JPH09299352A - Magnetic resonance imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the imaging efficiency, improve the image quality and to reduce a testee's burden by providing a patient table with a swing moving means capable of feeding a top plate into an opening part from any angle and swing-moving in such a manner that the longitudinal movement feeding direction is always directed to the center of a magnetic field in a gantry. SOLUTION: A patient table 71 is disposed on a patient table support table 10, and a roller 11 is fitted to the lower side of the support table 10 to be swing-moved in the circumferential direction of a circle taking the center of a magnetic field as the center in such a manner that the longitudinal movement feeding direction is always directed to the center of a magnetic field in a gantry 13. The roller 11 is fitted to the support table 10 at an angle according to the swing moving locus, and the support table 10 is connected to an intermediate connecting member 22 journalled to the rotating shaft 23 of the lower part of the gantry 13. The intermediate connecting member 22 is connected to a transmission member 24 for transmitting the driving force from a hydraulic cylinder 21, whereby the intermediate connecting member 22 is turned on the rotating shaft 101 by the advance and retreat in the driving direction 25 of a hydraulic cylinder 21 to swing-move the patient table support table 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic resonance imaging apparatus (hereinafter referred to as MRI) capable of easily and accurately moving a desired imaging region of a subject to a magnetic field center when the top plate is fed into a gantry. Device).

[0002]

2. Description of the Related Art An MRI apparatus has a gantry portion in which a static magnetic field generator, a gradient magnetic field generator, a high frequency irradiation device (R
F irradiation device) and a high frequency transmission / reception coil (high frequency (RF) coil). FIGS. 6 and 7 are views showing the gantry portion, and the static magnetic field generator is made to face each other through a measurement space 50 into which a subject (not shown) is inserted, as shown in FIGS. 6 and 7. Disc-shaped magnetic pole piece 51
a pair of yoke plates 53a for holding and fixing the permanent magnets 52a, 52b provided with a and 51b, and a pair of permanent magnets 52a, 52b having different polarities on the back surface side of the magnetic pole pieces 51a, 51b, respectively. , 53b, and further connecting the yoke plates 53a, 53b to each other,
It is provided with two yoke bars 54a and 54b for maintaining a constant distance between a and 53b. In this case, since the two yoke bars 54a and 54b are located on the rear surface side of the gantry 13, the openings for feeding and retracting the subject into the measurement space 50 without being blocked by the yoke bars 54a and 54b. The part 110 can be set large on the front side of the gantry 13. Gradient magnetic field generator (not shown) and R
The F irradiation devices 55a and 55b are of a flat type, and the opening 110 is not blocked even by these, and the RF irradiation devices 55a and 55b located on the measurement space 50 side.
The mutual distance is the opening height (height dimension of the measurement space 50).

Further, as shown in FIGS. 8 and 9, the patient table 71 for feeding the subject to the center of the magnetic field in the gantry 13 has a vertical movement which is a movement of the subject in the axial direction (longitudinal direction) 72. , A lateral movement which is a movement in a direction (horizontal direction) 73 orthogonal to the body axis direction 72 outside the gantry 13 and a vertical movement which is a movement in the vertical direction 74 have a top plate moving function. In this case, in the vertical movement, only the top plate 75 on which the subject lies down is fed into the gantry 13, and the horizontal movement and the vertical movement move together with the top plate support portion 76. In principle, the subject is placed on the top plate 75 when it is at the lower limit of vertical movement, and the roller (not shown) on the back surface of the top plate 75 is raised to a height just in contact with the RF irradiation device 55a below the gantry opening 110. Then, it is fed into the gantry 13 together with the top plate 75 by vertical movement. At this time, the roller on the back side of the top plate 75 is mounted on the RF irradiation device 55a on the lower side to support the top plate 75 in the gantry 13, so that the top plate 75 in the gantry 13 moves vertically (feeds). (Inclusion, retreat) only, not lateral movement.

Therefore, when it becomes necessary to move the gantry 13 laterally, the top plate 75 is once retracted to the outside of the gantry 13 and laterally moved, and then the gantry 13 is moved vertically again.
It is necessary to send it in. FIG. 10 shows the state after re-feeding. Moreover, the arrangement of the patient table 71 is
As shown in FIGS. 8 to 10, the gantry 13 is positioned and fixed in alignment with the center in the lateral direction (width direction), and the top plate 75 can be sent to the gantry 13 from only one direction, so that the subject is sent to the center of the magnetic field. Can also be positioned vertically and horizontally (2
Only the axis) can be selected. Furthermore, when imaging is completed and the subject is retracted from the gantry 13, it is necessary to retract the subject again to the original position (the position on which the subject is placed) even if the position is the vertical limit position.

[0005]

In the above-mentioned prior art, sufficient consideration has not been given to locating the region to be imaged of the subject at the center of the magnetic field and taking an image at the location with the best uniformity. Shooting at a location where magnetic field homogeneity is the best has the great advantage that a good image can be obtained that does not cause image folding or distortion due to magnetic field inhomogeneity and S / N deterioration. However, as described above, the patient table 71 is arranged in the gantry 1 as shown in FIGS.
3 Positioning is fixed according to the center of the lateral direction (width direction), and since the top plate 75 can be sent to the gantry 13 from only one direction, the positioning for sending the object to the center of the magnetic field is only in the longitudinal and lateral directions (two axes). There is no choice. For this reason, depending on the imaging site, it may not be easy to send or position the magnetic field center. In addition, since lateral movement within the gantry 13 is not possible, even when the user wants to move another imaging site to the magnetic field center in the measurement space 50 immediately after the completion of the imaging of a certain imaging site in the measurement space 50, once outside the gantry 13. Top plate 75
It is necessary to retreat, move laterally, and then feed the gantry 13 again by vertical movement. This complicates the operation, lowers the throughput, and lowers the imaging efficiency. Therefore, the feeding to the center of the magnetic field or the alignment cannot be performed accurately, and the quality of the obtained image may deteriorate. Also, if the technologist feels annoyed and tries to deal with it by moving the subject on the top plate 75 without laterally moving the top plate 75, a great burden is placed on the unhealthy subject. There were various problems, such as muddy.

It is an object of the invention of claim 1 to provide an MRI apparatus capable of improving imaging efficiency, improving image quality, reducing the burden on a subject, and eliminating the troublesomeness of an imaging engineer.

It is an object of the invention of claim 2 to provide an MRI apparatus capable of significantly improving imaging efficiency, improving image quality, reducing the burden on a subject, and eliminating the troublesomeness of an imaging engineer. is there.

[0008]

An object of the present invention is to provide a gantry having a static magnetic field and a gradient magnetic field generating means, each of which has a large opening on the front surface, and an object to be irradiated with electromagnetic waves. Alternatively, a high-frequency coil that detects a magnetic resonance signal from the subject, an image reconstruction unit that obtains an image that represents the physical properties of the subject based on the signal detected by the high-frequency coil, and a celestial body that lays down the subject. The plate is fed into the opening or is moved backward from the feeding position to the outside of the opening. Vertical movement in the axial direction of the subject, horizontal movement orthogonal to the direction of the vertical movement, and the ceiling outside the opening. In a magnetic resonance imaging apparatus comprising a patient table having a table moving means for vertically moving the plate, the patient table, the table on which the subject is laid, is placed in the opening. Okurikome and from any angle of opening of is accomplished by configuring provided swinging movable swing movement means so towards the center of the magnetic field of the always the gantry direction infeed its longitudinal movement. If the swing moving means as described above is provided, it is possible to easily position various imaging parts of the subject and send them to the magnetic field center in the gantry, and easily position the imaging part to the magnetic field center. Therefore, the imaging efficiency can be improved, the image quality can be improved, the burden on the subject can be reduced, and the annoyance of the imaging engineer can be eliminated.

A second object of the present invention is to provide a magnetic field generating means for each of a static magnetic field and a gradient magnetic field, and a gantry having a large opening on the front surface, and a magnetic field that irradiates an electromagnetic wave to a subject or a magnetic field from the subject. A high frequency coil for detecting a resonance signal, an image reconstructing means for obtaining an image showing the physical properties of the subject based on the signal detected by the high frequency coil, and a top plate on which the subject is laid in the opening. Vertical movement in the axial direction of the object to be fed or retracted from the feeding position to the outside of the opening, horizontal movement in the horizontal direction orthogonal to the direction of this vertical movement, and vertical movement of the top plate outside the opening, respectively. In a magnetic resonance imaging apparatus comprising a patient table having a top moving means for moving the patient table, a pair of the patient tables are arranged on both left and right sides of the gantry, and both tables are placed on the subject. A common couchtop can move between these tables with the magnetic field center in the gantry as its passage point, and when the couchtop on which the subject lies is located at the magnetic field center, the couchtop can move laterally. This is achieved by providing a horizontally movable supporting means for the top plate. By arranging a pair of patient tables on both the left and right sides of the gantry as described above, and by providing a top plate laterally movable support means, it is possible to easily position the various imaging parts of the subject and center the magnetic field in the gantry. It is possible to move to the center of the magnetic field can be easily moved to, the imaging efficiency can be improved, the image quality can be improved and the burden on the subject can be reduced, and the annoyance of the imaging engineer can be eliminated. In addition, the subject can be placed on and dropped from the patient table from either the left or right side of the gantry, further improving the imaging efficiency.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining an embodiment of the MRI apparatus according to the invention of claim 1.
Is a perspective view, FIG. 2 is a plan view showing the main part taken out from the bottom side, FIG. 3 is a perspective view showing the main part taken out from the bottom side, and FIG. 4 is a side view inside the patient table part. 1 to 4, the same reference numerals as those in FIGS. 6 to 10 denote the same or corresponding portions. Further, in FIGS. 1 to 4, the same reference numerals indicate the same parts. The MRI apparatus according to claim 1 sends a patient table 71, a top plate 75 on which a subject (not shown) is laid, into the opening 110 of the gantry 13 from any angle (direction) of the opening 110, In addition, a swing moving means is provided which is capable of swinging so that the vertical movement feeding direction is always directed to the magnetic field center in the gantry 13.

That is, as shown in FIG. 1, the patient table 71 is arranged on the patient table supporting base 10 and is movable in accordance with the movement of the supporting base 10. A roller 11 is attached to the lower portion of the support base 10 and moves in a circumferential direction 12 of a circle centered on the magnetic field center so that the vertical movement and feeding direction always faces the magnetic field center in the gantry 13 (swing movement). It is possible. Here, the swing movement will be described. As shown in FIGS. 2 and 3, the roller 11 is attached to the support base 10 at an angle matched with the swing movement locus 12 ′ so that the swing movement can be smoothly performed. Further, the support base 10 is connected to an intermediate connection member 22 which is axially fixed to a rotary shaft 23 attached to the lower part of the gantry 13. In this case, the intermediate connecting member 22
Is a transmission member 2 that transmits the driving force from the hydraulic cylinder 21.
4. That is, as the hydraulic cylinder 21 moves back and forth in the driving direction 25, the intermediate coupling member 22 is rotated about the rotation axis O1 via the transmission member 24, and the patient table support base 10 swings. ing. As shown in FIG. 4, a hydraulic drive unit 31 for driving the hydraulic cylinder 21 is arranged inside the patient table 71, and a hydraulic transmission path 32 is provided.
The driving force is transmitted to the hydraulic cylinder 21 via the, and the operation of the hydraulic cylinder 21 is controlled.

Since the MRI apparatus according to the first aspect is provided with the swing moving means as described above, it is possible to easily perform positioning for various imaged portions of the subject and send them to the magnetic field center in the gantry 13. The imaging region can be easily aligned with the center of the magnetic field, the imaging efficiency can be improved, the image quality can be improved, the burden on the subject can be reduced, and the annoyance of the imaging engineer can be eliminated.

FIG. 5 is a perspective view showing an embodiment of the MRI apparatus according to the invention of claim 2. As shown in FIG. In this FIG.
1 to 4 indicate the same or corresponding parts. 72
a and 72b are the object body axial direction (top plate vertical direction), 73a,
Reference numeral 73b represents the top plate lateral direction, and 74a and 74b represent the top plate vertical direction. That is, in the MRI apparatus shown in FIG. 5, a pair of patient tables 71 (71 a, 71 a) are provided on the left and right sides of the gantry 13.
b) Both tables 71a, 71 which are arranged and laid on the subject
The table 75 common to b is movable between the tables 71a and 71b with the magnetic field center in the gantry 13 as its passage point, and when the table 75 on which the subject lies down is located at the magnetic field center. A top plate laterally movable support means for supporting the top plate 75 in a laterally movable manner is provided. As the supporting means for moving the top plate laterally, the top plate 7 on which the subject is laid down is used.
When 5 is located at the center of the magnetic field in the gantry 13, it has top plate support portions 76a and 76b for simultaneously moving (horizontal movement) the top plate 75 in the horizontal directions 73a and 73b. The top plate 75 on which the subject is placed can be sent into the gantry 13 from either the left or right patient table 71a, 71b, and the top plate 75 can be used for both patient tables 71a, 71b.
71b, the RF below the opening 110
It is not necessary to support the top plate 75 on the upper surface of the irradiation device 55a, and the top plate support portions 7 of the left and right patient tables 71a and 71b are supported.
It is designed to be supported by 6a and 76b. At this time, the top plate support portions 76a and 76b of the left and right patient tables 71a and 71b are slightly raised so as not to touch the upper surface of the RF irradiation device 55a below the opening 110.

[0014]

According to the first aspect of the present invention, since the swing moving means is provided, it is possible to easily align various imaging parts of the subject with the magnetic field center in the gantry, thereby improving the imaging efficiency and the image quality. In addition, the burden on the subject can be reduced, and the annoyance of the imaging engineer can be eliminated. According to the invention of claim 2, since a pair of patient tables are arranged on both left and right sides of the gantry and the top plate laterally movable supporting means is provided, it is possible to easily move various imaging parts of the subject to the magnetic field center in the gantry. There is an effect that the position can be aligned, the imaging efficiency can be improved, the image quality can be improved, the burden on the subject can be reduced, and the annoyance of the imaging engineer can be eliminated. In addition, the subject can be placed on and off the patient table from either the left or right side of the gantry, which has the effect of further improving imaging efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an MRI apparatus according to the invention of claim 1. FIG.

FIG. 2 is a plan view showing a main part of the same apparatus as above taken out from the bottom surface side.

FIG. 3 is a perspective view showing the main part of the same from the bottom side.

FIG. 4 is a side view of the inside of a patient table portion of the MRI apparatus shown in FIG.

FIG. 5 is a perspective view showing an embodiment of the MRI apparatus according to the invention of claim 2;

FIG. 6 is a perspective view of a gantry portion of the MRI apparatus.

FIG. 7 is a partially cut front view of a gantry portion of the MRI apparatus.

FIG. 8 is a perspective view of a conventional MRI apparatus.

FIG. 9 is a perspective view of a conventional MRI apparatus.

FIG. 10 is a perspective view of a conventional MRI apparatus.

[Explanation of symbols]

10 Patient Table Support 11 Roller 12 Circumferential Direction 12 'Swing Trajectory 13 Gantry 21 Hydraulic Cylinder 22 Intermediate Connecting Member 23 Rotating Shaft 24 Transmission Member 25 Hydraulic Cylinder Driving Direction O1 Rotating Shaft 31 Hydraulic Driving Unit 32 Hydraulic Transmission Path 50 Measuring Space 51a, 51b Magnetic pole pieces 52a, 52b Permanent magnets 53a, 53b Yoke plate 54a, 54b Yoke bar 55a, 55b RF irradiation device 71, 71a, 71b Patient table 72, 72a, 72b Subject body axial direction (top plate vertical direction) 73 , 73a, 73b Direction orthogonal to the body axis direction (top plate lateral direction) 74, 74a, 74b Top plate vertical direction 75 Top plate 76, 76a, 76b Top plate support 110 Gantry opening.

Claims (2)

[Claims] 1. A gantry having magnetic field generating means for a static magnetic field and a gradient magnetic field and having a large front opening, and a high-frequency coil for irradiating a subject with electromagnetic waves or detecting magnetic resonance signals from the subject. And an image reconstructing means for obtaining an image showing the physical properties of the subject based on the signal detected by the high-frequency coil, and a top plate on which the subject is laid is fed into the opening or from its feeding position. It has a top plate moving means for respectively performing a vertical movement in the axial direction of the subject to be retracted outside the opening, a horizontal movement in a horizontal direction orthogonal to the direction of the vertical movement, and a vertical movement of the top outside the opening. In a magnetic resonance imaging apparatus comprising a patient table, the patient table is capable of feeding a tabletop on which the subject is laid into the opening from any angle of the opening. Magnetic resonance imaging apparatus and a direction infeed longitudinal movement always comprises a swinging movable swing movement means so towards the center of magnetic field within the gantry. 2. A gantry having magnetic field generating means for a static magnetic field and a gradient magnetic field and having a large front opening, and a high-frequency coil for irradiating a subject with electromagnetic waves or detecting magnetic resonance signals from the subject. And an image reconstructing means for obtaining an image showing the physical properties of the subject based on the signal detected by the high-frequency coil, and a top plate on which the subject is laid is fed into the opening or from its feeding position. It has a top plate moving means for respectively performing a vertical movement in the axial direction of the subject to be retracted outside the opening, a horizontal movement in a horizontal direction orthogonal to the direction of the vertical movement, and a vertical movement of the top outside the opening. In a magnetic resonance imaging apparatus including a patient table, a pair of the patient tables are arranged on both left and right sides of the gantry, and a table common to both tables on which a subject is laid has a table. It is possible to move between the bulls with the magnetic field center in the gantry as the passage point, and to support the top plate laterally movable when the top plate on which the subject lies is located at the magnetic field center. A magnetic resonance imaging apparatus comprising support means.