box body 1, several tubular components 2 and a partition 3,

[0032] The box body 1 is triangular in shape, and the two corners corresponding to the bottom edge of the wedge-shaped body 11 are rounded. The angle between the two bottom surfaces is between 20° and 25°. The triangular box body 1 is composed of the wedge-shaped body 11 and the wedge-shaped side panels 12, and the wedge-shaped side panels 12 are bonded to the left and right sides of the wedge-shaped body 11. The top wedge angle is 130° to 140°, and the distance from the highest point to the bottom is 30 to 35 mm. The length of the bottom surface is about 155 to 160 mm, and the width is about 135 to 140 mm. The triangular box body 1 can be a rigid plastic body and needs to have a certain strength to withstand the weight of a person lying on it. In order to prevent oil leakage, special glue can be applied to the surface of the triangular box body 1.

[0033] Figure 4 FIG. 1 is a schematic structural diagram of a tubular component 2 according to an embodiment of the present invention. Figure 3 As shown, several tubular components 2 are symmetrically and parallelly arranged within the housing 1, with the distance between any two tubular components 2 being equal. The length of each tubular component 2 is less than the width of the housing 1. In this embodiment, the tubular components 2 have an outer diameter of 11-13 mm and a length of 95-100 mm. The tubular components 2 are filled with air, water, fat, and bone mineral. These three components are distributed continuously within the tubular lumen in varying proportions, with the top portion of the tubular component 2 filled with air, followed by water and fat, and the bottom portion filled with bone mineral. For example, in this embodiment, the volume of material filled within the tubular component 2, from "top" to "bottom," is 0 ml for air, 10 ml for water, 10 ml for fat, and 5-10 mg for bone mineral. The water in the tubular component 2 is deionized water, the fat is coconut oil, and the bone mineral is calcium hydroxyapatite.

[0034] Both ends of the tubular component 2 are sealed with a high-pressure gland 21, within which a suction foam material 22 is disposed. The number of tubular components 2 is preferably an even number greater than two, preferably four in this embodiment. When there are four tubular components, the first tubular component is filled with air, the second with water, the third with water-fat, and the fourth with bone mineral. However, this is not a limitation and can be adjusted as needed by those skilled in the art.

[0035] Partitions 3 are provided between the tubular components 2 , and the material of the partitions 3 is preferably plastic, such as PVC.

[0036] The magnetic resonance imaging phantom is placed horizontally below the subject's lumbar spine. Its manufacturing method is as follows: first, a hard plastic is bent on both sides to form a wedge-shaped body 11. The wedge is not uniform, and one side of the wedge is longer than the other. Four tubular components 2 are placed on the bottom edge of the wedge, and the tubular components 2 are filled with water, fat, and bone mineral, respectively. A partition 3 is placed between each tubular component 2, and the three partitions 3 are bonded to the bottom plate of the wedge 11. The suction cover and high-pressure pressure cover 21 are closed, and a syringe is inserted into the suction cover to expel air bubbles. Two wedge-shaped side panels 12 are bonded to the left and right sides of the wedge 11, and the wedging point at the top is finally glued. Those skilled in the art should understand that the manufacturing method here is only a schematic illustration and is not the only method for manufacturing the imaging phantom in this application. More advanced and more industrialized methods can also be used for manufacturing.

[0037] like Figure 5 As shown, an MRI phantom was placed below the subject's lumbar spine. L3, L4, and L5 are used to represent the lumbar vertebrae. The MRI phantom is used to quantitatively measure T1WI and T2WI sequences. The T1WI sequence is a signal used in MRI to represent spin-lattice relaxation. The T1 value is the time required for the longitudinal magnetization to return to 63% of its equilibrium state. This sequence is used to detect bone marrow changes. The T2WI sequence is a signal used in MRI to represent spin-spin relaxation. The T2 value is the time required for the transverse magnetization to decay to 37% of its maximum value. This sequence is used to detect changes in bone marrow cell density.

[0038] The radio frequency coil is arranged on the magnetic resonance imaging phantom and is used for transmitting a radio frequency signal through the magnetic resonance imaging phantom;

[0039] A radio frequency receiving module, used to receive radio frequency signals transmitted by the radio frequency coil;

[0040] The data processing module is used to analyze the signal-to-noise ratio of the radio frequency signal received by the radio frequency receiving module to obtain the tissue characteristic evaluation results. At the same time, the proton density weighted image (PDWI) can be used to detect the cortical bone and cancellous bone information to calculate the bone density. Proton density weighted images are T1-weighted images and T2-weighted images, such as Figure 6 As shown, Figure 6 (a) is a T1-weighted image used to calculate fat fraction; Figure 6 (b) is a T2-weighted image used to calculate the water fraction. Tissue property evaluation includes bone density calculation and bone fraction calculation.

[0041] The bone density was calculated by calculating the average signal of each cone bone at the lumbar spine and dividing it by the noise to obtain the first signal-to-noise ratio;

[0042] Calculate the signal-to-noise ratio of the average lumbar vertebrae signal:

[0043] SNR1=[(SI L1 +SI L2 +SI L3 +SI L4 +SI L5 ) / 5] / SD

[0044] dividing the signal of the bone mineral filled tubular member by the noise to obtain a second signal-to-noise ratio;

[0045] SNR2=SI ca / SD

[0046] Among them, SI ca It is a signal to fill the tubular component of bone mineral;

[0047] The first signal-to-noise ratio is divided by the second signal-to-noise ratio to obtain a bone density signal.

[0048] Bone density BMD = SNR1 / SNR2.

[0049] Here, the noise is obtained by filling the air-filled tubular component with a signal.

[0050] Because the signal-to-noise ratio (SNR) generated by hydrogen protons (H-protons) in different materials in their microenvironments varies depending on the resonant frequency of protons in molecules such as water and fat, and the precession frequency of H-protons in water is higher than that in fat, vertebral bone density can be assessed by analyzing the changes in the SNR signal caused by differences in precession frequency using an MRI phantom. The specific method is as follows:

[0051] Among them, SI L1 To SI L1 are the radio frequency signals of the first to fifth vertebrae, and SD is the noise.

[0052] for Figure 6 The T1-weighted image in (a) can be obtained:

[0053] VBQ fat =[(SI L1 +SI L2 +SI L3 +SI L4 +SI L5 ) / 5] / SI water

[0054] VBQ fat =P

[0055] Q=SI fat / SI water

[0056] F-score = P / Q × 10.

[0057] Among them, SI fat and SI water The RF signals of fat and water in the phantom, VBQ fat is the fat mass in the vertebral bone mass, and F-score is the fat fraction in the vertebral bone.

[0058] for Figure 6 The T2-weighted image in (b) can be obtained:

[0059] VBQ water =[(SI L1 +SI L2 +SI L3 +SI L4 +SI L5 ) / 5] / SI fat

[0060] VBQ water =X

[0061] Y=SI water / SI fat

[0062] W-score = X / Y × 10.

[0063] Among them, VBQ water is the mass of water in vertebral bone mass, and W-score is the water fraction in vertebral bone.

[0064] Assuming the spine is composed of three tissue types: fat, water, and bone (as well as other substances in the microenvironment), each of which affects the image signal-to-noise ratio (SNR). Therefore, the vertebral bone score can be obtained by subtracting the fat score and water score from the full score. This score is then used to quantitatively evaluate bone quality. In this example, the full score is assumed to be 100.

[0065] F-score+W-score+B-score=100

[0066] B-score=100-(F-score+W-score)

[0067] Among them, B-score is the bone score in the vertebral bone.

[0068] Ultimately, the system in this embodiment provides more accurate, optimized, and consistent results for bone quality detection by calculating fat, water, and bone fractions, which can be used to quantitatively assess bone status and evaluate the risk of osteoporotic fractures.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be included within the scope of protection of the claims of the present invention. The above content is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A tissue property evaluation system based on magnetic resonance imaging, characterized in that: include: Radio frequency transmitting module, magnetic resonance imaging phantom, radio frequency coil, radio frequency receiving module and data processing module; A radio frequency transmitting module, used for transmitting radio frequency signals; The magnetic resonance imaging phantom is placed below the subject's lumbar spine for quantitative detection of T1WI sequences and T2WI sequences; The radio frequency coil is arranged on the magnetic resonance imaging phantom and is used to transmit a radio frequency signal passing through the magnetic resonance imaging phantom; The radio frequency receiving module is used to receive the radio frequency signal transmitted by the radio frequency coil; The data processing module is used to analyze the signal-to-noise ratio of the radio frequency signal received by the radio frequency receiving module, thereby obtaining a tissue characteristic evaluation result; The magnetic resonance imaging phantom comprises: a box, a plurality of tubular components and a partition, wherein the plurality of tubular components are arranged in the box, and the tubular components are filled with air, water, fat and bone mineral; and a partition is arranged between each of the tubular components; The tissue property evaluation includes bone density and bone score; The bone density is calculated as follows: Calculate the average signal of each vertebral bone at the lumbar spine and divide it by the noise to obtain the first signal-to-noise ratio; dividing the signal of the bone mineral filled tubular member by the noise to obtain a second signal-to-noise ratio; Dividing the first signal-to-noise ratio by the second signal-to-noise ratio to obtain a bone density signal; Calculation method of the bone score The method comprises the following steps: calculating the fat fraction and the water fraction; subtracting the fat fraction and the water fraction from the full score to obtain the bone fraction in the vertebral body; The fat fraction is calculated by dividing the average signal of each vertebral bone at the lumbar spine by the signal of the tubular component filled with water to obtain the fat mass VBQ in the vertebral bone mass. fat ; The fat fraction is equal to the fat mass in the vertebral bone mass VBQ fat Divide by Q, multiply by 10; Q is equal to the signal of the fat-filled tubular component divided by the signal of the water-filled tubular component; The water fraction is calculated by dividing the average signal of each vertebral bone at the lumbar spine by the signal of the tubular component filled with fat to obtain the water mass VBQ in the vertebral bone mass. water ; The fat fraction is equal to the fat mass in the vertebral bone mass VBQ water Divide by Y, multiply by 10; Y is equal to the signal of the water-filled tubular component divided by the signal of the fat-filled tubular component.

2. The tissue characteristic evaluation system according to claim 1, wherein: The box body is triangular and consists of a wedge-shaped body and wedge-shaped side panels. The two corners corresponding to the bottom edge of the wedge-shaped body are rounded, and the wedge-shaped side panels are bonded to the left and right sides of the wedge-shaped body.

3. The tissue characteristic evaluation system according to claim 2, wherein: Both ends of the tubular component are sealed with high-pressure glands, and a suction foam material is arranged inside the high-pressure gland.

4. The tissue characteristic evaluation system according to claim 2, wherein: The number of the tubular components is 4. The first tubular component is filled with air, the second tubular component is filled with water, the third tubular component is filled with water and fat, and the fourth tubular component is filled with bone mineral.

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