A nuclear magnetic calibration phantom for bone density measurement

Abstract

The present invention relates to the technical field of bone density measurement, and in particular to a nuclear magnetic calibration phantom for bone density measurement, comprising a shell and a plug-in arranged inside the shell; the shell is filled with nuclear magnetic solution; the plug-in is a three-dimensional reticular structure, made of a material with no magnetic resonance signal but CT signal; the shell is made of a material with no magnetic resonance signal and no CT signal. The material of the plug-in is one or a combination of hydroxyapatite, calcium phosphate, calcium sulfate, and bioglass, and the density of the plug-in is 20-200 mg / cm3. This nuclear magnetic calibration phantom is used for the comparison of magnetic resonance bone density tests. The magnetic resonance bone density data of the plug-in is first calibrated using the results of the CT bone density test to ensure the accuracy of the comparison of the magnetic resonance bone density test results; it has the advantages of simple structure and convenient operation.

Description

Technical Field

[0001] The present invention relates to the technical field of bone density measurement, and in particular to a nuclear magnetic field calibration phantom for bone density measurement. Background Art

[0002] Bone density stands for bone mineral density, which is an important indicator of bone strength and is expressed in mg / cm³. Osteoporosis is a systemic bone disease caused by a variety of reasons. Its main characteristics are decreased bone density and bone quality, damage to bone microstructure, increased bone brittleness, and a state that is prone to fractures.

[0003] With the aging of the population and the increasing number of bone diseases such as osteoporosis, higher requirements are placed on human bone density testing. At present, the traditional methods for measuring bone density mainly include X-ray, ultrasound, quantitative CT, etc. Quantitative CT and X-ray methods have the side effect of radiation, and ultrasound methods have the defect of low accuracy in measuring bone density.

[0004] Magnetic resonance imaging technology has the advantages of no radiation, high resolution, good repeatability, etc., and has broad application prospects in bone density measurement. Therefore, designing a nuclear magnetic resonance calibration phantom for bone density measurement has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0005] The technical problem that the present invention intends to solve is to provide a nuclear magnetic resonance calibration phantom for bone density measurement in view of the above shortcomings. The nuclear magnetic resonance calibration phantom is used for the comparison of magnetic resonance bone density tests. The magnetic resonance bone density data of the plug-in is first calibrated using the results of the CT bone density test to ensure the accuracy of the comparison of the magnetic resonance bone density examination results. It has the advantages of simple structure and easy operation.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A nuclear magnetic resonance calibration phantom for bone density measurement, characterized in that it comprises a shell and an insert arranged inside the shell; the shell is filled with a nuclear magnetic solution; the insert is a three-dimensional mesh structure, and is made of a material with no magnetic resonance signal but CT signal; the shell is made of a material with no magnetic resonance signal and no CT signal.

[0008] As an improvement, the material of the plug-in is one or a combination of hydroxyapatite, calcium phosphate, calcium sulfate, and bioglass, and the density of the plug-in is 20-200 mg / cm³.

[0009] As an improvement, a plurality of plug-ins are provided inside the shell, and different plug-ins have different densities.

[0010] As an improvement, the material of the shell is polymethyl methacrylate, polyethylene terephthalate, or polycarbonate, or a combination of the two or more thereof.

[0011] As an improvement, the nuclear magnetic solution is prepared from water and copper sulfate pentahydrate, and is prepared by adding 0.9 to 1.2 grams of copper sulfate pentahydrate to 1 liter of water.

[0012] As an improvement, the nuclear magnetic solution is prepared by adding 1 gram of copper sulfate pentahydrate to 1 liter of water.

[0013] As an improvement, the shell is a cylindrical shell, a through hole is provided on the shell, and a plug body is installed on the through hole.

[0014] The present invention adopts the above technical solution, and has the following advantages compared with the prior art:

[0015] The present invention discloses a nuclear magnetic calibration phantom for bone density measurement, which can compare and determine the results of magnetic resonance bone density examination, so that magnetic resonance technology can be applied to bone density examination. The nuclear magnetic calibration phantom is first calibrated by CT scanning to determine the accuracy of the nuclear magnetic calibration phantom, and then used for comparison of magnetic resonance bone density test to ensure the accuracy of the comparison result. Thus, magnetic resonance bone density examination can be promoted and applied, which can not only improve the accuracy of magnetic resonance bone density test, but also solve the problem of side effects such as radiation caused by traditional test, and can also improve the accuracy of the examination results.

[0016] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional schematic diagram of a nuclear magnetic calibration phantom for bone density measurement according to the present invention;

[0018] Figure 2 It is a structural schematic diagram of a nuclear magnetic calibration phantom for bone density measurement according to the present invention;

[0019] Wherein: 1-shell, 2-plug-in, 3-NMR solution, 4-through hole, 5-plug body. DETAILED DESCRIPTION

[0020] Example

[0021] Trabeculae are the extensions of the cortical bone in the cancellous bone, that is, the trabeculae are connected to the cortical bone and present an irregular three-dimensional network structure in the bone marrow cavity, like a loofah or sponge, which plays a role in supporting hematopoietic tissue.

[0022] The principle of using magnetic resonance to measure bone density: bone density is assessed by using the correlation between magnetic resonance signals and the content of hydrogen protons in bone. By measuring the signal intensity of different tissues in the magnetic field, the density and structure of bone can be indirectly reflected.

[0023] like Figure 1 and Figure 2 As shown together, a nuclear magnetic resonance calibration phantom for bone density measurement includes a shell 1 and an insert 2 arranged inside the shell 1, and the shell 1 is filled with a nuclear magnetic solution 3. The insert 2 is a trabecular bone-like structure, presenting a uniform, three-dimensional reticular structure, and is made of a material with no magnetic resonance signal but CT signal.

[0024] The shell 1 is a cylindrical shell, and a through hole 4 is provided on the shell 1, and a plug 5 is installed on the through hole 4. The shell 1 is made of a material without magnetic resonance signals and CT signals. The material of the shell 1 is selected from one or a combination of polymethyl methacrylate, polyethylene terephthalate, and polycarbonate. In this embodiment, the preferred material of the shell 1 is polymethyl methacrylate.

[0025] The material of the plug-in 2 is one or a combination of hydroxyapatite, calcium phosphate, calcium sulfate, and bioglass, and the density of the plug-in 2 is 20-200 mg / cm³. A plurality of plug-ins 2 are provided inside the housing 1, and the densities of different plug-ins 2 are different. In this embodiment, preferably, the material of the plug-in 2 is hydroxyapatite, and three plug-ins 2 are provided inside the housing 1, and the densities of the three plug-ins 2 are 80 mg / cm³, 120 mg / cm³, and 200 mg / cm³, respectively.

[0026] The nuclear magnetic solution 3 is prepared from water and copper sulfate pentahydrate, and is prepared by adding 0.9 to 1.2 grams of copper sulfate pentahydrate to 1 liter of water. In this embodiment, preferably, the nuclear magnetic solution 3 is prepared by adding 1 gram of copper sulfate pentahydrate to 1 liter of water.

[0027] The nuclear magnetic resonance calibration phantom for bone density measurement of the present invention is preferably made by 3D printing technology. Then, the prepared nuclear magnetic resonance solution 3 is filled into the housing 1 through the through hole 4, and the through hole 4 is blocked with a plug 5.

[0028] The use process of the nuclear magnetic resonance calibration phantom for bone density measurement of the present invention is as follows:

[0029] Step 1: Scan the NMR calibration phantom with a CT machine to determine and record the accurate content of hydroxyapatite in different plug-ins and calibrate the density of each plug-in 2.

[0030] Step 2: Place the phantom in the imaging area of ​​the magnetic resonance device, perform magnetic resonance imaging scanning, use the pattern corresponding to each plug-in 2 as a standard pattern, and mark the density corresponding to each standard pattern. For example, in this example, the densities of the three plug-ins 2 are 80 mg / cm³, 120 mg / cm³, and 200 mg / cm³, respectively.

[0031] Step three, use the magnetic resonance human bone density scanning system to perform magnetic resonance imaging scans on human parts, select the bone mineral content image within the imaging ROI, compare the distribution density of trabeculae in the image with the standard pattern in step two, and determine the bone mineral content analysis results of the test part.

[0032] In this example, after comparison, the test results may be: less than 80mg / cm³, between 80 and 120mg / cm³ or 120-200mg / cm³, or higher than 200mg / cm³. Taking the lumbar spine bone density value in the prior art as an example, when the measured bone density is lower than 80mg / cm³, it is diagnosed as osteoporosis. When the measured bone density is between 80 and 120mg / cm³, it is diagnosed as low bone mass. When the measured bone density is higher than 120mg / cm³, it is diagnosed as normal.

[0033] In actual application, multiple plug-ins 2 can be provided inside the shell 1 according to needs, and the multiple plug-ins 2 adopt different density values, such as 60mg / cm³, 70mg / cm³, 80mg / cm³, 90mg / cm³, 100mg / cm³, 110mg / cm³, and 120mg / cm³; to further optimize the accuracy of the test results.

[0034] The nuclear magnetic resonance calibration phantom of the present invention can set the density of multiple plug-ins 2 according to the normal range of bone density of people of different age groups, image the scanned part through magnetic resonance scanning, select the imaging area of ​​interest, and calculate the bone density value of the measured part through magnetic resonance bone density testing software. The obtained bone density value is compared with the calibration phantom to judge the bone density of the measured part.

[0035] In summary, the nuclear magnetic resonance calibration phantom for bone density measurement of the present invention can compare and determine the results of magnetic resonance bone density examination, so that magnetic resonance technology can be applied to bone density examination. The nuclear magnetic resonance calibration phantom for bone density measurement is first calibrated by CT scanning to determine the accuracy of the phantom, and then used for comparison of magnetic resonance bone density test to ensure the accuracy of the comparison result.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A nuclear magnetic resonance calibration phantom for bone density measurement, characterized in that: It comprises a shell (1) and a plug-in unit (2) arranged inside the shell (1); the shell (1) is filled with a nuclear magnetic solution (3); The plug-in (2) is a three-dimensional mesh structure, and is made of a material having no magnetic resonance signal but having CT signal; The housing (1) is made of a material having no magnetic resonance signal and no CT signal; The method for using the nuclear magnetic field calibration phantom for bone density measurement includes: Step 1: Scanning and testing the NMR calibration phantom with a CT machine to determine and record the accurate content of hydroxyapatite in different plug-ins and calibrate the density of each plug-in (2); Step 2, placing the phantom in an imaging area of ​​a magnetic resonance device, performing a magnetic resonance imaging scan, taking the pattern corresponding to each plug-in (2) as a standard pattern, and marking the density corresponding to each standard pattern; Step three, use the magnetic resonance human bone density scanning system to perform magnetic resonance imaging scans on human parts, select the bone mineral content image within the imaging ROI, and compare the distribution density of trabeculae in the image with the standard pattern in step two to determine the analysis result of the bone mineral content in the test part.

2. The nuclear magnetic resonance calibration phantom for bone density measurement according to claim 1, characterized in that: The material of the plug-in (2) is hydroxyapatite, calcium phosphate, calcium sulfate, or bioglass, and the density of the plug-in (2) is 20-200 mg / cm3.

3. The nuclear magnetic resonance calibration phantom for bone density measurement according to claim 2, characterized in that: A plurality of plug-ins (2) are arranged inside the housing (1), and different plug-ins (2) have different densities.

4. The nuclear magnetic resonance calibration phantom for bone density measurement according to claim 1, characterized in that: The material of the shell (1) is polymethyl methacrylate, polyethylene terephthalate, or polycarbonate.

5. The nuclear magnetic resonance calibration phantom for bone density measurement according to any one of claims 1 to 4, characterized in that: The nuclear magnetic resonance solution (3) is prepared from water and copper sulfate pentahydrate, and is prepared by adding 0.9 to 1.2 grams of copper sulfate pentahydrate to 1 liter of water.

6. The nuclear magnetic resonance calibration phantom for bone density measurement according to claim 5, characterized in that: The NMR solution (3) is prepared by adding 1 gram of copper sulfate pentahydrate to 1 liter of water.

7. The nuclear magnetic resonance calibration phantom for bone density measurement according to any one of claims 1 to 4, characterized in that: The housing (1) is a cylindrical housing, a through hole (4) is provided on the housing (1), and a plug body (5) is mounted on the through hole (4).

Images