Magnetic susceptibility correction device and medical equipment set

Abstract

The magnetic susceptibility correction device reduces the feeling of pressure it causes to the patient. [Solution] The magnetic susceptibility corrector (1) comprises a plurality of bags (10) which contain granular material with a magnetic susceptibility closer to that of water than air, and are arranged to be in close contact with the outer circumference of the inspection area (50) of the subject (5). Of the plurality of bags (10), the first bag (11) which is in close contact with the outer circumference of the inspection area (50) from the vertically upper side when the magnetic susceptibility corrector (1) is in use is configured separately from the other bags (12).

Description

Technical Field

[0001] The present disclosure relates to a magnetic susceptibility corrector and a medical device set.

Background Art

[0002] Patent Document 1 discloses a magnetic field distortion remover used in an MRI (Magnetic Resonance Imaging) apparatus, which includes a cushion body having a gas barrier property and enclosing air, and containing a water-soluble solution in which an iron or cobalt-based material is dissolved inside the bag body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in MRI examination images, artifacts may occur near the boundary between objects with significantly different magnetic susceptibilities. In order to prevent the occurrence of artifacts, it has been considered to closely attach a magnetic susceptibility corrector to the examination site of the subject. However, the magnetic susceptibility corrector closely attached to the examination site may give a sense of pressure to the subject. One aspect of the present disclosure aims to provide a magnetic susceptibility corrector that gives a small sense of pressure to the subject.

Means for Solving the Problems

[0005] To solve the above problems, a susceptibility correction device according to one aspect of the present disclosure is a susceptibility correction device that reduces artifacts caused by the difference between the susceptibility of the subject's tissue and the susceptibility of air during an MRI examination, comprising a plurality of bags containing granular material whose susceptibility is closer to that of water than that of air, and which are arranged to be in close contact with the outer circumference of the subject's examination area, wherein, of the plurality of bags, the first bag that is in close contact with the outer circumference of the examination area from the vertically above side when the susceptibility correction device is in use is separated from the other bags. [Effects of the Invention]

[0006] According to one aspect of this disclosure, a susceptibility correction device that causes less pressure on the subject can be provided. [Brief explanation of the drawing]

[0007] [Figure 1] This is an illustrative diagram showing the use of a magnetic susceptibility correction device according to one embodiment of the present disclosure. [Figure 2] This figure shows an example of an MRI scan image with artifacts. [Figure 3] This is a schematic diagram showing a state in which a bag body according to one embodiment of the present disclosure is in close contact with the neck. [Figure 4] A schematic plan view of a bag according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0008] Figure 1 is an illustrative diagram of the use of a susceptibility correction device according to one embodiment of the present disclosure. In Figure 1, a patient 5 is lying face up on the table of an MRI device 3, and the neck 50 of the patient 5 is encased in the susceptibility correction device 1. The susceptibility correction device 1 is composed of a plurality of bags 10.

[0009] MRI images can exhibit artifacts near the boundaries between objects with significantly different magnetic susceptibility. Because the magnetic susceptibility of human tissue differs greatly from that of air, artifacts are more likely to occur near the boundary between human tissue and surrounding air.

[0010] Figure 2 shows an example of an MRI image with artifacts. In the MRI image shown in Figure 2, artifacts are present in the cervical region 70, making the image of the neck unclear. The susceptibility correction device 1 shown in Figure 1 reduces artifacts that occur in MRI examinations due to the difference between the susceptibility of the patient's tissue and the susceptibility of the air.

[0011] The magnetic susceptibility corrector 1 is composed of multiple bags 10 selected from a set of medical devices (magnetic susceptibility corrector set) which consists of multiple types of bags 10. Each bag 10 contains granular material whose magnetic susceptibility is closer to that of water than to that of air. The granular material can be, for example, resin beads or organic material having a negative magnetic susceptibility. Examples of resin materials that can be used for beads include polyacetal, polypropylene, ABS, methacrylic resin, and polycarbonate. Examples of organic material having a negative magnetic susceptibility include grains of rice.

[0012] The multiple bags 10 include several types of bags 10 selected from a set of medical devices. The multiple bags 10 include a first bag 11 that adheres to the outer circumference of the subject's neck 50 from the vertically upward side when the magnetic susceptibility corrector 1 is in use, and a second bag 12 that adheres to the outer circumference of the subject's neck 50 from a direction other than vertically upward. When the first bag 11 and the second bag 12, which contain granular material, adhere to the outer circumference of the subject's neck 50, the magnetic susceptibility near the outer circumference of the neck 50 becomes close to that of human tissue.

[0013] Figure 3 is a schematic diagram showing a state in which a bag 10 according to one embodiment of the present disclosure is in close contact with the neck 50. The first bag 11, which is the bag 10, is in close contact with the anterior neck 53 of the neck 50 from the vertically upper side. The second bag 12, which is the bag 10, is in close contact with the neck 50 of the subject 5 from the left side, the right side, and the vertically lower side. The first bag 11 is separate from the other bags, for example, the second bag 12. Here, it is said that the first bag 11 is separate from the other bags. The one first bag 11 and the three second bags 12 are arranged in a cylindrical shape that encloses the neck 50 on the inside. The inner circumference of the cylinder is in close contact with the outer circumference of the neck 50 of the subject 5.

[0014] The second bag 12, which is in close contact with the outer circumference of the subject's neck 50 from the vertically downward side, is positioned between the subject's posterior neck 54 and the MRI machine 3's bed. By supporting the subject's neck 50 from the vertically downward side, the second bag 12 can reduce the subject's movement during the MRI examination.

[0015] The second bag 12, which is in close contact with the outer circumference of the neck 50 of the subject 5 from both sides, is supported from vertically below by the second bag 12, which is in close contact with the outer circumference of the neck 50 from vertically below, or by the bed of the MRI device 3.

[0016] The first bag 11 is lighter than the second bag 12. Since the second bag 12 is separate from the first bag 11, the load applied vertically to the neck 50 from the first bag 11 does not include the load from the second bag 12. By reducing the load applied vertically to the neck 50 in this way, the feeling of pressure experienced by the subject 5 during the MRI examination can be reduced. Even if the subject 5 remains in the same position for a long time during the MRI examination, the subject 5 is less likely to feel breathless.

[0017] As shown in Figure 1, the first bag 11 is inserted into the gap between the subject's neck 50 and jaw 51 (the submandibular gap) and covers the subject's neck 50. The second bag 12, which is in close contact with the neck 50 from the left and right sides, extends from the subject's ear 52 to the vicinity of the clavicle, respectively.

[0018] Each bag body 10 may be formed by wrapping an inner bag containing granular materials with an outer bag. By making the bag body 10 have a two-layer structure of an outer bag and an inner bag, even if the outer bag is damaged, the granular materials will not scatter.

[0019] Each bag body 10 has elasticity and flexibility to such an extent that it can maintain a state of being closely attached to the outer periphery of the examination site of the subject 5. Also, the outer bag of each bag body 10 is formed of a material having excellent durability and water repellency. For example, the outer bag of each bag body 10 is formed of nylon fabric. By forming the outer bag of the bag body 10 with a water-repellent material, the surface of the outer bag of the bag body 10 is difficult to be soiled by the sweat, body fluid, etc. of the subject. Also, by forming the outer bag of the bag body 10 with a water-repellent material, the outer bag of the bag body 10 can be easily sterilized with alcohol. The outer bag of each bag body 10 may be colored in a color such as navy, black, brown, etc., which is not easily noticeable for dirt. By making the outer bag of each bag body 10 a color that is not easily noticeable for dirt, even when dirt adheres to the outer bag, the subject 5 is less likely to feel uncomfortable.

[0020] FIG. 4 is a schematic plan view of the bag body 10 according to an embodiment of the present disclosure. A set of medical devices includes a plurality of types of bag bodies 10 having different sizes and weights. The size of the bag body 10 is, for example, the length X in the longitudinal direction and the length Y in the short direction shown in FIG. 4. The length X in the longitudinal direction of the bag body 10 is a length that is equal to or greater than the length Y in the short direction. Since the bag body 10 is flexible, its shape can be changed according to the outer peripheral shape of the examination site of the subject 5. The thickness of the bag body 10 varies within a range that can be taken depending on the length X in the longitudinal direction of the bag body 10, the length Y in the short direction of the bag body 10, the weight of the bag body 10, and the size of the granular materials. For example, the thickness of the bag body 10 varies within the range of 15 mm to 20 mm.

[0021] A set of medical devices includes a plurality of types of first bag bodies 11 that are adapted to the size of the examination site of the subject 5. For example, a set of medical devices for the neck includes a plurality of types of first bag bodies 11 that are adapted to the size of the neck 50 of the subject 5. For example, a set of medical devices for the neck includes the following three types of bag bodies 10. (Type 1) Length X in the longitudinal direction = 135 mm, length Y in the transverse direction = 85 mm, weight 250 g (Type 2) Length X in the longitudinal direction = 110 mm, length Y in the transverse direction = 85 mm, weight 200 g (Type 3) Length X in the longitudinal direction = 100 mm, length Y in the transverse direction = 70 mm, weight 100 g The lengths X in the longitudinal direction and Y in the transverse direction of the above-mentioned Type 1, Type 2 and Type 3 are the lengths before deformation.

[0022] The bag 10 used as the first bag body 11 is selected from the bags 10 of Type 1, Type 2 and Type 3 according to the neck 50 of the subject 5. For example, from the bags 10 of Type 1, Type 2 and Type 3, a bag 10 with a length Y in the transverse direction close to the length of the front neck of the subject 5 is selected as the first bag body 11.

[0023] Also, a set of medical devices for the neck contains a plurality of bags 10 mainly assumed to be used as the second bag body 12. For example, a set of medical devices for the neck contains three bags 10 with a length X in the longitudinal direction of 200 mm (before deformation), a length Y in the transverse direction of 95 mm (before deformation), and a weight of 500 g. The second bag bodies 12 that closely adhere to the neck 50 of the subject 5 from the left and right sides, for example, have the longitudinal direction facing from the ear 52 of the subject 5 to the vicinity of the collarbone and the transverse direction facing vertically.

[0024] The sizes of the plurality of bags 10 are determined such that the inner circumference of the cylindrical shape formed by one first bag body 11 and three second bag bodies 12 closely adheres to the outer circumference of the neck 50. Specifically, the sum of the length X in the longitudinal direction of the first bag body 11, the length Y in the transverse direction of each second bag body 12 that closely adheres to the neck 50 from the left and right, and the length X in the longitudinal direction of the second bag body 1 attached to the lower side of the neck 50 is determined to be equal to or greater than the length around the neck (for example, 360 - 400 mm). For example, when using a Type 3 bag as the first bag body 11, the sum is 490 mm (= 100 + 95×2 + 200), which exceeds 400 mm.

[0025] The inner circumference of the cylindrical shape can be adjusted to the length of the outer circumference of the neck 50 by changing the thickness of each bag 10 that makes up the cylindrical shape. For example, by increasing the thickness of the first bag 11 that makes up the cylindrical shape, the shape of the first bag 11 can be changed so that the length X in the longitudinal direction becomes smaller. By decreasing the thickness of the first bag 11 that makes up the cylindrical shape, the shape of the first bag 11 can be changed so that the length X in the longitudinal direction becomes larger. Similarly, the length Y in the short direction can be adjusted for the second bag 12 that makes up the cylindrical shape by changing its thickness.

[0026] [Variation] In the above embodiment, the susceptibility corrector 1 was described as reducing artifacts occurring in the examination image of the subject's neck 50. However, the susceptibility corrector 1 may also be used for MRI examinations of areas other than the subject's neck 50. For example, the susceptibility corrector 1 may be used for MRI examinations of the subject's elbow or knee. When the susceptibility corrector 1 is used for MRI examinations of areas other than the neck 50, the first bag 11 can be placed in close contact with the outer circumference of the examination area from the vertically upward side to reduce the feeling of pressure on the examination area of ​​the subject 5. In addition, the number of first bags 11 and second bags 12 constituting the susceptibility corrector 1 may be changed to suit the examination area.

[0027] In the above embodiment, the susceptibility corrector 1 consists of one first bag 11 and three second bags 12 included in a set of medical devices, which are placed in close contact with the outer circumference of the neck 50 of the subject 5. The second bags 12 placed in close contact with the outer circumference of the neck 50 of the subject 5 can be any number of one or more, as long as they can form a cylindrical shape that encloses the neck 50 of the subject 5 together with the one first bag 11. In addition, among the bags 10 included in a set of medical devices, those bags 10 that are not placed in close contact with the outer circumference of the neck 50 of the subject 5 may be used to fill the gap between the coil 30 and the neck 50 of the subject 5, or to prevent the susceptibility corrector 1 from collapsing.

[0028] In the above embodiment, one set of medical devices is assumed to contain three types of bags 10, primarily intended for use as the first bag 11: type 1, type 2, and type 3. However, the number of types of bags 10 included in one set of medical devices, primarily intended for use as the first bag 11, does not need to be limited to three types; it only needs to be one or more. Furthermore, the size of the multiple bags 10 is not limited to those described above.

[0029] In the above embodiment, one set of medical equipment includes three bags 10 of the same size, which are primarily intended for use as the second bag 12. However, the bags 10 primarily intended for use as the second bag 12 do not all have to be the same size. One set of medical equipment may include multiple types of bags 10 primarily intended for use as the second bag 12. For example, the bags 10 primarily intended for use as the second bag 12 may include bags 10 whose longitudinal length X is shorter than that of the second bag 12 described above. Bags 10 with a longitudinal length X shorter than that of the second bag 12 described above are useful, for example, when arranging the bag to avoid headphones worn by a patient undergoing an MRI examination.

[0030] 〔summary〕 A magnetic susceptibility correction device according to Embodiment 1 of the present disclosure is a magnetic susceptibility correction device for reducing artifacts caused by the difference between the magnetic susceptibility of a subject's tissue and the magnetic susceptibility of air during an MRI examination, comprising a plurality of bags containing granular material whose magnetic susceptibility is closer to that of water than that of air, and which are arranged to be in close contact with the outer circumference of the subject's examination area, wherein, of the plurality of bags, the first bag that is in close contact with the outer circumference of the examination area from the vertically above side when the magnetic susceptibility correction device is in use is separated from the other bags.

[0031] According to the above configuration, the first bag that adheres to the outer circumference of the inspection area from the vertically upward side is configured separately from the other bags that adhere to the outer circumference of the inspection area from sides other than vertically upward side. Therefore, the load from the other bags does not compress the inspection area in the vertical direction. As a result, a susceptibility correction device that causes less pressure on the subject can be provided. Such effects contribute to achieving, for example, Goal 3 of the United Nations' Sustainable Development Goals (SDGs), "Ensure healthy lives and promote well-being for all at all ages."

[0032] In the magnetic susceptibility corrector according to Embodiment 2 of the present disclosure, in Embodiment 1, the plurality of bags include a plurality of types of bags, and the first bag may be lighter than the other bags.

[0033] According to the above configuration, the first bag that adheres to the outer circumference of the inspection area from the vertically upper side is lighter than the bags that adhere to the outer circumference of the inspection area from sides other than the vertically upper side. Therefore, when the magnetic susceptibility corrector is adhered to the outer circumference of the inspection area of ​​the subject, the force applied to the inspection area from the vertically upper side can be reduced to the extent that the subject does not feel pressure.

[0034] In the magnetic susceptibility corrector according to aspect 3 of the present disclosure, in aspect 1 or 2, the other bag is composed of a plurality of second bags that adhere closely to the outer circumference of the inspection area from a direction other than vertically upward when the magnetic susceptibility corrector is in use.

[0035] When attempting to attach a single bag to the outer circumference of an inspection area from a direction other than vertically upward, it was difficult to maintain the bag's contact with the outer circumference of the inspection area. For example, if a single bag is configured in the shape of a rod, it would need to be positioned so as to pass vertically below the inspection area, with one end attached to the outer circumference of the inspection area from the left and the other end attached to the outer circumference of the inspection area from the right. To maintain both ends of a single bag in contact with the outer circumference of the inspection area from both sides, it was necessary to secure both ends of the bag with Velcro (registered trademark) or the like, making the installation process difficult. With the above configuration, since other bags are composed of multiple second bags, they can be easily attached to the outer circumference of the inspection area from directions other than vertically upward.

[0036] In the susceptibility corrector according to Embodiment 4 of the present disclosure, in any of Embodiments 1 to 3, when the inspection area is the neck, the plurality of bags are arranged in a cylindrical shape that encloses the neck inward when the susceptibility corrector is in use, the length of the inner circumference of the cylinder is greater than or equal to the length of the outer circumference of the neck, and the length of the inner circumference of the cylinder can be adjusted by changing the thickness of each bag constituting the cylinder when the susceptibility corrector is in use.

[0037] According to the above configuration, the length of the inner circumference of the cylindrical shape that encloses the neck can be adjusted by changing the thickness of each bag that makes up the cylinder. Therefore, the size of the susceptibility corrector can be easily adjusted to match the size of the patient's examination area.

[0038] A medical device set according to aspect 5 of the present disclosure is a medical device set comprising the plurality of bags according to any of aspects 1 to 4 above, wherein the medical device set includes a plurality of types of first bags that are suitable for the size of the examination site.

[0039] With the above configuration, the size of the magnetic susceptibility corrector can be easily adjusted to match the size of the subject's examination area by replacing the first bag. [Explanation of Symbols]

[0040] 1 Susceptibility correction device 5 Subject 10 Bag 11 First bag 12 Second bag (other bag) 50 Neck (examination site)

Claims

1. A magnetic susceptibility correction device that reduces artifacts caused by the difference between the magnetic susceptibility of the subject's tissue and the magnetic susceptibility of air during MRI examinations, The bag comprises multiple bags, each containing granular material with a magnetic susceptibility closer to that of water than air, and arranged to be in close contact with the outer circumference of the area being examined by the subject. A magnetic susceptibility corrector in which, among the plurality of bags, the first bag that adheres to the outer circumference of the inspection area from the vertically above when the magnetic susceptibility corrector is in use is separated from the other bags.

2. The aforementioned plurality of bags include multiple types of bags, The magnetic susceptibility corrector according to claim 1, wherein the first bag is lighter than the other bags.

3. The magnetic susceptibility corrector according to claim 1, wherein the other bag consists of a plurality of second bags that adhere closely to the outer circumference of the inspection area from a direction other than vertically upward when the magnetic susceptibility corrector is in use.

4. If the area to be examined is the neck, The plurality of bags are arranged in a cylindrical shape that encloses the neck portion inward when the magnetic susceptibility corrector is in use. The length of the inner circumference of the cylindrical part is greater than or equal to the length of the outer circumference of the neck. The magnetic susceptibility correction device according to claim 1, wherein the length of the inner circumference of the cylindrical shape can be adjusted by changing the thickness of each bag constituting the cylindrical shape when the magnetic susceptibility correction device is in use.

5. A medical device set comprising the plurality of bags according to claim 1, The medical device set includes a plurality of types of the first bag that are suitable for the size of the examination site.

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