JPH1057335A - Magnetic resonance imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To gain fine picture data by restraining move of an object specimen on improving a means to keep the object specimen and a signal detection means fixed on a bed. SOLUTION: A fixture belt 70 to keep fixed an object specimen and a signal detection coil is applied on a bed top board 80 to locate the object specimen in a measuring space. The fixture belt 70 is composed of a belt and a holder 75 to hold it, which is to catch a groove 85 processed on the top board 80 and capable of sliding free along it. In the groove 85 are processed several notches 86 to catch held the fixture belt 70 after having moved it onto a desired point along the top board 80. By this, it is possible to steadily fix the object specimen on most appropriate part according to it. The fixture belt 70 is favorably equipped with a hook means having a strong tight by reacting smaller strength. It comes thus able to gain accurate and clear MR picture data without running or ghost as it is possible to sufficiently restrain move of measuring object specimen and signal detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic resonance imaging apparatus, and more particularly to an improvement in means for arranging a subject in a measurement space and means for supporting and fixing the subject and the like.

[0002]

2. Description of the Related Art Magnetic resonance imaging (hereinafter, referred to as MRI) is a method in which a group of nuclei having a unique magnetic moment is placed in a certain static magnetic field, and a magnetic resonance is applied to a specific high-frequency magnetic field. (NMR) This is a method of measuring chemical and physical information of a substance by utilizing the phenomenon, and creating image data from the information. In the MRI apparatus using such a method, the region of interest of the subject is arranged so as to be located at the center of the static magnetic field (measurement space), and position information is added to the NMR signal based on the center position of the static magnetic field. Gradient magnetic field is applied.

Therefore, during the measurement of the physical and chemical information, if the position of the test object or the coil for signal detection in the static magnetic field changes even by about several millimeters, a flow or a false image appears in the image data, and an accurate and clear image is obtained. Image data cannot be obtained. Therefore, it is necessary to sufficiently support and fix the subject and the signal detecting means so that the positions of the subject and the signal detecting means in the static magnetic field do not change. For such a purpose, a belt or the like is attached to a bed for transferring and arranging the subject in the measurement space as a means for supporting and fixing the subject and the detection coil to the bed.

FIG. 12 shows an example of a conventional fixed belt 70 'provided for fixing a subject 60. The fixed belt has a fixed position on a bed top 80' on which both ends of the subject are placed. It is fixed to. Therefore, even if the body shape of the subject is different, the position where the support is fixed cannot be changed, so that the subject cannot be sufficiently fixed depending on the subject, and the fixing belt itself may hinder the operation and imaging.

On the other hand, a fixed belt 70 "shown in FIGS. 13 (a) and 13 (b) is attached to a groove 85 provided on a bed top plate 80 'via a support (not shown). The position of the fixing belt 70 "can move along the groove 85 of the bed top 80 '. In this case, the position of the fixing belt 70 "can be changed in accordance with the part of the subject 60 to be fixed, but as shown in FIG. When moving in a parallel direction, the fixed belt 70 "also slides along the groove 85 together with the subject 60,
In this method, the subject cannot be fixed sufficiently.
Also, when the fixing belt 70 "is to be fixed obliquely to the couch top 80 'as shown in FIG. 13B, the mounting position of the fixing belt 70" moves, and Cannot be fixed sufficiently.

Although not shown in FIGS. 12 and 13, these conventional fixing belts are provided with a connecting member or a fastening member of a magic tape or a seat belt type, and the subject is fixed by the connecting members or the like. It is configured as follows. In this case, in order to sufficiently suppress the movement of the subject, it is necessary to support and fix the subject with a considerably strong force, but the subject is sufficiently supported only by being tightened with these conventional coupling members. Cannot be fixed.

[0007]

As described above, the conventional MRI apparatus cannot sufficiently support and fix the object due to various differences in the object to be supported and fixed. There is a problem that an image is generated.

Accordingly, an object of the present invention is to solve such a problem and to provide an MRI apparatus capable of acquiring clear image data without a flow or a false image.

[0009]

In order to solve the above-mentioned problems, an MRI apparatus according to the present invention comprises: a magnetic field generating means for generating a static magnetic field, a gradient magnetic field, and a high-frequency magnetic field in a measurement space;
Subject placement means for placing the subject in the measurement space, signal detection means for detecting a magnetic resonance signal generated from the subject,
Fixing means for fixing the subject and / or the signal detecting means to the subject arranging means in an MRI apparatus comprising: an image processing means for processing a magnetic resonance signal to display image data of an arbitrary part of the subject. And support means for movably supporting the fixing means with respect to the subject placement means, and locking means for locking the fixing means at a desired position of the subject placement means.

According to such an MRI apparatus, the fixing means can be moved to a desired position of the object placing means and locked, so that the subject moves during measurement or the like, so that the fixing means has no effect. Even if such a force is applied, regardless of the direction of the applied force, the fixing means can be reliably fixed without moving in conjunction therewith.

The MRI apparatus according to the present invention is preferably configured such that the fixing means is detachable from the object placing means, and the optimal shape and number of fixing means can be attached to the object placing means according to the object to be fixed. Is done. Thus, a plurality of fixing means having an arbitrary shape can be easily attached.

Further, the MRI apparatus of the present invention comprises a magnetic field generating means for generating a static magnetic field, a gradient magnetic field, and a high-frequency magnetic field in a measuring space, an object arranging means for arranging an object in a measuring space, A signal detecting means for detecting the detected magnetic resonance signal, and an image processing means for processing the magnetic resonance signal to display image data of an arbitrary part of the subject.
In the RI apparatus, there is provided a fixing means for fixing the subject and / or the signal detecting means to the subject arranging means, and the fixing means is connected via the connecting means.
The coupling means comprises two members, and one of the two members is fixedly supported and the other is variably supported, and a fastening force approximately twice the force acting on the other member is applied.

[0013] By providing such coupling means,
The overall shape of the combined fixing means can be adjusted according to the object to be fixed, and the fixing force of the fixing means can be increased without increasing the acting force, so that it is easy and reliable with a relatively small force. The object can be fixed to the

In this case as well, it is preferable to provide a supporting means for movably supporting the fixing means with respect to the subject placing means, and a locking means for locking the fixing means at a desired position of the subject placing means. . Thus, similarly to the above, the movement of the fixing means accompanying the movement of the subject is suppressed, and the fixing can be reliably performed.

Further, in the MRI apparatus of the present invention, preferably, the fixing means is provided with a cushioning material at a portion in contact with the object to be fixed. As a result, even if a considerably strong fixing force acts, it is possible to prevent the subject from suffering or damage to the signal detecting means.

In the MRI apparatus configured as described above, since the position change of the subject and the signal detecting means during the detection of the NMR signal can be sufficiently suppressed, an accurate and clear image flow and no false image can be obtained. Image data can be obtained.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a configuration diagram of a medical diagnostic MRI apparatus according to an embodiment of the present invention.

This MRI apparatus includes a magnet 10 as a magnetic field generating means for generating a uniform static magnetic field in a fixed space,
Gradient magnetic field coils 21, 22, and 23 for generating gradient magnetic fields in the same direction (z direction) as the static magnetic field formed by 10 and in directions perpendicular thereto (x direction and y direction), and a high-frequency magnetic field (RF magnetic field)
And an RF signal coil 40 for irradiation and detection for detecting a magnetic resonance signal generated from the subject 60, and a sequence control unit for outputting various commands to each device at a constant timing. 51, RF signal coil
An image processing unit 52 that processes a detection signal from 40 to reconstruct an image and a central processing unit (CPU) 53 that performs arithmetic processing and controls the entire apparatus are provided. An RF signal detection coil 41 dedicated to detection for detecting a magnetic resonance signal is detachably provided to the subject 60.

Further, as means for arranging the subject 60 in the measurement space formed by the magnetic field generating means, a bed top 80 on which the subject 60 is laid down, a support table 81 fixed in the measurement space,
A bed mechanism 82 for moving the couch top 80 to a predetermined position on the support table 81 is provided, and the subject 60 placed on the couch top 80 is moved by the couch top 82 by the bed mechanism 82. It is moved on a support 81 together with 80, and is inserted into a uniform static magnetic field space (measurement space) generated by the magnet 10 at a desired position.

In such an MRI apparatus, the RF power amplifier 44 amplifies the output of the RF waveform generator 45 and supplies it to the RF signal coil 40. RF by supplied RF power
The signal coil 40 generates a high-frequency magnetic field and causes a magnetic resonance phenomenon in a desired region of the subject 60 arranged in the measurement space. At this time, the gradient coil
21, 22, and 23 are the amplifiers 31, 32, and 33 of the power supply 30, respectively.
Driven by The RF signal component detected by the RF signal coil 40 or the RF signal detection coil 41 passes through an RF signal receiver 42, is subjected to signal processing by a signal processing unit 43, and is converted into image data by an image processing unit 52. The sequence control unit 52 instructs the RF signal coil 40 and the gradient magnetic field coils 21, 22, and 23 to be driven in accordance with a predetermined sequence. The image data obtained by the image processing section 52 is displayed on the display 54 as a medical diagnosis image. The operation of the measure is performed by the operation unit 55.

During the measurement, the subject 60 is laid on the couch top 80 in the measurement space for several minutes to several tens of minutes. In this case, the signal measured from the subject 60 Since the positional information of the subject 60 and the RF signal detecting coil 41 are required to be securely fixed on the couch top 80, the positional information in the static magnetic field space is given by the gradient magnetic field. For this reason, in the present invention, a fixing means capable of securely supporting and fixing the subject 60 and the RF signal detection coil 41 to the couch top 80 is provided.

FIG. 2 is a view showing an embodiment of such a fixing means. In this embodiment, the fixing means comprises a fixing belt 70 and a support 75 fixed to an end thereof.
Engages with a guide groove 85 (supporting means) provided on the couch top 80 to support the fixed belt 70 so as to be movable along the longitudinal direction of the couch top 80. Further, a notch 86 (locking means) having substantially the same size as the width of the fixed belt 70 is provided on the inner edge of the groove 85 of the bed top plate 80. Although only one notch 86 is shown in the figure, a plurality of notches 86 are preferably provided along the longitudinal direction of the groove 85.

In such a configuration, the fixed belt 70
Free movement can be performed in the longitudinal direction of the couch top 80 along the groove 85, and the position of the fixing belt can be arbitrarily changed. When the fixing belt 70 is fastened to the subject 60 or the RF signal coil 41 in a state where the fixing belt 70 is hooked on the desired notch 86, the fixing belt 70 is fixed by the fastening force.
Is securely engaged with the notch 86, and the top plate 80 is prevented from moving in the longitudinal direction. If a plurality of notches 86 are provided, the mounting position of the fixed belt 70 can be arbitrarily selected.

In this embodiment, the case where the notch 86 with which the fixed belt portion is engaged is shown, but the notch 86 may be one with which the support 75 is engaged. Although notched, the same effect can be obtained by providing a projection on the inner edge of the groove 85 of the couch top 80 on which the fixing belt 70 or the support 75 can be hooked. Furthermore, such notches or projections can be provided alternately and continuously.

Means for locking the fixing belt 70 to the top plate 80 include notches or protrusions, and grooves 85 of the support 75.
It is also possible to provide a separate non-slip 90 for restraining movement in the direction along. FIG. 3 shows an embodiment of a structure to which such a non-slip 90 is attached. Such a non-slip 90 has a structure which can be easily attached to and detached from the groove 85 and has a locking mechanism. Preferably, the anti-slip 90 is attached to both ends of the fixing belt 70 to restrict movement in both directions. The locking mechanism is a groove
It is possible to employ screwing to the groove 85, geometric engagement with the groove 85, provision of a mechanism such as a spring or an elastic body in the slip stopper itself, and the like.

In such a configuration, if the non-slip 90 is removed, the support 75 can be freely moved in the groove 85 of the couch top 80, and by attaching the non-slip 90 at a desired position. The fixing belt 70 can be fixed at that position. Therefore, as in the embodiment of FIG. 2, even when a force to move due to the subject 60 fixed during the measurement acts, the movement can be prevented.

Further, in a preferred embodiment of the present invention, the fixing means is detachably attached to the couch top 80. This allows
An optimal shape and number of fixing means can be attached according to an object to be fixed.

FIG. 4 shows an embodiment of the fixing means provided with such a detachable mechanism. In this embodiment, the groove of the couch top 80
An embodiment of a structure in which the fixing belt 70 is detachable by opening an end of the fixing belt 70 is shown. In this configuration, the fixing belt 70 is moved along the groove 85 and easily removed from the opened end, and the groove 85 and the fixing belt 70 are removed at this end.
Can be easily attached by engaging the support member 75 of the first embodiment.
Although the figure shows a structure in which both ends of the groove are open, it is sufficient that at least one end is open. Further, although the fixing belt 70 has a structure that can be attached and detached only at the end of the couch top 80, a detachable opening (not shown) can be provided in the middle of the groove 85 of the couch top 80. Such an opening has the same shape as the bottom of the support 75 of the fixed belt 70.

As a result, a required number of fixing belts having an arbitrary shape corresponding to the object to be fixed can be attached to the grooves 85 to fix the object. FIG. 5 shows fixing belts 71, 72, and 73 having various shapes for the chest, the head, and the like. These fixed belts 71, 72, and 73 have a shape suitable for the place where the subject 60 is fixed, and by mounting a plurality of these fixed belts 71, 72, and 73, the subject 60 can be effectively supported and fixed. it can. Although only three types of fixing belts are illustrated in FIG. 5, various shapes of fixing belts can be effectively supported and fixed by preparing fixing belts of various shapes.

The fixing belt 70 is attached and detached by a groove.
In addition to the release of 85, as shown in FIG.
By attaching fittings 76 and 77 that fit together with the fixing belt 75, the fixing belt can be made detachable. Also in this case, a plurality of fixing belts having a desired shape can be easily attached and detached by attaching the fixing members 77 to the fixing belts having the respective shapes shown in FIG.

As shown in FIG. 7, the fixing belt of each embodiment described above comprises two portions 74a and 74b whose ends are respectively engaged with the grooves 85 on both sides of the couch top 80 by the support 75. Attach one end of each of the other parts 74a, 74b with suitable connecting means
At 95, the test object or the RF signal coil is fixed and an appropriate fastening force is applied. By changing the coupling position by the coupling means, it is possible to reliably support and fix the position according to the fixation target such as the body shape of the subject. As the connecting means, a known magic tape or a pair of connecting members 96 and 97 as shown in FIG. 8 can be employed. The connecting member 97 can be attached to an arbitrary position of the fixing belt 74b, so that a connecting point between the fixing belt 74a and the fixing belt 74b can be arbitrarily selected.

When an object or the like is fixed by such a fixing belt, it is necessary to fasten the object with a considerably strong force in order to reliably prevent the movement of the object or the like. According to a second aspect of the present invention, there is provided a structure of a connecting portion of a fixing means capable of obtaining a large fastening force with a relatively small force. Hereinafter, such fixing means will be described.

A coupling 98 shown in FIG. 9 is an example of a coupling which can easily increase the supporting and fixing force of the fixing belts 74a and 74b more than the applied force. Has a structure in which two rolls having a length substantially equal to the width of the belt are separated from each other and supported by a plate-like member, and fixed belts 74a and 74b are wound around these two rolls. Each of the fixing belts 74a and 74b is provided with another connecting member such as a magic tape at the turning portions A and B, and the turning portions A and B can be fixed to the fixing belt by such a connecting device. When fixing the object to be fixed, any one of the fixed belts (fixed belt 74b in the figure) is fixed with a velcro tape or the like, and the winding position can be freely changed by pulling the folded portion A of the other fixed belt 74a. can do. Further, the roll around which the fixed belts 74a and 74b are wound is rotatably supported by a shaft and rotates as the above-described fixed belt 74a or 74b moves, thereby acting as a pulley, thereby making the movement smooth.

In the coupling member 98 having such a structure, when the folded portion A of the fixing belt 74a is pulled by the force of f in the direction of the arrow, the coupling member 98 acts as a pulley, and the force f 'pulls the fixing belt 74b. Is twice as large as f. Therefore, a larger fastening force can be generated with less force. In such a fixed belt, the subject 60 and the like are fastened with a strong fastening force by pulling the folded portion A of the fixed belt 74a, and then the folded portion A
Is fixed to the fixing belt 74a. In this case as well, by changing the fixing position of the folded portion A as shown in FIG.
Irrespective of the difference in the size of the object 60, the subject 60 can be supported and fixed effectively.

In this embodiment, a case has been described in which both of the two fixed belts can change the fixing position. However, at least one of the two fixed belts may have such a structure. However, by adopting a configuration in which the fixing position can be adjusted for both, the position of the coupling member 98 can be shifted regardless of the length of the belt, and the fastening work can be performed from either of the fixing belts. improves.

The fixing belt according to the second embodiment of the present invention as described above with reference to FIGS. 9 and 10 is provided with an MRI apparatus according to the present invention, which includes means for locking the fixing belt to the couch top 80. In addition, the present invention can be applied to a conventional MRI apparatus having no such locking means.
And locking means (notch 86, non-slip 9
By the combination with (0), an effect is obtained that the object can be fixed more reliably and with a stronger fastening force.

As described above, according to the MRI apparatus of the present invention, a fixing means capable of fixing an object with a strong fastening force is provided. At this time, if the fastening force is too strong, the subject 60 may be distressed. , The RF signal coil may be damaged.
Therefore, the fixing means of the present invention is preferably provided with a member for buffering such a fastening force. FIG. 11 shows an embodiment of a fixed belt provided with a buffer member.

In this embodiment, the fixed belt 70 is
Alternatively, a cushioning material 100 may be provided on a part of the contact surface with the RF signal coil 41.
Is affixed. The buffer material 100 may be attached to at least a part as shown in the figure, but may be attached to the entire surface. The presence of such a cushioning material 100 can relieve excessive pressure locally applied to the subject 60 from the fixed belt 70. The cushioning material 100 may be any material having a cushioning function, such as an elastomer, a porous material, or a nonwoven fabric. be able to.

The structure of the fixing belt provided with the cushioning member 100 can be applied to all the fixing means (fixing belt) of the present invention described above. If the fixing belt 100 does not have the fixed belt adhered thereto, the cushioning material 100 can be used as an independent component by being interposed between the fixing belt 70 and the object to be fixed.

[0041]

As described above, according to the present invention, the mounting position of the fixing means can be arbitrarily changed according to the shape of the object or the place to be supported and fixed. Can be maintained. Also,
By adopting a structure in which the fixing means can be attached to and detached from the object placement means, a desired shape and a desired number of fixing means can be attached as necessary, and the object can be fixed more effectively.

Further, according to the present invention, by providing a connecting means having a function of increasing the fastening force without increasing the applied force, as the connecting means of the fixing means composed of two members, the object can be effectively removed. Support can be fixed.

The MRI apparatus equipped with such a fixing means can effectively suppress the movement of the subject and the signal detecting means, and can obtain accurate and clear MR image data without a flow or a false image. it can.

[Brief description of the drawings]

FIG. 1 is an apparatus configuration diagram showing an embodiment of an MRI apparatus to which the present invention is applied.

FIG. 2 is a view showing one embodiment of a fixing means according to the present invention.

FIG. 3 is a view showing another embodiment of the fixing means according to the present invention.

FIG. 4 is a view showing an embodiment of a supporting means for supporting the fixing means according to the present invention.

FIG. 5 shows various shapes of the fixing means according to the present invention.

FIG. 6 is a view showing another embodiment of the fixing means according to the present invention.

FIG. 7 is a view showing an embodiment of the connecting means of the fixing means according to the present invention.

FIG. 8 is a view showing another embodiment of the connecting means of the fixing means according to the present invention.

FIG. 9 is a view showing still another embodiment of the connecting means of the fixing means according to the present invention.

FIG. 10 is a view showing an example of attachment of fixing means by the coupling means of FIG. 9;

FIG. 11 is a view showing still another embodiment of the fixing means according to the present invention.

FIG. 12 is a view showing a conventional support fixture.

FIG. 13 is a view showing another conventional support fixture (a),
(B) is a figure which shows a different use state, respectively.

[Explanation of symbols]

10 ... magnet (magnetic field generating means) 21, 22, 23 ... gradient coil (magnetic field generating means) 40 ... RF signal coil (high-frequency magnetic field generating means, signal detection) Means) 41 RF signal detection coil (signal detection means) 51 Image processing means 60 Subject 70, 71, 72, 73, 74a, 74b ···························································································· ... Notch (locking means) 90... Non-slip (locking means) 95, 98... Coupling portion (coupling means) 100...

Claims (5)

[Claims] 1. Magnetic field generating means for respectively generating a static magnetic field, a gradient magnetic field, and a high-frequency magnetic field in a measurement space, an object arranging means for arranging an object in the measurement space, and a magnetic resonance signal generated from the object A magnetic resonance imaging apparatus comprising: a signal detection unit that detects the object; and an image processing unit that processes the magnetic resonance signal and displays image data of an arbitrary part of the subject. Fixing means for fixing the means to the subject placing means, supporting means for movably supporting the fixing means with respect to the subject placing means, and placing the fixing means at a desired position of the subject placing means. A magnetic resonance imaging apparatus comprising: locking means for locking. 2. The apparatus according to claim 1, wherein said fixing means is detachable from said object placing means, and said supporting means having an optimum shape and number of said fixing means can be attached to said object placing means according to an object to be fixed. The magnetic resonance imaging apparatus according to claim 1, wherein 3. A magnetic field generating means for generating a static magnetic field, a gradient magnetic field, and a high-frequency magnetic field in a measurement space, an object arranging means for arranging an object in the measurement space, and a magnetic resonance signal generated from the object. A magnetic resonance imaging apparatus comprising: a signal detection unit that detects the object; and an image processing unit that processes the magnetic resonance signal and displays image data of an arbitrary part of the subject. Fixing means for fixing the means to the object placement means, the fixing means comprising at least two members connected via a connecting means, wherein the connecting means fixes any one of the two members A magnetic resonance imaging apparatus, wherein the other is variably supported and a fastening force approximately twice as large as a force acting on the other member is applied. 4. An apparatus according to claim 1, further comprising: a supporting means for movably supporting said fixing means with respect to said subject placing means; and a locking means for locking said fixing means at a desired position of said subject placing means. The magnetic resonance imaging apparatus according to claim 3, wherein: 5. The fixing means according to claim 1, wherein said fixing means includes a buffer material at least in a portion in contact with an object to be fixed.
5. The magnetic resonance imaging apparatus according to any one of claims 4 to 4.