JPH0568975B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing an MRI magnet device that collects magnetic resonance signals from a subject (usually a patient) and uses the collected magnetic resonance signals for diagnosis. .

(Prior Art) A sectional view of a conventional MRI magnet device is shown in FIG. 6a, and a perspective view is shown in FIG. 6b. Here, MRI refers to a magnetic resonance imaging device that collects magnetic resonance signals from a subject and uses them for diagnosis.
Abbreviated as MRI. 1 is an MRI magnet, 2 is a subject, 3
4 is a gradient magnetic field coil portion, 4 is an inner sound insulating member, 5 is an outer sound insulating member, 6 is a sound insulating side plate, 8a and 8b are supports, and 8c is a vibration isolating rubber. Gradient magnetic field coil section 3
, a non-magnetic resin 3 is attached to a gradient magnetic field coil 3b made of copper.
It has a structure in which it is molded with a and formed into a cylindrical shape. The outer sound insulating member 5 is coaxially arranged outside the inner sound insulating member 4 with a gap therebetween. The sound insulating side plates 6 have a ring shape and are provided at both ends of the outer sound insulating member 5. The outer sound insulating member 5 and the inner sound insulating member 4
and a sound insulating side plate 6 to form an integral structure, this integral structure forms a sealed space 7 inside, and is attached to the magnet 1 with a support 10 in the internal space of the MRI magnet 1. The gradient magnetic field coil section 3 is provided in the closed space 7 for the purpose of preventing noise caused by vibrations generated by the coil section 3 from being transmitted to the outside. In addition, inside the inner sound insulating member 4, RF waves are irradiated to the subject and noise from the subject is emitted.
It has a transmitting/receiving coil (not shown) for receiving MR signals.

Furthermore, for the same purpose, the gradient magnetic field coil section 3
is supported with a vibration isolating rubber 8c interposed between a support 8a attached to the coil portion 3 and a support 8b attached to the inner sound insulating member 4. When photographing, the subject 2 is placed into the opening 4a of the inner sound insulating member 4 as shown in FIG. 6a. Next, a pulsed current is passed through the gradient magnetic field coil 3b of the gradient magnetic field coil section 3 to superimpose the gradient magnetic field on the static magnetic field generated by the MRI magnet 1. At the same time, an excitation rotating magnetic field is generated from the transmitter/receiver coil, and the MR from the subject 2 is
A signal is received by the transmitting/receiving coil, processed by an external image processing device (not shown), and displayed as an image.

The conventional MRI magnet device is configured in this way, so that when a pulsed current flows through the gradient magnetic field coil 3b of the gradient magnetic field coil section 3, the current flowing through the coil 3b corresponds to the current flowing through the coil 3b due to electromagnetic force. This force is generated in the coil 3b, and the gradient magnetic field coil section 3 is deformed. Since this current changes in a pulsed manner, the force acting on the coil portion 3 also changes in a pulsed manner, so that the coil portion 3 vibrates. Anti-vibration rubber 8
c insulates this vibration from being transmitted to others.
However, when the coil portion 3 vibrates, the inner sound insulating member 4 vibrates due to the sound pressure, and this vibration mainly becomes noise due to air propagation and propagates to the subject 2 within the opening 4a.

(Problems to be Solved by the Invention) Conventional MRI magnet devices have not been able to sufficiently reduce noise from the gradient magnetic field coil section used in the device. This has caused discomfort to the subject (usually the patient).

The purpose of the present invention is to provide an MRI system with reduced noise.
It is an object of the present invention to provide a method for manufacturing a magnet device for use in a magnet.

[Structure of the Invention] (Means for Solving the Problems) To achieve the above object, the invention according to claim 1 provides a method for manufacturing an MRI magnet device having a coil portion formed into a cylindrical shape by molding a coil. In,
bonding a first glass fiber mat to one side of a viscoelastic sheet to form a laminated member; and at least one of the inner and outer surfaces of the coil portion and the viscoelastic sheet side surface of the laminated member. a step of laminating a second glass fiber mat impregnated with resin on the surface of the laminated member on the first glass fiber mat side, and a step of curing the impregnated resin. It is characterized by:

Further, the invention according to claim 2 provides a method for manufacturing an MRI magnet device having a coil portion formed into a cylindrical shape by molding a coil, in which resin is provided on at least one of the inner and outer surfaces of the coil portion. a step of laminating a first glass fiber mat impregnated with a viscoelastic sheet, a step of adhering a second and a third glass fiber mat to both surfaces of a viscoelastic sheet to form a laminated member, and a step of laminating a first glass fiber mat impregnated with a viscoelastic sheet; a step of laminating the laminated member on a mat, a step of laminating a fourth glass fiber mat impregnated with resin on the laminated member, and curing the resin impregnated with the first and fourth glass fiber resins. It is characterized by having a process.

In addition, the invention according to claim 3 provides that the coil:
It is characterized by being a gradient magnetic field coil.

In addition, the invention according to claim 4 provides that the coil:
It is characterized by being a transmitting/receiving coil.

Further, the invention according to claim 5 provides an inner sound insulating member formed in a cylindrical shape, and an outer sound insulating member arranged coaxially with a gap outside the inner sound insulating member and formed in a cylindrical shape. , a ring-shaped sound insulating side plate is provided at both ends of the both sound insulating members, a sealed space is formed by both the sound insulating members and the sound insulating side plate, and a gradient magnetic field coil is provided in the sealed space with a non-magnetic resin. In a method for manufacturing an MRI magnet device equipped with a gradient magnetic field coil portion molded into a cylindrical shape, a laminated member is formed by adhering glass fiber mat before impregnated with resin to both sides of a viscoelastic sheet, and then the resin is applied. During the step of laminating impregnated glass fiber mats multiple times to form a glass fiber reinforced resin, the method further includes the step of laminating the laminated members and curing the impregnated resin to form the inner sound insulating member. It is characterized by this.

In addition, the invention according to claim 6 includes a first cylindrical body made of non-magnetic resin, and a second cylindrical body coaxially arranged inside the first cylindrical body and made of non-magnetic resin. , a method for manufacturing an MRI magnet device having a gradient magnetic field coil section configured of a gradient magnetic field coil section provided between the second cylindrical body and the first cylindrical body; A viscoelastic sheet is adhered to the surface of the cylindrical body facing the second cylindrical body, and
A gradient magnetic field coil is temporarily fixed to the surface of the cylindrical body facing the first cylindrical body, the first cylindrical body and the second cylindrical body are held coaxially with a gap, and the gap is The method is characterized in that it has a step of injecting a thermosetting resin into the magnetic field, curing the thermosetting resin, and molding the gradient magnetic field coil section.

(Function) According to the invention described in claim 1, when the coil part, the viscoelastic sheet, the first glass fiber mat, and the second glass fiber mat impregnated with resin are laminated in this order, the second glass fiber mat is laminated in this order. The resin impregnated with the resin permeates the first glass fiber mat and reaches the viscoelastic sheet. Next, by curing the resin, the bond between the viscoelastic sheet and the glass fiber mat layer becomes strong. In addition, if the surface of the coil part to which the viscoelastic sheet is attached is smooth, even if the coil part and the viscoelastic sheet are adhered, the adhesion surface of the viscoelastic sheet is smooth, so the adhesion area will be large, and sufficient adhesive strength will be obtained. is obtained. Therefore, the coil portion, the viscoelastic sheet and the glass fiber mat layer are firmly bonded to each other.

As a result, when a pulsed current is passed through the coil, an electromagnetic force corresponding to this current is generated and the coil section vibrates, but this vibration is absorbed by the viscoelastic sheet and becomes smaller, so the noise is small. Become.

According to the invention described in claim 2, the coil portion, the first glass fiber mat impregnated with resin, the second glass fiber mat, the viscoelastic sheet, the third glass fiber mat, and the fourth glass fiber mat impregnated with resin. When the glass fiber mats are laminated in this order, the resin impregnated in the first and fourth glass fiber mats soaks into the second and third glass fiber mats, respectively, and reaches the viscoelastic sheet. Next, by curing the resin, the bond between the coil portion, the viscoelastic sheet, and the glass fiber mat layer becomes strong. Furthermore, if the surface of the coil portion to which the viscoelastic sheet is attached is not smooth, the coil portion and the viscoelastic sheet are firmly bonded by laminating the viscoelastic sheets via a glass fiber mat as described above.

As a result, when a pulsed current is passed through the coil, an electromagnetic force corresponding to this current is generated and the coil section vibrates, but this vibration is absorbed by the viscoelastic sheet and becomes smaller, so the noise is small. Become.

According to the invention set forth in claim 3, even when the coil is a gradient magnetic field coil, the same effect as the invention set forth in claims 1 and 2 is achieved.

According to the invention set forth in claim 4, even when the coil is a transmitting/receiving coil, the same effect as the invention set forth in claims 1 and 2 is achieved.

According to the invention described in claim 5, when the viscoelastic sheet is laminated inside the inner sound insulation member made of glass fiber reinforced resin, each surface of the glass fiber reinforced resin layer is not a smooth surface. It may be performed in the same order as the described method for joining with an uneven surface.

If the gradient magnetic field coil part that vibrates in this way is placed in a sealed space, and a viscoelastic sheet is laminated inside the inner sound insulation member forming the sealed space,
Noise caused by vibration of the gradient magnetic field coil section will no longer leak out from the closed space. Furthermore, since the vibration of the inner sound insulating member due to the sound pressure in the closed space generated by the vibration of the gradient magnetic field coil section is absorbed by the viscoelastic sheet of the inner sound insulating member, the inner sound insulating member in which the subject enters is particularly effective. It is possible to reduce noise near the central axis of the

According to the sixth aspect of the invention, the viscoelastic sheet can also be laminated in the process of molding the gradient magnetic field coil with non-magnetic resin. the second of the first cylinder
Assuming that the surface facing the cylinder is smooth, a viscoelastic sheet can be applied directly to this surface, and a thermosetting resin is injected into the gap between the first cylinder and the second cylinder. When this thermosetting resin is cured, the bond between the viscoelastic sheet and the second cylinder becomes strong.

(Example) Hereinafter, examples of the present invention will be described based on the attached drawings.
Explain in detail.

An MRI magnet device according to an embodiment of the present invention is shown in FIG. This figure is a sectional view of a main part of the A part of the sectional view of the conventional device shown in FIG. 6a, and shows an improved part of the embodiment device according to the present invention.

1 is a magnet for MRI, 300 is a low-vibration type gradient magnetic field coil section consisting of a gradient magnetic field coil section 3 and a vibration absorbing member 30, 5 is an outer sound insulating member, 400 is an inner sound insulating member, and 6 is a ring-shaped sound insulating side plate. . The outer sound insulating member 5 is disposed coaxially with a gap outside the inner sound insulating member 400, and the sound insulating side plates 6 are provided at both ends of the outer sound insulating member 5, and the outer sound insulating member 5 and the inner sound insulating member 400 and the sound insulation side plate 6
is an integral structure that forms a sealed space 7 inside, and a support 1 is placed in the internal space of the MRI magnet 1.
0 (see FIG. 6b) and is attached to the magnet 1. The low vibration type gradient magnetic field coil section 300 includes:
Supports 8a and 8b (Fig. 6a) are provided in the sealed space 7.
It is supported by a vibration isolating rubber 8c (FIG. 6a). The gradient magnetic field coil section 3 has a structure in which a copper gradient magnetic field coil 3b is molded with a non-magnetic resin 3a to form a cylindrical shape. The low vibration type gradient magnetic field coil section 300 is composed of the gradient magnetic field coil section 3 and a vibration absorbing member 30 laminated on the outer periphery of the coil section 3. This vibration absorbing member 30 is formed by forming a glass fiber reinforced resin (hereinafter referred to as FRP) layer around the outer periphery of a viscoelastic sheet 3c. Here, the viscoelastic sheet 3c is a plastic sheet having viscoelastic properties. The inner sound insulating member 400 includes a transmitting/receiving coil section 40 that irradiates the subject with RF waves and receives MR signals from the subject.
, viscoelastic sheet 40c, and glass fiber mat 4
0d (hereinafter referred to as glass fiber mat after resin impregnation) and is formed into a cylindrical shape. The transmitting/receiving coil section 40 includes a transmitting/receiving coil 4 made of copper.
It has a structure in which 0b is molded with FRP40a.
A plurality of glass fiber mats 40d are laminated around the transmitting/receiving coil section 40, and a viscoelastic sheet 40c is provided in this lamination.

In the MRI magnet device using the low-vibration gradient magnetic field coil unit 300 configured as described above,
When a pulsed current is passed through the coil 3b, an electromagnetic force corresponding to this current is generated, and since the low-vibration gradient magnetic field coil section 300 has a thin wall thickness, the electromagnetic force is perpendicular to the circumferential surface of the coil section 300. It vibrates mainly in the direction. When vibrated in this direction, strain occurs in parallel to the circumferential surface, as shown in the cross-sectional view of the principal part showing the behavior of the viscoelastic sheet in FIG. 2a. When this strain occurs, shear stress τ is generated in the viscoelastic sheet 3c, and the vibration energy is converted into thermal energy due to the deformation of the viscoelastic sheet 3c, thereby damping the vibration. A diagram showing the attenuation of this vibration is shown in Fig. 2b, where the horizontal axis represents time (in seconds) and the vertical axis represents vibration acceleration (in gal), which was measured at the outer periphery of the vibration absorbing member 30. . From Figure b, it can be seen that even if the vibration occurs, it decays in only about 0.1 seconds. Therefore, the noise generated is also reduced. Moreover, the gradient magnetic field coil section 3
Even if it vibrates, it is vibrating within the closed space 7, so the possibility of this vibration leaking outside as noise is reduced.

Further, the gradient magnetic field coil section 3 is arranged in a closed space 7.
When the inner sound insulating member 400 vibrates, sound pressure is generated within the sealed space 7, which may cause the inner sound insulating member 400 to vibrate. Therefore, in order to absorb this vibration, a viscoelastic sheet 40c is laminated on the inner sound insulating member 400 to further reduce the noise entering the opening 4a of the inner sound insulating member 400 into which the subject enters. Therefore, quiet
It can be an MRI magnet device.

Next, an example of a method for manufacturing an MRI magnet device in which the viscoelastic sheets 3c and 40c are applied to the device will be described.

FIGS. 3a to 3d are diagrams showing the manufacturing process of the first embodiment of the low-vibration type gradient magnetic field coil section 300 of the apparatus of this embodiment. This manufacturing process includes: (a) First step (Fig. 3a): A step of bonding the glass fiber mat 3dd before resin impregnation and the viscoelastic sheet 3c to form a laminated member 3cd; (b) Second step (Figure 3b): Gradient magnetic field coil section 3
(c) Third step (Fig. 3c): impregnating the outside of the laminated member 3c with resin so that the viscoelastic sheet 3c is on the attachment surface. glass fiber mat 3d
(hereinafter simply referred to as glass fiber mat 3d) one or more times, (d) Fourth step (Fig. 3 d): A vibration absorbing member 30 in which the resin is cured and the glass fiber mat 3d is made into FRP 34. (e) Fifth step (not shown): a step of incorporating the low-vibration type gradient coil section 300 into the MRI magnet 1.

FIGS. 4a to 4e are diagrams showing the manufacturing process of an embodiment of the inner sound insulating member 400 of the apparatus of this embodiment.

This manufacturing process consists of (a) a first process (Fig. 4a): a process of laminating a resin-impregnated glass fiber mat 40d on a transmitting/receiving coil part 40 whose outer periphery is made of FRP; (b) a second process (Fig. 4a); Figure 4b): Step of bonding the glass fiber mat 40dd before resin impregnation to both sides of the viscoelastic sheet 40c to form the laminated member 40cd, (c) Third step (Figure 4c): The laminated member 40cd
Glass fiber mat 40 impregnated with the resin
(d) Fourth step (Fig. 4 d): The laminated member 40 cd
Glass fiber mat 4 whose outer periphery is impregnated with resin
(e) Fifth step (Fig. 4 e): Curing the resin to form FRPs 41, 42; (F) Sixth step (not shown): Inner sound insulating member 400
is combined with the outer sound insulating member 5, the sound insulating side plate 6, and the low-vibration gradient magnetic field coil section 300 to form the MRI magnet 1.
It consists of the process of incorporating into.

FIGS. 5a to 5c are diagrams showing the manufacturing process of the second embodiment of the device of this embodiment. This manufacturing process is as follows: (a) First step (Fig. 5a): Temporarily fixing the coil 3b to the second cylindrical member 31 made of non-magnetic resin.
(b) Second step (FIG. 5b): A step of adhering the viscoelastic sheet 3c to the inner surface of the first cylindrical body 32 made of non-magnetic resin, (c) Third step (FIG. 5b): Figure 5c): The first cylinder 32
and the second cylindrical body 31 are held coaxially with a gap between them, and an epoxy resin 33c, which is a thermosetting resin, is injected into the gap, and the resin 33 is hardened to form a low-vibration gradient magnetic field coil. (d) Fourth step (not shown): a step of incorporating the low vibration type gradient magnetic field coil section 300 into the MRI magnet 1.

An effective structure for vibration energy absorption of the viscoelastic sheet 3c is a structure in which the gradient magnetic field coil section 3, which is the inner layer of the viscoelastic sheet 3c, and the FRP 34, which is the outer layer of the viscoelastic sheet 3c, have equal bending rigidity. be. (See Figure 3) That is, when the gradient magnetic field coil section 3 and the FRP 34 are made of the same material,
All you have to do is make the wall thickness the same, FRP34
If the gradient magnetic field coil section 3 is made of a material with lower bending rigidity, the same bending rigidity can be achieved by reducing the thickness of the FRP 34.

Although one embodiment of the MRI magnet device has been described above, the present invention is not limited thereto, and various modifications can be made without changing the gist thereof.

For example, when it is desired to interpose a plurality of viscoelastic sheets within a vibration absorbing member or an inner sound insulating member, a vibration absorbing member such as FRP may be interposed between a plurality of viscoelastic sheets, or a plurality of The viscoelastic sheets may be brought into close contact with each other.

Furthermore, although the low-vibration type gradient magnetic field coil section of the device of this embodiment has a structure in which a viscoelastic sheet is laminated on the outside of the gradient magnetic field coil section, it may be laminated on the inside or both sides of the gradient magnetic field coil section.

Furthermore, although the device of this embodiment has a low-vibration gradient magnetic field coil section in a closed space, the coil section is not directly connected to the coil section.
Even if a gradient magnetic field coil section without a viscoelastic sheet is installed in the internal space of the MRI magnet device or in a closed space formed by an inner sound insulating member laminated with a viscoelastic sheet, the noise of the device can be reduced. can be measured.

Furthermore, although the inner sound insulating member of the device of this embodiment has a structure including a transmitting/receiving coil, it may have a structure not including the transmitting/receiving coil. In this case, a transmitting/receiving coil may be provided inside the inner sound insulating member.

[Effects of the Invention] According to the invention described in claim 1 detailed above, the bond between the viscoelastic sheet and the glass fiber mat layer becomes strong, and when the surface of the coil portion to which the viscoelastic sheet is applied is smooth, , Even if the coil part and the viscoelastic sheet are bonded together, the adhesion surface of the viscoelastic sheet is smooth, so
Since the bonding area is increased and sufficient bonding strength is obtained, the coil portion, viscoelastic sheet, and glass fiber mat layer are firmly bonded to each other. As a result, a pulsed current is passed through the coil, and an electromagnetic force corresponding to this current is generated, and even if the coil part vibrates,
Since this vibration is absorbed by the viscoelastic sheet and becomes smaller, the noise is reduced, and the noise in the central axis direction can be reduced.

According to the invention as claimed in claim 2, the bond between the viscoelastic sheet and the glass fiber mat layer becomes strong, and if the surface of the coil portion to which the viscoelastic sheet is applied is not smooth, the viscoelastic sheet is bonded to the glass fiber mat layer. By stacking the sheets, the coil portion and the viscoelastic sheet are firmly bonded, and the bond between the coil portion, the viscoelastic sheet, and the glass fiber mat layer becomes strong. As a result, a pulsed current is passed through the coil, and an electromagnetic force corresponding to this current is generated. Even if the coil part vibrates, this vibration is absorbed by the viscoelastic sheet and becomes smaller, resulting in less noise. Therefore, noise reduction in the direction of the central axis can be achieved.

According to the invention set forth in claim 3, even when the coil is a gradient magnetic field coil, the same effects as those of the inventions set forth in claims 1 and 2 can be achieved.

According to the invention set forth in claim 4, even when the coil is a transmitting/receiving coil, the same effects as those of the inventions set forth in claims 1 and 2 can be achieved.

According to the invention set forth in claim 5, the gradient magnetic field coil portion is placed in a sealed space, and the viscoelastic sheet is laminated within the inner sound insulating member forming the sealed space, so that the gradient magnetic field coil portion The noise caused by the vibration of the parts will not leak out from the closed space. Furthermore,
The vibration of the inner sound insulating member due to the sound pressure in the closed space generated by the vibration of the gradient magnetic field coil section is absorbed by the viscoelastic sheet in the inner sound insulating member.
In particular, noise near the central axis of the inner sound insulating member into which the subject enters can be reduced.

According to the invention set forth in claim 6, the first cylindrical body and the second cylindrical body and the gradient magnetic field coil and the second cylindrical body can be simultaneously coupled by simply injecting the thermosetting resin. Therefore, a low vibration type gradient magnetic field coil section can be manufactured in a short time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an MRI magnet device according to an embodiment of the present invention. Figure 2 shows the MRI of the present invention.
FIG. 2 is a diagram relating to the behavior of a viscoelastic sheet in a low-vibration type gradient magnetic field coil section of an embodiment used in a magnet device, in which FIG. 3a to 3d are manufacturing process diagrams of the low-vibration type gradient magnetic field coil section according to the first embodiment of the present invention, FIGS. Figures a to c are manufacturing process diagrams of a low-vibration type gradient magnetic field coil section according to a second embodiment of the present invention.
Figure 6 is a diagram of a conventional MRI magnet device.
Figure a is a sectional view, and figure b is a perspective view. 1... MRI magnet, 3... Gradient magnetic field coil section, 3
a, 40a... Non-magnetic resin, 3b... Gradient magnetic field coil, 3c, 40c... Viscoelastic sheet, 3cd, 40
cd...Laminated member, 3d, 40d...Glass fiber mat after resin impregnation, 3dd, 40dd...Glass fiber mat before resin impregnation, 30...Vibration absorbing member, 31...
Second cylindrical body, 32... First cylindrical body, 31c... Temporary fixing member, 33... Thermosetting resin, 34, 41, 42...
FRP, 400...inner sound insulating member, 5...outer sound insulating member, 6...sound insulating side plate, 7...closed space.

Claims (1)

[Claims] 1. A method for manufacturing an MRI magnet device having a coil portion formed into a cylindrical shape by molding a coil,
bonding a first glass fiber mat to one side of a viscoelastic sheet to form a laminated member; and at least one of the inner and outer surfaces of the coil portion and the viscoelastic sheet side surface of the laminated member. a step of laminating a second glass fiber mat impregnated with resin on the surface of the laminated member on the first glass fiber mat side, and a step of curing the impregnated resin. MRI characterized by
A method for manufacturing a magnetic device for 2. In a method for manufacturing an MRI magnet device having a coil portion formed into a cylindrical shape by molding a coil,
A step of laminating a first glass fiber mat impregnated with resin on at least one of the inner and outer surfaces of the coil portion, and laminating second and third glass fiber mats on both sides of the viscoelastic sheet, respectively. a step of adhering to form a laminated member; a step of laminating the laminated member on the first glass fiber mat; a step of laminating the laminated member with a fourth glass fiber mat impregnated with a resin; A method for manufacturing an MRI magnet device, comprising the step of curing resins impregnated with first and fourth glass fiber resins. 3. The method for manufacturing an MRI magnet device according to claim 1 or 2, wherein the coil is a gradient magnetic field coil. 4. The method for manufacturing an MRI magnet device according to claim 1 or 2, wherein the coil is a transmitting/receiving coil. 5. An inner sound insulating member formed in a cylindrical shape, an outer sound insulating member arranged coaxially with a gap outside the inner sound insulating member and formed in a cylindrical shape, and a cylindrical outer sound insulating member at both ends of the two sound insulating members. A ring-shaped sound insulating side plate is provided, a sealed space is formed by both the sound insulating members and the sound insulating side plate, and a gradient magnetic field coil is molded with a non-magnetic resin in the sealed space to form a cylindrical shape. In a method for manufacturing an MRI magnet device equipped with a magnetic field coil section, glass fiber mats that have not been impregnated with resin are bonded to both sides of a viscoelastic sheet in advance to form a laminated member, and the glass fiber mats impregnated with resin are bonded multiple times. An MRI magnet device characterized by having a step of laminating the laminated members and curing the impregnated resin to form the inner sound insulating member during the step of laminating the laminated members to form the glass fiber reinforced resin. manufacturing method. 6 A first cylindrical body made of non-magnetic resin, and
a second cylindrical body coaxially arranged inside the cylindrical body and made of non-magnetic resin; and a gradient magnetic field coil provided between the second cylindrical body and the first cylindrical body. It has a gradient magnetic field coil section consisting of a section and a gradient coil section.
In the method for manufacturing an MRI magnet device, the first
A viscoelastic sheet is adhered to the surface of the cylinder facing the second cylinder, a gradient magnetic field coil is temporarily fixed to the surface of the second cylinder facing the first cylinder, and a gradient magnetic field coil is temporarily fixed to the surface of the second cylinder facing the first cylinder. The cylindrical body and the second cylindrical body are held coaxially with a gap, a thermosetting resin is injected into the gap, and the thermosetting resin is cured to form a gradient magnetic field coil part. 1. A method for manufacturing an MRI magnet device, comprising the steps of: