JPH07303621A - Rf coil for mri - Google Patents

Abstract

PURPOSE:To provide an RF coil for MRI which can utilize the space enclosed by magnets effectively and can obtain wide uniform area. CONSTITUTION:The RF coil for MRI has a current track with the first loop and the second loop connected within the same level and arranged in the shape of letter 8 and a first coil 11 which is so structured that the current direction of the current track at the part where the first loop and the second loop are facing with each other is the same. Further, the subject coil has a current track with the third loop and the fourth loop connected within the same level and arranged in the shape of letter 8 and a second coil 12 which is so structured that the current direction of the current track at the part where the third loop and the fourth loop are facing with each other is the same but reverse to that of the first coil and so arranged that the current track of the part at which the third loop and the fourth loop are facing with each other comes to another level at the specified interval from the current track of the part at which the first loop and the second loop are facing with each other but parallel thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RF coil for MRI used in a magnetic resonance imaging (MRI) apparatus, and in particular, an MRI suitable for an MRI apparatus using a facing magnet.
RF coil for use.

[0002]

2. Description of the Related Art An MRI apparatus measures the density distribution, relaxation time distribution, etc. of nuclear spins at a desired examination site in a subject by utilizing the nuclear magnetic resonance phenomenon, and the cross section of the subject is determined from the measured data. The image is displayed.

Nuclear spins of a subject placed in a uniform and strong static magnetic field generator perform precession around the direction of the static magnetic field at a frequency (Larmor frequency) determined by the strength of the static magnetic field. Therefore, when a high frequency pulse having a frequency equal to this Larmor frequency is irradiated from the outside, spins are excited and transition to a high energy state. This is called a nuclear magnetic resonance phenomenon. When the irradiation of this high-frequency pulse is stopped, the spin returns to the original low energy state with a time constant corresponding to each state, and at this time, the electromagnetic wave is emitted to the outside. This is detected by the high frequency receiving coil tuned to the frequency. At this time, a triaxial gradient magnetic field is applied to the static magnetic field space for the purpose of adding position information to the space. As a result, position information in the space can be captured as frequency information.

Further, such an MRI apparatus is provided with an RF coil for irradiating the high frequency pulse and for receiving the high frequency. Figure 8 shows this type of MR
It is a block diagram which shows a mode that the RF coil vicinity of I device was seen from the front. In FIG. 8, the magnet 2 and the magnet 3 are vertically arranged so as to be surrounded by the yoke 1 made of a magnetic material.
Are placed to generate a static magnetic field. This magnet 2
The magnet 3 is provided with magnetic shunting plates 4 and 5 which are arranged so as to eliminate the distortion of the static magnetic field generated. The RF coil 6 is arranged in a space surrounded by the magnetic shunts 4 and 5 (hereinafter, the magnetic shunts 4 and 5 and the magnets 2 and 3 are collectively referred to as a magnet or a facing magnet). .

The RF coil 6 is a saddle type coil shown in FIG. 9, and a subject is placed in a space surrounded by the RF coil 6. Here, as shown in FIG. 9, the current paths 6a and 6b in the Z direction are configured so that the current directions are the same, and the current paths 6c and 6d are currents in the opposite directions to the current paths 6a and 6b. It is configured to be oriented.

[0006]

Here, a general MR is used.
Taking the device I as an example, the opening length X0 in the X direction of the magnet is about 100 cm, and the opening length Y0 in the Y direction is 45 cm.
It is a degree. RF coil 6 of saddle type coil in this case
Has a height Yc of about 40 cm as shown in FIG.
Also, the current path distance Xc in the X direction is about 23 cm.

Therefore, in the case of the RF coil of this size, a region (hereinafter referred to as a uniform region) where a uniform magnetic field (for example, within an error range of +6, -6%) can be obtained is 12 cm in the Y direction.
It is about 24 cm in the X direction.

As described above, compared to the size of the space (X0: 100 cm, Y0: 45 cm) surrounded by the opposed magnets, the uniform area obtained by the saddle type RF coil 6 becomes very narrow. Had. Further, since the uniform area is narrow, there is a problem that shading (shading: a phenomenon in which the average luminance decreases due to a decrease in sensitivity in the peripheral portion of the image) appears in the image.

According to the saddle type coil, the XY
The presence of the arcuate portion in the plane obstructs the openness of the space surrounded by the opposed magnets, and limits the movement of the subject. As described above, there is a problem that the space generated by the opposed magnet cannot be effectively used.

The present invention has been made in view of the above points, and an object thereof is to make an effective use of a space surrounded by a magnet and to obtain a wide uniform region.
It is to realize the F coil.

[0011]

[Means for Solving the Problems] A first means for solving the above-mentioned problems is to provide a current line in which a first loop and a second loop are connected in the same plane and are arranged in a figure eight shape. Have,
The first coil and the third loop and the fourth loop which are configured so that the current directions are the same in the current lines of the portions where the first loop and the second loop face each other are connected in the same plane. And the current lines are arranged in the shape of a figure 8, and the current directions are the same in the portions of the current lines where the third loop and the fourth loop face each other, and this current direction is the first direction. The current line of the portion in which the third loop and the fourth loop face each other is configured to be opposite to the current direction of the coil of the first loop and the portion in which the first loop and the second loop face each other. An RF coil for MRI, comprising: a second coil arranged in parallel on a different plane with a predetermined distance from the current line.

A second means for solving the above-mentioned problem is to have a current line in which the first loop and the second loop are connected in the same plane and are arranged in a figure-eight shape. The first coil and the third loop and the fourth loop are connected in the same plane so that the first coil and the second loop are configured so that the current directions are the same in the current lines in the portions where the first loop and the second loop face each other. And the current lines are arranged in a figure 8 shape, and the current directions are the same in the portions of the current lines where the third loop and the fourth loop face each other, and this current direction is the same as the first line. It is configured to be in the opposite direction to the current direction of the coil,
The current line of the portion where the third loop and the fourth loop face each other is parallel to the current line of the portion where the first loop and the second loop face each other on a different plane with a predetermined interval. And a second coil arranged in parallel with each other, and a current line in a portion where the first loop and the second loop face each other and a current line in a portion where the third loop and the fourth loop face each other The RF lines for MRI, wherein the current lines of the first coil and the second coil are arranged so that the magnetic field in the enclosed space is uniform.
It is a coil.

A third means for solving the above problem is to provide a current line in which a first double loop and a second double loop are connected in the same plane and arranged in a figure eight shape. Have,
A first coil configured such that two current line portions on the opposite sides of the first double loop and the second double loop have the same current direction, and a third coil. The loop and the fourth double loop are connected in the same plane and have a current line arranged in a figure-eight shape, and the third double loop and the fourth double loop are on opposite sides of each other. In each of the two current line portions, the current direction is the same,
This current direction is configured to be opposite to the current direction of the first coil, and two current line portions each on the side where the third double loop and the fourth double loop face each other. Is a second coil arranged in parallel on different planes with a predetermined distance from each of the two current line portions on the opposite sides of the first double loop and the second double loop. And an MRI characterized by having
RF coil for use.

A fourth means for solving the above-mentioned problem is to provide a current line in which a first double loop and a second double loop are connected in the same plane and arranged in a figure 8. Have,
A first coil configured such that two current line portions on the opposite sides of the first double loop and the second double loop have the same current direction, and a third coil. The loop and the fourth double loop are connected in the same plane and have a current line arranged in a figure-eight shape, and the third double loop and the fourth double loop are on opposite sides of each other. In each of the two current line portions, the current direction is the same,
This current direction is configured to be opposite to the current direction of the first coil, and two current line portions each on the side where the third double loop and the fourth double loop face each other. Is a second coil arranged in parallel on different planes with a predetermined distance from each of the two current line portions on the opposite sides of the first double loop and the second double loop. And having a first double loop and a second
Each of the double loops is surrounded by two current line portions on the opposite side, and the third double loop and the fourth double loop are surrounded by two current line portions on the opposite side, respectively. So that the magnetic field in space is uniform,
The RF coil for MRI is characterized in that the respective current lines of the first coil and the second coil are arranged.

[0015]

The RF for MRI which is the first means for solving the problems
In the coil, the eight-shaped first coil composed of two loops and the second coil having substantially the same shape are arranged so as to face each other in the vertical direction of the magnet,
There is no shield when placed inside the magnet.

In the MRI RF coil which is the second means for solving the problem, the figure 8 first coil and the second coil are arranged so as to face each other in the vertical direction of the magnet. , There is no shield when placed inside the magnet. Then, the magnetic field in the space surrounded by the current lines in the portions where the first loop and the second loop face each other and the current lines in the portions where the third loop and the fourth loop face each other becomes uniform. By arranging the current lines of the first coil and the second coil in the, the uniform region of the magnetic field is expanded.

In the MRI RF coil which is the third means for solving the problem, the eight-shaped first coil composed of two double loops and the second coil of substantially the same shape are the magnets. They are arranged so as to face each other in the vertical direction, and there is no shield when arranged in the magnet.

In the RF coil for MRI which is the fourth means for solving the problem, the figure 8 shaped first coil composed of two double loops and the second coil of substantially the same shape are magnets. They are arranged so as to face each other in the vertical direction, and there is no shield when arranged in the magnet. Then, each of the two current line portions on the side where the first double loop and the second double loop face each other and on the side where the third double loop and the fourth double loop face each other, respectively. By arranging the current lines of the first coil and the second coil so that the magnetic field in the space surrounded by the two current line portions becomes uniform, the uniform region of the magnetic field is expanded.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an MRI RF coil according to an embodiment of the present invention (hereinafter, simply referred to as an RF coil in the embodiments).
It is a block diagram which shows the structure of. Further, FIG. 2 is a configuration diagram showing a state in which the coil is arranged in the magnet.

In these figures, the RF coil 10 is an opposed type figure 8 coil in which so-called figure 8 coils 11 and 12 are connected so as to face each other. That is, two loops are connected to each other in the same plane to have a current line arranged in a figure-eight shape, and the two loops of the figure-eight current line are opposed to each other (main path portion). ) 11a and 11b have the same shape as the first figure-eight coil 11 that is arranged in parallel so that the current directions are the same, and the shape of the figure-8 is the same. The current lines (main path portions) 12a, 12b at the portions where the two loops of the current line of FIG. 2 are opposed to each other are configured so as to be in the direction opposite to the direction of the first coil, and each current line 12a, 12b, 12c. , 12d are the corresponding current lines 11a, 11b of the first coil,
The RF coil 10 is composed of a second figure-eight coil 12 that is configured to face 11c and 11d at a predetermined interval. Here, the current line 11
Reference numerals c, 11d, 12c and 12d are return path parts.

As shown in FIG. 2, a magnet 2 and a magnet 3 for generating a static magnetic field are vertically arranged so as to be surrounded by a yoke 1 made of a magnetic material. Magnetic compensating plates 4 and 5 are attached to the magnet 3 so as to eliminate distortion of the generated static magnetic field.
Then, in the space surrounded by the opposed magnets composed of the magnet 2 and the magnetic shunt plate 4, and the magnet 3 and the magnetic shunt plate 5, the 8-shaped coil 11 is in contact with the magnetic shunt plate 4, and An 8-shaped coil 12 is arranged so as to be in contact with the magnetic shunt plate 5.

As shown in FIG. 2, an opposed type 8-shaped coil 11, 1 provided so as to be in contact with the opposed magnet.
According to the RF coil 10 constituted by 2, the arc portion in the XY plane, which is different from the conventional saddle coil, is eliminated, so that the opening of the magnet is not limited particularly in the X direction. Therefore, it becomes possible to effectively utilize the openness of the space around the subject in the MRI apparatus using the facing magnet.

FIG. 3 shows the same size as that of FIG. 8 (X of magnet).
The opening length X0 in the direction is about 100 cm, and the opening length Y0 in the Y direction is
Is a configuration diagram showing an example of the RF coil 10 of the present embodiment when it is used for a facing magnet of about 45 cm. Here, the main path section is 30.4 cm, the main path section and the return path section are 14 cm, and the figure 8 coil is 3 sections.
It is 8.1 cm. From FIG. 3 also, it is clear that the conventional saddle coil is improved in openness by eliminating the arc portion in the XY plane.

Further, as will be described below, four elements (11a, 11b,
11c, 11d, 12a, 12b, 12c, 12d) can be set to a predetermined value to widen the uniform region of the magnetic field.

That is, as the design of the element arrangement for expanding the uniform region, the element intervals of the main path part and the return path part are selected so that the quadratic inhomogeneity term of the magnetic field becomes 0, and then the elements of the return path part are selected. The arrangement is adjusted so that the uniform area is expanded.

The design of the arrangement of the elements for expanding the uniform area will be described in detail below. In order to obtain the homogeneity of the magnetic field in the opposed type 8-shaped coil, the element interval of the coil is the second derivative of the magnetic field generated by the coil =
Ideally, the interval should satisfy 0, 4th derivative = 0 at the same time. However, when the current values of the main path portion and the return path portion are the same, it has been found that there is no element interval that makes them zero at the same time.

Therefore, the element intervals shown in FIG. 4 in this case are determined by the following policy. Here, the distance from the center of the main path portion to the main path portion is r1, and the distance to the return path portion is r2.
Consider a desired magnetic field B1 in the X direction at the center of the F coil 10.

The element intervals of the main path part and the return path part that make the second derivative of the magnetic field zero are obtained. At this time, magnetic field homogeneity equivalent to that when a conventional saddle type RF coil is used is obtained.

Next, the magnetic field sensitivity of the RF coil 10 can be expanded within a certain error range as shown by the solid line in FIG. 5 by appropriately selecting the term of the fourth derivative (D (4)). . FIG. 5 shows the result of the magnetic field sensitivity in the entire X direction by the final main pass portion and the return pass portion.
That is, by slightly shifting the return path part or the main path part from the point where the optimum value is obtained, the uniform region of the magnetic field can be expanded.

The result of the experiment conducted by the inventor is +
When the error range of 6% and -6% is allowed, the uniform area is X.
The result obtained is to spread about 30 cm in the direction. This indicates that the uniform region is sufficiently expanded as compared with the uniform region of 24 cm under the same conditions in the saddle coil described in the conventional example. This also greatly improves image shading.

That is, by using a figure 8 coil and taking into consideration the design of the return path section, and designing using the term of the fourth derivative, the uniform region is greatly expanded compared to the conventional saddle coil. It became possible to do.

FIG. 6 is a block diagram showing another example of the RF coil 10. When the inventor conducted an experiment, as shown in FIG. 6, the main path portions 11a, 11b, 12a,
Good results were also obtained by arranging the elements such that the center point O of 12b was 60 ° to each other when viewed from the side of each 8-shaped coil.

FIG. 7 is a block diagram showing another example of the RF coil. The RF coil 20 is characterized in that coils 21, 22 having four main path portions are arranged so as to face each other instead of the above-mentioned figure 8 coil.

That is, two double loops are connected in the same plane and have a current line arranged in a figure eight shape,
Two double loops (two main loops), each of which has two (4) double loops on opposite sides.
a, 21b, 21e, 21f), the first coil 21 configured to have the same current direction, and the current paths 22a, 22b of the main path portion having substantially the same shape as the first coil 21. , 22e, 22f are the first coil 2
The second current path is configured so as to be opposite to the current direction of the corresponding main path portion of No. 1, and each current line opposes the corresponding current line of the first coil 21 at a predetermined interval Y1. The RF coil 20 is composed of the coil 22 of FIG. Incidentally, here, the current lines 21c, 21
d, 21g, 21h, 22c, 22d, 22g, 22h
Is the return path section.

In the case of such an RF coil 20 as well, when it is arranged in the facing magnet, the openness can be improved because there is no arc portion in the XY plane as compared with the conventional saddle coil. it can. The design of the uniform area can be made similar to the design of the main path section and the return path section described above, and the uniform area can be expanded. Further, in this case, since the number of elements is large, there is an advantage that the degree of freedom in design is further increased.

According to the results obtained by the inventor through experiments, when the interval between the inner main path parts is X1, the interval between the outer main path parts is X2, and the interval between the opposing coils 21 and 22 is Y1. , X2 = Y1, X1 / X2 = 0.26
And the RF coil 20 configured such that the current density of the outer main path portion is twice the current density of the inner main path portion. Got

As described in detail above, the first loop and the second loop are connected in the same plane and have the current line arranged in a figure-eight shape. The first coil, which is configured so that the current directions are the same in the current lines of the portions where the loops of the two are opposed to each other, and the third loop and the fourth loop are connected in the same plane to form a figure eight shape. The current direction is the same in the current lines of the portion having the arranged current lines, and the third loop and the fourth loop face each other, and the current direction is opposite to the current direction of the first coil. The current line of the portion in which the third loop and the fourth loop are opposed to each other is configured to have a predetermined direction with respect to the current line of the portion where the first loop and the second loop are opposed to each other. Placed in parallel on different planes with a gap According to the MRI RF coil having two coils, the first coil and the second coil are arranged so as to face each other in the vertical direction of the magnet, and are arranged in the magnet. In this case, there is no shield, the openness is excellent, the space surrounded by the opposed magnets can be effectively used, and an MRI RF coil that can obtain a wide uniform area can be realized.

Further, the first loop and the second loop are connected in the same plane to have a current line arranged in a figure eight shape, and the first loop and the second loop are opposed to each other. In the partial current line, the first coil configured to have the same current direction, the third loop, and the fourth loop are connected in the same plane, and the current line is arranged in a figure eight shape. And the current direction is the same in the current lines of the portions where the third loop and the fourth loop face each other, and the current direction is opposite to the current direction of the first coil. The current lines of the portions where the third loop and the fourth loop face each other are different planes with a predetermined distance from the current lines of the portions where the first loop and the second loop face each other. Second placed in parallel with
Magnetic field in a space surrounded by a current line in a portion where the first loop and the second loop face each other and a current line in a portion where the third loop and the fourth loop face each other. According to the RF coil for MRI, in which the respective current lines of the first coil and the second coil are arranged so as to be uniform, the eight-shaped first coil and the second coil Are arranged so as to face each other in the vertical direction of the magnet, and there is no shield when arranged inside the magnet. Then, the magnetic field in the space surrounded by the current lines in the portions where the first loop and the second loop face each other and the current lines in the portions where the third loop and the fourth loop face each other becomes uniform. By arranging the current lines of the first coil and the second coil in the, the uniform region of the magnetic field is expanded.

Further, the first double loop and the second double loop are connected in the same plane, and there is a current line arranged in a figure eight shape, and the first double loop and the second double loop are provided. The first coil configured such that the current directions of the two current line portions on the opposite sides of each of the double loops, and the third double loop and the fourth double loop are Having current lines arranged in a figure 8 connected in the same plane,
The current direction is the same in each of the two current line portions on the opposite sides of the third double loop and the fourth double loop, and the current direction is opposite to the current direction of the first coil. Two current line portions each of which is arranged so as to face each other and on which the third double loop and the fourth double loop are opposite to each other are formed by the first double loop and the second double loop. An RF coil for MRI, characterized in that the loop has second coils arranged in parallel on different planes with a predetermined distance from each of two current line portions on opposite sides. For example, an 8-shaped first coil composed of two double loops and a second coil of substantially the same shape are arranged so as to face each other in the vertical direction of the magnet, and are arranged in the magnet. If there is no shield, The space surrounded by the superior opposed magnets release can be utilized effectively, and can be realized an MRI RF coil a wide uniform region can be obtained.

The first double loop and the second double loop are connected in the same plane to have a current line arranged in a figure eight shape, and the first double loop and the second double loop are provided. The first coil configured such that the current directions of the two current line portions on the opposite sides of each of the double loops, and the third double loop and the fourth double loop are It has current lines arranged in the shape of a figure that are connected in the same plane, and in each of the two current line portions on the side where the third double loop and the fourth double loop face each other, The current directions are the same, the current direction is configured to be opposite to the current direction of the first coil, and the third double loop and the fourth double loop are on opposite sides of each other. Each of the two current line portions includes the first double loop and the second double loop. Each side 2 but facing to each other
A second coil arranged parallel to each other in a different plane with a predetermined interval with respect to the current line portion of the book, and the side where the first double loop and the second double loop face each other. So that the magnetic field in the space surrounded by the two current line portions and the two current line portions on the side where the third double loop and the fourth double loop face each other become uniform. According to the RF coil for MRI, in which the respective current lines of the first coil and the second coil are arranged, the first coil in the shape of a figure 8 formed of two double loops and The second coils having substantially the same shape are arranged so as to face each other in the vertical direction of the magnet, and there is no shield when arranged in the magnet. And, each of the two current line portions on the side where the first double loop and the second double loop face each other, and the third double loop
Of the first coil and the second coil such that the magnetic field in the space surrounded by the two current line portions on the opposite sides of the double loop and the fourth double loop becomes uniform. By arranging the current lines, the uniform region of the magnetic field is expanded.

[0041]

As described in detail above, the opposing coil provided in contact with the magnet in the vertical direction is used as the R type coil.
By constructing the F coil, since the arc portion in the XY plane like the saddle coil is eliminated, the shield is eliminated and the openness around the RF coil is enhanced. In addition, by constructing an RF coil by making the figure 8 coils face each other, a design that utilizes the change in magnetic field due to the arrangement of each element is performed, and the uniform area is greatly expanded compared to the conventional saddle coil. Will be possible. Further, the RF coil in which the 8-shaped coil composed of two double loops is arranged so as to face each other in the up-down direction of the magnet also increases the openness around the RF coil, and a significantly uniform area compared to the conventional saddle coil. Can be expanded, the space surrounded by the magnets can be effectively used, and an MRI RF coil that can obtain a wide uniform area can be realized. Further, by arranging the current lines of the first coil and the second coil so that the magnetic field in the space surrounded by the current line portions on the sides where the respective loops face each other becomes uniform, a uniform magnetic field region is obtained. Is expanded.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration example of an MRI RF coil according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an arrangement example in a magnet of an MRI RF coil according to an embodiment of the present invention.

FIG. 3 is a configuration diagram showing a configuration example of an MRI RF coil according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a design state of an MRI RF coil according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a design state of an MRI RF coil according to an embodiment of the present invention.

FIG. 6 is a configuration diagram showing another configuration example of the MRI RF coil according to the embodiment of the present invention.

FIG. 7 is a configuration diagram showing another configuration example of the MRI RF coil according to the embodiment of the present invention.

FIG. 8 is a configuration diagram showing a configuration example of a conventional MRI RF coil.

FIG. 9 is a configuration diagram showing a configuration example of a conventional MRI RF coil.

FIG. 10 is a configuration diagram showing a configuration example of a conventional MRI RF coil.

[Explanation of symbols]

 10 RF coil 11 1st coil 12 2nd coil 20 RF coil 21 1st coil 22 2nd coil

Claims (4)

[Claims] 1. A first loop and a second loop are connected to each other in the same plane, and have a current line arranged in a shape of 8, and the first loop and the second loop are opposed to each other. In the partial current line, the first coil configured so that the current directions are the same, the third loop and the fourth loop are connected in the same plane, and the current line is arranged in the shape of a figure 8. And the current direction is the same in the current lines of the portions where the third loop and the fourth loop face each other, and the current direction is opposite to the current direction of the first coil. The current lines of the portions where the third loop and the fourth loop face each other are different planes with a predetermined distance from the current lines of the portions where the first loop and the second loop face each other. A second coil arranged in parallel with MRI RF coil according to claim. 2. A first loop and a second loop are connected in the same plane, and have a current line arranged in a figure eight shape, and the first loop and the second loop are opposed to each other. In the partial current line, the first coil configured so that the current directions are the same, the third loop and the fourth loop are connected in the same plane, and the current line is arranged in the shape of a figure 8. And the current direction is the same in the current lines of the portions where the third loop and the fourth loop face each other, and the current direction is opposite to the current direction of the first coil. The current lines of the portions where the third loop and the fourth loop face each other are different planes with a predetermined distance from the current lines of the portions where the first loop and the second loop face each other. A second coil arranged in parallel with The first magnetic field in a space surrounded by the current lines in the portions where the first loop and the second loop face each other and the current lines in the portions where the third loop and the fourth loop face each other are uniform, An RF coil for MRI, in which the respective current lines of the first coil and the second coil are arranged. 3. A first double loop and a second double loop are connected in the same plane and have a current line arranged in a figure eight shape, and the first double loop and the second double loop are provided. The first coil configured such that the current directions of the two current line portions on the opposite sides of each of the double loops, and the third double loop and the fourth double loop are A current line arranged in a figure 8 connected in the same plane,
The current directions are the same in each of the two current line portions on the opposite sides of the double loop and the fourth double loop, and the current direction is opposite to the current direction of the first coil. The third double loop and the fourth double loop are arranged on the opposite sides of the two double loops, respectively.
The current line portion for each of the first and second double loops and the second
Second coil arranged in parallel on different planes at predetermined intervals with respect to each of the two current line portions on opposite sides of each other, RF coil. 4. The first double loop and the second double loop are connected in the same plane, and have a current line arranged in a figure eight shape, and the first double loop and the second double loop are provided. The first coil configured such that the current directions of the two current line portions on the opposite sides of each of the double loops, and the third double loop and the fourth double loop are A current line arranged in a figure 8 connected in the same plane,
The current directions are the same in each of the two current line portions on the opposite sides of the double loop and the fourth double loop, and the current direction is opposite to the current direction of the first coil. The third double loop and the fourth double loop are arranged on the opposite sides of the two double loops, respectively.
The current line portion for each of the first and second double loops and the second
A double coil having a second coil arranged in parallel on different planes with a predetermined distance from each of the two current line portions on opposite sides, the first double loop And two current line portions on the side where the second double loop faces each other and two current line portions on the side where the third double loop and the fourth double loop face each other. R for MRI, wherein each current line of the first coil and the second coil is arranged so that the magnetic field in the enclosed space is uniform.
F coil.