JP5722308B2 - Magnetic resonance imaging apparatus and maintenance method thereof - Google Patents

Description

  The present invention relates to a magnetic resonance imaging (hereinafter referred to as “MRI”) apparatus, and more particularly, to a cover that covers an MRI apparatus main body.

  The MRI device measures NMR signals generated by the spins of the subject, especially the tissues of the human body, and visualizes the form and function of the head, abdomen, limbs, etc. in two or three dimensions Device. In imaging, the NMR signal is subjected to phase encoding and frequency encoding by a gradient magnetic field and measured as time series data. The measured NMR signal is reconstructed into an image by two-dimensional or three-dimensional Fourier transform.

  The main body of the MRI system consists of a so-called tunnel type that lays the subject in the internal space of a cylindrical magnetic field generator with the axial direction oriented horizontally, and a pair of magnetic field generators arranged at intervals above and below There is a so-called open type in which the subject is inserted between them and the test is performed.

  The MRI apparatus includes a cover that integrally covers and covers a magnetic field generator and the like. This cover serves to protect the device from the subject's blood, vomit, etc., to prevent accidents, and to improve the appearance.

  In Patent Document 1, the upper magnet of the open-type MRI apparatus is covered with a cylindrical upper magnet cover, the lower magnet is covered with a cylindrical inspection table, and a column for the column between the upper magnet and the lower magnet is supported. A structure for covering a cover for the device is disclosed. In the MRI apparatus of Patent Document 1, such a structure enables access to the subject from a range of 180 degrees or more around the cylindrical examination table.

  On the other hand, Patent Document 2 discloses a structure in which a flat cover (floor cover) that covers an upper surface (floor) of a lower magnet of an open MRI apparatus is a slide type. As a result, the floor cover can be detached and attached by one person.

Japanese Patent No. 4093736 Japanese Patent Laid-Open No. 2002-320597

When performing maintenance of the MRI apparatus main body, such as adjustment (shimming) of static magnetic field uniformity, it is necessary to remove the cover. However, the cover disclosed in Patent Document 1 needs to remove the cylindrical upper magnet cover and the cylindrical inspection table (lower magnet cover).
When removing the upper magnet cover, the operator must perform the removal work while supporting the weight of the cover. Further, when removing the inspection table from the lower magnet, it is necessary to lift the lower end of the cylindrical inspection table above the upper surface of the lower magnet and remove it. These operations place a heavy burden on the operator and are difficult to work alone. The same applies to the attachment.

  The structure disclosed in Patent Document 2 only considers the attachment and detachment of the flat cover that covers the surface of the lower magnet of the open MRI apparatus. The burden on the operator is large.

  On the other hand, if the number of cover divisions is increased, the burden on the operator in reducing the individual covers and supporting the weight of the cover is reduced, but many covers must be removed when removing. Therefore, it takes time to remove and the efficiency becomes worse. In addition, when the number of cover divisions is large, the number of cover mating surfaces increases accordingly, and there is also a problem that the aesthetic appearance of the apparatus tends to be impaired.

  Further, since the bed is disposed adjacent to the lower magnet, in order to remove the lower magnet cover, it is necessary to move the entire bed and create a space around the lower magnet. However, the work of moving a bed that is heavy and is aligned is heavy on the operator. In addition, re-positioning is required when returning to the original state, and the number of maintenance work steps increases.

  An object of the present invention is to provide an MRI apparatus in which the number of cover divisions is small and the cover can be easily attached and detached.

  In order to solve the above problems, according to the first aspect of the present invention, the following MRI apparatus is provided. That is, an MRI apparatus having a magnetic field generation unit that generates at least a static magnetic field in a space in which a subject is disposed, and a cover that covers the magnetic field generation unit, wherein the cover is divided into two or more members, and two or more Of these members, the first and second members are connected at one end by a hinge. The magnetic field generator is exposed by opening the first and second members on both sides around the hinge. Therefore, the magnetic field generator can be easily exposed by opening the cover on both sides.

  For example, the first and second members are members obtained by dividing the cover along a vertical dividing line, and can be configured to open to the left and right around the hinge.

  In addition, the third member of the two or more members constituting the cover can be configured to be detachably fixed at a position covering the region where the bed is adjacent on the side surface of the magnetic field generation unit. The first and second members are configured to be openable and closable around the hinge while the third member is fixed to the side surface of the magnetic field generation unit. As a result, the first and second members can be opened and the magnetic field generator can be exposed while the bed is placed.

  The magnetic field generator has, for example, a configuration having a pair of magnets that are vertically opposed to each other with a predetermined interval, and a column that is connected to the side surfaces of the pair of magnets. In this case, the first and second members of the cover are members that cover at least part of the side surfaces of the pair of magnets. The hinge can be placed along the post. A part of the end portion opposite to the one end connected to the hinges of the first and second members is configured to abut on the side surface of the magnet opposite to the support column.

  The hinge may be configured to be fixed to the magnetic field generator. Accordingly, at least a part of the weight of the first and second members can be supported by the magnetic field generation unit via the hinge.

  Further, the lower ends of the first and second members can be configured to support at least part of the weight of the first and second members with respect to the floor surface. In this case, it is possible to arrange a member that reduces the friction coefficient at a portion where the lower ends of the first and second members are in contact with the floor surface. Accordingly, the first and second members can be easily opened and closed by sliding the floor surface. For example, a wheel or a slide rail is used as the member for reducing the friction coefficient.

  For example, the lower magnet of the pair of magnets has a disk shape, and the first and second members have a shape covering at least part of the left side surface and the right side surface of the lower magnet. Of the two or more members of the cover, the fourth member is configured to cover the upper surface of the lower magnet and the upper portion of the first and second members and prevent the first and second members from opening. . As a result, the first and second members can be prevented from opening at an unintended timing such as during photographing.

  Each of the first and second members can be divided into a part that covers the upper part of the magnetic field generation unit and a part that covers the lower part. Thereby, it becomes possible to open and close the part which covers an upper part, and the part which covers a lower part independently.

  Moreover, according to the second aspect of the present invention, a maintenance method for an MRI apparatus is provided. That is, a method of removing the cover of the magnetic field generator that generates a magnetic field in the space where the subject is placed and performing maintenance of the MRI apparatus, wherein the first and second covers connected by the hinge are connected to the hinge Rotate each center to open on both sides, expose the magnetic field generator, perform predetermined maintenance work on the magnetic field generator, and close the first and second covers from both sides to cover the magnetic field generator is there.

  The operation of opening the first cover and the second cover on both sides is performed with the bed and the third cover fixed to the side surface of the magnetic field generator at the position where the bed is adjacent to the bed, and the influence of the bed. It is also possible to perform maintenance work in consideration of the above.

  According to the present invention, the cover can be easily opened and closed by opening the first and second members on both sides around the hinge, and the magnetic field generation unit can be exposed. As a result, the burden on the operator is small and the work efficiency of maintenance can be increased. Further, since the first and second members can be opened while the bed is arranged, maintenance such as shimming can be performed in consideration of the influence of the bed.

1 is a block diagram showing the overall configuration of an MRI apparatus according to a first embodiment. The perspective view of the gantry 1 and the bed 119 of the MRI apparatus of 1st Embodiment. FIG. 3 is a perspective view of a gantry 1 of the MRI apparatus of FIG. The side view of the gantry 1 of the MRI apparatus of FIG. FIG. 3 is a rear view of the gantry 1 of the MRI apparatus of FIG. FIG. 3 is a perspective view of each component of the gantry and cover of FIG. FIG. 6 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a cross-sectional view taken along the line BB in FIG. (a) The front view of the hinge of 1st Embodiment, (b) The front view of another example of the hinge which can be used in 1st Embodiment. FIG. 4 is a top view of the gantry 1 with the main covers 2 and 3 in FIG. 3 open. FIG. 5 is a cross-sectional view taken along arrow C in FIG. 6 is a flowchart showing a maintenance procedure according to the first embodiment. FIG. 3 is a perspective view of the gantry 1 with the cover 20 of the first embodiment opened. 1 is a cross-sectional view of a gantry 1 in a state where a cover 20 of a first embodiment is opened. FIG. 6 is a top view of the gantry 1 with the main covers 2 and 3 according to the second embodiment open. Sectional drawing of the gantry 1 of the state which opened the cover 20 of 3rd Embodiment. The perspective view of the gantry 1 of the state which opened the cover 20 of 3rd Embodiment. Sectional drawing of the gantry 1 of the state which has arrange | positioned the slide rail 15 of 3rd Embodiment, and opened the cover 20. FIG. FIG. 19 is a view on arrow D in FIG. The perspective view of the gantry 1 in the state of opening the cover 20 of the fourth embodiment.

  An MRI apparatus according to an embodiment of the present invention will be described.

<Configuration of MRI machine>
First, the overall configuration of the MRI apparatus of the present embodiment will be described. FIG. 1 is a schematic diagram of an overall configuration of an MRI apparatus without a cover attached. This MRI apparatus includes a static magnetic field generation apparatus 101 that generates a static magnetic field, a gradient magnetic field coil 111, a radio frequency (RF) coil 113, a shim plate 110, a bed 119 on which a subject 102 is mounted, and a gradient magnetic field power. The amplifier 112 includes a high-frequency power amplifier 114, a high-frequency amplifier circuit 116, a computer 117, and a display 118. The static magnetic field generator 101, the gradient magnetic field coil 111, the high frequency coil 113, and the shim plate 110 are referred to as a gantry 1.

  The static magnetic field generator 101 of the gantry 1 has an open structure, and includes an upper magnet 104 and a lower magnet 105 above and below an imaging space 103 in which a subject 102 is placed. The upper magnet 104 and the lower magnet 105 are connected by a column 106. As a result, an open structure in which the front, rear, left and right of the imaging space 103 are wide and open is provided, so that it is possible to provide an examination environment with less pressure on the subject 102. The upper magnet 104 and the lower magnet 105 may be permanent magnets, normal conducting magnets, or superconducting magnets, but here permanent magnets are employed.

  The static magnetic field generator 101 generates a static magnetic field in the imaging space 103. In order to improve the magnetic field uniformity to a predetermined value or less, shim plates 110 are attached to the surfaces of the imaging space 103 of the upper magnet 104 and the lower magnet 105, respectively. A plurality of screw holes (not shown) are formed in the shim plate 110, and magnetic screws are mounted at appropriate positions. The magnetic field uniformity is adjusted to a predetermined value or less by correcting the distribution of the magnetic flux generated by the static magnetic field generator 101 with the magnetic flux of the magnetic screw.

  A pair of gradient magnetic field coils 111 that generate a gradient magnetic field are arranged on the surface of the imaging space 103 of the pair of shim plates 110. The gradient magnetic field coil 111 has a flat plate structure so as not to disturb the open structure of the static magnetic field generator 101. Each of the pair of upper and lower gradient magnetic field coils 111 is built in a state in which three types of coils of x, y, and z that generate gradient magnetic fields in three axial directions orthogonal to each other are stacked. A gradient magnetic field power amplifier 112 that applies current independently is connected to each of the x, y, and z coils.

  The z coil forms a gradient magnetic field in which the magnetic flux density gradually decreases from the top to the bottom of the z axis (vertical axis) of the imaging space 103. Similarly, the x coil and the y coil form gradient magnetic fields of the x axis and the y axis (both horizontal axes), respectively. As a result, a gradient magnetic field in a predetermined axial direction is superimposed on the magnetic field generated by the static magnetic field generator 101.

  A pair of high-frequency coils 113 are attached to the imaging space 103 side of the pair of gradient magnetic field coils 111. The high frequency coil 113 also has a flat plate structure. A high frequency power amplifier 114 is connected to the pair of upper and lower high frequency coils 113 and supplied with a high frequency current. As a result, a high-frequency magnetic field having a predetermined frequency is irradiated to the examination site of the subject 102, and nuclear magnetic resonance (NMR) is generated in the nuclear spin of the examination site. By combining the high-frequency magnetic field with the gradient magnetic field formed by the gradient magnetic field coil 111, the NMR signal is selectively emitted to the examination site of the subject 102. The NMR signal is added with phase encoding and frequency encoding which are three-dimensional position information by a gradient magnetic field.

  A detection coil 115 that detects precession of nuclear spins is disposed at the examination site of the subject 102. The detection coil 115 detects the NMR signal and passes it to the high frequency amplification circuit 116. The high frequency amplifier circuit 116 amplifies and detects the detection signal and converts it into a digital signal. The computer 117 processes the detection signal converted into the digital signal, reconstructs an image of the subject 102, and displays it on the display 118.

  The computer 117 outputs control signals to the gradient magnetic field power amplifier 112, the high frequency power amplifier 114, and the high frequency amplifier circuit 116 via the bus line 120, and also performs control to execute imaging in a predetermined imaging sequence.

  As another main unit, a bed 119 that conveys the subject 102 to the center of the imaging space 103 is disposed adjacent to the lower magnet 105 of the static magnetic field generator 101. The static magnetic field generator 101 and the bed 119 are installed in an examination room 109 provided with an electromagnetic shield.

<Composition of cover>
As shown in FIGS. 2 to 8, the outside of the gantry 1 is covered with a cover 20. FIG. 2 is a perspective view of the gantry 1 and the bed 119 covered with the cover 20. 3, 4 and 5 are a perspective view, a side view and a rear view of the gantry 1 covered with the cover 20. FIG. FIG. 6 shows a perspective view of the parts constituting the cover 20 and the gantry 1. 7 is a cross-sectional view (partial) taken along the line AA in FIG. FIG. 8 is a cross-sectional view (partial) of BB in FIG.

  As shown in FIG. 6, the outer shape of the upper magnet 104 of the static magnetic field generation apparatus 101 is a disk shape whose upper part is inclined obliquely. The lower magnet 105 has a disk shape and is supported on the floor surface by two or more legs 131 arranged on the lower surface. The support 106 is in contact with the floor and has a height up to the upper surface of the upper magnet 104, supports the upper magnet 104, and connects the upper magnet 104 and the lower magnet 105. The gradient magnetic field coil 111, the high frequency coil 113, and the shim plate 110 are integrally fixed to the lower surface of the upper magnet 104 and the upper surface of the lower magnet 105, respectively.

  The configuration of the cover 20 will be described with reference to FIGS. The cover 20 includes a right main cover 2, a left main cover 3, a hinge 4, a hinge cover 8, a center cover 5, an upper RF cover 6, a lower RF cover 7, and a connecting portion cover 9.

  The right main cover 2 has a shape covering the upper magnet 104 and the right half and the right side of the upper surface of the support and a part of the right side of the lower magnet 105 when viewed from the front. The portion of the lower magnet 105 that is not covered by the right main cover 2 on the right side front side is covered with the connecting portion cover 9. The left main cover 3 has a shape that covers the left half and the left side of the upper surface of the upper magnet 104 and the column 106 and the left side of the lower magnet 105.

At the lower ends of the right and left main covers 2, 3, integrally formed legs 2a, 3a are provided.
The right and left main covers 2 and 3 are designed to have strength and weight so that the right and left main covers 2 and 3 can stand on the floor surface by the legs 2a and 3a while being connected to the rear hinge 4.

  The right main cover 2 and the left main cover 3 are abutted at the position of the center line 31 on the front and top surfaces of the upper magnet 104 and at the position of the back center line 32 on the back side. A latch mechanism 80 shown in FIG. 8 is provided at the position of the front center line 31. A hinge 4 is provided at the position of the center line 32 on the back surface. As a result, the right and left main covers 2 and 3 are abutted at the position of the center line 31, connected by the latch mechanism 80, and fixed to a part of the internal gantry 1.

  The latch mechanism 80 in FIG. 8 will be specifically described. At the butted ends of the center line 31 on the front surface of the right main cover 2 and the left main cover 3, the flanges 81 are fixed to the inner wall surface. On the other hand, on the outer surface of the upper magnet 104, a receiving portion 82 having a shape that engages with the flange portion 81 is fixed. Therefore, the right main cover 2 and the left main cover 3 are butted at the position of the center line 31, and the end portions of the right and left main covers 2 and 3 are connected to the center line by engaging the respective flange portions 81 with the receiving portions 82. It can be fixed to the upper magnet 104 in a state of being butted at 31.

  The hinge 4 will be described with reference to FIGS. 5, 7, and 9 (a). FIG. 9 (a) is an enlarged front view of the hinge 4. FIG. As shown in FIGS. 5 and 7, a plurality of hinges 4 are fixed along the center line 32 on the back side of the support column 106. The hinge 4 includes two rotating shafts 4a and 4b arranged side by side with a center line 32, a support plate 4c that supports the rotating shafts 4a and 4b, and a wing portion that is rotatably fixed to the rotating shafts 4a and 4b. 4e, 4f, a fixing portion 4d for fixing the support plate 4c to the column 106, and a hinge cover 8. Note that the hinge cover 8 is not shown in FIGS. 5 and 9 (a).

  The rear end portions of the right main cover 2 and the left main cover 3 are connected to the wing portions 4e and 4f, respectively. As a result, the right main cover 2 and the left main cover 3 rotate about the hinge 4 as shown in the top view in FIG. 10, and the right main cover 2 is on the right side when viewed from the front. The main cover 3 has a double-open structure that opens to the left when viewed from the front.

  The hinge cover 8 is fixed to the support plate 4c at a distance from the rotation shafts 4a and 4b. The surface of the hinge cover 8 is configured to form the same surface as the outer surfaces of the right and left main covers 2, 3 as shown in FIGS. Thus, the cover 20 that covers and hides the unevenness of the hinge 4 and is excellent in a smooth aesthetic appearance can be provided. Further, the size and position of the hinge cover 8 are designed so that the right and left main covers 2 and 3 can be opened and closed while the hinge cover 8 is attached to the support plate 4. Since the surface of the hinge cover 8 is arranged on the same plane as the outer surfaces of the right and left main covers 2 and 3, the wings 4e and 4f are bent.

The center cover 5 is a cover that covers the front-side surface of the column 106 as shown in FIGS.
The center cover 5 is configured to have a shape that partially overlaps the right main cover 2 and the left main cover 3 and covers the column 12 with the right main cover 2 and the left main cover 3 closed.
As shown in FIG. 6, hook-shaped metal fittings 5a and 5b are attached to the top and bottom of the center cover 5. By engaging this with a receiving side metal fitting (not shown) attached to the column 106 side, the center cover 5 is detachably fixed to the column 106.

  The upper RF cover 6 and the lower RF cover 7 are disk-shaped covers that cover the lower surface of the upper magnet 104 and the upper surface of the lower magnet 105 to which the gradient magnetic field coil 111, the high-frequency coil 113, and the shim plate 110 are fixed. The upper and lower RF covers 6 and 7 are provided with screw through holes 6a and 7a in the main plane. Screws are inserted into the screw through holes 6a and 7a and screw holes provided in the high-frequency coil 114 (not shown). ) To be fixed.

  As shown in the cross section of FIG. 11, the lower RF cover 7 is configured to be placed on and fitted to the upper part of the portion covering the side surface of the lower magnet 105 of the right and left main covers 2 and 3. Yes. Although not shown in the drawing, the upper RF cover 6 is also placed on the lower part of the portion covering the side surface of the upper magnet 104 of the right and left main covers 2 and 3 in the same manner as the lower RF cover 7, and is fitted therewith. Configured to match. Thereby, the right and left main covers 2, 3 are locked by the upper and lower RF covers 6, 7. Therefore, the right and left main covers 2 and 3 are locked by the latch structure 80 in the front portion and the upper and lower RF covers 6 and 7, and do not open when the MRI apparatus is used. In addition, the upper and lower RF covers 6 and 7 cover the right and left main covers 2 and 3 from the outside, so that liquid and dust do not enter the inside of the right and left main covers 2 and 3 and the hygiene is improved. . Furthermore, the seam of the main covers 2 and 3 is not conspicuous and the aesthetics are improved as viewed from the operator and the subject.

  A flat portion 33 is provided at a predetermined position on the edge of the lower RF cover 7. A bed 119 is disposed adjacent to the flat portion 33 as shown in FIG. When the subject 102 is carried into the imaging space 103, the flat portion 33 serves as a travel path of the slide top plate 119a on which the subject 102 is mounted by arranging the slide surface 119b of the bed 119 at the same height.

  The connecting portion cover 9 is fixed so as to cover the lower portion of the flat portion 33, that is, the side surface region of the lower magnet 105 adjacent to the side surface of the bed 119. Fixing is performed by screwing the metal fittings 9a and 9b provided in the connecting portion cover 9 to the side surface of the lower magnet 105. As described above, since the connecting portion cover 9 is disposed below the flat portion 33, the right and left main covers 2 and 3 that cover portions other than the connecting portion cover 9 are not interfered with the bed 119. Therefore, the right and left main covers 2 and 3 can be opened while the bed 119 is disposed adjacent to the lower magnet 105.

  Note that the upper part of the right main cover 2 is provided with switches 2b and 2c for operation by the operator. Electrical wiring (not shown) is connected to the switches 2b and 2c, and the electrical wiring is connected to a predetermined portion of the gantry 1 inside the right main cover 2.

  As a material constituting the cover 20, a light and strong resin can be used. For example, glass fiber reinforced plastics (GFRP) are suitable.

<Maintenance work>
Next, a work flow when removing the cover 20 and maintaining the gantry 1 (for example, adjusting the shim coil 110) will be described with reference to FIG. 13 and 14 show a perspective view and a cross-sectional view of the state in which the right and left main covers 2, 3 are opened for maintenance.

  First, the upper RF cover 6 is removed by removing a screw (step 121). Next, the lower RF cover 7 is removed by removing a screw (step 122). As a result, the right and left main covers 2, 3 can be opened.

  Next, the latch structure 80 at the front abutting portion of the right and left main covers 2 and 3 is removed, and the operator pushes and opens the abutting portion of the right and left main covers 2 and 3, so that the right and left main covers 2 , 3 rotate around the hinge 4 on the back and open to the left and right as shown in FIGS. 10, 13 and 14 (step 123). At this time, the leg portions 2a and 3a slide on the floor surface, and the right and left main covers 2 and 3 are opened by the leg portions 2a and 3a while being independent on the floor surface. For this reason, it is not necessary for the operator to support the weight of the right and left main covers 2 and 3. Further, since the bed 119 does not interfere with the rotation of the right and left main covers 2 and 3, it can be opened with the bed 119 disposed.

  The gantry 1 is exposed by opening the right and left main covers 2 and 3. As a result, access to the gantry 1 becomes possible and desired maintenance (for example, shimming) can be performed (step 124).

  At this time, since it is not necessary to retract the bed 119, when performing shimming by adjusting the shim plate 110, the influence of the magnetic material included in the bed 119 disposed at the same position as the time of shooting is taken into consideration. Magnetic field uniformity can be adjusted with high accuracy.

  Further, if necessary, the center cover 5 can be removed from the support 106 to perform maintenance of the support 106.

  After the maintenance is completed, the operator attaches the center cover 5 when it is removed, closes the right and left main covers 2, 3, and engages the collar portion 81 of the latch structure 80 with the receiving portion 82. As a result, the front portions of the right and left main covers 2, 3 are fixed in a state where they are abutted at the center line 31. Thereafter, the upper RF cover 6 and the lower RF cover 7 are attached by screwing. Thus, the maintenance work is completed.

  In the MRI apparatus of the present embodiment, the right main cover 2 and the left main cover 3 are supported by the hinge 4 and the leg portions 2a and 2b, and the leg portions 2a and 2b slide on the floor surface. It can be opened and closed while being supported by the parts 2a and 2b. Thereby, during the work of attaching / removing the cover, it is not necessary for the operator to support the weight of the right main cover 2 and the left main cover 3, thereby improving workability. The right main cover 2 and the left main cover 3 can be removed by one worker.

  Further, since the upper RF cover 6, the lower RF cover 7, and the center cover 5 have a small area and are light, they can be easily removed without imposing a heavy burden on the operator.

  Moreover, since the right main cover 2 and the left main cover 3 can cover most of the MRI apparatus main body 1, the number of covers can be reduced as compared with the conventional case. Therefore, the number of work steps for attaching and removing the cover is small, and the cover 20 can be removed efficiently in a short time.

  Further, in the present embodiment, since the number of covers is smaller than that in the prior art, the number of types of covers is small, and the price of the entire cover can be reduced.

  In addition, since the number of covers is small, the mating surfaces of the covers are reduced, and the MRI apparatus with a good appearance and excellent aesthetics can be provided.

  During maintenance, the right and left main covers 2 and 3 can be opened and closed while the connecting portion cover 9 and the bed 119 and the center cover 5 are arranged, so that the work process can be reduced. Work efficiency can be increased.

  Since the bed 119 includes a magnetic material in a part of the constituent material, it influences the static magnetic field uniformity of the MRI apparatus. In this embodiment, since maintenance such as shimming can be performed while the bed 119 is disposed, maintenance can be performed in a state close to that at the time of photographing considering the influence of the bed 119, and high-precision maintenance is possible.

  In the present embodiment, as shown in FIG. 9 (a), using a hinge 4 having two rotating shafts 4a, 4b, the right and left main covers 2, 3 are connected to different rotating shafts 4a, 4b, respectively. However, the structure of the hinge 4 is not limited to this structure. As shown in FIG. 9 (b), it is also possible to have one rotating shaft 91 of the hinge 4.

  Further, in the present embodiment, the hinge 4 is structured so as to be covered by the flat hinge cover 8 as shown in FIGS. 4 and 7 in order to improve the appearance. Is possible. Further, the hinge 4 may be hidden by another means such as providing the hinge 4 inside the right and left main covers 2 and 3.

  In the first embodiment, the weights of the right and left main covers 2 and 3 are supported by the hinge 4 and the legs 2a and 3a. However, it is also possible to adopt a configuration in which the weight is supported only by the hinge 4. . In this case, since the lower portions of the right and left main covers 2, 3 can be made to float from the floor surface, the force required to open and close the main covers 2, 3 can be reduced.

(Second embodiment)
The MRI apparatus according to the second embodiment will be described with reference to FIG.

  In the first embodiment, the hinge 4 is fixed to the column 106, but as shown in FIG. 15, the hinge 4 is not fixed to the column 106, and the right and left main covers 2, 3 are connected by the hinge 4. It is also possible to do. In this case, the weights of the right and left main covers 2, 3 are supported with respect to the floor surface only by the legs 2a, 3a. Other configurations are the same as those of the first embodiment, and thus description thereof is omitted.

  In the case of the configuration shown in FIG. 15, the right and left main cover covers 2 and 3 can be opened and moved in the rear direction to be removed from the gantry 1. Therefore, since the gantry 1 is exposed to the back surface of the support column 106, an operator can go around the support column 106 and perform maintenance work.

(Third embodiment)
A third embodiment will be described. 16 and 17 are a cross-sectional view and a perspective view of an MRI apparatus provided with wheels on the leg portions 2a and 3a of the main covers 2 and 3, respectively.

  As described in the first embodiment, the weights of the right main cover 2 and the left main cover 3 are supported by the support 106 via the leg portions 2a and 3a and the hinge 4. At the time of opening and closing, the operator pushes the right main cover 2 and the left main cover 3 to slide and move the leg portions 2a and 3a by sliding on the floor surface. In the third embodiment, a plurality of wheels 14 are arranged as means for reducing the friction coefficient of the contact surface between the right main cover 2, the left main cover 3, and the floor in order to further reduce the burden on the operator when opening and closing. did.

  Thus, the right main cover 2 and the left main cover 3 can move on the floor surface by the rotation of the wheels 14. The wheels 14 support the weights of the right main cover 2 and the left main cover 3 with respect to the floor surface.

  In the present embodiment, as shown in FIG. 16, two wheels 14 in the right main cover 2 and three wheels 14 in the left main cover 3 are provided near the floor surface inside each cover. The mounting positions and the number of wheels 14 are not limited to the structures shown in FIGS. 16 and 17, and may be provided outside the right and left main covers 2 and 3, or more wheels may be provided. good. Further, the wheel can be structured to be removable.

  The means for reducing the friction coefficient of the contact surface between the right main cover 2, the left main cover 3, and the floor is not limited to the wheel 14, and other configurations may be used. 18 and 19 show a configuration using the slide rail 15. FIG.

In the configuration of FIG. 18, a plurality of linear slide rails 15 are arranged on the floor surface, and notches 16 that engage with the slide rails 15 are provided on the bottom surfaces of the right and left main covers 2 and 3.
The surface of the slide rail 15 and the inner wall surface of the notch 16 are processed smoothly so as to reduce the friction coefficient.

  By arranging the slide rail 15 in this way, the right and left main covers 2, 3 can be moved along the slide rail 15, and the right and left main covers 2, 3 can be opened and closed with a small force. .

  The slide rail 15 can be configured to be removable from the floor surface, configured to be attached / removed each time the main cover is opened / closed, or configured to be foldable and retractable inside the cover. Further, the slide rail 15 can be a curved shape in addition to a linear shape. Further, it is possible to adopt a configuration in which the notches 16 of the main covers 2 and 3 are not provided.

  It is also possible to use a structure in which a material having a small coefficient of friction with respect to the floor surface, such as a fluororesin sheet, is attached to the bottom surfaces of the leg portions 2a, 3a of the right and left main covers 2, 3 without using the wheels 14 and the slide rails 15. Is possible. Also in this case, the right and left main covers 2, 3 can be slid on the floor surface with a small force.

  In the configuration of the third embodiment, by providing the wheels 14 and the slide rail 15 near the floor surface of the main covers 2 and 3, the operation force when the main cover is opened and closed can be reduced, and the main cover can be opened and closed smoothly.

  By providing the wheel 14 and the slide rail 15, the weight of the main cover supported by the wheel 14 and the slide rail 15 can be increased, so that the load on the hinge 4 can be reduced. Therefore, the rigidity of the hinge 4 can be reduced, leading to cost reduction.

  In addition, it is also possible to employ | adopt the structure which reduces friction coefficients, such as the wheel 14 of the 3rd Embodiment, the slide rail 15, etc. to the structure which does not fix the hinge 4 to the support | pillar 106 like 2nd Embodiment.

(Fourth embodiment)
The MRI apparatus of the fourth embodiment will be described using the perspective view of FIG.

  In this embodiment, as shown in FIG. 20, the right and left main covers 2, 3 are each divided into two members in the vertical direction. The right main cover 2 is divided into an upper right main cover 202 and a lower right main cover 212. The left main cover 3 is divided into an upper left main cover 203 and a lower left main cover 203.

  Two or more hinges 4 are also provided, and the hinge 4 to which the upper right and upper left main covers 202 and 203 are attached is different from the hinge 4 to which the lower right and lower left main covers 212 and 213 are attached. Thus, the upper main covers 202 and 203 and the lower main covers 212 and 213 can be opened and closed independently.

  In the configuration of the present embodiment, the main covers 2 and 3 are divided into upper and lower parts. Therefore, when one of the upper magnet 104 and the lower magnet 105 is to be maintained, only the upper main cover 202 or 203 or the lower main cover 212 or 213 is used. Maintenance work is possible by opening and closing. Since the main cover divided into two is smaller and lighter than the main covers 2 and 3 that are not divided, the opening / closing operation can be easily performed. Therefore, maintenance work can be easily performed.

  Note that the bottom surface of the lower right and lower left main covers 212 and 213 can employ a configuration for reducing the friction coefficient with the floor surface as in the fourth embodiment.

  Further, since the weights of the lower right and lower left main covers 212 and 213 are reduced by being divided, it is easy to configure so that all the weights are supported by the hinge 4.

  Further, the lower right and lower left main covers 212 and 213 can be configured to be detachable from the gantry 104 without fixing the hinge 4 to the column 106 as in the second embodiment.

1 Gantry, 20 cover, 2 Right main cover, 2a leg, 2b, 2c switch, 3 Left main cover, 3a leg, 4 Hinge, 4a, 4b Rotating shaft, 4c Support plate, 4d Fixed part, 4e, 4f Wings , 5 Center cover, 5a, 5b Mounting bracket, 6 Upper RF cover, 6a Screw through hole, 7 Lower RF cover, 7a Screw through hole, 8 Hinge cover, 9 Connection cover, 9a, 9b Mounting bracket, 14 Wheel, 15 slide rail, 16 notch, 31 front and top center line, 32 back center line, 33 flat part, 80 latch structure, 81 collar, 82 receiving part, 101 static magnetic field generator, 102 subject, 103 Imaging space, 104 Upper magnet, 105 Lower magnet, 106 Post, 109 Inspection room, 111 Gradient magnetic field coil, 112 Gradient magnetic field power amplifier, 113 High frequency coil, 114 High frequency power amplifier, 115 Detection coil, 116 High frequency amplification circuit, 117 Computer , 118 display, 119 base De, 119a slide table, 119b slide surface, 131 legs, 202 upper right main cover, 203 upper left main cover, 212 lower right main cover, 213 bottom left main cover

Claims (14)

A pair of magnets arranged opposite to each other at a predetermined interval and a column connected to the side surfaces of the pair of magnets, and at least generate a static magnetic field in a space in which the subject is placed A magnetic field generator to
A cover covering the magnetic field generation unit ;
Have
The cover is divided into two or more members, and the first and second members of the two or more members are members that cover at least part of the side surfaces of the pair of magnets, and one ends thereof are connected by a hinge. ,
A magnetic resonance imaging apparatus characterized in that at least a part of the magnetic field generator is exposed by opening the first and second members to both sides around the hinge. In the magnetic resonance imaging apparatus according to claim 1,
The magnetic resonance imaging apparatus, wherein the first and second members are members obtained by dividing the cover along a dividing line in a vertical direction, and open left and right with the hinge as a center. In the magnetic resonance imaging apparatus according to claim 1 or 2,
A bed disposed adjacent to the magnetic field generator;
Of the two or more members constituting the cover, the third member is detachably fixed at a position covering the region adjacent to the bed of the side surface of the magnetic field generation unit,
The magnetic resonance imaging apparatus according to claim 1, wherein the first and second members are openable and closable around the hinge in a state where the third member is fixed to a side surface of the magnetic field generation unit. In the magnetic resonance imaging apparatus according to any one of claims 1 to 3 ,
Before SL hinge is disposed along the strut, the A part of the end portion opposite to the first and connected to one end to the hinge of the second member, opposite side of said magnet and said post A magnetic resonance imaging apparatus characterized in that they are abutted on each other. In the magnetic resonance imaging apparatus according to any one of claims 1 to 4 ,
The magnetic resonance imaging apparatus according to claim 1, wherein the hinge is fixed to the magnetic field generator. In the magnetic resonance imaging apparatus according to any one of claims 1 to 5 ,
The magnetic resonance imaging apparatus, wherein lower ends of the first and second members support at least a part of a weight of the first and second members with respect to a floor surface. In the magnetic resonance imaging apparatus according to claim 6,
A magnetic resonance imaging apparatus, wherein a member for reducing a friction coefficient is disposed at a lower end of each of the first and second members at a portion in contact with a floor surface. In the magnetic resonance imaging apparatus according to claim 7,
The member for reducing the coefficient of friction is a wheel or a slide rail. In the magnetic resonance imaging apparatus according to any one of claims 1 to 8 ,
The lower magnet of the pair of magnets has a disk shape,
The first and second members are shaped to cover at least part of the left side surface and the right side surface of the lower magnet,
A fourth member of the two or more members of the cover is placed on the upper surface of the lower magnet and the upper portions of the first and second members, and prevents the opening operation of the first and second members. A magnetic resonance imaging apparatus having a configuration. In the magnetic resonance imaging apparatus according to any one of claims 1 to 8 ,
The first and second members are each divided into a part covering the upper part of the magnetic field generating part and a part covering the lower part, and the part covering the upper part and the part covering the lower part can be opened and closed independently. A magnetic resonance imaging apparatus comprising: A pair of magnets arranged opposite to each other at a predetermined interval and a column connected to the side surfaces of the pair of magnets, and at least generate a static magnetic field in a space in which the subject is placed And a cover that covers the magnetic field generator. The cover is divided into two or more members, and the first and second members of the two or more members are the pair of members. A member that covers at least a part of a side surface of a magnet, and is a method for performing maintenance of the magnetic resonance imaging apparatus by removing the cover in a magnetic resonance imaging apparatus having one end connected by a hinge ,
The first and second cover coupled with the hinge, open on both sides are respectively rotated about the hinge, to expose the magnetic field generating unit,
Perform predetermined maintenance work on the magnetic field generator,
A maintenance method for a magnetic resonance imaging apparatus, wherein the magnetic field generator is covered by closing the first and second covers from both sides. In the maintenance method of the magnetic resonance imaging apparatus according to claim 11,
With the bed disposed adjacent to the magnetic field generation unit and the third cover fixed to the side surface of the magnetic field generation unit at a position adjacent to the bed being disposed, the first and second covers are disposed. A maintenance method for a magnetic resonance imaging apparatus, wherein the maintenance operation is performed. A magnetic field generator that generates at least a static magnetic field in a space in which the subject is placed;
A cover covering the magnetic field generation unit;
Have
The cover is divided into two or more members, and the first and second members of the two or more members are connected at one end with a hinge,
The lower ends of the first and second members support at least part of the weight of the first and second members with respect to the floor surface,
A magnetic resonance imaging apparatus characterized in that at least a part of the magnetic field generator is exposed by opening the first and second members to both sides around the hinge. A magnetic field generator that generates at least a static magnetic field in a space in which the subject is placed;
A cover covering the magnetic field generation unit;
Have
The cover is divided into two or more members, and the first and second members of the two or more members are connected at one end with a hinge,
The first and second members are each divided into a part covering the upper part of the magnetic field generating part and a part covering the lower part, and the part covering the upper part and the part covering the lower part can be opened and closed independently. Yes,
A magnetic resonance imaging apparatus characterized in that at least a part of the magnetic field generator is exposed by opening the first and second members to both sides around the hinge.

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