JP5319214B2 - Magnetic resonance imaging system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus, and more particularly to a mechanism for allowing a top plate on which a patient is placed to move a larger distance and move with high accuracy in the magnetic resonance imaging apparatus.

In a magnetic resonance imaging apparatus (hereinafter referred to as “MRI apparatus”), a top plate is required for sleeping on a patient and carrying it in the MR imaging space.
Conventionally, imaging is possible by determining an imaging position outside the imaging space, moving a sleeping patient into the imaging space, and moving the imaging part to an imaging space having a certain size.

  By the way, a mechanism for supporting the top plate is required to accurately send the top plate on which the patient is placed into the imaging space. Since a certain degree of rigidity is required for the mechanism for supporting the top plate, it is desirable to use a highly rigid metal member (see, for example, Patent Document 1).

However, because of the performance of the MR apparatus, it is not desirable to install a metal top plate support mechanism in the magnet in order to acquire an image. Therefore, the mechanism for supporting the top plate is installed outside the magnet.
In the future, we are moving to a high-performance MR device with a higher magnetic field strength. However, if the magnet is increased in size to increase the magnetic field strength, the patient must be sent to the center of the magnetic field of the enlarged magnet. In addition, the bed is also increased in size to ensure the stroke. In this case, the top plate needs to have a certain length, which increases the cost of the apparatus, and requires a larger room to be installed. Since it is assumed that the room cannot be widely remodeled, it is impossible to install an MR device using a large-sized high-performance magnet.

Japanese Patent Laid-Open No. 2003-180652

Regarding the medical bed of the MRI apparatus, some MRI apparatuses adopting the horizontal magnetic field method realize a stroke using a multi-stage slide mechanism for whole body imaging.
In the horizontal magnetic field method, the magnetic field space is secured in a cylindrical shape, and the above-described mechanism portion can be accommodated using the space below the cylinder.

  However, since this mechanism becomes large in the vertical direction, the vertical magnetic field method so-called open type MRI apparatus cannot be used for securing an imaging space. Furthermore, as the magnets become stronger, the magnets become larger, and the bed needs to be enlarged accordingly.

  Accordingly, an object of the present invention is to enable whole-body imaging while suppressing the enlargement of the bed, so that a long stroke can be realized while a vertical magnetic field system space is secured, and lateral movement within the magnetic field space is also possible. It is to provide a mechanism part of the bed.

  In order to solve the above problems, the main configuration of the magnetic resonance imaging apparatus of the present invention includes a top plate on which a patient is placed, a table on which the top plate is placed, and a driving force provided on the top plate. An auxiliary top plate that transmits the driving force, a first driving force transmission mechanism that transmits the driving force to the top plate, and a second driving force transmission mechanism that transmits the driving force to the auxiliary top plate. The auxiliary top plate is juxtaposed on both sides of the top plate on the surface on which the table is placed, and by moving the auxiliary top plate, The top board is moved via the first driving force transmission mechanism, and a desired examination site of the patient lying on the top board is moved into the imaging space.

  Furthermore, the moving distance of the top plate with respect to the table is larger than the moving distance of the auxiliary top plate with respect to the table.

  Thus, what can be larger than the moving distance of the auxiliary top plate relative to the table can be achieved by using the belt mechanism. That is, the first belt for transmitting the driving force from the drive unit to the auxiliary top plate, and the second belt provided on the auxiliary top plate, a part of which is fixed to the auxiliary top plate, A part of the first belt is fixed to the auxiliary top plate, a second belt is further fixed to a part of the top plate, and the second belt is moved to the auxiliary top according to the movement of the auxiliary top plate. This can be achieved by rotating through a pair of rotating bodies provided on the plate, and with the rotation, the top plate is configured to move in the direction of movement of the auxiliary top plate.

  ADVANTAGE OF THE INVENTION According to this invention, the mechanism part of the bed which can implement | achieve a long stroke, ensuring the space of a perpendicular magnetic field system, and can also move laterally within a magnetic field space can be provided. Thereby, the open space obtained by the vertical magnetic field method can be used effectively, and the examination can be performed without giving the patient a feeling of pressure.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows a horizontal magnetic field type bed 200.

  In the case of a horizontal magnetic field type MRI apparatus, the magnetic field space is cylindrical, and a top plate on which a patient is laid is sent to that portion and imaged. Since the imaging region of the patient is arranged so as to be in the center of the cylindrical portion, the multistage mechanism can be arranged in the space below the cylindrical portion.

  Since the top plate 100 on which the patient is placed is used in the magnetic field space of the MR magnet 300, it is necessary to manufacture the top plate 100 with a nonmagnetic material such as a resin that does not affect the static magnetic field of the MRI apparatus. Since a space that can be formed on the lower side of the top board 100 on which the patient is placed can be used, a mechanism for supporting the weight of the patient can be sufficiently arranged even if a resin material is used.

FIG. 2 shows an outline of a vertical magnetic field type bed that is an example of the present invention.
The bed 30 includes a top board 1 on which a patient is placed, a table body 4 on which the top board 1 is placed, and a support portion 7 that supports the table body 4. The support part 7 is usually composed of a table lift part (not shown) having a function of moving in the vertical direction. Further, auxiliary top plates 3 and 3 ′ are provided on the left and right sides of the top plate 1 via drive belts 2 for driving the top plate 1.
The auxiliary couchtops 3 and 3 ′ are placed on the top surface of the couchtop 1, and the driving force of the driving unit 5 built in the table body 4 is applied to the auxiliary couchtop 3 via the belt mechanism having the belt 6. , 3 '.

The details of this belt mechanism will be described in detail with reference to FIGS. 3 and 4, but the top plate 1 is above the table body 4 with respect to the auxiliary top plate 3 by the same distance as the auxiliary top plate 3 moves on the table 4. It has become a mechanism to move. Therefore, the top plate 1 can move twice as much as the auxiliary top plate 3 with respect to the table 4.
Therefore, as compared with the conventional method, the top board 1 on which the patient is placed can easily reach the imaging space 22 as shown in FIG.

  As described above, although the configuration is simple, a long stroke capable of imaging the whole body can be realized even if the room in which the apparatus is installed is not large. Furthermore, by using a toothed belt as the belt 6, position reproducibility can also be realized.

FIG. 3 shows an overhead view of a mechanism portion for moving the auxiliary top plate 3 and the top plate 1.
First, in the auxiliary top plate 3, a part of the second belt 6 is fixed to the auxiliary top plate column 16, and the driving force of the second belt 6 is transmitted to the auxiliary top plate 3 through the auxiliary top plate column 16. On the other hand, the top plate 1 is fixed by a first belt 2 and a first belt-top plate fixture 14 provided on the auxiliary top plate 3, and the driving force of the first belt is transmitted to the top plate 1.
Further, the table 4 is fixed by a first belt-auxiliary top plate fixing tool 15 attached to a position of the first belt facing the first belt-top plate fixing tool 14.

When the motor 5 receives the electrical signal, the rotation of the motor 5 is transmitted to the second belt pulley 12 via the driving force transmission shaft 9, and the second belt moves in a predetermined direction in accordance with the rotation of the second belt pulley 12. Start rotating. The rotation of the second belt moves the auxiliary top plate 3 via the auxiliary top plate support 16. By this movement, since the second belt is fixed to the table 1 by the first belt-auxiliary top plate fixing tool 15, the second belt starts to rotate in the direction opposite to the movement of the auxiliary top plate. Due to this rotation, the top plate 1 is fixed by the first belt-top plate fixture 14, and therefore starts to move in accordance with the movement of the second belt.
In the above description, the auxiliary top plate 3 arranged on one side of the top plate 1 has been described. However, the same applies to the auxiliary top plate 3 ′ arranged on the other side.

  4A) shows a cross section of the mechanism portion shown in FIG. 3, and FIG. 4B) is a cross section showing a cross section in a direction perpendicular to the cross section of the mechanism portion shown in FIG.

The moving mechanism of the top plate and the auxiliary top plate will be described with reference to this figure.
The rotational driving force from the motor 5 is transmitted to the pulley 12 via the drive transmission shaft 9. As the second belt pulley 12 rotates, the second belt 6 moves in a predetermined direction. The second belt 6 is fixed to the auxiliary top plate 3 by a second belt-auxiliary top plate fixing bracket 15. Accordingly, the auxiliary top plate 3 moves in the same direction as the second belt 6 as the second belt 6 moves. On the other hand, the first belt 2 is fixed by an auxiliary top plate 3 and a first belt-auxiliary top plate fixing bracket 14. Therefore, when the auxiliary top plate 3 moves, the first belt 2 rotates through the first belt pulleys 13 and 13 ′. The moving direction of the first belt-top plate fixing bracket 14 and the moving direction of the first belt-auxiliary top plate fixing bracket 15 move in directions opposite to each other. The top plate 1 fixed to the first belt-top plate fixing bracket 14 by the movement starts to move in the same direction as the first belt-top plate fixing bracket 14. From the above, it can be seen that the auxiliary top plate 3 and the top plate 1 move in the same direction.

  Here, assuming that the first belt does not rotate, the top plate 1 is connected to the auxiliary top plate 3 via the first belt, so the movement of the auxiliary top plate 3 and the movement of the top plate 1 are the same. In the direction and the same distance. Further, in practice, the first belt is fixed to the table 15 and the auxiliary top plate 3 by the movement of the auxiliary top plate 3 as shown in FIG. Along with the movement, the fixing device 15 of the first belt must be moved in the direction opposite to the auxiliary top plate. As a result, the first belt rotates around the first belt pulleys 13, 13 '. Since the movement distance of the auxiliary top plate and the movement distance of the fixture 15 are the same, eventually, the top board 1 moves relative to the table with the top board movement distance when the first belt does not rotate. The plate 3 will move twice the distance it moves.

  Further, by adopting a structure in which the auxiliary top plate 3 and the top plate 1 are juxtaposed on the table 4, the top plate 1 can be moved vertically, horizontally, and obliquely with respect to the longitudinal direction. The reason is that the top plate 1 can be moved in the vertical direction by the driving force of the auxiliary top plate 3, while the auxiliary top plate 3 is provided with another drive mechanism in the direction perpendicular to the longitudinal direction. Is movable. Thereby, the top plate 1 can be substantially moved also in the lateral direction. This lateral movement mechanism is a mechanism for moving the drive system including the auxiliary top plate 3 and the second belt 6 in the lateral direction, and can be housed in a table (not shown).

  As described above, in the present invention, by providing the auxiliary couchtops 3 and 3 ′ on the same plane of the table 4 in parallel with the couchtop 1, the vertical magnetic field can be compared with the horizontal magnetic field type MRI apparatus. The problems of the MRI apparatus of the system can be solved. That is, in the case of a horizontal magnetic field type MRI apparatus, the imaging part of the patient can be arranged so as to be the central part of the cylindrical part, so a multi-stage mechanism for moving the top plate to the space below the cylindrical part is arranged. However, in the case of a vertical magnetic field type MRI apparatus, since this spatial region does not exist, the multi-stage mechanism cannot be arranged. However, since the top plate 1 and the auxiliary top plate 3 are juxtaposed on the same surface as the table 4 as in the present invention, there is no need to stack the top plate moving mechanism in the vertical direction.

  Furthermore, as described above, by providing the belt mechanism including the auxiliary top plate and the first and second belts, the moving distance of the top plate 1 can be doubled as the moving distance of the auxiliary top plate. It has the effect of being compact.

FIG. 5 shows an example in which the vertical magnetic field type bed according to the present invention is applied to an MRI apparatus.
The patient 20 laid on the top 1 is transported to the imaging space 22 as the top 1 moves. At this time, the auxiliary couchtop 3 moves to the entrance of the gantry 21, but the couchtop 1 can move to the imaging space 22 further behind the entrance. The reason is that, as described above, the top plate 1 can be moved twice relative to the table 4 by the moving distance of the auxiliary top plate 3.

  FIG. 6 shows a plan view of the MRI apparatus as viewed from above. The circular portion 23 shows the gantry 21.

  The position of the top board 1 at the time when the patient is laid down is outside the gantry 21 as shown by the solid line part in FIG. Thereafter, the auxiliary top plate 3 is moved into the gantry 21 through the second belt 6 and the first belt 2 by the rotation of the motor 5, and finally the tip portion of the top plate 1 is a circular portion 23 of the gantry 21. Projects outward. It can be seen that the foot of the patient 20 is located at the center of the gantry 21.

  As described above, by using the vertical magnetic field type bed according to the present invention, it is possible to realize a long stroke top plate movement with a short top plate while ensuring a vertical magnetic field type space.

Schematic which shows a horizontal magnetic field type bed. Schematic which shows the perpendicular magnetic field system bed of this invention. The overhead view which shows the auxiliary top plate drive mechanism part of this invention. (a) is sectional drawing which shows the cross section of the auxiliary top plate drive mechanism part of this invention, b) is sectional drawing which shows the cross section orthogonal to the cross section. The bird's-eye view which shows the example of application of the perpendicular magnetic field system bed of this invention. The top view which shows the example of application of the perpendicular magnetic field system bed of this invention.

Explanation of symbols

1 ... top plate,
2,2 '... the first belt,
3, 3 '... auxiliary top plate,
4 ... Table,
5 ... Drive unit,
6,6 '... second belt,
7 ... Table lift,
8 …… Second belt-Auxiliary top plate fixing bracket,
9, 9 '... driving force transmission shaft,
11 ... Bottom of gantry,
12, 12 '... pulley for second belt,
13, 13 '... pulley for first belt,
14 ... 1st belt-top plate fixing tool,
15 ... 1st belt-auxiliary top plate fixing tool,
16 ... Auxiliary top plate support,
20 ... patient,
21, 23 ... Gantry,
22: Imaging space,
30 ... Bed,
100 ... top plate,
200 ... sleeper,
300 ... Gantry.

Claims (9)

A tabletop for sleeping patients,
A table on which the top plate is placed;
An auxiliary top plate provided on the table and transmitting a driving force to the top plate;
A first driving force transmission mechanism that is provided on the auxiliary top plate and transmits a driving force to the top plate;
A second driving force transmission mechanism for transmitting a driving force to the auxiliary top plate;
A driving unit that applies a driving force to the second driving force transmission mechanism;
The auxiliary top plate is a on the surface of the table being juxtaposed on the outside of both side surfaces of the top plate,
A magnetic resonance imaging apparatus, wherein the top plate is moved through the first driving force transmission mechanism by the movement of the auxiliary top plate. The first driving force transmission mechanism has a belt that rotates around a pair of rotating bodies provided on the auxiliary top plate as the auxiliary top plate moves,
By translating the top plate with the rotation of the belt, and further translating the top plate by movement of the auxiliary top plate, the top plate has a translation distance by the rotation and a translation distance by the auxiliary top plate. 2. The magnetic resonance imaging apparatus according to claim 1, wherein the magnetic resonance imaging apparatus is moved by a synthesized distance. The first driving force transmission mechanism is provided on the auxiliary top plate, and has a first belt that rotates around a pair of rotating bodies,
The second driving force transmission mechanism has a second belt that transmits the driving force from the driving unit to the auxiliary top plate,
A part of the first belt is fixed to the top plate, and the other part is fixed to the table.
The auxiliary top plate is moved by the rotation of the second belt,
In response to the movement, the first belt rotates through the pair of rotating bodies provided on the auxiliary top plate,
2. The magnetic resonance imaging apparatus according to claim 1, wherein the top plate is configured to move in the direction of movement of the auxiliary top plate in accordance with the rotation.   The magnetic resonance imaging apparatus according to claim 1, wherein a moving distance of the top plate with respect to the table is larger than a moving distance of the auxiliary top plate with respect to the table.   The magnetic resonance imaging apparatus according to claim 1, wherein the top plate can move more than a length in a longitudinal direction of the top plate.   The top plate includes means capable of moving in a longitudinal direction of the top plate, a direction perpendicular to the longitudinal direction, and an oblique direction in which the longitudinal direction and the perpendicular direction are combined. Item 2. The magnetic resonance imaging apparatus according to Item 1.   The magnetic resonance imaging apparatus according to claim 1, wherein the table is supported by a support member.   The magnetic resonance imaging apparatus according to claim 7, wherein the support member has a mechanism for moving the table in a vertical direction.   2. The imaging apparatus according to claim 1, wherein after the imaging, the top plate can be accurately moved to desired longitudinal, lateral and oblique positions with respect to the longitudinal direction using the movable means based on the captured image. The magnetic resonance imaging apparatus according to 1.

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