JP4843469B2 - Magnetic resonance imaging system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging (hereinafter referred to as MRI) apparatus using a superconducting magnet apparatus.

  An MRI apparatus images a living tissue by utilizing the fact that the nuclear magnetic resonance (hereinafter referred to as NMR) phenomenon of hydrogen nuclei of hydrogen atoms constituting a living body varies depending on the tissue in the living body. In addition, the strength of resonance that differs for each tissue and the speed of temporal change in resonance appear as contrast for each position of the image.

  In the MRI apparatus, a living body can be formed into a tomographic image by the density of hydrogen nuclei by measuring an electromagnetic wave emitted by a hydrogen nucleus spin due to an NMR phenomenon and performing arithmetic processing using the electromagnetic wave as a signal. Since the strength of the electromagnetic field generated by the electromagnetic waves emitted by the hydrogen nuclear spins is proportional to the strength of the static magnetic field in the examination region where the living body is placed, a superconducting magnet device that can generate a high-strength static magnetic field is used.

  The MRI apparatus uses a gradient magnetic field coil and a high-frequency irradiation coil. The gradient magnetic field coil generates a gradient magnetic field that spatially changes the magnetic field so as to be superimposed on the static magnetic field of the examination region in order to obtain position information in the examination region, and the high-frequency irradiation coil causes the NMR phenomenon. By applying an electromagnetic wave having a resonance frequency, it is possible to measure the electromagnetic wave emitted by the hydrogen nuclear spin for each minute region in the inspection region.

  When a pulsed current is applied to generate a gradient magnetic field, the gradient magnetic field coil vibrates due to the Lorentz force due to the static magnetic field generated by the superconducting magnet device. If this vibration is transmitted to the superconducting coil, which is the source of the static magnetic field of the superconducting magnet device, and the superconducting coil is vibrated, the superconducting coil is time-consuming even if the amplitude of the micron order is vibrated. Therefore, the tomographic image of the MRI apparatus is adversely affected. For this reason, the MRI apparatus employs a structure in which the vibration of the gradient magnetic field coil is not easily transmitted to the superconducting coil.

  On the other hand, the MRI apparatus is manufactured in a factory, operates in a hospital, etc., and is used for diagnosis of a subject. Therefore, the MRI apparatus must be transported between the factory and the hospital. During transportation, impacts due to road surface conditions, etc., and impacts caused by crane and forklift operations during shipping occur. Even if such impacts occur, the MRI apparatus must support the built-in superconducting coil. Don't be. In general, if you try to support it firmly, it is thought that vibration will be transmitted easily through the support, and the vibration of the gradient coil during operation will not be transmitted to the superconducting coil, and the superconducting coil will also withstand the impact during transportation Thus, a support structure that can be supported firmly has not been proposed.

In addition, in the MRI apparatus using a permanent magnet, the structure which suppresses that a support body of a permanent magnet deform | transforms at the time of transport is proposed (for example, refer patent document 1).
JP 2002-325743 A

  The present invention is intended to solve the above-mentioned problems, and its purpose is not to transmit the vibration of the gradient magnetic field coil to the superconducting coil during operation, but to support the superconducting coil to withstand the impact during transportation during transportation. An MRI apparatus is provided.

In order to achieve the above object, an MRI apparatus of the present invention includes a superconducting coil that generates a static magnetic field in an examination region by flowing a predetermined current, supports the superconducting coil, and stores the superconducting coil together with a refrigerant. In an MRI apparatus having a coil container and a vacuum container that surrounds the coil container and is maintained in a vacuum, the first heat insulating support part that can support the coil container in a heat-insulating manner, and the first inside the vacuum container. securable to the heat-insulating supporting part has a through support extending through said vacuum vessel, on the outside of the vacuum vessel, Ri fastenable der and the vacuum container and the through-supporting unit,
And the penetration support part is always fixed to the first heat insulation support part,
Alternatively, the first heat insulating support part is a pipe or a rod having one end fixed to the coil container and the other end fixed to the penetrating support part, and an extension line in the axial direction of the first heat insulating support part. The points where they intersect each other are located inside the penetration support part,
Alternatively, the first heat insulating support part is a pipe or a rod having one end fixed to the coil container and the other end fixed to the penetrating support part, and an extension line in the axial direction of the first heat insulating support part. The arrangement angle intersecting each other is approximately 90 degrees,
Or it is provided so that the said coil container may be surrounded, it has a heat shield which is heat-insulated and supported by the said 1st heat insulation support part, and the said 1st heat insulation support part penetrates, It is characterized by the above-mentioned.

  According to such an MRI apparatus, it is possible to provide an MRI apparatus that does not transmit vibration of the gradient magnetic field coil to the superconducting coil during operation and supports the superconducting coil so as to withstand an impact during transportation.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
As shown in FIG. 1, the MRI (magnetic resonance imaging) apparatus 1 according to the first embodiment of the present invention can be an open MRI apparatus. The open-type MRI apparatus includes a superconducting magnet device 2, a bed 4 on which the subject is placed, a control device that controls the superconducting magnet device 2 and the bed 4 and analyzes a nuclear magnetic resonance signal from an arbitrary part of the subject. 3. The superconducting magnet device 2 includes a vacuum container 5 whose inside is maintained in a vacuum, a penetration support part 11, a fastening part 15 that fastens the penetration support part 11 and the vacuum container 5, and a vacuum container 5 of the penetration support part 11. And an adjusting screw 14 for adjusting the height with respect to. The fastening portion 15 is disposed between the vacuum vessel 5 and the penetration support portion 11, maintains a constant distance between the vacuum vessel 5 and the penetration support portion 11, penetrates the spacer 13, and reaches the vacuum vessel 5 and the penetration support portion. 11 and a fastening screw 12 for fastening the spacer 13 to each other. The vacuum vessel 5 has a pair of first vacuum vessel 5a, second vacuum vessel 5b, and a vacuum connection tube 5c that are arranged vertically. Two vacuum connection pipes 5c are erected on the outer peripheral portion of the second vacuum container 5b, and the first vacuum container 5a is supported by these vacuum connection pipes 5c. Since the vacuum connection pipe 5c communicates with the first vacuum container 5a and the second vacuum container 5b, the atmospheric pressure inside the first vacuum container 5a and the second vacuum container 5b is set to a reduced pressure state of equal pressure. Can do.

In the open MRI apparatus, an examination region 9 is formed between a first vacuum vessel 5a and a second vacuum vessel 5b separated by a vacuum connecting tube 5c, and a subject is put into the examination region 9 for medical care. Therefore, the field of view of the subject is not closed and is open and popular with the subject.
Each of the first vacuum vessel 5a and the second vacuum vessel 5b has a cylindrical shape having the Z axis as a common central axis. The first vacuum vessel 5a and the second vacuum vessel 5b are symmetrical with respect to a plane passing through the inspection region 9 and having the Z axis as a normal line.

  FIG. 2 is a perspective view from above of the superconducting magnet device 2 according to the first embodiment of the present invention, and FIG. 3 is a cross-sectional view in the AA direction of FIG. FIG. 4 is an enlarged view (at the time of transportation) of the periphery of the penetration support portion 11 of FIG.

  As shown in FIG. 3, the superconducting magnet device 2 generates a static magnetic field in the inspection region 9 by flowing a predetermined permanent current, and a pair of annular superconducting coils 6 a and 6 b whose central axis coincides with the Z axis. The coil container 8 that supports the superconducting coils 6a and 6b and accommodates the superconducting coils 6a and 6b together with the refrigerant 22, the heat shield 7 provided so as to surround the coil container 8, the coil container 8 and the heat And a vacuum vessel 5 that surrounds the shield 7 and is maintained in a vacuum.

  The refrigerant 22 is directly cooled by immersing the superconducting coils 6a and 6b. Liquid helium (He) is used as the coolant 22. The coil container 8 is formed in a cylindrical shape with the Z axis as the central axis so as to be accommodated along the annular superconducting coils 6a and 6b, and the volume thereof is made as small as possible. Similarly, the heat shield 7 is formed in a cylindrical shape having the Z axis as a central axis so as to cover the cylindrical coil container 8 and suppresses intrusion heat by making the surface area as small as possible.

  Even if the superconducting magnet device 2 is disposed in a room temperature room, the vacuum vessel 5 is in a vacuum, so that the heat in the room is not transmitted to the coil vessel 8 by conduction or convection. Moreover, since the heat shield 7 is cooled by a refrigerator (not shown), it absorbs the radiant heat from the vacuum vessel 5 and releases it to the refrigerator, so that the coil vessel 8 is not heated by the radiant heat. The heat shield 7 may be set to a medium low temperature between the extremely low temperature of the refrigerant 22 and the room temperature. As described above, the superconducting coils 6 a and 6 b and the coil container 8 can be stably set to the cryogenic temperature of the refrigerant 22.

  The superconducting coils 6a and 6b are arranged to face each other in the vertical direction, and have a first superconducting coil 6a and a second superconducting coil 6b that form a pair with the center axis thereof coinciding with the Z axis.

  The coil container 8 includes a first coil container 8a enclosing the first superconducting coil 6a, a second coil container 8b enclosing the second superconducting coil 6b and separated downward from the first coil container 8a, and a first coil container 8a. The coil container 8a and the second coil container 8b are connected to each other, and the coil 22 passes through the refrigerant 22 to support the first coil container 8a and to be supported by the second coil container 8b. The coil connection pipe 8c is disposed on the outer periphery of the first coil container 8a and the second coil container 8b. The number of coil connecting pipes 8c may be one, or two or more.

  The heat shield 7 includes a first heat shield 7a containing the first coil container 8a, a second heat shield 7b containing the second coil container 8b and separated from the first heat shield 7a, a first heat shield 7a, It has a shield connection pipe 7c that connects the second heat shield 7b and encloses the coil connection pipe 8c, and a shield support portion 7d that supports the heat shield 7. The shield connecting pipe 7c is disposed on the outer periphery of the first heat shield 7a and the second heat shield 7b. The shield connecting pipe 7c may be one or two or more according to the number of the coil connecting pipes 8c.

  The vacuum vessel 5 includes a first vacuum vessel 5a including a first coil vessel 8a, a first heat shield 7a, a first heat insulating support portion 16, and a fitting / removing portion 18, a second coil vessel 8b, and a second heat shield. 7b and the second heat insulating support portions 23 and 24, the second vacuum container 5b separated downward from the first vacuum container 5a, and the first vacuum container 5a and the second vacuum container 5b are connected to each other. 5a is supported by the second vacuum vessel 5b, and has a coil connection tube 8c and a vacuum connection tube 5c containing the shield connection tube 7c. The vacuum connection pipe 5c is disposed on the outer peripheral portion of the first vacuum container 5a and the second vacuum container 5b. The vacuum connection pipe 5c may be one or two or more according to the number of the coil connection pipes 8c. As described above, the inspection region 9 can be provided between the first vacuum vessel 5a, the second vacuum vessel 5b, and the vacuum connection tube 5c.

  The first superconducting coil 6a, the first coil container 8a, the first heat shield 7a, and the first vacuum container 5a can be considered to constitute the first cryostat 21a. Similarly, it can be considered that the second cryostat 21b is constituted by the second superconducting coil 6b, the second coil container 8b, the second heat shield 7b, and the second vacuum container 5b. Further, it can be considered that the connecting column 21c is constituted by the coil connecting tube 8c, the shield connecting tube 7c, and the vacuum connecting tube 5c. The first cryostat 21a and the second cryostat 21b are spaced apart from each other by a connecting column 21c.

  An inspection part 26 and an inspection part 27 are provided on the mutually opposing wall surfaces of the first vacuum container 5a and the second vacuum container 5b, respectively. Each of the inspection units 26 and 27 has a gradient magnetic field coil and a high-frequency irradiation coil. The gradient magnetic field coil and the high-frequency irradiation coil are fixed to the first vacuum vessel 5a and the second vacuum vessel 5b. The MRI apparatus 1 measures a nuclear magnetic resonance signal emitted from a hydrogen nuclear spin due to an NMR phenomenon, and performs an arithmetic process on the nuclear magnetic resonance signal to form a tomographic image of the inside of a subject based on the hydrogen nuclear density. At that time, first, a permanent current is passed through the superconducting coils 6 a and 6 b to generate a static magnetic field in the inspection region 9. Next, the gradient magnetic field coil applies a gradient magnetic field in which the magnetic field is spatially changed to the inspection region 9 for the purpose of obtaining positional information in the inspection region 9. Further, the high frequency irradiation coil applies an electromagnetic wave having a resonance frequency for causing the NMR phenomenon to the inspection region 9. As a result, the nuclear magnetic resonance signal emitted from the hydrogen nuclear spin is measured for each micro area in the examination area 9 and the nuclear magnetic resonance signal is processed to form a tomographic image of the inside of the subject by the hydrogen nuclear density. be able to.

  The superconducting coils 6a and 6b, the coil container 8, the heat shield 7 and the vacuum container 5 are each provided with a heat insulating support to maintain a healthy positional relationship and maintain a high heat insulating performance in order to maintain the mutual positional relationship. Realized. When a pulsed current is applied to a gradient coil to generate a gradient magnetic field, the gradient coil is in a static magnetic field, so Lorentz force acts on the gradient coil in which current flows, and induces vibration in the gradient coil. To do. This vibration is transmitted to the vacuum vessel 5 that fixes the gradient magnetic field coil, and causes the vacuum vessel 5 to vibrate.

  Even if the vacuum vessel 5 vibrates, it does not vibrate as a whole, and the bottom of the vacuum vessel 5 pressed against the floor 25 due to its own weight or the like hardly vibrates. Therefore, the second heat insulating support portions 23 and 24 are fixed to the bottom portion of the vacuum vessel 5 (second vacuum vessel 5b) and support the coil vessel 8 and the heat shield 7 with heat insulation. Since the bottom of the vacuum vessel 5 (second vacuum vessel 5b) is difficult to vibrate, the second heat insulating support portions 23 and 24 hardly vibrate, and the vibration of the vacuum vessel 5 is coiled via the second heat insulating support portions 23 and 24. There is almost no transmission to the container 8, the heat shield 7, and the superconducting coils 6a, 6b.

  However, the second heat insulating support portions 23 and 24 alone provide a support system that is close to a cantilever, and when subjected to an impact during transportation, the heat shield 7 and the coil container 8 fall down, and the upper portions of the heat shield 7 and the coil container 8 move greatly. However, it is considered that an excessive load is applied to the second heat insulating support portions 23 and 24 due to bending or axial force, resulting in large deformation or damage.

  Therefore, as shown in FIG. 3 and FIG. 4A, in the first embodiment, the coil is fixed to the upper part of the coil container 8 (first coil container 8a) and the heat shield 7 (first heat shield 7a). The first heat insulating support 16 capable of supporting the container 8 and the heat shield 7 in a heat insulating manner, the vacuum container 5 (first vacuum container 5a), the coil container 8 (first coil container 8a), and the heat shield 7 (first heat shield 7a). ), And can be fixed to the first heat insulating support portion 16 inside the vacuum vessel 5, and a through support portion 11 penetrating the upper portion of the vacuum vessel 5 (first vacuum vessel 5 a) is provided. ing. Furthermore, the vacuum vessel 5 (first vacuum vessel 5a) can be disposed outside the upper portion, and is fixed to the fastening portion 15 that can fasten the penetration support portion 11 and the vacuum vessel 5, and the first heat insulation support portion 16. A fitting / removal portion 18 for fitting / removing the penetration support portion 11 is provided. The fastening portion 15 includes a spacer 13 that can be disposed between the vacuum vessel 5 and the penetration support portion 11, and a fastening screw 12 that passes through the spacer 13 and can fasten the vacuum vessel 5 and the penetration support portion 11. ing. By changing the height of the penetration support portion 11 with respect to the fitting / removal portion 18, the cylindrical portion of the penetration support portion 11 is fitted into the annular fitting / removal portion 18 to be joined or detached and separated. Can do. By fitting the penetration support part 11 into the fitting / removing part 18, the penetration support part 11 can be fixed to the fitting / removing part 18 and the first heat insulating support part 16.

  An opening is provided in the upper part of the vacuum vessel 5 (first vacuum vessel 5a), and the penetration support portion 11 penetrates the opening. In the opening, the vacuum vessel 5 (first vacuum vessel 5a) and the through support portion 11 are not in contact with each other, and a gap 19 is formed over the entire circumference of the opening.

  Similarly to the second heat insulating support portions 23 and 24, the first heat insulating support portion 16 supports the coil container 8 at the liquid helium temperature from the room temperature fitting / removal portion 18 and the penetration support portion 11. It is made of a material that reduces heat conduction to the container 8. For example, as shown in FIG. 4B, a low thermal conductivity fiber reinforced plastic (FRP) pipe is used as the first heat insulating support 16. An FRP having a plate shape or a rod shape may be used instead of the pipe shape. The first heat insulating support portion 16 is laid in the horizontal direction perpendicular to the Z axis. One end of the first heat insulating support portion 16 is fixed to the coil container 8, the other end is fixed to the fitting / removing portion 18, and the penetration supporting portion 11 is fitted to the fitting / removing portion 18, so that the first heat insulating supporting portion 16 can be fixed to the penetration supporting portion 11. is there.

  In addition, the intermediate point of the length direction of the 1st heat insulation support part 16 is a thermal anchor similarly to the 2nd heat insulation support parts 23 and 24, and the heat shield 7 is the 1st heat insulation support part in this intermediate point. 16 is supported. Since the temperature of the intermediate point of the first heat insulating support 16 is set to the temperature of the heat shield 7, the temperature profile from one end to the other end of the first heat insulating support 16 from the room temperature to the extremely low temperature is not dependent on the device. Can be constant. The 1st heat insulation support part 16 has penetrated the heat shield 7 in the intermediate point. A bag-shaped shield support portion 7 d is provided on the low temperature side of the intermediate point of the first heat insulation support portion 16 in order to cover the first heat insulation support portion 16.

  A seal portion 17 that seals between the vacuum vessel 5 (first vacuum vessel 5a) and the penetration support portion 11 is provided on the upper portion of the vacuum vessel 5 (first vacuum vessel 5a). According to the seal part 17, the vacuum in the vacuum vessel 5 can be maintained. In addition, since the penetration support part 11 moves up and down with respect to the vacuum container 5, the seal part 17 must hold | maintain the vacuum in the vacuum container 5 also in such up-and-down movement. A bellows can be used as the sealing portion 17 as described above.

  In addition, an adjustment screw 14 capable of adjusting the distance between the vacuum container 5 and the penetration support portion 11 is provided on the upper part of the vacuum container 5 (first vacuum container 5a). Adjustment when the penetrating support portion 11 is moved up and down with respect to the vacuum vessel 5 can be easily performed. The adjustment method will be described later.

  When transporting the MRI apparatus 1, as shown in FIG. 3, the penetration support portion 11 is fitted to the fitting / removal portion 18 and fixed to the first heat insulation support portion 16, and the penetration support portion 11 and the vacuum container are fastened by the fastening portion 15. 5 is concluded. On the other hand, when the MRI apparatus 1 is operating, the penetration support portion 11 is detached from the fitting / removal portion 18 so that the penetration support portion 11 is not fixed to the first heat insulation support portion 16. Opened away. Further, the penetration support part 11 and the vacuum vessel 5 are fastened by the fastening part 15.

  At the time of transportation, not only the heat shield 7 and the lower part of the coil container 8 are supported by the second heat insulating support parts 23 and 24 but also the upper part of the heat shield 7 and the coil container 8 is supported by the first heat insulating support part 16. Therefore, unlike the cantilever support system, even if an impact is applied during transportation, the heat shield 7 and the coil container 8 do not fall down, and the upper part of the heat shield 7 and the coil container 8 do not move. For this reason, an excessive load is not generated by bending or axial force on the second heat insulating support portions 23 and 24, and the heat shield 7 and the coil container 8 can be supported without being deformed or damaged.

  Moreover, since the penetration support part 11 is detached from the fitting / removal part 18 and separated from the first heat insulation support part 16 during operation, the penetration support part 11 is not fixed to the first heat insulation support part 16 and vibration of the gradient magnetic field coil is performed. However, even if it is transmitted to the vacuum vessel 5 and further to the penetration support portion 11, it is not transmitted from the penetration support portion 11 to the first heat insulation support portion 16. Note that not only the transmission of vibration can be interrupted, but also the conduction of heat can be interrupted.

  Further, by using the seal portion 17, the penetration support portion 11 can be fixed to or released from the fitting / removal portion 18 while the vacuum vessel 5 is kept in a vacuum. The vacuum vessel 5 can be held in vacuum not only during operation and transportation, but also when adjusting the vertical movement of the penetration support portion 11. Compared to the case where no vacuum is maintained, the work time at the transportation destination can be reduced.

  As shown in FIG. 2, a plurality of penetration support portions 11 may be arranged. For example, two penetration support portions 11 can be arranged as shown in FIG. 2. By using a plurality, the load load per location can be reduced, and the shape of the penetration support portion 11 per location can be reduced.

  Further, one of the penetration support portions 11 can fix a plurality of first heat insulation support portions 16 via the fitting / removal portions 18. For example, two can be provided as shown in FIG. By making it into multiple pieces, the load load per piece is reduced and the shape of the 1st heat insulation support part 16 per piece can be reduced in size. In addition, in the plurality of first heat insulating support portions 16 as described above, the arrangement angle at which the extension lines in the axial direction intersect with each other is set to approximately 90 degrees. The movement of the heat shield 7 and the coil container 8 due to the impact during transportation can be suppressed in any radial direction.

  The first heat insulating support portion 16 is a straight pipe or rod, and the point where the extension lines in the axial direction of the first heat insulating support portion 16 intersect with each other is located inside the penetration support portion 11. It is possible to reduce a bending moment due to an impact at the time of transportation that occurs in the penetration support portion 11 and the fitting / removal portion 18. Further, by causing the axial direction of the first heat insulating support portion 16 to be along the circumferential direction of the coil container 8, shrinkage deformation due to cooling of the heat shield 7 and the coil container 8 is reduced, and the spring constant of the first heat insulating support portion 16 is weak. It is possible to escape by deformation in a direction perpendicular to the axis, and it is possible to suppress not only the radial movement of the heat shield 7 and the coil container 8 due to the impact during transportation but also the circumferential movement.

  In addition, although the arrangement position of the adjustment screw 14 is on the outer side with respect to the fastening screw 12 on the penetration support portion 11, it is not limited thereto, and may be arranged on the inner side, or the adjustment screw 14 and the fastening screw 12. May be arranged on the same radius. In addition, the number of adjusting screws 14 is preferably three or more in order to increase the penetrating support portion 11 without applying an excessive load, and the number of the fastening screws 12 also applies an excessive load to the penetrating support portion 11. 3 or more are preferable for fastening to the vacuum vessel 5 without any problem. Note that the adjustment screw 14 and the fastening screw 12 do not have to be the same number on the one through-supporting portion 11, and need not have the same pitch in the circumferential direction.

  An adjustment method when the penetration support part 11 is moved up and down with respect to the vacuum vessel 5 will be described.

  The penetration support part 11 of FIG. 4 has shown the state at the time of transport. In order to shift from transportation to operation, the penetrating support 11 is moved upward so as to be removed from the vacuum vessel 5.

  As shown in FIG. 5, first, the fastening screw 12 is removed in order to release the fastening between the vacuum vessel 5 and the penetration support portion 11 while the adjustment screw 14 is pressed against the vacuum vessel 5. The penetration support part 11 is attracted to the vacuum vessel 5 side by atmospheric pressure.

  The adjusting screw 14 is turned and pushed out between the vacuum vessel 5 and the penetration support portion 11. As a result, the penetrating support portion 11 rises so as to be pulled out of the vacuum vessel 5. By this rise, the penetration support part 11 is extracted from the fitting / removal part 18 and detached. Moreover, the bellows of the seal part 17 also extends. The spacer 13 that is no longer sandwiched between the vacuum vessel 5 and the penetration support portion 11 is removed.

  Finally, as shown in FIG. 6, a spacer 13a having a height higher than that of the spacer 13 is inserted between the vacuum vessel 5 and the penetrating support portion 11, and the fastening screw 12a is passed through the spacer 13a and the fastening screw is inserted. At 12a, the vacuum vessel 5 and the penetration support portion 11 are fastened. With the above, the adjustment for shifting from the transportation time to the operation time is completed, and the penetrating support portion 11 is in the state of operation. This series of adjustments can be performed with the seal portion 17 while keeping the vacuum inside the vacuum vessel 5, so there is no need to evacuate or raise or lower the temperature of the superconducting coil to room temperature before and after the adjustment. In addition, the adjustment for shifting from the time of operation reverse to the present explanation to the time of transportation may be performed in the reverse order. Further, a jack may be used instead of the adjusting screw 14.

  As shown in FIG. 6, during operation, the penetration support portion 11 and the fitting / removing portion 18 are separated from each other, so that vibration transmitted to the vacuum vessel 5 is affected by the penetration support portion 11, the fitting / detaching portion 18 and the first heat insulation. It does not travel to the coil container 8 and the heat shield 7 via the support portion 16, and does not adversely affect the MRI image.

(Modification of the first embodiment)
As shown in FIG. 7, in the MRI apparatus according to the modification of the first embodiment of the present invention, the bellows of the seal portion 17 is a shaft seal 28 compared to the MRI apparatus 1 of the first embodiment. Is different. Moreover, the point by which the end surface by the side of fitting to the fitting / removal part 18 of the penetration support part 11 is a taper shape differs. Moreover, the point by which the end surface of the side by which the fitting / removal part 18 is fitted is round shape differs. The difference is that the adjusting screw 14 is omitted. If there is no adjustment screw 14, a jack may be used as described above.

  By using the shaft seal 28 for the seal portion 17, the penetration support portion 11 can be moved up and down with respect to the vacuum vessel 5 while keeping the inside of the vacuum vessel 5 in a vacuum, and the seal portion 17 is damaged by any chance. Even if it is compared with the bellows attached by welding, if it is the shaft seal 28 wound around the shaft part of the penetration support part 11, replacement | exchange can be carried out rapidly and it can hope for shortening of the time until restoration of an MRI apparatus.

  Further, the end face on the side to be fitted into the fitting / removing part 18 of the penetration support part 11 is tapered, or the end face on the side to which the fitting / removing part 18 is fitted is rounded, whereby the penetration support part 11 and the fitting / removing part are provided. Even when a slight misalignment occurs with respect to 18, the penetration support portion 11 can be easily fitted into the fitting / removing portion 18. In addition, it is not restricted to the modification of 1st Embodiment, The end surface by the side of fitting to the fitting / removal part 18 of the penetration support part 11 is made into a round shape, or the end surface of the fitting side of the fitting / removal part 18 is made into a taper shape May be.

(Second Embodiment)
FIG. 8 is a perspective view from above of the superconducting magnet device 2 according to the second embodiment of the present invention, and FIG. 9 is a cross-sectional view in the BB direction of FIG. FIG. 10 is an enlarged view (at the time of transportation) of the periphery of the penetration support portion 11 of FIG.

  As shown in FIG. 9 and FIG. 10, the superconducting magnet device 2 according to the second embodiment has a through-supporting portion 11 that is always in comparison with the superconducting magnet device 2 of the first embodiment, that is, It is different in that it is directly fixed to the first heat insulating support 16 during transportation, operation, and adjustment. Further, the difference is that the adjusting screw 14 is omitted. If there is no adjustment screw 14, a jack may be used as described above.

  Since the penetration support part 11 is always fixed to the first heat insulation support part 16, when the MRI apparatus 1 is transported, the penetration support part 11 and the vacuum vessel 5 may be fastened by the fastening part 15. Also in the second embodiment, similarly to the first embodiment, it is possible to suppress the movement of the heat shield 7 and the coil container 8 due to an impact during transportation and to prevent the second heat insulating support portions 23 and 24 from being deformed. it can.

  As shown in FIG. 11, when the MRI apparatus is moved from the time of transportation to the time of operation, the fastening screw 12 and the spacer 13 are removed and replaced with a vibration isolation support portion 29 composed of a plurality of coil springs. The vibration isolation support portion 29 is supported by the vacuum vessel 5 when the fastening portion 15 does not fasten the penetration support portion 11 and the vacuum vessel 5, and does not transmit vibration transmitted to the vacuum vessel 5 to the penetration support portion 11. In this way, the through-supporting portion 11 is supported while removing vibration.

  Thus, when the MRI apparatus is operating, although the penetration support portion 11 is fixed to the first heat insulation support portion 16, the fastening portion 15 has fastened the penetration support portion 11 and the vacuum vessel 5. First, since the penetration support part 11 is supported by the weak coil spring that can support only the load and the atmospheric pressure of the penetration support part 11 from the vacuum vessel 5, the vibration transmitted to the vacuum vessel 5 is absorbed by the coil spring, Since it is not transmitted to the coil container 8 or the heat shield 7, the MRI image is not adversely affected.

  In addition, in the opening which the penetration support part 11 of the vacuum vessel 5 penetrates, the vacuum container 5 and the penetration support part 11 do not contact, but the clearance gap 19 is formed over the perimeter of the opening. Moreover, although the coil spring was used as the vibration isolation support part 29, not only this but a disc spring, a leaf | plate spring, an air spring, and a vibration-proof rubber can be used.

  Moreover, although the vibration isolation support part 29 can be replaced from the fastening part 15, it may be attached to a place where the fastening part 15 is not disposed not only during operation but also during transportation. Support by a weak spring coil is possible only by removing the fastening portion 15.

(Modification 1 of 2nd Embodiment)
As shown in FIGS. 12 and 13, the superconducting magnet device according to the first modification of the second embodiment of the present invention has a seal portion 17 as compared with the superconducting magnet device 2 of the second embodiment. The difference is that the bellows is a shaft seal 28.

  By using the shaft seal 28 for the seal portion 17, the penetration support portion 11 can be moved up and down with respect to the vacuum vessel 5 while keeping the inside of the vacuum vessel 5 in a vacuum, and the seal portion 17 is damaged by any chance. Even if it is compared with the bellows attached by welding, if it is the shaft seal 28 wound around the shaft part of the penetration support part 11, replacement | exchange can be carried out rapidly and it can hope for shortening of the time until restoration of an MRI apparatus. Further, the shaft seal 28 not only functions as a vibration isolation rubber but also functions to reliably form the clearance 19.

(Modification 2 of the second embodiment)
As shown in FIG. 14, the superconducting magnet device according to the second modification of the second embodiment of the present invention is different from the superconducting magnet device 2 of the second embodiment in the coil of the vibration isolation support portion 29. The difference is that the spring is anti-vibration rubber. If it is a vibration isolator, fine adjustment of height etc. is easy and adjustment time can be shortened.

(Modification 3 of the second embodiment)
As shown in FIG. 15, the superconducting magnet device according to the third modification of the second embodiment of the present invention is compared with the superconducting magnet device 2 of the second embodiment. The difference is that there is only one spring. The coil spring 31 is arranged on the outer diameter side of the bellows so that the bellows and the central axis coincide. The coil spring 31 can be arranged not only on the outer diameter side of the bellows but also on the inner diameter side of the bellows. The number of coil springs is changed from two or more to one, and the adjustment time can be shortened.

1 is a perspective view of a magnetic resonance imaging apparatus according to a first embodiment of the present invention. It is a perspective view from the upper part of the superconducting magnet device concerning a 1st embodiment of the present invention. It is sectional drawing (at the time of transport) of the AA direction of FIG. (A) is an enlarged view (at the time of transport) of the periphery of the penetration support part of FIG. 3, (b) is a perspective view of a 1st heat insulation support part. FIG. 4 is an enlarged view (at the time of adjustment) of the periphery of the through support portion of FIG. 3. It is an enlarged view of the periphery of the penetration support part of FIG. 3 (at the time of operation). It is sectional drawing of the penetration support part periphery of the superconducting magnet apparatus which concerns on the modification of the 1st Embodiment of this invention, and respond | corresponds to FIG. It is a perspective view from the upper part of the superconducting magnet device concerning a 2nd embodiment of the present invention. It is sectional drawing (at the time of transport) of the BB direction of FIG. FIG. 10 is an enlarged view (at the time of transportation) of the periphery of the penetration support portion of FIG. FIG. 10 is an enlarged view (at the time of operation) of the periphery of the through support portion of FIG. 9. It is sectional drawing (at the time of transport) of the penetration support part periphery of the superconducting magnet apparatus which concerns on the modification 1 of the 2nd Embodiment of this invention, and respond | corresponds to FIG. It is sectional drawing (at the time of operation | movement) surrounding a penetration support part of the superconducting magnet apparatus which concerns on the modification 1 of the 2nd Embodiment of this invention, and respond | corresponds to FIG. It is sectional drawing (at the time of operation | use) of the penetration support part periphery of the superconducting magnet apparatus which concerns on the modification 2 of the 2nd Embodiment of this invention, and respond | corresponds to FIG. It is sectional drawing (at the time of operation | movement) surrounding a penetration support part of the superconducting magnet apparatus which concerns on the modification 3 of the 2nd Embodiment of this invention, and respond | corresponds to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic resonance imaging (MRI) apparatus 2 Superconducting magnet apparatus 3 Control apparatus 4 Bed 5 Vacuum container 5a 1st vacuum container 5b 2nd vacuum container 5c Vacuum connection pipe 6a, 6b Superconducting coil 7 Heat shield 7a 1st heat shield 7b 2nd heat shield 7c Shield connection pipe 7d Shield support part 8 Coil container 8a 1st coil container 8b 2nd coil container 8c Coil connection pipe 9 Inspection area 11 Penetration support part 12, 12a Fastening screw 13, 13a Spacer 14 Adjustment screw 15, 15a Fastening part 16 1st heat insulation support part 17 Bellows (seal part)
18 fitting / removal part 19 clearance 21a first cryostat 21b second cryostat 21c connecting pillar 22 refrigerant 23, 24 second heat insulation support part 25 floor 26, 27 inspection part (gradient magnetic field coil, high frequency irradiation coil)
28 Shaft seal (seal part)
29 Anti-vibration support (spring)
30 Anti-vibration support (rubber)
31 Anti-vibration support (spring)

Claims (20)

A superconducting coil that generates a static magnetic field in the examination region by flowing a predetermined current;
A coil container for supporting the superconducting coil and storing the superconducting coil together with a refrigerant;
In a magnetic resonance imaging apparatus having a vacuum container that surrounds the coil container and whose inside is maintained in a vacuum,
A first heat insulating support portion capable of supporting the coil container by heat insulation;
The inside of the vacuum vessel can be fixed to the first heat insulating support portion, and has a through support portion that penetrates the vacuum vessel,
On the outside of the vacuum vessel, the penetration support part and the vacuum vessel can be fastened,
The through support portion is always magnetic resonance imaging apparatus you characterized in that it is fixed to the first insulation support. When the through supporting portion and said vacuum container has not been concluded, the is supported by the vacuum vessel, in claim 1, characterized in that it comprises a vibration damping support portion for supporting the penetrating supporting part while vibration isolation The magnetic resonance imaging apparatus described. The magnetic resonance imaging apparatus according to claim 2 , wherein the vibration isolation support portion includes at least one of a spring and rubber. A superconducting coil that generates a static magnetic field in the examination region by flowing a predetermined current;
A coil container for supporting the superconducting coil and storing the superconducting coil together with a refrigerant;
In a magnetic resonance imaging apparatus having a vacuum container that surrounds the coil container and whose inside is maintained in a vacuum,
A first heat insulating support portion capable of supporting the coil container by heat insulation;
The inside of the vacuum vessel can be fixed to the first heat insulating support portion, and has a through support portion that penetrates the vacuum vessel,
On the outside of the vacuum vessel, the penetration support part and the vacuum vessel can be fastened,
The first heat insulating support part is a pipe or a rod having one end fixed to the coil container and the other end fixed to the penetrating support part, and the extension lines in the axial direction of the first heat insulating support part intersect each other. point is, the through support portion magnetic resonance imaging apparatus you being located inside the. The magnetic resonance imaging apparatus according to claim 4 , wherein an axial direction of the first heat insulating support portion is along a circumferential direction of the coil container. The first heat insulating support part is a pipe or a rod having one end fixed to the coil container and the other end fixed to the penetrating support part, and the extension lines in the axial direction of the first heat insulating support part intersect each other. magnetic resonance imaging apparatus according to any one of claims 1 to 5 disposed angle is equal to or is approximately 90 degrees. A superconducting coil that generates a static magnetic field in the examination region by flowing a predetermined current;
A coil container for supporting the superconducting coil and storing the superconducting coil together with a refrigerant;
In a magnetic resonance imaging apparatus having a vacuum container that surrounds the coil container and whose inside is maintained in a vacuum,
A first heat insulating support portion capable of supporting the coil container by heat insulation;
The inside of the vacuum vessel can be fixed to the first heat insulating support portion, and has a through support portion that penetrates the vacuum vessel,
On the outside of the vacuum vessel, the penetration support part and the vacuum vessel can be fastened,
The first heat insulating support part is a pipe or a rod having one end fixed to the coil container and the other end fixed to the penetrating support part, and the extension lines in the axial direction of the first heat insulating support part intersect each other. magnetic resonance imaging apparatus you wherein the arrangement angle is approximately 90 degrees. A superconducting coil that generates a static magnetic field in the examination region by flowing a predetermined current;
A coil container for supporting the superconducting coil and storing the superconducting coil together with a refrigerant;
In a magnetic resonance imaging apparatus having a vacuum container that surrounds the coil container and whose inside is maintained in a vacuum,
A first heat insulating support portion capable of supporting the coil container by heat insulation;
The inside of the vacuum vessel can be fixed to the first heat insulating support portion, and has a through support portion that penetrates the vacuum vessel,
On the outside of the vacuum vessel, the penetration support part and the vacuum vessel can be fastened,
The provided so as to surround the coil vessel, insulated supported by the first heat-insulating supporting part, magnetic resonance imaging apparatus further comprising a heat shield which the first heat-insulating supporting portion passes. When transporting the magnetic resonance imaging apparatus, the penetration support part is fixed to the first heat insulation support part, and the penetration support part and the vacuum vessel are fastened,
When the magnetic resonance imaging apparatus is in operation, the penetration support part is not fixed to the first heat insulation support part, or the penetration support part and the vacuum vessel are not fastened, or at least one of them. The magnetic resonance imaging apparatus according to any one of claims 4, 5, and 7, wherein: The magnetic resonance imaging apparatus according to claim 1 , further comprising a seal portion that seals between the vacuum container and the penetration support portion. The magnetic resonance imaging apparatus according to claim 10 , wherein the seal portion includes at least one of a bellows and a shaft seal. 10. The magnetic resonance imaging apparatus according to claim 9 , further comprising a fitting / removing part that is fixed to the first heat insulating support part and that fits and removes the penetration support part. The magnetic resonance imaging apparatus according to claim 12 , wherein at least one of the penetrating support part and the fitting / removing part has a tapered shape or a round shape. The through support portion, a magnetic resonance imaging apparatus according to any one of claims 1 to 13, characterized in that characterized in that through the upper portion of the vacuum vessel. The through support portion, a magnetic resonance imaging apparatus according to any one of claims 1 to 14, characterized in that it is plural arranged. The magnetic resonance imaging apparatus according to claim 15 , wherein one of the penetration support portions is capable of fixing a plurality of the first heat insulation support portions. A spacer that can be disposed between the vacuum vessel and the penetration support;
A fastening screw that penetrates the spacer and is capable of fastening the vacuum vessel and the penetration support portion;
Magnetic resonance imaging apparatus according to any one of claims 1 to 16 and having a fastening portion can be disposed outside the vacuum container. The fixed to the bottom of the vacuum vessel, a magnetic resonance imaging apparatus according to any one of the claims 1 to 17 and having a second insulation support portion of the coil container to thermal insulating support. The superconducting coil has a first superconducting coil and a second superconducting coil, which are opposed to each other in the vertical direction, and whose center axes coincide with each other to form a pair,
The coil container
A first coil container containing the first superconducting coil;
A second coil container enclosing the second superconducting coil and spaced downward from the first coil container;
Connecting the first coil container and the second coil container, supporting the first coil container, and having a coil connection tube supported by the second coil container;
The vacuum vessel is
A first vacuum container containing the first coil container and the first heat insulating support;
A second vacuum container containing the second coil container and spaced downward from the first vacuum container;
Connecting the first vacuum container and the second vacuum container, supporting the first vacuum container, supported by the second vacuum container, and having a vacuum connection pipe containing the coil connection pipe;
The inspection region 9 is provided between the first vacuum vessel, the second vacuum vessel, and the vacuum connection tube,
The penetration support part penetrates the first vacuum vessel,
The first heat insulation support part is fixed to an upper part of the first coil container,
The magnetic resonance imaging apparatus according to claim 18 , wherein the second heat insulating support part is fixed to a bottom part of the second vacuum container and supports the second coil container.   20. The magnetic resonance imaging apparatus according to claim 1, further comprising an adjustment screw capable of adjusting an interval between the vacuum vessel and the penetration support portion.

Images