WO2007007630A1 - Dispositif d’imagerie par résonance magnétique - Google Patents

Dispositif d’imagerie par résonance magnétique Download PDF

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Publication number
WO2007007630A1
WO2007007630A1 PCT/JP2006/313472 JP2006313472W WO2007007630A1 WO 2007007630 A1 WO2007007630 A1 WO 2007007630A1 JP 2006313472 W JP2006313472 W JP 2006313472W WO 2007007630 A1 WO2007007630 A1 WO 2007007630A1
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WIPO (PCT)
Prior art keywords
magnetic field
resonance imaging
generating means
imaging apparatus
static magnetic
Prior art date
Application number
PCT/JP2006/313472
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English (en)
Japanese (ja)
Inventor
Takeshi Yatsuo
Original Assignee
Hitachi Medical Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Medical Corporation filed Critical Hitachi Medical Corporation
Priority to JP2007524606A priority Critical patent/JP5149004B2/ja
Publication of WO2007007630A1 publication Critical patent/WO2007007630A1/fr

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Classifications

    • 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
    • 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
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
    • 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
    • G01R33/3806—Open magnet assemblies for improved access to the sample, e.g. C-type or U-type magnets
    • 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
    • G01R33/381—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets
    • G01R33/3815—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets with superconducting coils, e.g. power supply therefor
    • 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

Definitions

  • the present invention relates to a magnetic resonance imaging (hereinafter referred to as MRI) apparatus, and more particularly to a magnetic resonance imaging apparatus with improved openness to reduce claustrophobia felt by a subject.
  • MRI magnetic resonance imaging
  • a static magnetic field generator is used to generate a static magnetic field, and a superconducting coil or the like is used as the static magnetic field generation source.
  • a static magnetic field source using a superconducting coil is called a superconducting magnet.
  • This superconducting magnet mainly includes a tunnel type structure and an opposed type structure.
  • the tunnel-type superconducting magnet has a cylindrical void space inside and generates a uniform static magnetic field in the cylindrical axis direction of the void space. The subject is then imaged in the cylindrical void space so that the body axis direction matches the static magnetic field direction.
  • a pair of superconducting coils are arranged coaxially with a gap space in between, and a uniform static magnetic field is generated in the opposite direction of the gap space.
  • the subject is photographed by being placed in this void space so that the body axis and the direction of the static magnetic field are perpendicular to each other.
  • Non-patent Document 1 Some patients who become subjects with an MRI apparatus have claustrophobia. With MRI equipment, reducing the fear of claustrophobia in such patients is an issue. The counter-type superconducting magnet is required to reduce claustrophobia even in force tunnel type magnets that can reduce the claustrophobia.
  • Non-patent Document 1 One solution is the conventional technique described in (Non-patent Document 1).
  • Patent Document 1 Novel Short Whole Body MRI Magnet Design using Genetic Algorithms, Proc. Intl. Soc. Mag. Reson. Med 9 (2001) pi 148
  • Non-Patent Document 1 a magnet with a short axial length is provided using 8 coils and 10 shim coils!
  • the uniformity with which distortion does not occur in an image captured with an MRI apparatus is about 0.5 ppm, but in the case of the prior art described in Non-Patent Document 1, the size of the imaging space with a uniformity of 0.5 ppm is 30 cm It stops to the extent. If the subject's size is large, do not move the moving table to the left and right! / ⁇ can not be photographed! / ⁇ will occur, but this was not possible with a tunnel-type magnet with a circular cross section.
  • An object of the present invention is to improve openness in order to reduce the feeling of claustrophobia that the subject feels, and at the same time to move a moving bed for mounting the subject left and right to move a large subject.
  • the object is to provide an MRI apparatus capable of imaging.
  • the static magnetic field generating means is arranged around the imaging space where the subject is arranged, and generates a static magnetic field in the imaging space, and is arranged on the imaging space side of the static magnetic field generating means.
  • MRI comprising a gradient magnetic field generating means for generating a gradient magnetic field in the imaging space, and a high frequency magnetic field generating means arranged on the imaging space side of the gradient magnetic field generating means and generating a high frequency magnetic field in the imaging space
  • the static magnetic field generating means has a substantially polygonal shape inside and Z or outside of a cross section in a direction perpendicular to the static magnetic field.
  • FIG. 1 is a block diagram showing an overall configuration of an MRI apparatus constituting the present invention.
  • FIG. 2 is a perspective view of a static magnetic field generation system according to Embodiment 1 of the present invention, in which a superconducting system is employed as a magnet device (superconducting magnet device).
  • FIG. 3 is a diagram showing an example of the arrangement of superconducting coils inside the superconducting magnet device in FIG. 2.
  • FIG. 4 is a diagram showing the inner surface of the gantry when the shape of a substantially triangular coil is a Rouleau triangle.
  • FIG. 5 A diagram in which a triangle of a roulette with a passing width of 1 is formed in a substantially triangular shape with the distance a expanded outwardly.
  • FIG. 11 is a view showing a static magnetic field generator in which the apexes of a pair of magnets having a substantially triangular shape are installed so as to be in positions corresponding to each other in the vertical direction.
  • FIG. 12 is a view of the outer shape of a counter-type superconducting magnet as viewed from above in the vertical direction.
  • FIG. 13 is a diagram showing an example of the arrangement of superconducting coils inside the superconducting magnet shown in FIG. 11.
  • FIG. 14 is a diagram showing an example of the arrangement of support posts in Example 4.
  • FIG. 15 is an example of a coil pattern of an X-direction gradient magnetic field coil.
  • FIG. 1 is a block diagram showing the overall configuration of an MRI apparatus constituting the present invention.
  • this MRI apparatus mainly includes a static magnetic field generation system 1, a gradient magnetic field generation system 2, a transmission system 3, a reception system 4, a signal processing system 5, a control system (sequencer 6 and CPU7).
  • the static magnetic field generation system 1 generates a uniform static magnetic field in the space around the subject 8 (imaging space), and includes a permanent magnet type, a normal conduction type, or a superconducting type magnet device.
  • the gradient magnetic field generation system 2 has, for example, three gradient magnetic field coils 9 that generate gradient magnetic field pulses in these three axial directions when the direction of the static magnetic field is the z direction and the two orthogonal directions are X and y. And a gradient magnetic field power source 10 for driving them respectively.
  • gradient magnetic field pulses can be generated in the three axes X, y, and z or in the direction in which these are combined.
  • the gradient magnetic field pulse is applied to give positional information to the NMR signal generated from the subject 8.
  • the transmission system 3 includes a high frequency oscillator 11, a modulator 12, a high frequency amplifier 13, and a high frequency for transmission. It consists of an irradiation coil 14.
  • the RF pulse generated by the high-frequency oscillator 11 is modulated into a predetermined envelope signal by the modulator 12, amplified by the high-frequency amplifier 13, and applied to the high-frequency irradiation coil 14.
  • An electromagnetic wave (high frequency signal, RF pulse) that causes magnetic resonance is irradiated.
  • the high-frequency irradiation coil 14 is usually arranged close to the subject.
  • the receiving system 4 includes a receiving high-frequency receiving coil 15, an amplifier 16, a quadrature detector 17, and an A / D converter 18.
  • the high frequency irradiation coil for transmission The NMR signal generated from the subject as a response to the RF pulse irradiated by 14 pulses is detected by the high frequency reception coil 15 for reception, amplified by the amplifier 16, and then detected by quadrature phase detection. It is converted into a digital quantity by the A / D converter 18 via the device 17 and sent to the signal processing system 5 as two series of collected data.
  • the signal processing system 5 includes a CPU 7, a storage device 19, and an operation unit 20.
  • the digital signal received by the reception system 4 in the CPU 7 is subjected to various transformations such as Fourier transform, correction coefficient calculation, and image reconstruction. Perform signal processing.
  • the storage device 19 includes a ROM 21, a RAM 22, an optical disk 23, a magnetic disk 24, and the like.
  • a program for performing image analysis processing and measurement over time and an invariant parameter used for the execution are stored in the ROM 21 for all measurements.
  • the measurement meter and the echo signal detected by the receiving system are stored in the RAM 22 and the reconstructed image data are stored in the optical disk 23 and the magnetic disk 24, respectively.
  • the operation unit 20 includes input means such as a track ball or a mouse 25 and a keyboard 26, and a display 27 for displaying a GUI necessary for input and displaying a processing result in the signal processing system 5.
  • Information necessary for various processing and control performed by the CPU 7 is input via the operation unit 20.
  • the image obtained by the shooting is displayed on the display 27.
  • the control system is composed of sequencers 6 and 7, and controls the operations of the gradient magnetic field generation system 2, the transmission system 3, the reception system 4, and the signal processing system 5 described above.
  • the application timing of gradient magnetic field pulses and RF pulses generated by the gradient magnetic field generation system 2 and the transmission system 3 and the acquisition timing of the echo signal by the reception system 4 are controlled via a sequencer 6 according to a predetermined time chart determined by the imaging sequence.
  • FIG. 6 is a perspective view of the static magnetic field generation system in which a superconducting system is employed as a magnet device (superconducting magnet device).
  • 8 is a subject
  • 25 is a superconducting magnet device which is a magnet constituting the static magnetic field generation system 1 in FIG. 1
  • 26 is a z-axis which is a direction in which a superconducting magnet device generates a static magnetic field
  • 27 is a superconducting magnet.
  • the axial length of the device, 28 is the inner surface of the superconducting magnet device on the side where the subject is placed
  • 29 is the outer surface of the superconducting magnet device.
  • the cross section perpendicular to the z-axis of the space in which the subject is arranged has a substantially triangular shape, and one vertex of the substantially triangular shape is in the vertical direction. It is arranged on the upper side. That is, the imaging space in which the subject is arranged is a substantially triangular columnar space.
  • the outer shape (outer surface) 29 of the superconducting magnet device is also substantially triangular.
  • the outer shape (outer surface) 29 of the superconducting magnet device does not have to be substantially triangular. For example, it may be circular or elliptical.
  • the gradient magnetic field coil 9 and the high-frequency irradiation coil 14, which are other components necessary for generating a magnetic field in the MRI apparatus, are arranged according to the shape of the inner surface of the superconducting magnet apparatus. This will be described later.
  • FIG. 3 is an example of the arrangement of superconducting coils inside the superconducting magnet device in FIG.
  • Fig. 3 shows an example with 10 superconducting coils.
  • 5 superconducting coils are arranged symmetrically in the positive and negative z-axis directions around the xy plane at the position where the force z-coordinate is zero. Therefore, only + direction (positive direction) shows 5 (31).
  • Each of the coils has a substantially triangular shape, and the plane including each substantially triangular shape is perpendicular to the z axis.
  • An imaging space for arranging the subject is formed inside each substantially triangular shape.
  • each substantially triangular shape is on the central axis of the static magnetic field, and the subject to be placed is arranged so that the body axis coincides with the z-axis (central axis in the static magnetic field direction) in FIG. It has become.
  • the substantially triangular superconducting coil group (31) is contained in a cooling vessel and immersed in a cooling medium such as liquid helium, and is brought to a critical temperature or lower so as to maintain a superconducting state.
  • the superconducting current continues to flow in the permanent current mode, and a stable static magnetic field is generated in the approximately triangular coil.
  • the cooling container is built in the heat insulating material and the vacuum container. The detailed structure is described in, for example, JP-A-9-153408. It is as it is.
  • the cooling container and the vacuum container are shaped in accordance with the shape of the superconducting coil in order to secure an imaging space in which the subject is arranged. That is, the surfaces of the cooling container and the vacuum container on the imaging space side are also substantially triangular on the XY plane. And, the almost triangular cylindrical space becomes the imaging space where the subject is placed! / Speak.
  • the shoulder width of a human body is generally wide and the cross section is elliptical, there is an advantage that the human body can be loosely arranged on the side close to the bottom of the lower side in the vertical direction of a substantially triangle. Further, since the lower side in the vertical direction of the substantially triangular imaging space is flat, there is also an advantage that the moving bed for mounting the subject can be easily arranged on the lower side in the lead direction.
  • Embodiment 2 will be described with reference to FIGS. 4 and 5.
  • the present embodiment is an embodiment regarding a more specific shape of the substantially triangular coil shown in the first embodiment.
  • the shape of the approximately triangular coil is the Rouleau triangle shape
  • the shape of the inner surface of the gantry of the static magnetic field source is formed to match that (the case of the Rouleau triangle coil case).
  • the coil having the triangular shape of the roulau is called the roux one coil.
  • the shape of the gantry inner surface (inner surface of the circular coil case) in the case of a circular coil shape is also shown superimposed (hereinafter, the circular coil is referred to as a circular core;).
  • a Rouleau triangle is a figure that is formed by connecting arcs whose radii are one side of an equilateral triangle centered on each vertex of the equilateral triangle.
  • the Rouleau triangle with a passing width of 2r is a figure consisting of the center (center of gravity) force and the three vertex forces with the distance described in Equation (1). 2v / fi (1)
  • FIG. 4 shows a moving bed 32a installed to mount a subject in a circular coil and a rouleau coil.
  • 32a indicates the position and width of the moving bed that can be arranged in the case of a circular coil
  • 32b indicates the space in which the moving bed can be moved in the horizontal direction in the case of a roulau coil.
  • the width on the lower side in the vertical direction is wider than the circular coil only at the portions indicated by 32b on both sides of the bed 32a. Space for moving the table horizontally can be secured.
  • the air gap in the imaging space is widened by (33c-33b) at the apex 33a, which is located above the Reuleaux triangle, rather than the circular coil. It has also been shown that the feeling of claustrophobia felt by the subject can be reduced.
  • the merit of adopting the rouleau coil as the shape of the substantially triangular coil is that the above-mentioned passing width is constant. This means that when viewed from the inside of the coil, a 2r length line can be placed in any direction inside. In this case, the passing width corresponds to the shoulder width of the subject in the case of a superconducting magnet in which the subject is arranged.
  • the Rouleau triangle with a passing width of 1 is expanded outward by a distance a as shown in Fig. 5.
  • the approximate triangle shown in Fig. 5 is an approximate triangle that is a triangle of the inner Reuleaux with a passing width of 1 and is expanded outward by a, and the radius around each vertex of the inner Reuleau triangle (1 + a) This figure is formed by connecting a circular arc and a circular arc of radius a centered on each vertex.
  • a substantially triangular shape as shown in Fig. 4 has a 120-degree bend at each vertex.
  • superconducting wires have poor superconducting properties when they are below a certain bending radius, which is weak to bending force S. Therefore, by extending the Rouleau triangle with the required bend radius a as shown in Fig. 5, it is possible to suppress the deterioration of the superconducting characteristics.
  • FIG. 6 shows the uniformity characteristics of the static magnetic field generated by the rouleau coil shown in FIG.
  • Fig. 7 shows the uniformity characteristics of the static magnetic field generated by a circular coil.
  • the axis is symmetric with respect to the z axis, but in the case of a rouleaux coil, it is no longer axisymmetric.
  • Fig. 8 shows the case of a rouleaux coil
  • Fig. 9 shows the case of a circular coil.
  • the variation in the uniformity of the static magnetic field within the circumference of a radius of 0.2m is 500 to + 600ppm for the circular coil in Fig. 9 and 400 to + 200ppm for the Rouleaux coil in Fig. 8. It has become.
  • the rouleaux coil it is possible to obtain the same static magnetic field uniformity as in the case of the circular coil.
  • shim coil 9 is within the range that can be sufficiently corrected by using shim coils.
  • a 500 ppm magnetic field inhomogeneity corresponds to 750 ⁇ .
  • a current of about 150 A should be passed through the superconducting shim coil to correct the magnetic field of 750 T.
  • FIG. 10 shows a comparison of leakage magnetic fields.
  • Figure 10 shows the leakage magnetic field on the y-z plane. Is expressed using the unit Gauss. According to this, the direction of the roulor coil (broken line) spreads more than the circular coil (solid line), and there are more directions. From the viewpoint of the leakage magnetic field characteristic, the roulor coil has better magnetic field characteristics. Recognize.
  • the tunnel type superconducting magnet is configured using the rouleau coil, and compared with the tunnel type superconducting magnet using the conventional circular coil. It can be seen that it is possible to provide a tunnel-type superconducting magnet with high openness while maintaining the same magnetic characteristics (magnetic field uniformity, etc.) as the equivalent cost.
  • the static magnetic field generator of the present embodiment is a counter-type magnet configuration in which two magnets (34 and 34b) having a substantially triangular cross-sectional shape are arranged to face each other.
  • FIG. 11 shows a static magnetic field generator in which the apexes of a pair of magnets having a substantially triangular shape are installed so as to be in positions corresponding to each other in the vertical direction. That is, the upper magnet vertex 35a and the lower magnet vertex 35b, the upper magnet vertex 36a and the lower magnet vertex 36b, the upper magnet vertex 37a and the lower magnet vertex 3 in FIG. 7b is paired in the vertical direction.
  • the two magnets arranged above and below are mechanically, thermally, and magnetically connected by struts (38a and 38b).
  • Fig. 12 shows a view of the outer shape of the opposing superconducting magnet as viewed from the vertical upper force.
  • FIG. 12 shows an example in which the above-mentioned rouleau coil is used as a substantially triangular shape.
  • circular coils are overlapped with their centers (center of gravity) matched.
  • the marks indicated by 38a and 38b are the pillars in FIG.
  • the magnets protrude from the positions near the vertices of the substantially triangular shape to the outside in the horizontal direction as compared with the circular coil.
  • the distance to the static magnetic field center 41 is shortened and the operator can easily access the subject.
  • the radius of the circular coil is r
  • the distance in the direction of the thick arrows 40a, 40b, and 40c is about 0.85r in the case of a rouleau coil with the same span width, and a static magnetic field of about 15% The distance to the center 41 is shortened.
  • the roulor coil is more accessible to the operator and the subject than the circular coil. The openness for the specimen can be improved.
  • FIG. 13 shows an example of arrangement of superconducting coils inside the superconducting magnet shown in FIG.
  • FIG. 13 shows only a perspective view of an internal arrangement example of the upper superconducting magnet, and is composed of five upper coils (42).
  • FIG. 14 shows an example of the arrangement of the columns in the present embodiment.
  • each figure of (a) to () in Fig. 14 is an example of the arrangement of the superconducting magnet as viewed from the vertical upward force.
  • 32 is a moving bed for arranging the subject. Is a substantially triangular superconducting magnet, 38 is a support, and Fig. 14 (a) to (: c) are examples of the arrangement of the support force 3 ⁇ 4, and Fig. 14 (d) to ( 14 (a) to 14 (e) will be described in order below.
  • FIG. 14 (a) is an example in which the struts are arranged in the vicinity of two vertices of a substantially triangular shape. In this example, it is possible to access the subject with directional force on the sides of the three approximately triangular triangles indicated by the thick arrows.
  • Fig. 14 (b) shows an example in which one strut is placed near one vertex of a substantially triangular shape and the other struts are placed near the side facing this vertex. In this example, the remaining two side forces that are not close to the support can also access the subject placed in the imaging space.
  • Fig. 14 (c) shows an example in which two columns are arranged in the vicinity of two sides of a substantially triangle.
  • FIG. 14 (d) shows an example in which the support is placed at one of the apexes of a substantially triangular shape.
  • the direction forces of the three sides can also access the subject placed in the imaging space.
  • Fig. 14 (e) shows an example of placing the struts near either side of the approximate triangle.
  • FIG. 14 (b) it is possible to access the subject placed in the imaging space from the direction of the remaining two sides where the support is not placed.
  • Each figure shows a preferred arrangement position of the movable bed 32 on which the subject is placed.
  • FIG. 14 (a) a configuration in which the moving bed 32 is arranged in the vicinity of the remaining apex where no support is arranged is preferable.
  • FIG. 14 (b) a configuration in which the movable bed 32 is arranged in the vicinity of one of the remaining two sides on which no support is arranged is preferable.
  • FIG. 14 (c) a configuration in which the moving bed 32 is arranged in the vicinity of the remaining one side where no support is arranged is preferable.
  • FIG. 14 (d) a configuration in which the moving bed 48 is disposed in the vicinity of one of the remaining two vertices where the support column is not disposed is preferable.
  • FIG. 14 (e) is the same as FIG. 14 (b).
  • the accessibility to the subject and the openness to the subject can be improved as compared with the opposed superconducting magnet using the circular coil.
  • the static magnetic field generation source used in the present invention may not be a superconducting magnet but may be a permanent magnet.
  • the gradient magnetic field coil 9 and the high-frequency irradiation coil 14 in Example 3 are arranged in a plane along the opposed surface of the opposed magnet, and the outer shape thereof is in a direction perpendicular to the static magnetic field of the magnet.
  • the cross-sectional shape being a substantially polygon or a substantially triangle, it may be a substantially polygon or a substantially triangle.
  • FIG. 15 (a) is a cross section of a substantially triangular coil, and the position of each coil of the approximately triangular shape is represented by an angle ⁇ with the center of gravity as the origin (the positive direction of the Y axis is 0 °).
  • Fig. 15 (b) An example of the coil pattern is shown in Fig. 15 (b). However, the vertical axis in Fig. 15 (b) is the angle ⁇ in Fig. 15 (a). According to Fig. 15 (b), it can be appreciated that the coil pattern has a high coil density at a position of 120 °, which is far from the center of gravity.
  • the high-frequency irradiation coil used in the MRI apparatus of the present invention (especially of the tunnel type structure) is considered to conform to the structure described in JP-A-7-222729 [FIG. 5].
  • the ring 202 in FIG. 5 is substantially triangular (or substantially polygonal depending on the shape of the superconducting coil), and the interval between adjacent rungs 201 is set to the angle shown in FIG. 15 (a). It is considered that adjustment should be made accordingly.

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Abstract

La présente invention concerne un dispositif d’imagerie par résonance magnétique comportant un générateur de champ magnétique statique, qui est disposé autour d’un espace de photographie où un spécimen à inspecter est disposé, et qui génère un champ magnétique statique dans l’espace de photographie ; un générateur de champ magnétique incliné, qui est disposé sur un côté de l’espace de photographie du générateur de champ magnétique statique, et qui génère un champ magnétique incliné dans l’espace de photographie ; et un générateur de champ magnétique à haute fréquence, qui est disposé sur un côté de l’espace de photographie du générateur de champ magnétique incliné, et qui génère un champ magnétique à haute fréquence dans l’espace de photographie. Dans le générateur de champ magnétique statique, la forme d’un côté interne et/ou externe d’une section transversale dans une direction verticale au champ magnétique statique est sensiblement polygonale.
PCT/JP2006/313472 2005-07-08 2006-07-06 Dispositif d’imagerie par résonance magnétique WO2007007630A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012024114A (ja) * 2010-07-20 2012-02-09 Hitachi Medical Corp 磁気共鳴イメージング装置

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