WO2006062028A1 - 磁気共鳴イメージング装置 - Google Patents
磁気共鳴イメージング装置 Download PDFInfo
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- WO2006062028A1 WO2006062028A1 PCT/JP2005/022115 JP2005022115W WO2006062028A1 WO 2006062028 A1 WO2006062028 A1 WO 2006062028A1 JP 2005022115 W JP2005022115 W JP 2005022115W WO 2006062028 A1 WO2006062028 A1 WO 2006062028A1
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- Prior art keywords
- magnetic field
- magnetic resonance
- gradient
- cover
- vibration
- Prior art date
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- 238000002595 magnetic resonance imaging Methods 0.000 title claims abstract description 29
- 238000013016 damping Methods 0.000 claims abstract description 58
- 239000000463 material Substances 0.000 claims abstract description 58
- 230000003068 static effect Effects 0.000 claims description 46
- 238000005481 NMR spectroscopy Methods 0.000 claims description 16
- 238000007789 sealing Methods 0.000 claims description 13
- 230000005540 biological transmission Effects 0.000 claims description 11
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims description 3
- 230000007246 mechanism Effects 0.000 abstract description 26
- 238000003384 imaging method Methods 0.000 abstract description 25
- 239000011347 resin Substances 0.000 abstract description 3
- 229920005989 resin Polymers 0.000 abstract description 3
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 230000002459 sustained effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 8
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- 239000000853 adhesive Substances 0.000 description 5
- 230000001070 adhesive effect Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- 230000006870 function Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 208000019901 Anxiety disease Diseases 0.000 description 3
- 230000036506 anxiety Effects 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 239000012811 non-conductive material Substances 0.000 description 2
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000002861 polymer material Substances 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 238000013500 data storage Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/385—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils
- G01R33/3854—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils means for active and/or passive vibration damping or acoustical noise suppression in gradient magnet coil systems
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
Definitions
- the present invention relates to a magnetic resonance imaging apparatus, and more particularly to a technique for reducing noise generated by driving a gradient coil.
- a magnetic resonance imaging apparatus is an apparatus that obtains an imaging cross-sectional image inside a subject placed in an imaging space by using a nuclear magnetic resonance phenomenon of a nucleus.
- An MRI apparatus includes a static magnetic field generating means such as a superconducting coil that generates a static magnetic field in an imaging space, a gradient magnetic field coil that superimposes the static magnetic field to provide a linear gradient magnetic field, and a nucleus that constitutes a subject
- a static magnetic field generating means such as a superconducting coil that generates a static magnetic field in an imaging space, a gradient magnetic field coil that superimposes the static magnetic field to provide a linear gradient magnetic field, and a nucleus that constitutes a subject
- An RF coil for generating high-frequency electromagnetic waves for generating nuclear magnetic resonance, and a receiving coil for detecting an echo signal emitted by the nuclear magnetic resonance. Then, for example, a two-dimensional tomographic image of the subject is reconstructed using the echo signal.
- the MRI apparatus applies a pulse current to the gradient magnetic field coil during image capturing, but simultaneously, Lorentz force acts to cause mechanical distortion in the gradient magnetic field coil. This action causes the gradient coil to vibrate and generate noise.
- This noise may cause discomfort and anxiety to the subject (patient) located in the imaging space.
- Patent Document 1 provides noise generated by a gradient magnetic field coil by providing a vacuum space that maintains the airtightness inside the pole piece in which the gradient magnetic field coil is installed. It is a thing that cuts off the sound air propagation.
- Patent Document 2 supports the gradient magnetic field coil with a vibration isolating material, so that not only the vacuum of noise is interrupted but also the static magnetic field from the gradient magnetic field coil. It also suppresses the solid propagation of vibration to the generating means.
- Patent Document 1 Japanese Patent Application Laid-Open No. 11 137535
- Patent Document 2 JP 2001-258864 A
- Patent Document 2 proposes to provide an anti-vibration support mechanism between the gradient magnetic field coil and the static magnetic field generating means. It is not something that can completely block vibrational solid propagation.
- An object of the present invention is to realize a magnetic resonance imaging apparatus capable of reducing noise caused by vibration of a gradient coil.
- the magnetic resonance imaging apparatus of the present invention includes a static magnetic field generation means for generating a static magnetic field region, a gradient magnetic field generation means having a gradient magnetic field coil, a high frequency transmission means for irradiating a subject with a high frequency signal, A receiving means for receiving a nuclear magnetic resonance signal from the subject, a signal processing means for performing an image reconstruction operation using the nuclear magnetic resonance signal received by the receiving means, and the gradient magnetic field generating means, A hermetic cover that forms a hermetic space for accommodating the magnetic field coil; and a vibration isolating member that is fixed to the static magnetic field generating means and contacts the hermetic cover. And supporting column means supported by the static magnetic field generating means.
- At least the front side of the hermetic cover or the front side of the gradient coil is at least. Also have damping material at one or more locations.
- the vacuum hermetic cover improves the vibration attenuation effect while supporting the load due to the vacuum pressure.
- the high-frequency transmission means and the sealing cover are in a single body.
- a means for evacuating the sealed space is provided, and the sealed space is evacuated.
- the vibration isolating member of the support means contacts the vibration damping material and supports the vacuum hermetic cover.
- the magnetic resonance imaging apparatus of the present invention forms a sealed space for housing the gradient magnetic field coil together with the static magnetic field generating means, and has a vacuum damping material disposed on the surface of the sealed space side. Provide a hermetic cover.
- the vacuum hermetic cover is supported by the static magnetic field generation means via the damping material.
- FIG. 1 is a schematic configuration diagram of an MRI apparatus to which the present invention is applied.
- FIG. 2 is a schematic cross-sectional view of a main part when an embodiment of the present invention is applied to a superconducting magnet type open magnetic resonance imaging apparatus.
- FIG. 3 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to an embodiment of the present invention.
- FIG. 5 is a graph for explaining the function of a damping material.
- FIG. 6 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to another embodiment of the present invention.
- FIG. 7 is a further enlarged embodiment of the present invention, and is an enlarged cross-sectional view of a portion where a gradient magnetic field coil and a cover are arranged when a damping material is attached only to the upper surface of the hermetic cover.
- FIG. 8 is still another embodiment of the present invention, and is a cross-sectional enlarged view of a portion where a gradient magnetic field coil and a cover are disposed when a damping material is attached to both surfaces of a hermetic cover.
- FIG. 9 is still another embodiment of the present invention, and is an enlarged cross-sectional view of a portion where a gradient magnetic field coil and a cover are disposed when a damping material is attached only to one surface of the gradient magnetic field coil.
- FIG. 10 is still another embodiment of the present invention, and is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged when a damping material is attached only to the other surface of the gradient coil.
- FIG. 11 is still another embodiment of the present invention, and is an enlarged cross-sectional view of a portion where the gradient magnetic field coil and the cover are arranged when vibration damping materials are attached to both surfaces of the gradient magnetic field coil.
- FIG. 12 is still another embodiment of the present invention, and is an enlarged cross-sectional view of a portion where the gradient magnetic field coil and the cover are arranged when vibration damping materials are attached to both surfaces of the hermetic cover and the gradient magnetic field coil. is there.
- FIG. 1 is an overall schematic configuration diagram of an MRI apparatus to which the present invention is applied.
- the MRI apparatus is for obtaining a tomographic image of a subject using a magnetic resonance phenomenon, and includes a static magnetic field generating means 1, a gradient magnetic field generating means 102, and a transmission system. 103 and receiving system 1 04, a signal processing system 105, a control unit 106 that controls the operation of the static magnetic field generating means 1 and the like, a central processing unit 5, and an operation unit 108.
- the static magnetic field generating means 1 is configured to generate a uniform magnetostatic force in a direction perpendicular to or parallel to the body axis around the subject 108 from a magnet disposed in a wide space around the subject 108. Generate a field.
- the gradient magnetic field generating means 102 includes a gradient magnetic field power supply 110 and a gradient magnetic field coil 2, and images the subject 108 with the gradient magnetic fields in the three axial directions of the X, Y, and Z axes. Occurs in space.
- the imaging cross section of the subject 108 is set by applying the gradient magnetic field.
- the transmission system 103 includes a high-frequency oscillator 111, a modulator 112, a high-frequency amplifier 113, and a high-frequency irradiation coil 3 .
- This transmission system 103 is output from the high-frequency oscillator 111 in order to excite the atomic nuclei constituting the biological tissue of the imaging cross section of the subject 108 set by the gradient magnetic field generating means 102 to cause nuclear magnetic resonance.
- a high frequency pulse is supplied to a high frequency amplifier 113 via a modulator 112.
- the high-frequency pulse is supplied to the high-frequency irradiation coil 3 installed close to the subject 108 to irradiate the subject 108 with a high-frequency pulse.
- the receiving system 104 includes a high-frequency receiving coil 4, a receiving circuit 116, and an analog Z digital (hereinafter referred to as “A / D”) transformation 117. Then, an NMR signal, which is an echo signal due to magnetic resonance of the nuclei of the biological tissue of the subject 108 by the electromagnetic wave irradiated from the high-frequency irradiation coil 3 of the transmission system 103, is placed close to the subject 108. Detect with 4.
- the NMR signal detected by the high frequency receiving coil 4 is input to the A / D converter 117 via the receiving circuit 116 and converted into a digital signal.
- the A / D converter 117 sends the signal to the signal processing system 105 as the collected data sampled at the timing according to the command from the control unit 106.
- the control unit 106 operates under the control of the CPU 5, and repeatedly generates slice encoding, phase encoding, and frequency encoding gradient magnetic fields and high-frequency magnetic field pulses in a predetermined pulse sequence.
- control unit 106 issues various commands necessary for acquiring tomographic image data of the subject 108. This is sent to the gradient magnetic field generating means 102, the transmission system 103, and the reception system 104.
- the signal processing system 105 includes a CPU 5, a signal processing device 118, a memory 119, a magnetic disk 120, an optical disk 121, and a display (display means) 122.
- the CPU 5 performs Fourier transformation and control of the sequencer 106 on the collected data. Also
- the signal processing device 118 performs processing necessary for reconstructing correction calculations and acquired data into tomographic images.
- the memory 119 stores a time-series image analysis process, a program of a specified measurement sequence, parameters used for the execution, and the like, which are obtained in advance measurement performed on the subject.
- the measurement parameters and the collected data of the NMR signal detected by the receiving system 104 and the image used for setting the region of interest are temporarily stored, and the parameters for setting the region of interest are recorded.
- the magnetic disk 120 and the optical disk 121 are data storage units that store reconstructed image data.
- the display 122 performs image reconstruction calculation using the NMR signal detected by the receiving system 104 and displays the image.
- the operation unit 108 includes a trackball, a mouse, a keyboard, and the like, and is used to input control information for processing performed by the signal processing system 105.
- Images obtained by reconstructing the NMR signals detected by the receiving system 104 are sequentially displayed on the display 122.
- the position and angle of the next imaging on the continuously displayed images are set by the operation unit 108.
- the set information is displayed on the display 122.
- the magnetic field generator may be a vertical type or a horizontal type! / ⁇ .
- a static magnetic field generating magnet as a static magnetic field generating magnet
- Permanent magnet type, normal conducting type or superconducting type magnetic field generating means can be used.
- FIG. 2 is a schematic cross-sectional view of a main part when an embodiment of the present invention is applied to an open type magnetic resonance imaging apparatus of a superconducting magnet system.
- an MRI apparatus to which a ball piece having a gradient coil 2 disposed therein is applied has a pair of static magnetic field generating means 1 facing each other across an imaging space, and a biological tissue of a subject.
- An irradiation coil 3 that irradiates a high-frequency signal to cause nuclear magnetic resonance in the nuclei constituting the, and position information for each signal emitted from the measurement target A magnetic field generator composed of the gradient magnetic field coil 2 is required.
- a receiving coil 4 for receiving a signal emitted from the subject, and an image reconstruction calculating means 5 for obtaining an image representing the physical property of the inspection object using the received signal are provided.
- a magnetic field generating means of a permanent magnet system, a normal electric magnet system or a superconducting magnet system is installed around an imaging space in which the subject is inserted, and the magnetic field generating means 1 is arranged around the subject.
- a uniform static magnetic field is generated in the body axis direction or in a direction perpendicular to the body axis.
- the cover 8 mounts the irradiation coil 3, and is attached to the static magnetic field generating means 1 via a bolt 13.
- FIG. 3 is an enlarged cross-sectional view (a cross-sectional view of the pole piece portion) of a portion where the gradient magnetic field coil 2 and the cover 8 (irradiation coil 3) are arranged.
- the magnetic field adjusting means 7 is installed.
- the gradient magnetic field coil attaching means 6 is fixed to the magnetic field adjusting means 7 on the static magnetic field generating means 1 and has an anti-vibration support mechanism.
- the magnetic field adjustment means 7 is composed of a magnetic group, and the magnetic field uniformity of the space in which the subject is inserted is adjusted by changing the amount and arrangement of the magnetic group. Since the amount of adjustment varies depending on various conditions, it should be selected appropriately for each aircraft.
- the gradient magnetic field coil 2 is attached to the inside of the pole piece by the gradient magnetic field coil attachment means 6, and the anti-vibration damper is installed in the gradient magnetic field attachment means 6. This is to prevent the vibration generated by the gradient magnetic field coil 2 from being propagated to the static magnetic field generating means 1 as a solid.
- the inside of the pole piece is kept airtight by the vacuum hermetic cover 8, and the internal air is drawn out by the vacuum pump. And the vacuum inside the pole piece is reduced to about 1000 [Pa], which is about 1Z100 of atmospheric pressure, and the air propagation to the cover 8 etc. of the noise generated by the gradient magnetic field coil 2 is blocked. .
- Pa the vacuum inside the pole piece
- the air propagation to the cover 8 etc. of the noise generated by the gradient magnetic field coil 2 is blocked.
- the anxiety of the subject placed in the imaging space it is one of the important matters to secure a wide imaging space in the MRI apparatus. In order to widen the imaging space, it is possible to increase the magnetic field strength and widen the pole piece spacing, but this is not desirable because it increases the overall size of the device and increases costs.
- the irradiation coil 3 is mounted on the vacuum hermetic cover 8 as described above in order to secure a wide imaging space.
- a vacuum hermetic cover 8 that secures a vacuum space inside the ball piece is rigidly fixed to the static magnetic field generating means 1 with a bolt or the like at the outer periphery. For this reason, there is a possibility that the vacuum sealing cover 8 may stagnate or fall off inside the pole piece due to a load that generates a pressure difference between the external pressure and the vacuum pressure. To prevent this, multiple vacuum sealing covers 8 are used.
- the static magnetic field derivation generating means 1 is supported by a stud (post member) 9.
- These studs 9 are rigidly fixed to the static magnetic field generating means 1, and pass through the middle of the gradient magnetic field coil in a non-contact manner while avoiding the gradient magnetic field coil 2, and are located above the gradient magnetic field coil 2. Has reached. Further, an anti-vibration support mechanism 10 is provided at a place where the stud 9 is in contact with the vacuum hermetic cover 8.
- the vacuum hermetic cover 8 and the vibration isolating support mechanism 10 in contact therewith are not structured to be fixedly connected to each other by bolts or the like. That is, the vacuum hermetic cover 8 has a structure that is pressed against the antivibration support mechanism 10 by a vacuum pressure generated between the atmospheric pressure and the vacuum pressure.
- a vibration damping material 11 having a resin-based material force such as plastic rubber is laminated, and this is integrated with this. is doing.
- vacuum hermetic cover 8 and the vibration damping material 11 have a structure that is not separated from each other by vibration using bolt fastening, an adhesive, or the like.
- the anti-vibration support mechanism 10 may be attached to the tip of the stud 9 with an adhesive. Further, the vibration isolating support mechanism 10 has a cylindrical shape, and a cylindrical portion that can be inserted into the hollow portion of the cylindrical anti-vibration support mechanism 10 is formed at the tip of the stud 9. The structure 10 may be configured to be attached to the stud 9.
- the material used for the vacuum hermetic cover 8 needs to be nonmagnetic and nonconductive.
- the vacuum sealing cover 8 be formed of a reinforced plastic material such as glass fiber resin.
- the damping material 11 attached to the vacuum hermetic cover 8 also needs to be a non-magnetic and non-conductive material, and a material that absorbs the vibration of the vacuum hermetic cover 8 is required.
- the materials used for the vibration damping material are metal materials and polymer materials such as plastic and rubber.
- the damping material 11 also needs to be a non-magnetic 'non-conductive material, plastics • Polymer materials such as rubber are preferred, and plastic is used in the vacuum sealing cover 8 in particular. Therefore, it is desirable to attach a rubber material having a greater damping effect to the vacuum hermetic cover 8 as a damping material 11.
- the shape of the damping material 11 is the same area as the attachment surface of the vacuum hermetic cover 8.
- the damping material 11 when the damping material 11 is thickened, A part of the vacuum hermetic cover 8 occupies the imaging space, and the imaging space is reduced accordingly. This is not preferable in terms of reducing anxiety and discomfort given to the patient.
- the vibration propagating from the gradient magnetic field coil 2 to the static magnetic field generating means 1 is attenuated by the anti-vibration support mechanism by the gradient magnetic field attaching means 6, and the solid propagation from the static magnetic field generating means 1 to the vacuum hermetic cover 8 is performed. Vibration is attenuated by the anti-vibration support mechanism 10.
- the vacuum hermetic cover 8 generates noise due to vibrations that are solid-propagated from the static magnetic field generating means 1 through the stud 9, it is stuck to the damping material 11 and is it integrated? Therefore, the vibration energy of the vacuum sealing cover 8 is converted into thermal energy, and the vibration of the vacuum sealing cover 8 is suppressed.
- the vertical axis in FIG. 4 represents the vibration transmissibility from the gradient magnetic field coil 2 to the static magnetic field generating means 1 and the vacuum hermetic cover 8, and the horizontal axis represents the vibration frequency.
- the broken line 14 in FIG. 4 shows the frequency characteristics when there is no vibration damping damper, and the solid line 15 shows the frequency characteristics when the vibration damping damper is provided.
- the resonance frequency of the characteristic 15 is shifted to a frequency f lower than the resonance frequency of the characteristic 14.
- the vibration transmissibility from the gradient magnetic field coil 2 to the magnetostatic field generating means 1 and the vacuum hermetic cover 8 can be reduced at a high frequency.
- the gradient magnetic field attaching means 6 and the vibration isolating support mechanism 10 are constituted by an elastic body such as rubber having an elastic modulus and dimensions so as to have the characteristics shown in FIG.
- the vertical axis in FIG. 5 represents the vibration transmissibility from the gradient coil 2 to the vacuum hermetic cover 8, and the horizontal axis represents the vibration frequency.
- a broken line 16 in FIG. 5 shows the frequency characteristics when the damping material 11 is not provided, and a solid line 17 shows the frequency characteristics when the damping material 11 is provided.
- the vibration transmissibility at the resonance frequency of the characteristic 17 is smaller than the resonance frequency of the characteristic 16.
- the vacuum sealed cover from the gradient coil 2 is smaller than the resonance frequency of the characteristic 16.
- the vibration transmission rate to 8 can be reduced.
- the noise generated by the gradient coil 2 is reduced, and the noise given to the subject located in the imaging space can be reduced.
- FIG. 6 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to another embodiment of the present invention.
- the cover 8 is attached to the static magnetic field generating means 1 by a bolt 13.
- the static magnetic field generating means 1 is attached to the static magnetic field generating means 1 by means of an adhesive via a vibration damping material 11.
- vibration damping material 11 and the vibration proof support mechanism 10 are bonded with an adhesive.
- the gradient magnetic field coil 8 and the static magnetic field generating means 1 and the bolt 1 are identical to the example shown in FIG. 6, the gradient magnetic field coil 8 and the static magnetic field generating means 1 and the bolt 1
- the vibration transmitted to the cover 8 via 3 can be damped by the damping material 11, and noise can be further reduced.
- FIG. 7 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to still another embodiment of the present invention.
- the damping material 11 is attached to one surface of the cover 8 that comes into contact with the vibration isolating support mechanism 10.
- the vibration damping material 11 is attached to the other surface not in contact with the vibration isolating support mechanism 10.
- the vibration transmitted to the cover 8 can be damped by the damping material 11 attached to the cover 8.
- FIG. 8 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to still another embodiment of the present invention.
- the damping material 11 is attached only to the surface of the cover 8 that comes into contact with the vibration isolating support mechanism 10.
- the damping material 11 is attached to both surfaces of the cover 8.
- vibration damping material 11 and the vibration isolating support mechanism 10 are bonded with an adhesive.
- the vibration transmitted to the cover 8 via 3 can be damped by the damping material 11, and noise can be further reduced.
- FIG. 9 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to still another embodiment of the present invention.
- FIG. 10 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to still another embodiment of the present invention.
- the damping material 11 is attached to the surface (other surface) on the static magnetic field generating means 1 side of the gradient magnetic field coil 2 that is not the cover 8.
- FIG. 11 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged according to still another embodiment of the present invention.
- the damping material 11 is attached to both surfaces of the gradient coil 2 that is not covered by the cover 8.
- Fig. 12 is an enlarged cross-sectional view of a portion where a gradient coil and a cover are arranged in still another embodiment of the present invention.
- the damping material 11 is attached to both surfaces of the gradient magnetic field coil 2 and attached to both surfaces of the cover 8.
- the vibration transmitted to the cover 8 can be attenuated by the damping material 11, and noise can be reduced.
- the vacuum hermetic cover 8 is supported by the stud 9.
- the vacuum hermetic cover 8 may be configured to be supported by another member other than the stud 9. It is.
- a vibration isolating member having a shape in which the damping material 11 is expanded is partially arranged on the surface of the gradient magnetic field coil 2 on the side of the vacuum hermetic cover 8 (effective in terms of vibration suppression).
- the vacuum hermetic cover 8 can be supported by the vibration isolating member.
- the force of providing the damping material 11 on the vacuum sealing cover 8 Even if the damping material 11 is omitted, the vibration of the vacuum sealing cover 8 can be suppressed.
- the vibration of the vacuum hermetic cover 8 can be suppressed.
- the sealed space in which the gradient magnetic field coil is accommodated is a force that is evacuated by the vacuum sealed cover 8.
- the present invention can also be applied to the case where the sealed space is not vacuum.
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Abstract
Description
Claims
Priority Applications (1)
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JP2006548012A JPWO2006062028A1 (ja) | 2004-12-10 | 2005-12-01 | 磁気共鳴イメージング装置 |
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JP2004-357671 | 2004-12-10 | ||
JP2004357671 | 2004-12-10 |
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WO2006062028A1 true WO2006062028A1 (ja) | 2006-06-15 |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10120046B2 (en) | 2015-01-28 | 2018-11-06 | Toshiba Medical Systems Corporation | Magnetic resonance imaging apparatus |
US10656225B2 (en) | 2016-09-01 | 2020-05-19 | Canon Medical Systems Corporation | Magnetic resonance imaging apparatus |
KR102242796B1 (ko) * | 2020-05-26 | 2021-04-22 | 주식회사 마이브레인 | 두부 전용 자기공명영상장치 |
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JPH04250136A (ja) * | 1991-01-28 | 1992-09-07 | Toshiba Corp | 磁気共鳴イメージング装置 |
JPH11137535A (ja) * | 1997-11-13 | 1999-05-25 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
JP2000232966A (ja) * | 1999-02-15 | 2000-08-29 | Toshiba Corp | 傾斜磁場コイル装置 |
JP2001299719A (ja) * | 2000-04-27 | 2001-10-30 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
JP2004194974A (ja) * | 2002-12-19 | 2004-07-15 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
-
2005
- 2005-12-01 WO PCT/JP2005/022115 patent/WO2006062028A1/ja not_active Application Discontinuation
- 2005-12-01 JP JP2006548012A patent/JPWO2006062028A1/ja active Pending
Patent Citations (5)
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JPH04250136A (ja) * | 1991-01-28 | 1992-09-07 | Toshiba Corp | 磁気共鳴イメージング装置 |
JPH11137535A (ja) * | 1997-11-13 | 1999-05-25 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
JP2000232966A (ja) * | 1999-02-15 | 2000-08-29 | Toshiba Corp | 傾斜磁場コイル装置 |
JP2001299719A (ja) * | 2000-04-27 | 2001-10-30 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
JP2004194974A (ja) * | 2002-12-19 | 2004-07-15 | Hitachi Medical Corp | 磁気共鳴イメージング装置 |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10120046B2 (en) | 2015-01-28 | 2018-11-06 | Toshiba Medical Systems Corporation | Magnetic resonance imaging apparatus |
US10656225B2 (en) | 2016-09-01 | 2020-05-19 | Canon Medical Systems Corporation | Magnetic resonance imaging apparatus |
KR102242796B1 (ko) * | 2020-05-26 | 2021-04-22 | 주식회사 마이브레인 | 두부 전용 자기공명영상장치 |
WO2021246696A1 (ko) * | 2020-05-26 | 2021-12-09 | 주식회사 마이브레인 | 두부 전용 자기공명영상장치 |
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