JP2001095772A - Fixing tool for examining body, medical diagnostic apparatus, and magnetic resonance imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the fixing tool of which certain restriction of movement is possible corresponding to the shapes of various different picture taken positions, especially to provide the examining body fixing tool which no pain is given to the examining body by shielding pulse noises generated by impression of gradient magnetic field at MRI inspection. SOLUTION: The examining body fixing tool F of this invention is provided with a thermoplastic plastic board 12, and a viscoelastic foam 13 adhered to the prescribed position of examining body P at usage. At the case of practical usage of such examining body fixing tool F, for instance, the viscoelastic foam 13 is made of adhere to a head part Ph by proper bending deformation according to the shape of head part Ph. By the arrangement of this on the headrest 15 on the bed 1, the head part Ph is almost perfectly restricted and fixed. The pulse noise is shielded to the examining body P by providing a noise absorbing material 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical diagnostic apparatus and a nuclear magnetic resonance imaging apparatus and, more particularly, to a fixture for a subject which is installed on a bed or the like provided in each of the above-described apparatuses for restraining and fixing the subject. It is about.

[0002]

2. Description of the Related Art Conventionally, as an example of a medical diagnostic apparatus, a nuclear magnetic resonance signal (RF magnetic field) obtained by applying an excitation magnetic field (RF magnetic field) and a gradient magnetic field to a subject placed in a static magnetic field space is known. There is a nuclear magnetic resonance imaging apparatus that forms a nuclear magnetic resonance imaging (MRI) image (tomographic image) of the subject based on the NMR signal). In particular,
For example, an apparatus as shown in FIG. 8 is provided.

[0003] In FIG. 8, a subject P lies on a bed 1 having a top plate 1a installed so as to be capable of translating in the horizontal direction in the figure. The receiving coil 2 for receiving the above-mentioned NMR signal is installed on the top plate 1a. The installation position of the receiving coil 2 with respect to the top plate 1a is adjusted in advance so as to coincide with a part relating to the subject P for which a tomographic image is to be obtained.
On the other hand, a gantry G having an air core H is provided so as to face the moving direction of the top plate 1a. In the gantry G, a main magnet 3, an RF coil 4, and a gradient magnetic field coil 5 for forming a static magnetic field (polarizing magnetic field), an RF magnetic field (excitation magnetic field), and a gradient magnetic field, respectively, are provided with air-core portions. They are arranged concentrically with the central axis L of H being coaxial. Note that these coils and the like are separately connected to a power supply (not shown) that can be arbitrarily controlled.

[0004] Such a nuclear magnetic resonance imaging apparatus operates as follows. The subject P and the receiving coil 2 on the top 1a are inserted into the air core H together with the top 1a,
By applying a static magnetic field to the air core portion H, the alignment of nuclear magnetic moments in the subject P and the Larmor precession of the magnetic moment around the static magnetic field direction are generated,
Applying an RF magnetic field here to absorb magnetic resonance (spin excitation)
Is generated, the NMR signal obtained at this time is received by the receiving coil 2, and a tomographic image of the subject P is formed by an image forming unit (not shown). The application of the gradient magnetic field makes it possible to localize the position of the tomographic image when the tomographic image is formed.

[0005] In the nuclear magnetic resonance imaging apparatus having such a configuration and operation, the bed 1 described above is simply for placing the subject P as described above. It plays an important role of introducing the subject P into the static magnetic field space, and in particular, also plays a role of giving a predetermined constraint to the subject P in order to obtain a diagnostic image without so-called “blur”. It is normal that there is. Conventionally, as a fixture for restraining the subject P, for example, focusing on the head of the subject P, as shown in FIG. 9, a pillow 10 in which a flat plate is curved with a constant curvature and the like. Was used. In addition, the pillow 10 is constituted by the sponge 11, and is configured not to give unnecessary pain to the subject P.

[0006] In addition to the above-described nuclear magnetic resonance imaging apparatus, there are many well-known medical diagnostic apparatuses such as an X-ray CT apparatus. In many of these apparatuses, similarly to the above-described nuclear magnetic resonance imaging apparatus, the bed 1 on which the subject P is placed is a constituent element in many cases. Even in such a case, as described above, since it is generally necessary to restrain the subject P, a structure similar to the pillow 10 or the sponge 11 is usually provided.

[0007]

However, the bed 1 or the subject fixture attached to the conventional medical diagnostic apparatus has the following problems. That is, specific imaging parts set for the subject P, such as the subject P itself, the above-described head, the elbow, and the knee, generally have various shapes. When the above-mentioned pillow 10 or sponge 11 is used to restrain these imaging parts, since the sponge 11 is a very flexible material, it wraps around the imaging parts and suffers from the subject P However, if the subject P moves, the sponge 11 is easily crushed and deformed into various shapes, and as a result, the imaging region moves. I was Spontaneously, it is difficult for the sponge 11 to completely match the sponge 11 with the body shape of the subject P, and there is a problem that the holding power of the subject P is weak.

In the case described above, the original performance required for the couch 1 or the fixture for the subject, which is to restrain the subject P, is impaired. In some cases, the image quality of the tomographic image may cause a problem.

[0009] More generally, when the pillow 10 or the sponge 11 is used, the imaging region of the subject P is often fixed at one point, which may eventually cause pain to the patient. Was. Further, assuming the above-described nuclear magnetic resonance imaging apparatus as a medical diagnostic apparatus, when performing an MRI examination on the head of the subject P, when the head is fixed with the pillow 10 or the like, Is
Normally, as shown in FIG. 9, the pillow 10 is used only at the contact point between the head and the top plate 1a, so that the ears of the subject P are exposed to the outside. However, in the MRI examination, since the pulse sound accompanying the generation of the pulse sequence for driving the gradient magnetic field coil 5 generally reaches 90 dB or more, the pulse sound reaches the ears of the subject P, thereby making the subject P unnecessary. There was also a problem that it could give great pain.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an object or an imaging part which corresponds to various shapes for each object and each imaging part. An object of the present invention is to provide a subject fixture capable of reliably restraining and fixing the movement of the subject. In particular, MR
The present invention also provides a subject fixture which does not cause pain to the subject by isolating a pulse sound generated when the gradient magnetic field of I is applied. Further, the present invention provides a medical diagnostic apparatus including such a fixture for a subject.

[0011]

The present invention employs the following means in order to solve the above problems.

That is, the subject fixing device according to the first aspect is for fixing a predetermined portion of the subject to the subject mounting member, and is attached to the thermoplastic plate and attached to the thermoplastic plate. And a viscoelastic body that adheres to the predetermined portion of the subject during use.

Further, the subject fixture according to claim 2 is
2. The fixing device according to claim 1, wherein a sound absorbing material is arranged on the thermoplastic plate. Further, the subject fixing device according to a third aspect is characterized in that, in the fixing device according to the second aspect, a viscoelastic body is further provided on the sound absorbing material.

Next, a medical diagnostic apparatus according to a fourth aspect of the present invention is the medical diagnostic apparatus for collecting medical information relating to a predetermined portion of a subject fixed to a subject mounting member by a subject fixture. The subject fixture is characterized by comprising a thermoplastic plate and a viscoelastic body attached to the thermoplastic plate and in close contact with the predetermined portion of the subject during use. .

Next, a nuclear magnetic resonance imaging apparatus according to a fifth aspect of the present invention provides an excitation means for applying an excitation magnetic field to a subject arranged in a static magnetic field space, and a gradient magnetic field for applying a gradient magnetic field to the subject. A gantry having an imaging space in which the static magnetic field space is formed, and a receiving means for receiving an NMR signal detected from the subject; and A nuclear magnetic resonance imaging apparatus, comprising: a bed having a top plate directly mounted thereon; and introducing the top plate into the imaging space to capture a tomographic image of the subject. A fixture for a subject, comprising a viscoelastic body adhered to a predetermined portion of the subject during use and attached to a plate, is provided on the top plate.

According to a sixth aspect of the present invention, there is provided a nuclear magnetic resonance imaging apparatus according to the fifth aspect, wherein a sound absorbing material is disposed on the thermoplastic plate.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram schematically showing a nuclear magnetic resonance imaging apparatus (medical diagnostic apparatus) according to this embodiment. In the drawings referred to in the following description, FIG.
In the case of instructing an apparatus having the same configuration as the conventional nuclear magnetic resonance imaging apparatus described with reference to FIG.
Will be described using the same reference numerals as those used in.

In FIG. 1, a nuclear magnetic resonance imaging apparatus is installed so as to oppose the direction of movement of a top board 1a on a bed (subject placing member) 1 and has an air core (to which the top board 1a can be inserted). A gantry G having an imaging space H) is provided. The gantry G includes a main magnet 3, an RF coil (excitation means) 4, and a gradient magnetic field coil (gradient magnetic field applying means) 5.
Are concentrically arranged with the center axis L of the air core H being coaxial.

The main magnet 3 forms a strong static magnetic field in the air core H. In the present embodiment, a permanent magnet,
Any of an electromagnet, a superconducting magnet, and the like can be applied. In particular, in the latter two cases, the main magnet 3 and the RF
The coil 4 may have an externally integrated structure. R
The F coil 4 is a coil that applies an RF magnetic field (excitation magnetic field) for causing nuclear magnetic resonance absorption in the subject P in the static magnetic field. The RF coil 4 is connected to a transmitter 4a and is driven discretely with respect to time, that is, based on a pulse signal. The gradient coil 5 has different magnetic fields (Gx, G) for each of the three orthogonal axes (x, y, z) defined in the air core H.
y, Gz). The degree of the inclination is set by the gradient magnetic field power supply system 5a. Position localization of the NMR signal obtained by the receiving coil (receiving means) 2 can be performed based on the degree of the inclination described above.

Further, the nuclear magnetic resonance imaging apparatus according to the present embodiment includes a control unit 6 for controlling the above-described components as a whole. The control unit 6 determines the pulse sequence of the sequencer 7 and, according to this,
a, operate the gradient magnetic field power supply system 5a. Accordingly, in the air core portion H in which the static magnetic field space is formed by the main magnet 3, a gradient magnetic field is applied to the subject P arranged in the static magnetic field space by the gradient magnetic field coil 5, and The application of the RF pulse by the RF coil 4 causes nuclear magnetic resonance absorption of the subject P. Then, the NMR signal generated at this time is received by the receiver 21 via the receiving coil 2 and collected by the control unit 6. The control unit 6 reconstructs an MRI image based on the collected NMR signals, and displays the MRI image on the display unit D.

Next, a description will be given of a configuration of the subject fixture F which is installed and used on the bed 1 as a characteristic configuration of the present embodiment. As shown in the perspective view of FIG. 2, the subject fixture F is composed of a thermoplastic plastic plate (thermoplastic plate) 12 and a viscoelastic foam (viscoelastic body) 13 attached and adhered to the upper surface thereof. ing. Among these, the viscoelastic foam 13 is formed in a substantially rectangular parallelepiped shape as shown in FIG. Further, with respect to the viscoelastic foam 13, the area of the viscoelastic foam 13 surface in contact with the thermoplastic plastic plate 12 is
It is formed slightly smaller than that of the surface relating to the entire thermoplastic plate 12. At this time, it is preferable that the area of the thermoplastic plastic plate 12 is approximately the same as that of A3 (JIS standard) paper. Further, while the thickness of the viscoelastic foam 13 is about 20 mm,
The thickness of the thermoplastic plate 12 is about 5 mm.

Next, the properties of the thermoplastic plate 12 and the viscoelastic foam 13 will be described. The thermoplastic plate 12 has a property of softening or hardening at a set temperature peculiar thereto. In the present embodiment, the thermoplastic plate 12 has a softening temperature of 50 to 60 degrees Celsius and a curing temperature of 40 degrees Celsius.
I use something different. On the other hand, the viscoelastic foam 13
Has the property that the speed of the restoration is small (slow) when the shape itself is restored to the original shape after the shape deformation is given due to the inherent viscous resistance. As a specific material, for example, polyurethane or the like may be adopted.

Further, a sound absorbing material 14 is attached to the lower surface of the thermoplastic plastic plate 12 on the fixture F for a subject.
Glued. The material constituting the sound absorbing material 14 is particularly limited, except that the thermoplastic plastic plate 12 is bent and deformed as described later. Since there is no reason to do so, basically, any well-known material can be freely selected and adopted. Specifically, for example, if it is not particularly required to have a function related to sound absorption, a form similar to the viscoelastic foam 13 described above may be used as the material of the sound absorbing material 14.

Then, such a fixture F for a subject is
It is installed via the headrest 15 provided on the bed 1 so that the positional relationship with the bed 1 is as shown in FIG. 3 (the details will be described later with reference to the operation or FIG. 4). reference). The headrest 15 is provided on the bed 1 and has a shape substantially enclosing a human head. The subject fixture F is configured to be mounted in the headrest 15 at the time of use, so that the subject fixture F can be freely attached and detached. Note that reference numeral 1b indicates a mattress provided on the top plate 1a.

In the following, the operation and effect of the nuclear magnetic resonance imaging apparatus having the above-described configuration, in particular, the fixture F for a subject installed on the bed 1 will be described with reference to FIG. . In the following, the basic operation related to the nuclear magnetic resonance absorption phenomenon, that is, the operation mode of the RF coil 4, the gradient coil 5, the transmitter 4a, the gradient power supply system 5a, etc. in the gantry G, or the sequencer 7 Since the specific mode such as the pulse sequence does not correspond to the gist of the present invention, the description thereof will be omitted.

In order to use the above nuclear magnetic resonance imaging apparatus, the subject P must first be set on the couch 1. In the present embodiment, prior to this, the subject P is placed on the head Ph of the subject P. The subject fixture F is mounted. In this mounting method, first, the entire flat object fixing tool F as shown in FIG. 2 is heated to the softening temperature of the thermoplastic plastic plate 12, that is, about 50 to 60 degrees Celsius. As a result, the thermoplastic plastic plate 12 is softened, and as shown by the arrow A in FIG.
The inner surface of the viscoelastic foam 13 is brought into close contact with both side surfaces of the head Ph while the entire body is appropriately curved and deformed, and the setting is made so as to completely cover the relevant portion. At this time, care should be taken that the inner surface of the viscoelastic foam 13 is set so as to cover both ears of the subject P.

After the head Ph is covered with the subject fixture F, the head Ph with the subject fixture F mounted thereon is next.
As shown by an arrow B in FIG. 4, both are brought into contact with the inner side surface 15a of the headrest 15 so that the outer side surface of the sound absorbing material 14 of the fixture F for the subject comes into close contact. This completes the installation or mounting of the subject fixture F on the couch 1. Then, after this, the thermoplastic plate 12
Is lowered to the curing temperature or lower, that is, to room temperature of 40 degrees Celsius or lower, the thermoplastic plastic plate 12 cures, and the subject fixture F completely restrains the head Ph.

After the restraint of the head Ph is completed, the normal MRI inspection procedure is followed. That is, the subject P is inserted into the air core H of the gantry G where the static magnetic field is formed by the main magnet 3 together with the receiving coil 2 and the top plate 1a. 5 is applied, and the NMR signal from the subject P obtained by this is received by the receiving coil 2, a tomographic image is reconstructed based on the signal, and the tomographic image is displayed on the display means D. I do.

Here, as described above, the application of the gradient magnetic field by the gradient magnetic field coil 5 is achieved by the cooperative operation of the gradient magnetic field power supply system 5a, the sequencer 7, and the control unit 6. In the embodiment, it should be noted that the driving of the sequencer 7 which directly controls the generation of the pulse sequence generates a pulse sound existing in a high frequency band. As a specific form of the pulse sequence, for example, the one shown in FIG. 5 is exemplified. In the figure, G _{S, G} E _and G _R is meant respectively a slice selective pulse, encoding pulse and a read pulse, typically in this order, z-axis is defined as the y-axis, and the x-axis. In this figure, R
RF pulse (π / 2, π pulse in the figure) for driving the F coil 4 and acquired NMR signal (S1, S2 in the figure)
Is also shown. In general, the pulse sound generated by such a pulse sequence may reach 90 dB or more. In such a case, the pulse sound is not a simple noise that causes the subject P to feel pain. It is not a thing.

The following effects are derived from the description of the configuration and operation of the subject fixture F in the present embodiment. First, the restraint / fixation of the head Ph of the subject P is realized as an extremely good one. That is, the head Ph is almost completely adhered by the viscoelastic foam 13, the cured thermoplastic plastic plate 12 fixes it from the outside, and is further restrained by the headrest 15 provided on the bed 1. Thereby, the head Ph is strongly held and its movement is almost impossible. However, the subject fixture F according to the present embodiment does not cause the subject P to feel unnecessary pressure. This is because the viscoelastic foam 13 inherently has a viscous property to exert a body pressure dispersing function, thereby reducing the feeling of pressure felt by the subject P.

After all, according to the subject fixture F in the present embodiment, it is possible to reliably restrain the imaging region, and therefore, there is no problem with the image quality of the tomographic image to be obtained. Absent. In addition, the subject fixture F
Is, from its configuration, for a subject P of any body type,
It is easy to see that it is possible to respond flexibly. In other words, the effects described above can be similarly enjoyed for any subject P or any imaging part having any shape.

In the above-mentioned fixture F for a subject,
Since the sound-absorbing material 14 was attached to the outside of the thermoplastic plastic plate 12, the above-described pulse sound generated with respect to the application of the gradient magnetic field required for performing the MRI examination was transmitted to the subject P
Sound can be isolated in relation to the ears. That is, the subject fixture F in the present embodiment does not cause unnecessary pain to the subject P.

The limitation on the shape of the fixture F for the subject using specific numerical values and the like described in the above embodiment is the most suitable shape for the purpose of restraining the “head” of the subject P. It is something that should be grasped. That is, when setting other imaging parts such as elbows and knees with respect to the subject P, the thermoplastic plastic plate 12 and the viscoelastic foam 13 having shapes suitable for the elbows and knees and the like are naturally used. Can be considered completely separately from the above.

For example, FIGS. 6 and 7 show an outline of a case where the subject fixture F according to the present invention is applied to a knee Pk. In these figures, the subject fixture F has a form in which a viscoelastic foam 13 is attached and adhered to both surfaces of a thermoplastic plastic plate 12. In this embodiment, as shown in FIG. 7, the receiving coil 2 'formed in accordance with the shape of the knee Pk is used to move in the direction of the arrow in the figure to cover the fixture F. As a result, in addition to the original function of receiving the NMR signal, the receiving coil 2 'also exerts a function as a restraining member provided in the headrest 15 shown in FIG.

By the way, as described above, preparing the subject fixture F adapted to each imaging region is only a matter of design. If necessary, these specific descriptions do not unduly limit the scope of the present invention, but merely mean that it is a proposal for a more preferred embodiment. That is, the shapes of the thermoplastic plate 12 and the viscoelastic foam 13 are basically arbitrary in the present invention.

In the above embodiment, the main magnet 3
And an RF coil 4 etc. are described in consideration of a nuclear magnetic resonance imaging apparatus in which concentrically arranged around the central axis L of the air core H, but the fixture for a subject according to the present invention is described. F is not limited to this form. For example, the present invention can be applied to an MRI apparatus provided with an “opposite magnet”.
In any other medical diagnostic device such as a T device and, in some cases, an ultrasonic diagnostic device, it is necessary to restrain the subject P or the imaging region, for example, by including a subject mounting member similar to the bed 1 described above. With a certain device, the subject fixture F according to the present invention can naturally be applied or used, and similar effects can be enjoyed.

Further, the fixture F for the subject in the above embodiment is provided with the sound absorbing material 14, but as is clear from the above description, this fixture F is used in the nuclear magnetic resonance imaging apparatus. When using on bed 1
This is expected to have the effect of blocking the pulse sound related to the application of the gradient magnetic field. That is, this is the main background of the arrangement of the sound absorbing material 14. Therefore, when the subject fixture F according to the present invention is used in a medical diagnostic apparatus that does not particularly generate noise, the sound absorbing material 14 is not necessarily required. However, as described briefly above, when the same material as the viscoelastic foam 13 is used as the material of the sound absorbing material 14, the action / effect relating to “sound absorption” is not required to be “strong”. Against the backdrop of the expectation that the effect of more effectively restraining the vehicle and the desire to absorb the vibration of the headrest 15, even the provision of any member on the thermoplastic plastic plate 12 (the back surface in FIG. 1) itself is positive. It is not hindered. For example, FIG.
An example is the subject fixture F shown in FIG.

Further, regarding the sound absorbing material 14, furthermore,
Even when the sound absorbing material 14 is provided on the subject fixture F, the viscoelastic foam 13 is further provided outside the sound absorbing material 14.
It is a matter of course that the embodiment may be configured such that the sound absorbing material 14 is expected to exhibit the sound absorbing effect and the newly provided viscoelastic foam 13 is also expected to absorb the vibration of the headrest 15 described above.

In any case, the various variations as described above are still matters to be recognized as falling within the scope of the present invention.

[0041]

As described above, according to the subject fixture and the image diagnostic apparatus of the present invention, the subject or the imaging site where a diagnostic image of the subject is desired to be obtained is pressed against the subject. It can be securely restrained and fixed without causing pain. Therefore, for example, it is possible to obtain a diagnostic image that always has good image quality without causing “blur” or the like.

In addition, the subject fixture of the present invention can be used in principle for an object of any body type or an imaging part of any shape. The effect of the restraint / fixing is similarly exhibited.

Further, when a nuclear magnetic resonance imaging apparatus is assumed as a medical diagnostic apparatus, and a fixture for a subject provided with a sound absorbing material is used, a pulse generated when the gradient magnetic field is applied is used. Sound can be isolated in relation to the subject's ear. That is,
According to the fixture for a subject according to the present invention, unnecessary pain is not given to the subject.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration example of a nuclear magnetic resonance imaging apparatus according to an embodiment.

FIG. 2 is a perspective view showing an outline of a subject fixture.

FIG. 3 is an explanatory view showing a positional relationship between the subject fixture shown in FIG. 2 when the fixture is installed on a bed;

FIG. 4 is an explanatory view showing a state where the head is fixed by the subject fixture shown in FIG. 2;

FIG. 5 is an explanatory diagram showing an example of a pulse sequence for a gradient magnetic field coil.

FIG. 6 is a schematic diagram of a case where a subject fixture is applied to a knee.

FIG. 7 is a schematic diagram showing a situation in FIG. 6 in which the receiving coil also acts as a restraining member.

FIG. 8 is a schematic diagram showing a configuration example of a conventional nuclear magnetic resonance imaging apparatus.

FIG. 9 is an explanatory view showing an outline of a conventional fixture for a subject.

[Explanation of symbols]

 P subject Ph head F subject fixture 1 couch (subject placing member) 1a top plate 1b mattress 10 pillow 11 sponge 12 thermoplastic plastic plate (thermoplastic plate) 13 viscoelastic foam (viscoelastic body) 14 Sound absorbing material 15 Headrest 15a Inner surface of headrest 2, 2 'Receiving coil 3 Main magnet 4 RF coil (excitation means) 4a Transmitter 5 Gradient magnetic field coil (gradient magnetic field applying means) 5a Gradient magnetic field power supply system 6 Control unit 7 Sequencer G Gantry H Air core (Shooting space) L Central axis

Claims (6)

[Claims] 1. A subject fixing device for fixing a predetermined portion of a subject to a subject mounting member, comprising: a thermoplastic plate; and a predetermined portion of the subject which is affixed to the thermoplastic plate and used during use. A fixture for a subject, comprising: a viscoelastic body that adheres to a site. 2. The fixture for a subject according to claim 1, wherein a sound absorbing material is disposed on the thermoplastic plate. 3. The subject fixture according to claim 2, wherein a viscoelastic body is further provided on the sound absorbing material. 4. A medical diagnostic apparatus for collecting medical information relating to a predetermined portion of a subject fixed to a subject mounting member by a subject fixing tool, wherein the subject fixing tool includes a thermoplastic plate and A viscoelastic body that is attached to the thermoplastic plate and adheres to the predetermined portion of the subject when in use. 5. An apparatus according to claim 1, further comprising: an excitation unit configured to apply an excitation magnetic field to a subject disposed in the static magnetic field space; and a gradient magnetic field applying unit configured to apply a gradient magnetic field to the subject. A gantry having an imaging space to be received, receiving means for receiving an NMR signal detected from the subject, and a couch provided with the receiving means and having a top plate on which the subject is directly mounted. A nuclear magnetic resonance imaging apparatus that introduces the top plate into the imaging space and captures a tomographic image of the subject, wherein the thermoplastic plate is attached to the thermoplastic plate and a predetermined amount of the subject is used during use. A nuclear magnetic resonance imaging apparatus, wherein a subject fixture having a viscoelastic body that is in close contact with a part is provided on the top plate. 6. The nuclear magnetic resonance imaging apparatus according to claim 5, wherein a sound absorbing material is disposed on the thermoplastic plate.