Magnetic field homogeneity correction tool

Abstract

To provide a magnetic field homogeneity correction tool which facilitates adjusting a shape according to the body of a subject.SOLUTION: A magnetic field homogeneity correction tool (1) comprises: a first bag (10) which has resin granular material encapsulated internally and whose predetermined first surface is in close contact with a subject (5); and a second bag (11) which has granular material encapsulated internally and is abutted onto a second surface different from the first surface of the first bag (10) to be disposed between the second surface and the subject (5).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a magnetic field homogeneity corrector. [Background technology]

[0002] Patent Document 1 discloses a magnetic field distortion removal device for use in MRI (Magnetic Resonance Imaging) devices, which comprises a cushion body that has a gas barrier property and contains air inside, and that contains an aqueous solution containing iron or cobalt-based material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5212026 Summary of the Invention [Problem to be solved by the invention]

[0004] However, subjects have a wide range of body sizes, and there is a need for a magnetic field homogeneity corrector whose shape can be easily adjusted to fit the subject's body. One aspect of the present disclosure aims to provide a magnetic field homogeneity corrector whose shape can be easily adjusted to fit the subject's body. [Means for solving the problem]

[0005] In order to solve the above problems, a magnetic field homogeneity corrector according to one embodiment of the present disclosure is a magnetic field homogeneity corrector that reduces artifacts caused by the difference between the magnetic susceptibility of a subject's tissue and the magnetic susceptibility of air during an MRI examination, and includes: a first bag body having resin granules sealed inside, the first bag body having a predetermined first surface that is brought into close contact with the subject; and a second bag body having the granules sealed inside, the second bag body being placed between the second surface and the subject by being abutted against a second surface different from the first surface of the first bag body. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, the magnetic field homogeneity corrector can be easily adjusted in shape to fit the subject's body. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a conceptual diagram illustrating the use of a magnetic field homogeneity corrector according to a first embodiment of the present disclosure. [Figure 2] FIG. 10 is a diagram showing an example of an inspection image in which an artifact occurs. [Figure 3] 1A and 1B are diagrams illustrating an example of a first bag body according to the first embodiment of the present disclosure. [Figure 4] 3A and 3B are diagrams illustrating an example of a second bag body according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram showing an example of a first bag body according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Embodiment 1] FIG. 1 is a conceptual diagram illustrating the use of a magnetic field homogeneity corrector according to a first embodiment of the present disclosure. In FIG. 1, a subject 5 of an MRI examination lies on a bed of an MRI apparatus 3. In an MRI examination image, artifacts may occur near the boundary between objects with significantly different magnetic susceptibility. Because the magnetic susceptibility of the tissue of the subject 5 is significantly different from that of air, it is preferable to minimize the gap between the subject 5 and the coil 30 of the MRI apparatus 3. However, a gap is likely to occur between the neck 50 and the coil 30, making artifacts more likely to occur.

[0009] Fig. 2 is a diagram showing an example of an examination image in which an artifact has occurred. In the examination image shown in Fig. 2, an artifact has occurred in the neck peripheral region 70, making the image of the neck unclear. The magnetic field homogeneity corrector 1 reduces such artifacts that occur in MRI examinations due to the difference in magnetic susceptibility between the subject's tissue and the air.

[0010] The magnetic field homogeneity corrector 1 shown in FIG. 1 includes a first bag 10 and a second bag 11. The first bag 10 and the second bag 11 are bags in which resin granules are enclosed. The resin granules are, for example, polyacetal beads. The magnetic susceptibility of the resin granules is closer to that of water than to that of air.

[0011] In FIG. 1 , the first bag 10 has an annular shape in the state of use shown in FIG. 1 , with the inner circumferential surface of the annular shape in close contact with the neck 50 of the subject 5, and a portion of the surface that is not in close contact with the neck 50 facing the lower jaw 51 of the subject 5. Because the size of the neck 50 of the subject 5 varies, when the first bag 10 is brought into close contact with the neck 50 of the subject 5, a gap may be formed between the first bag 10 and the lower jaw 51 of the subject 5. The second bag 11 abuts against the surface of the first bag 10 facing the lower jaw 51, and is disposed between the first bag 10 and the lower jaw 51 of the subject 5. The magnetic field homogeneity corrector 1 reduces the boundary between the neck 50 and air, thereby reducing artifacts.

[0012] FIG. 3 is a diagram showing an example of a first bag according to the first embodiment of the present disclosure. Reference numeral 1000 in FIG. 3 is an example of a rear view of the first bag 10. Reference numeral 1001 is an example of a plan view of the first bag 10. Reference numeral 1002 is an example of a front view of the first bag 10. FIG. 4 is a diagram showing an example of a second bag according to the first embodiment of the present disclosure. Reference numeral 2000 in FIG. 4 is an example of a front view of the second bag 11. Reference numeral 2001 in FIG. 4 is an example of a bottom view of the second bag 11.

[0013] As indicated by reference numeral 1000 in Fig. 3, the first bag body 10 can have a rod-like shape when not in use. A hook-and-loop fastener 25 is provided on the back surface 21 of the first bag body 10 on the side of the first end 90 of the rod shape. As indicated by reference numeral 1002 in Fig. 3, a hook-and-loop fastener 24 is provided on the front surface 20 of the first bag body 10 on the side of the second end 91 of the rod shape.

[0014] The hook-and-loop fasteners 24 and 25 are, for example, Velcro (registered trademark), one being a male member and the other a female member. The first bag body 10 has sufficient stretchability to allow the hook-and-loop fastener 24 on the first end 90 side of the back surface 21 to be joined to the hook-and-loop fastener 25 on the second end 91 side of the front surface 20. When the first bag body 10 is in use, the hook-and-loop fastener 24 on the first end 90 side of the back surface 21 is joined to the hook-and-loop fastener 25 on the second end 91 side of the front surface 20, thereby connecting the first end 90 to the second end 91 to form a ring shape. The back surface 21 of the first bag body 10 is an example of a first surface, and forms the inner circumferential surface of the ring-shaped first bag body 10, which comes into close contact with the neck 50 of the subject 5.

[0015] The length of hook and loop fastener 24 in the longitudinal direction of back surface 21 is longer than hook and loop fastener 25. By adjusting the position where hook and loop fastener 25 joins to hook and loop fastener 24, the length of the inner circumference when first bag body 10 forms a ring can be adjusted to fit neck 50 of subject 5.

[0016] The first bag body 10 can have a rod-like shape when not in use, so even if it becomes dirty with sweat or the like of the subject 5, the dirt can be easily wiped off. The back surface 21 of the first bag body 10, which is brought into close contact with the neck 50 of the subject 5, is preferably made of a water-repellent material. By making the back surface 21 of a water-repellent material, dirt such as sweat from the subject 5 is less likely to adhere to it.

[0017] As indicated by reference numeral 1001 in Fig. 3, a hook-and-loop fastener 23 is provided on the upper surface 22 of the first bag 10 on the rod-shaped second end 91 side. Furthermore, as indicated by reference numeral 2001 in Fig. 4, a hook-and-loop fastener 28 is provided on the lower surface 27 of the second bag 11. The upper surface 22 of the first bag 10 is an example of the second surface, and is the surface facing the lower jaw of the subject 5. The hook-and-loop fasteners 23 and 28 are, for example, Magic Tape (registered trademark), one of which is a male member and the other a female member. By joining the hook-and-loop fastener 28 of the second bag 11 to the hook-and-loop fastener 23 of the first bag 10, the lower surface 27 of the second bag 11 abuts against the upper surface 22 of the first bag 10.

[0018] As shown by reference numeral 1001 in Fig. 3, an inner bag 12 in which resin granules are enclosed is housed in the first bag 10. The first bag 10 does not directly enclose the resin granules, but houses the inner bag 12 in which the resin granules are enclosed, thereby reducing the possibility that the MRI device 3 will be contaminated with the resin granules when the first bag 10 is damaged.

[0019] The first bag body 10 and the second bag body 11 are prepared in a plurality of types with different sizes. The user can use a combination of the first bag body 10 and the second bag body 11 of an appropriate size to match the size of the neck 50 of the subject 5. For example, the first bag body 10 is prepared with different lengths L1 in the short direction of the back surface 21 of the first bag body 10 as shown by reference numeral 1000 in FIG. 3. For example, the second bag body 11 is prepared with different lengths L2 in the short direction of the front surface 26 of the second bag body 11 as shown by reference numeral 2000 in FIG. 4.

[0020] If the particle size of the resin granules is too large, gaps will form between the granules, reducing the artifact reduction effect. The particle size of the resin granules is determined taking into consideration the artifact reduction effect and the processing costs for crushing, etc.

[0021] [Embodiment 2] A second embodiment of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the first embodiment, and the description thereof will not be repeated.

[0022] A magnetic field homogeneity corrector 1 according to a second embodiment of the present disclosure differs from that according to the first embodiment in the shape of the first bag 10. FIG. 5 is a diagram showing an example of a first bag according to the second embodiment of the present disclosure. Reference numeral 3000 in FIG. 5 denotes an example of a plan view of the first bag 10 according to the second embodiment. Reference numeral 3001 denotes an example of a bottom view of the first bag 10 according to the second embodiment.

[0023] As indicated by reference numeral 3000 in Fig. 5, the first bag body 10 according to the second embodiment can have an arc-like shape in a plan view when not in use. The first bag body 10 according to the second embodiment has a hook-and-loop fastener 25 provided on the first end 90 side of the upper surface 100, and a hook-and-loop fastener 23 provided on the upper surface 100 at a position that does not overlap with the hook-and-loop fastener 25. In the first bag body 10 according to the second embodiment, the upper surface 100 is an example of the second surface.

[0024] As indicated by reference numeral 3001 in Fig. 5, the first bag body 10 according to the second embodiment is provided with a hook-and-loop fastener 24 on the second end 91 side of the lower surface 101. When the first bag body 10 according to the second embodiment is in use, the hook-and-loop fastener 24 on the second end 91 side of the lower surface 101 is joined from above to the hook-and-loop fastener 25 on the first end 90 side of the upper surface 100, thereby connecting the first end 90 to the second end 91 to form a ring shape.

[0025] The inner circumferential surface 130 of the first bag body 10 according to the second embodiment is an example of a first surface. When the first bag body 10 according to the second embodiment is in use, the inner circumferential surface 130 of the first bag body 10, which has an annular shape, is brought into close contact with the neck 50 of the subject 5. The first bag body 10 according to the second embodiment can have an arc-like shape in a plan view, and therefore wrinkles are less likely to occur on the inner circumferential surface 130 when the annular shape is brought into close contact with the neck 50 of the subject 5.

[0026] In the first bag body 10 according to the second embodiment, the hook and loop fastener 25 may be provided on the lower surface 101, and the hook and loop fastener 24 may be provided on the upper surface 100. When the hook and loop fastener 24 is provided on the upper surface 100, it is preferable that the hook and loop fastener 23 is provided at a position on the upper surface 100 that does not overlap with the hook and loop fastener 24.

[0027] [Modification] In the above embodiment, the magnetic field homogeneity corrector 1 has been described as reducing artifacts occurring in examination images of the neck 50 of the subject 5. However, the magnetic field homogeneity corrector 1 can also be used to reduce artifacts occurring in examination images of body parts other than the neck 50 of the subject 5.

[0028] In the above embodiment, the first bag 10 houses the inner bag 12 in which resin granules are enclosed, but the resin granules may be enclosed directly without the inner bag 12. The first bag 10 may further enclose something other than the resin granules, for example, powder such as barium sulfate.

[0029] In the above embodiment, the hook and loop fasteners 28 of the second bag body 11 are joined to the hook and loop fasteners 23 of the first bag body 10, thereby causing the second bag body 11 to abut against the first bag body 10. However, the method of abutting the second bag body 11 against the first bag body 10 is not limited to joining the male and female members of the hook and loop fasteners. For example, the first bag body 10 may be formed from a material to which the male member of the hook and loop fastener can be joined, so that the second bag body 11 can abut against any part of the surface of the first bag body 10. A material to which the male member of the hook and loop fastener can be joined is a material having a portion on its surface onto which the male member of the hook and loop fastener can be fastened, such as a material with a fluffy surface or a material with a loop pile attached to a base fabric.

[0030] In the first embodiment, the first bag body 10 can have a rod-like shape in the unused state, and in the second embodiment, it can have an arc-like shape. However, the shape of the first bag body 10 in the unused state may be other than a rod-like or arc-like shape. The first bag body 10 can have any shape as long as it can fit closely to the neck 50 of the subject 5 in the used state. For example, the first bag body 10 may be a rod-like bag body with bands attached to both ends, and fixed using the bands so as to fit closely to the front and both sides of the neck 50 of the subject 5. Furthermore, the first bag body 10 may have a U-shape in the unused state and be inserted into the neck 50 of the subject 5 from the front side of the neck 50.

[0031] In the first embodiment described above, the first bag body 10 is formed into a ring shape by joining the hook and loop fastener 24 on the first end 90 side of the back surface 21 to the hook and loop fastener 25 on the second end 91 side of the front surface 20. However, the method for forming the ring shape of the first bag body 10 is not limited to this. For example, the first bag body 10 may have the hook and loop fastener 24 on the second end 91 side of the back surface 21 and the hook and loop fastener 25 on the first end 90 side of the front surface 20.

[0032] 〔summary〕 The magnetic field homogeneity corrector according to aspect 1 of the present disclosure is a magnetic field homogeneity corrector that reduces artifacts caused by the difference between the magnetic susceptibility of a subject's tissue and the magnetic susceptibility of air during an MRI examination, and includes a first bag body having resin granules enclosed therein, the first bag body having a predetermined first surface that is brought into close contact with the subject, and a second bag body having the granules enclosed therein, the second bag body being placed between the second surface and the subject by being brought into contact with a second surface different from the first surface of the first bag body.

[0033] According to the above configuration, by disposing the second bag body in contact with the first bag body, the shape of the magnetic field homogeneity corrector can be easily adjusted to fit the body of the subject.

[0034] In the magnetic field homogeneity corrector according to aspect 2 of the present disclosure, in the above-mentioned aspect 1, it is preferable that the first bag body can have a rod-like or arc-like shape when the magnetic field homogeneity corrector is in a non-use state, and when the magnetic field homogeneity corrector is in a use state, one end of the rod-like shape is connected to the other end to form a ring-like shape, and the first surface is an inner peripheral surface of the ring-like shape.

[0035] According to the above configuration, the first bag body can have a rod-like or arc-like shape when not in use, making it easy to wipe off dirt.

[0036] In the magnetic field homogeneity corrector according to aspect 3 of the present disclosure, in the above-mentioned aspect 2, it is preferable that, when the magnetic field homogeneity corrector is in use, the first surface of the first bag body, which is the inner peripheral surface of the annular shape, is in close contact with the neck of the subject, the second surface thereof faces the lower jaw of the subject, and the second bag body is disposed between the second surface of the first bag body and the lower jaw of the subject.

[0037] When performing an MRI examination of the subject's neck, the shape of the magnetic field homogeneity corrector can be easily adjusted to fit the space near the subject's lower jaw by abutting the second bag body against the second surface of the first bag body.

[0038] Furthermore, the above configuration maintains cleanliness and reduces the need for re-examination due to artifacts, thereby reducing the burden on patients and improving diagnostic accuracy. These effects also contribute to achieving Goal 3 of the United Nations' Sustainable Development Goals (SDGs), such as "Ensure healthy lives and promote well-being for all at all ages."

[0039] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0040] 1 Magnetic field uniformity corrector 5. Subjects 10 First bag body 11 Second bag body 21 Back 22, 100 top surface 50 Cervical 51 Lower jaw 90 1st end 91 2nd end 130 Inner surface

Claims

1. A magnetic field homogeneity corrector for reducing artifacts caused by a difference between the magnetic susceptibility of a subject's tissue and the magnetic susceptibility of air in an MRI examination, a first bag body having resin granules sealed therein, the first bag body having a predetermined first surface that is brought into close contact with the subject; A magnetic field homogeneity corrector comprising: a second bag body in which the granular material is sealed and which is positioned between the second surface and the subject by abutting the second surface different from the first surface of the first bag body.

2. 2. The magnetic field homogeneity corrector according to claim 1, wherein the first bag body can have a rod-like or arc-like shape when the magnetic field homogeneity corrector is in an unused state, and when the magnetic field homogeneity corrector is in an used state, one end of the rod-like shape is connected to the other end to form a ring-like shape, and the first surface forms an inner peripheral surface of the ring-like shape.

3. When the magnetic field homogeneity corrector is in use, the first surface of the first bag body, which is an inner peripheral surface of the annular shape, comes into close contact with the neck of the subject, and the second surface faces the lower jaw of the subject, The magnetic field homogeneity corrector according to claim 2 , wherein the second bag is disposed between the second surface of the first bag and the lower jaw of the subject.

Images