JP4980171B2 - Magnetic shield room, magnetic shield panel - Google Patents

Description

  The present invention provides a magnetic shield room and a magnetic shield panel suitable for shielding the influence of magnetism from a closed space using magnetism to the outside or shielding the influence of magnetism from the outside to a closed space using magnetism. About.

  Magnetic resonance imaging apparatuses (MRI apparatuses) have been used particularly frequently in recent years. This MRI device is a device that forms a strong magnetic field in the central space of the magnetic field. When the formed magnetic field is applied to the human body, hydrogen nuclei in the body resonate with this magnetic field and generate weak radio waves. Therefore, it is possible to generate an image by receiving this radio wave.

  In such an MRI apparatus, it is necessary to ensure normal operation by preventing the measurement magnetic field and radio waves from being influenced by the outside. In addition, it is necessary to prevent magnetic influences on other devices and human bodies outside the closed space in which such an MRI apparatus is accommodated. For this reason, the request | requirement with respect to the magnetic shield room which covers the closed space which accommodates an MRI apparatus with a magnetic shield panel is increasing.

  As a magnetic shield panel applied to a conventional magnetic shield room, for example, a directional magnetic steel sheet, non-oriented electromagnetic steel sheet, permalloy, soft magnetic steel sheet, amorphous, liquid quenching ribbon with high permeability are crystallized. A so-called sealed magnetic shield structure has been proposed in which a wall surface of a space to be shielded is constituted by a magnetic plate made of a crystalline magnetic material or the like. However, this hermetically sealed magnetic shield structure has problems that it may be difficult to obtain the shielding characteristics expected from the material characteristics of the magnetic material, and that air and light permeability cannot be obtained. It was.

For this reason, a so-called open-type magnetic shield structure in which a group of magnetic material plates is arranged in a bowl shape or a louver shape has been proposed (see, for example, Patent Documents 1 to 3). In this open type magnetic shield structure, a strip-shaped or long magnetic material plate is laminated in a plurality of stages at a predetermined interval in the plate thickness direction to form a row-shaped housing. It has been experimentally confirmed that by constructing such a row-shaped housing, a high shielding performance is exhibited as compared with a sealed magnetic shield structure. In addition, this open type magnetic shield structure can improve air and light permeability.
JP 2002-164686 A JP 2006-351598 A PCT / JP2004 / 003457

  Incidentally, in a general magnetic shield room 70, for example, as shown in FIG. 10, the magnetic flux of the leakage magnetic field leaking from the annular coil radiates on the gantry surface 72 orthogonal to the center line 75 of the annular coil. These are spread toward the surface circumference 74 of the gantry surface 72. As a result, the angular directions that can be taken by the magnetic fluxes of the leakage magnetic field radiated to the gantry surface 72 are different from each other, and the propagation directions are dispersed at every angle.

  However, since the conventional open type magnetic shield structure is to form a row-shaped casing in which magnetic material plates are laminated in a plurality of steps at a predetermined interval in the thickness direction, such magnetic flux In order to dispose this on the gantry surface 72 that is dispersed at an angle, a panel in which a columnar housing of magnetic material plates is formed in the horizontal direction and a columnar housing of magnetic material plates in the vertical direction are formed. There was nothing else to deal with by making two types of panels and overlaying them on top of each other. For this reason, compared to the ceiling surface, floor surface, and other side wall surfaces, only the thickness of the panel of the gantry surface 72 is doubled, leading to wasteful consumption of space, and further, the material. There was room for improvement in terms of cost. Furthermore, the difference in panel thickness between the gantry surface 72 and other ceiling surfaces, floor surfaces, etc. complicates the structure of the connection fitting when connecting them together, complicating the work, There was room for improvement in terms of securing magnetic shielding properties.

  Further, in the construction method in which a panel in which a columnar housing of magnetic material plates is formed in a horizontal direction and a panel in which a columnar housing of magnetic material plates is formed in a vertical direction are arranged on the gantry surface 72 in an overlapping manner. There is a problem that the amount of magnetic material used increases. Further, since the magnetic flux radiated to the gantry surface 72 propagates not only in the horizontal direction and the vertical direction but also in all angular directions, and the distribution of the magnetic flux density is locally different. However, it cannot cope with the direction and distribution of all the magnetic fluxes with respect to the gantry surface 72 as described above, and a region in which a shortage or surplus of the magnetic material occurs partially, and there is a problem in terms of magnetic shielding properties.

  Furthermore, since the conventional open type magnetic shield structure is difficult to cope with the case where an external magnetic field has been radiated, the operation of the MRI apparatus accommodated in the closed space requires an external operation. There was also a problem that it was impossible to completely prevent the magnetic field from causing trouble.

  Accordingly, the present invention has been devised in view of the above-described problems, and provides a magnetic shield room and a magnetic shield panel that can effectively shield a leakage magnetic field from an MRI apparatus with a small amount of electromagnetic steel sheet used. The purpose is to do.

In order to solve the above-described problem, the magnetic shield room according to claim 1 is a magnetic shield room surrounded by a shield face material that shields a leakage magnetic field from the housed magnetic resonance imaging apparatus. A first shield face material and a second shield face material orthogonal to the center line in the annular coil provided in the third shield face material orthogonal to the first shield face material and the second shield face material, The fourth shield face material, the fifth shield face material, and the sixth shield face material are constituted by six surfaces, and the first shield face material and the second shield face material are constituted by a single panel, and the first shield face material . In the shield face material, a rectangular electromagnetic steel sheet is disposed such that the long side of the rectangular cross section is in the surface thickness direction of the shield face material. It is extended at any angle intervals from substantially orthogonal point up to the surface periphery of the center line in de surface material and the second shield surface material, above which is disposed the third to sixth shielding surface material in The strip-shaped electrical steel sheet is characterized in that the long side of the rectangular cross section is inclined toward the center line .

  The magnetic shield room according to claim 2 is the magnetic shield room according to claim 1, wherein the third to sixth shield face materials are extended to the circumferences of the first shield face material and the second shield face material. The strip-shaped electrical steel sheets are arranged in a plurality of stages at predetermined intervals so as to connect the strip-shaped electrical steel sheets to each other.

The magnetic shield room according to claim 3 is the magnetic shield room according to claim 1 or 2, wherein the first to sixth shield face materials are further circumscribed by a flat electromagnetic steel sheet from the outside or from the inside. It is characterized by being.

The magnetic shield room according to claim 4 is the magnetic shield room according to any one of claims 1 to 3 , wherein the end of the strip-shaped electrical steel sheet protrudes from the surface circumference of the first and second shield face materials. And the edge part of the said strip-shaped electromagnetic steel plate protruded from the side edge part of the said 3rd-6th shield surface material is connected with the electromagnetic steel plate for a connection constructed mutually.

A magnetic shield panel according to a fifth aspect is characterized in that it constitutes a part of the first shield face material or the second shield face material in the magnetic shield room according to any one of the first to fourth aspects.

  In the magnetic shield room to which the present invention is applied, in the first shield face material, the strip-shaped electromagnetic steel sheet is radially formed from the substantially orthogonal point of the center line in the annular coil provided in the magnetic resonance imaging apparatus to the circumference of the face. Is arranged. For this reason, the leakage magnetic field leaking from the magnetic resonance imaging apparatus is drawn by the strip-shaped electrical steel plates arranged radially, and the magnetic flux flows along the strip-shaped electrical steel plates arranged radially. It will be. In the first shield face material, since the center line of the leakage magnetic field from the magnetic resonance imaging apparatus coincides with the intersection of the strip-shaped electromagnetic steel sheet, the leakage magnetic field distributed radially around this is used. It can be absorbed efficiently and can be guided to the surface circumference.

  The leakage magnetic field guided to the surface circumference is guided to the third to sixth shield face materials, and flows through the strip-shaped electrical steel sheet over several stages to the third to sixth shield face materials 13 to 16, thereby the second shield. Reach the face material. Similarly, a leakage magnetic field flows into the strip-shaped electrical steel sheet disposed on the second shield face material via the connection electrical steel sheet, and further passes through the center line again from the second shield face material. As a result, the leakage magnetic field returns to the magnetic resonance imaging apparatus.

  That is, in the magnetic shield room to which the present invention is applied, strip-shaped electrical steel sheets are arranged along the magnetic flux direction of the leakage magnetic field from the MRI apparatus. As a result, the leakage magnetic field from the magnetic resonance imaging apparatus can be absorbed and guided again from the second shield face material side to the magnetic resonance imaging apparatus, and the leakage of the magnetic field to the external space can be suppressed. Become.

  Further, in the present invention, it is possible to prevent leakage of magnetism if the strip-shaped electromagnetic steel plates arranged radially in the first shield face material and the second shield face material are constituted by one panel. Thus, it is not necessary to produce two panels in which a row of magnetic material plates are formed in the vertical and horizontal directions and to bond them together. For this reason, it becomes possible to comprise thin plate | board thickness of a 1st shield face material and a 2nd shield face material, and it becomes possible to utilize construction space effectively. These first and second shield face materials can be made equal to the plate thickness of the third to sixth shield face materials, and the connecting metal fitting can be made simple, and workability can be improved. It becomes possible. In the present invention in which the first shield face material and the second shield face material can be configured by one panel, the amount of strip-shaped electrical steel sheet to be used can be reduced as much as possible. Furthermore, in the present invention, since the strip-shaped electrical steel sheets are arranged along the magnetic flux direction of the leakage magnetic field from the magnetic resonance imaging apparatus, there is a partial area where the short-circuited electrical steel sheet is insufficient or surplus in each shield face material. Can be eliminated, and the magnetic shielding property can be further improved.

  Hereinafter, as a best mode for carrying out the present invention, a magnetic shield room surrounded by a shield face material that shields a leakage magnetic field from an accommodated magnetic resonance imaging apparatus will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of a magnetic shield room 1 to which the present invention is applied. A magnetic resonance imaging (MRI) apparatus 9 is accommodated in the magnetic shield room 1. With respect to the first shield face material 11 and the second shield face material 12 orthogonal to the center line 10 in the annular coil provided in the resonance imaging apparatus 9, and the first shield face material 11 and the second shield face material 12 The third shield face material 13, the fourth shield face material 14, the fifth shield face material 15, and the sixth shield face material 16 are surrounded by six surfaces that are orthogonal to each other.

  The filler in each of the shield face materials 11 to 16 is preferably made of a heat insulating material, but may be made of any material. In the following example, the case where the fillers in the shield face materials 11 to 16 are made of rock wool will be described as an example. That is, rock wool is an artificial mineral fiber formed by mixing lime or the like with basalt, steel slag, etc., and dissolving at high temperature. In addition, as an example of the filler in the shield face materials 11 to 16, a fiber-based heat insulating material such as glass wool or carbonized cork may be used, or calcium silicate, water-repellent pearlite, or polyethylene foam. For example, a foam heat insulating material such as the above may be used. Furthermore, a foamed inorganic heat insulating material such as glass foam may be applied.

  Moreover, each shield face material 11-16 is not limited to when comprised with one sheet, You may make it comprise the one face material by mutually connecting the several panel body mentioned later. .

  Incidentally, the shield surface material 11 constitutes a so-called gantry surface on which the magnetic flux of the leakage magnetic field leaking from the annular coil in the MRI apparatus 9 is directly incident, and the shield surface material 14 is the ceiling surface. Further, the shield face material 16 constitutes a floor surface. The shield face materials 11, 12, 13, and 15 constitute the side wall surfaces in the magnetic shield room 1.

  The strip-shaped electromagnetic steel plates 3 are disposed on the shield face materials 11 to 16. The strip-shaped electrical steel sheet 3 is made of a strip-shaped magnetic body, and is made of, for example, an electrical steel sheet having a permeability in the longitudinal direction larger than a permeability in the cross-sectional direction. The strip-shaped electrical steel sheet 3 may be configured as a single electrical steel sheet by laminating a plurality of thin magnetic material sheets in the thickness direction.

  As shown in FIG. 2, the strip-shaped electrical steel sheets 3 provided on the shield face materials 11 and 12 are arranged so that the long side e of the rectangular cross section is in the surface thickness direction F of the shield face material. . Further, the strip-shaped electromagnetic steel sheets 3 arranged on the first shield face material 11 and the second shield face material 12 are arranged radially as shown in FIG. 3, for example. The strip-shaped electromagnetic steel sheet 3 is extended from a point substantially perpendicular to the center line 10 of the first shield face material 11 and the second shield face material 12 to the surface circumference 20 thereof. Further, the angle formed between the adjacent strip-shaped electrical steel sheets 3 extending to the surface circumference 20 may be arbitrary. However, the angular interval of the strip-shaped electrical steel sheet 3 disposed on the first shield face material 11 is the same as the angular interval and the number of the strip-shaped electrical steel sheets 3 disposed on the second shield face material 11. The same when the magnetic field is uniform, and not the same when there is a difference in the magnetic field. Further, the substantially orthogonal point 19 is not limited to a point that completely coincides with a point orthogonal to the center line 10, and there may be some deviation.

  Moreover, as shown in FIG. 1, the strip-shaped electromagnetic steel plate 3 is arrange | positioned in the 3rd-6th shield surface materials 13-16 over several steps. This strip-shaped electromagnetic steel sheet 3 ends with the first shield face material 11, is connected to the first to third shield face materials 13 to 16, the first shield face material 11, and the third shield face material 11. It will be embodied in any one of ˜6 shield face materials 13 to 16 and those connected to the second shield face material 12. 4 is a cross-sectional view taken along the line AA in FIG. In the strip-shaped electromagnetic steel sheets 3 disposed on the third to sixth shield face materials 13 to 16, the long side of the rectangular cross section is inclined toward the center line 10.

  FIG. 5 is an enlarged cross-sectional view of the sixth shield face material 16 indicated by the dotted line portion G in FIG. 4. Incidentally, in this FIG. 5, the case where the shield face material 16 is comprised by connecting the some panel body 30 is assumed, and the structure of only the panel body 30 is shown.

  The shield face material 16 is configured such that a pair of conductive metal plates 26 are provided opposite to each other, and a filler is filled between the pair of metal plates 26. Further, a frame member 25 is embedded in the shield face material 16.

  The structure of the left end of the panel body 30 is configured by bending both left ends of the pair of metal plates 26 inward, and forms at least a first contact surface 34. Further, the right end structure of the panel body 30 is configured by bending the right ends of both of the pair of metal plates 26 inward to form at least a second contact surface 35.

  By configuring the left end and the right end of the panel body 30 in this way, when the panel body 30 is connected in the horizontal direction, the mating first contact surface 34 and the second contact surface 35 are They can be brought into contact with each other, and as a result, leakage of radio waves through the contact surfaces 34 and 35 can be prevented.

  As the metal plate 26, a galvalume steel plate or a galvanized steel plate as an aluminum-zinc alloy plated steel plate is applied. A coating film such as a galvalume steel plate, a galvanized steel plate, or a stainless steel plate is usually used as it is at a joint with a metal fitting, but may be peeled off. Incidentally, as the metal plate 26, a stainless steel plate, an aluminized steel plate, or the like may be applied. That is, the metal plate 26 made of such a material is inexpensive and can exhibit a high electromagnetic shielding ability. Moreover, this metal plate 26 is not limited to the case where it is provided on both surfaces of the panel body 30, and may be provided on any one surface. When the panel body 30 has only the magnetic shielding performance and does not have the electromagnetic shielding performance, the metal plate 26 may be omitted, or a normal esguard structure without an edge or a gasket. It is good.

  A frame member 25 having a rectangular cross section is embedded in the filler in the panel body 30. A space in which the strip-shaped electromagnetic steel sheet 3 can be placed is formed inside the frame member 25. The strip-shaped electrical steel sheet 3 can be disposed at an arbitrary angle in the space formed in the frame member 25, and the long side of the rectangular cross section of the strip-shaped electrical steel sheet 3 is directed toward the center line 10 as described above. It is also possible to arrange them so as to be inclined. The cross-sectional shape of the frame material may be a circle or an ellipse other than a rectangle.

  The panel body 30 is applied not only to the sixth shield face material 16 as described above but also to the other third to fifth shield face materials 16.

  FIG. 6A shows a connecting portion of other panel bodies 30 adjacent to each other in FIG. FIG. 6 (b) shows the B section at the connecting portion shown in FIG. 6 (a), and FIG. 6 (c) shows the C section. When the strip-shaped electrical steel sheet 3 is connected in the longitudinal direction at this connecting portion, for example, as shown in FIGS. 6 (a) and 6 (b), the U-shaped provided at the side end of each panel body 30 is used. The end portions of the strip-shaped electromagnetic steel plates 3 may be protruded from the reinforcing material 39, and the connecting electromagnetic steel plates 33 may be further installed on the upper and lower surfaces of the strip-shaped electromagnetic steel plates 3. At this time, both surfaces of the panel body 30 constituting the connecting portion are constructed by connection fittings 31 and 32, respectively. For example, the connection fitting 31 may be configured in a hat shape. Further, when these connection fittings 31 and 32 are fixed to each other, as shown in FIG. 6 (c), they are connected with screws 38, bolts or the like in the C cross section where the strip-shaped electromagnetic steel sheet 3 is not provided. It may be.

  FIG. 7A shows an enlarged view of the P portion in FIG. 1 viewed from the y direction. An electromagnetic steel plate 41 for connecting the strip-shaped electrical steel sheet 3 projecting from the side end of the first shield face material 11 and the strip-shaped electrical steel sheet 3 projecting from the side end part of the fourth shield face material 14 is installed. It is connected by doing. In this connecting portion, the connection fitting 42 is inscribed from the inside, and the connection fitting 43 is circumscribed from the outside. Both ends of the connection metal fittings 42 and 43 are bent, and come into contact with the metal plates 26 provided on both sides of the shield face materials 11 and 14, respectively.

  FIG.7 (b) has shown the enlarged view seen from the y direction of Q part in FIG. 1 which is a part in which the electromagnetic steel plate 41 is not provided. The connection fittings 42 and 43 are fixed to each other by screws 47, bolts, or the like at the Q portion or the like.

  FIG. 7C shows an enlarged view of the R portion in FIG. 1 viewed from the x direction. In the R portion, the strip-shaped electromagnetic steel sheet 3 disposed on the first shield face material 11 is extended in the diagonally upward direction in the drawing. In order to connect to the strip-shaped electromagnetic steel sheet 3 extending in the obliquely upward direction, the strip-shaped electromagnetic steel sheet 3 disposed on the fourth shield surface material 14 is also inclined at the same angle, and the electromagnetic steel sheet 41 These are connected to each other via the. At this time, by arranging the rectangular electromagnetic steel sheet 3 in the fourth shield surface material 14 so that the long side of the rectangular cross section of the rectangular electromagnetic steel sheet 3 is inclined toward the center line 10, the first shield surface material is obtained. Thus, it is possible to align with the extending direction of the strip-shaped electromagnetic steel sheet 3 arranged in the plate 11.

  FIG.7 (d) has shown sectional drawing of the arrow part in Fig.7 (a). The strip-shaped electrical steel sheet 3 disposed on the first shield face material 11 is extended in the obliquely upward direction in the drawing. In contrast to the strip-shaped electrical steel sheet 3 extending in the obliquely upward direction, the strip-shaped electrical steel sheet 3 disposed on the fourth shield surface material 14 is perpendicular to the fourth shield surface material 14. It is arranged. In such a case as well, these are connected to each other via the electromagnetic steel plate 41.

  Incidentally, the connection structure shown in FIG. 7 is applied to the connection portion between the other first and second shield face materials 11 and 12 and the third to sixth shield face materials 13 to 16.

  Next, the function and effect of the magnetic shield room 1 having the above-described configuration will be described in detail with reference to the drawings.

  FIG. 8 shows the distribution on the inner wall surface of the leakage magnetic field leaking from the MRI apparatus 9 accommodated in the magnetic shield room 1 to which the present invention is applied. Incidentally, in the magnetic shield room 1, the magnetic flux of the leakage magnetic field leaking from the annular coil spreads radially around the center line 10, and these spread toward the surface circumference 20 of the first shield surface 11. become. As a result, the angular directions that can be taken by the magnetic fluxes of the leakage magnetic field radiated to the first shield surface 11 are different from each other, and the propagation directions are dispersed at every angle.

  In the magnetic shield room 1 to which the present invention is applied, in the first shield face material 11, the strip-shaped electromagnetic steel sheet 3 is arranged radially from a point approximately perpendicular to the center line 10 to the surface circumference 20. For this reason, the leakage magnetic field leaking from the MRI apparatus 9 is drawn by the strip-shaped electrical steel sheet 3 arranged radially, and the magnetic flux flows along the strip-shaped electrical steel sheet 3 arranged radially. Will go. In the first shield face material 11, since the center line 10 of the leakage magnetic field from the MRI apparatus 9 and the intersection of the strip-shaped electromagnetic steel sheet 3 are made coincident, the leakage that is distributed radially around this is the center. The magnetic field can be drawn efficiently and can be guided to the surface circumference 20.

  The leakage magnetic field guided to the surface circumference 20 is guided to the third to sixth shield face materials 13 to 16 via the electromagnetic steel plate 41 for connection shown in FIG. It flows through the strip-shaped electrical steel sheet 3 over several stages from 13 to 16 and reaches the second shield face material 12. Similarly, a leakage magnetic field flows into the strip-shaped electromagnetic steel sheet disposed on the second shield face material 12 via the connection electromagnetic steel sheet 41, and the center line again starts from the second shield face material 12. The leakage magnetic field flows into the MRI apparatus 9 through 10.

  That is, in the magnetic shield room 1 to which the present invention is applied, the strip-shaped electromagnetic steel plates 3 are arranged along the magnetic flux direction of the leakage magnetic field from the MRI apparatus 9. As a result, the leakage magnetic field from the MRI apparatus 9 can be drawn and guided again from the second shield face material 12 side to the MRI apparatus 9, and the leakage of the magnetic field to the external space can be suppressed. .

  Further, in the present invention, if the strip-shaped electromagnetic steel sheets 3 arranged radially in the first shield face material 11 and the second shield face material 12 are constituted by one panel, it is possible to prevent magnetic leakage. Thus, as in the prior art, it is not necessary to fabricate two panels in which a columnar housing of magnetic material plates is formed in the vertical and horizontal directions and to bond them together. For this reason, it becomes possible to comprise thin plate | board thickness of the 1st shield face material 11 and the 2nd shield face material 12, and it becomes possible to utilize construction space effectively. It is possible to equalize the plate thicknesses of the first and second shield face materials 11 to 12 and the third to sixth shield face materials 13 to 16, and the connection fittings 42 and 43 can be configured simply. Thus, workability can be improved. In the present invention in which the first shield face material 11 and the second shield face material 12 can be configured by a single panel, the amount of the strip-shaped electromagnetic steel sheet 3 to be used can be reduced as much as possible. Furthermore, in this invention, since the strip-shaped electromagnetic steel sheet 3 is arranged along the magnetic flux direction of the leakage magnetic field from the MRI apparatus 9, the shortage or surplus of the strip-shaped electromagnetic steel sheet 3 occurs in each shield face material 11-16. The region is not partially generated, and the magnetic shielding property can be further improved.

  In the present invention, in order to enhance the magnetic flux drawing effect in the first shield face material 11, the following improvements may be made.

  The strip-shaped electrical steel sheet 3 in the dotted circle in FIG. 4 has a high permeability in the longitudinal direction but a low permeability in the non-longitudinal direction (the depth direction on the paper). In particular, in the area within the dotted circle in the strip-shaped electromagnetic steel sheet 3, the magnetic flux from the MRI apparatus 9 is radiated from a direction substantially perpendicular to the first shield face material 11. In order to enhance such a magnetic flux drawing effect, the strip-shaped electromagnetic steel sheet 3 may be further arranged in the non-longitudinal direction.

  Further, the effect of attracting magnetic flux may be further enhanced by increasing the number of strip-shaped electrical steel sheets within the solid circle in FIG. Note that the positions of the dotted line and the solid line in FIG. 4 may be interchanged.

  FIGS. 9A and 9B show another embodiment in the magnetic shield room 1 to which the present invention is applied. FIG.9 (c) is the example which has arrange | positioned the strip-shaped electromagnetic steel plate 3 arrange | positioned by the 3-6 shield surface materials 13-16 perpendicularly | vertically with respect to the said 3-6 shield surface materials 13-16. is there.

  Each of the first to sixth shield face materials 11 to 16 is further circumscribed by a flat electromagnetic steel plate 51 from the outside. As a result, a magnetic field leaking from another device in the external space is drawn by the electromagnetic steel plate 51 and can be prevented from leaking into the magnetic shield room 1. As described above, in the present invention, even when an external magnetism is radiated while adopting an open type magnetic shield structure, this can be dealt with, and the MRI apparatus 9 accommodated in the internal space can be dealt with. It is possible to completely prevent the trouble caused by the external magnetic field that is actuated.

  Incidentally, this electrical steel sheet 51 may be inscribed from the inside with respect to each of the first to sixth shield face materials 11 to 16, and of course may be inscribed and inscribed from the outside and inside. It is.

It is a perspective view of a magnetic shield room to which the present invention is applied. It is sectional drawing of the shield surface material in which the strip-shaped electromagnetic steel plate was arrange | positioned. It is a figure which shows the example of the strip-shaped electromagnetic steel plate arrange | positioned radially in the 1st shield surface material. It is AA sectional drawing in FIG. It is an expanded sectional view of the 6th shield face material shown by the dotted line portion G in FIG. It is a figure for demonstrating the connection structure of panel bodies. It is another figure for demonstrating the connection structure of panel bodies. It is a figure which shows distribution in the inner wall surface of the leakage magnetic field which leaks from the MRI apparatus accommodated in the magnetic shield room to which this invention is applied. It is a figure for demonstrating other embodiment in the magnetic shield room to which this invention is applied. It is a figure which shows distribution of the leakage magnetic field of the gantry surface in a general magnetic shield room.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic shield room 3 Strip-shaped electromagnetic steel plate 9 MRI apparatus 10 Center line 11 1st shield face material 12 2nd shield face material 13 3rd shield face material 14 4th shield face material 15 5th shield face material 16 6th shield surface Material 19 Approximately orthogonal point 20 Surface circumference 25 Frame material 26 Metal plate 30 Panel body

Claims (5)

In the magnetic shield room surrounded by the shield surface material that shields the leakage magnetic field from the housed magnetic resonance imaging apparatus,
The first shield face material and the second shield face material orthogonal to the center line of the annular coil provided in the magnetic resonance imaging apparatus, and the first shield face material and the second shield face material orthogonal to each other. 3 shield face material, 4th shield face material, 5th shield face material, 6th shield face material is comprised, and the said 1st shield face material and 2nd shield face material are comprised with one panel. And
In the first and second shield face materials, a strip-shaped electrical steel sheet is disposed so that the long side of the rectangular cross section is in the surface thickness direction of the shield face material, and the strip-shaped electrical steel sheet is the first shield. The strips extended from each other at an arbitrary angular interval from a point substantially perpendicular to the center line of the face material and the second shield face material to the circumference of the face, and disposed in the third to sixth shield face materials. The magnetic shield room is characterized in that the long side of the rectangular cross section is inclined toward the center line . In the third to sixth shield face materials, the strip-shaped electrical steel sheets are spaced at predetermined intervals so as to connect the strip-shaped electrical steel sheets extended to reach the circumference of the first shield face material and the second shield face material. The magnetic shield room according to claim 1, wherein the magnetic shield room is arranged in a plurality of stages. 3. The magnetic shield room according to claim 1, wherein a flat electromagnetic steel plate is further circumscribed from the outside or inscribed from the inner side to the first to sixth shield face materials. The ends of the strip-shaped electrical steel sheet protruding from the surface circumference of the first and second shield face materials and the ends of the strip-shaped electrical steel sheet protruding from the side ends of the third to sixth shield face materials The magnetic shield room according to any one of claims 1 to 3 , wherein the magnetic shield rooms are connected by electromagnetic steel plates for connection that are installed on each other. A magnetic shield panel comprising a part of the first shield face material or the second shield face material in the magnetic shield room according to any one of claims 1 to 4 .

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