RF coil array

Abstract

To provide an RF coil array capable of obtaining relatively high sensitivity in subjects of various sizes.SOLUTION: An RF coil array according to the present disclosure includes a first coil unit including a first securing belt made of a first stretch material stretchable in a first direction and a plurality of RF coils disposed independently on the first securing belt, and a second coil unit including a second securing belt made of a second stretch material stretchable in the first direction and a plurality of RF coils disposed independently on the second securing belt. The first coil unit is attached to the subject with the distal end of the first fixing belt directed from one side to the other side in the first direction of the subject, and the second coil unit is attached to the subject with the distal end of the second fixing belt directed from the other side to the one side in the first direction of the subject such that at least a part of the second fixing belt overlaps the first coil unit.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an RF coil array, and more particularly to a technique for fixing an RF coil array for a magnetic resonance imaging apparatus to a subject. [Background technology]

[0002] A magnetic resonance imaging apparatus (hereinafter referred to as an MRI apparatus) receives magnetic resonance signals generated in a subject and reconstructs the received signals to obtain a magnetic resonance image. In such an MRI apparatus, an RF coil array, in which multiple RF (Radio Frequency) coils are arranged, must be fixed to the subject to receive the magnetic resonance signals.

[0003] Patent document 1 describes an MR coil including at least one antenna element, the antenna element having at least one expandable conductor section with a plastic cover and a core containing a conductive fluid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 10,209,326 Summary of the Invention [Problem to be solved by the invention]

[0005] RF coils can achieve relatively high sensitivity by being placed close to the subject. However, a single-piece RF coil array with a fixed size cannot always cover variations in subject size. In this case, it is not possible to place an RF coil to cover the body of a large subject, which reduces the sensitivity of the RF coil and creates the problem of not being able to obtain a sufficient signal-to-noise ratio (SNR) of the magnetic resonance signal.

[0006] In contrast, the MR coil described in Patent Document 1 expands and contracts to fit closely to the body of the subject even when the size of the subject changes, providing an appropriate SNR. However, the MR coil described in Patent Document 1 uses special electrical components, which poses a problem of cost.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide an RF coil array that can solve at least one of the above problems and obtain relatively high sensitivity for subjects of various sizes. [Means for solving the problem]

[0008] In order to achieve the above object, an RF coil array according to a first aspect of the present disclosure is an RF (Radio Frequency) coil array for a magnetic resonance imaging apparatus, and includes: a first coil unit including a first fixing belt made of a first stretch material stretchable in a first direction and a plurality of RF coils independently arranged on the first fixing belt; and a second coil unit including a second fixing belt made of a second stretch material stretchable in the first direction and a plurality of RF coils independently arranged on the second fixing belt, wherein the centers of the plurality of RF coils of the first coil unit are arranged on a first straight line, and the RF coils relatively closer to the tip of the first fixing belt have relatively smaller diameters. The centers of the multiple RF coils of the second coil unit are arranged on a second line, and the RF coils closer to the tip of the second fixing belt have relatively smaller diameters, the first line and the second line are arranged offset from each other in a second direction that intersects the first direction, the first coil unit is attached to the subject with the tip of the first fixing belt facing from one side of the subject in the first direction to the other side, and the second coil unit is attached to the subject with at least a portion overlapping the first coil unit with the tip of the second fixing belt facing from the other side of the subject in the first direction to one side.

[0009] An RF coil array according to a second aspect of the present disclosure is the RF coil array according to the first aspect, wherein the first straight line and the second straight line are preferably parallel to the first direction.

[0010] In the RF coil array according to the third aspect of the present disclosure, in the RF coil array according to the first or second aspect, when the first coil unit and the second coil unit are attached to a subject, it is preferable that any one of the multiple RF coils of the first coil unit and any one of the multiple RF coils of the second coil unit at least partially overlap each other.

[0011] In the RF coil array according to the fourth aspect of the present disclosure, in the RF coil array according to the first or second aspect, when the first coil unit and the second coil unit are attached to a subject, it is preferable that the RF coil with the largest diameter among the multiple RF coils of the first coil unit and the RF coil with the smallest diameter among the multiple RF coils of the second coil unit at least partially overlap each other.

[0012] In the RF coil array according to the fifth aspect of the present disclosure, in the RF coil array according to any one of the first to fourth aspects, it is preferable that at least one of the first fixing belt and the second fixing belt is partially made of a non-stretch material having a relatively smaller elongation rate in the first direction than the first stretch material and the second stretch material.

[0013] An RF coil array according to a sixth aspect of the present disclosure is preferably an RF coil array according to any one of the first to fifth aspects, further comprising a stopper structure that restricts the first fixing belt and the second fixing belt from extending beyond a certain level in the first direction.

[0014] An RF coil array according to a seventh aspect of the present disclosure is preferably the RF coil array according to the sixth aspect, wherein the stopper structure is made of a non-stretch material having a relatively smaller elongation rate in the first direction than the first stretch material and the second stretch material, and includes stopper bands that are pre-flexed in the first direction and provided on the first fixing belt and the second fixing belt.

[0015] An RF coil array according to an eighth aspect of the present disclosure is an RF coil array according to any one of the first to seventh aspects, wherein the first coil unit and the second coil unit are preferably connected at their ends opposite to the tips of the first fixing belt and the second fixing belt, respectively, to a tabletop on which the subject is placed.

[0016] An RF coil array according to a ninth aspect of the present disclosure is the RF coil array according to the eighth aspect, wherein the first fixing belt and the second fixing belt each preferably have rail hooks at their opposite ends that can engage with rail grooves provided in the top plate and move along the rail grooves.

[0017] The RF coil array according to the tenth aspect of the present disclosure is preferably the RF coil array according to the eighth or ninth aspect, further comprising a tightening mechanism for adjusting the amount of extension in the first direction of at least one of the first fixing belt and the second fixing belt after being attached to the subject.

[0018] An RF coil array according to an eleventh aspect of the present disclosure is the RF coil array according to the tenth aspect, wherein the tightening mechanism comprises a ring-shaped member connected to the top plate, and at least one of the first fixing belt and the second fixing belt has an end opposite to the tip passed through the inside of the ring-shaped member and folded back to be fixed.

[0019] An RF coil array according to a twelfth aspect of the present disclosure is an RF coil array according to any one of the first to seventh aspects, wherein the first coil unit and the second coil unit are preferably connected to a connection unit and integrally configured.

[0020] An RF coil array according to a thirteenth aspect of the present disclosure is the RF coil array according to the twelfth aspect, wherein the connection unit preferably includes a plurality of RF coils.

[0021] The RF coil array according to the fourteenth aspect of the present disclosure is preferably the RF coil array according to the twelfth or thirteenth aspect, further comprising a tightening mechanism for adjusting the amount of extension in the first direction of at least one of the first fixing belt and the second fixing belt after being attached to the subject.

[0022] An RF coil array according to a fifteenth aspect of the present disclosure is the RF coil array according to the fourteenth aspect, wherein the tightening mechanism comprises a tightening belt connected to at least one of the first fixing belt and the second fixing belt, and an annular member, and it is preferable that the tightening belt is passed through the inside of the annular member and folded back to be fixed.

[0023] An RF coil array according to a sixteenth aspect of the present disclosure is an RF coil array according to any one of the first to fifteenth aspects, wherein the plurality of RF coils of the first coil unit overlap with the adjacent RF coils, and the plurality of RF coils of the second coil unit overlap with the adjacent RF coils.

[0024] An RF coil array according to a seventeenth aspect of the present disclosure is an RF coil array according to any one of the first to sixteenth aspects, wherein the first and second fixing belts preferably have first and second surfaces of a pair of hook-and-loop fasteners that engage with each other at positions where they come into contact with each other when the first coil unit and the second coil unit are placed on top of each other and attached to the subject.

[0025] An RF coil array according to an 18th aspect of the present disclosure is an RF coil array according to any one of the 1st to 17th aspects, wherein the first coil unit is attached to the subject by stretching the first fixing belt, and the second coil unit is attached to the subject by stretching the second fixing belt. [Effects of the Invention]

[0026] The present invention provides relatively high sensitivity for specimens of various sizes. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view showing an example of an MRI apparatus. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line 2-2 of FIG. [Figure 3] FIG. 3 is a perspective view showing an example of an MRI apparatus according to the present disclosure. [Figure 4] FIG. 4 is a plan view of the first coil unit and the second coil unit. [Figure 5] FIG. 5 is a perspective view showing an example of an MRI apparatus. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. [Figure 7] FIG. 7 is a planar perspective view of the first coil unit and the second coil unit. [Figure 8] FIG. 8 is a diagram for explaining the relationship between the size of the subject and the arrangement of the RF coil. [Figure 9] FIG. 9 is a diagram for explaining the relationship between the size of the subject and the arrangement of the RF coil. [Figure 10] FIG. 10 is a diagram for explaining the relationship between the size of the subject and the arrangement of the RF coil. [Figure 11] FIG. 11 is a plan perspective view of the first coil unit. [Figure 12] FIG. 12 is a plan perspective view of the first coil unit. [Figure 13] FIG. 13 is a diagram showing an RF coil array. [Figure 14] FIG. 14 is a diagram showing an RF coil array. [Figure 15] FIG. 15 is a diagram showing an RF coil array. [Figure 16] FIG. 16 is a diagram showing an RF coil array. [Figure 17] FIG. 17 is a diagram showing an RF coil array. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, preferred embodiments of the RF coil array according to the present disclosure will be described with reference to the accompanying drawings. In this specification, the same components are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0029] [Typical Device Configuration] Fig. 1 is a perspective view showing an example of a typical MRI apparatus 10. As shown in Fig. 1, the MRI apparatus 10 includes a magnet 12 that generates a static magnetic field and a bed 16. The magnet 12 has a cylindrical examination (imaging) space 14. In addition, the magnet 12 is provided with an MRI magnet (not shown) as a magnetic field generation source, and various other coils (not shown).

[0030] The bed 16 is installed on the front side of the magnet 12, facing the examination space 14. The bed 16 is equipped with a top plate 18. A subject 20 is placed on the top plate 18 along the longitudinal direction. The top plate 18 is configured to be movable in the X direction, which is the width direction perpendicular to the longitudinal direction of the top plate 18, the Y direction, which is the vertical direction, and the Z direction, which is the longitudinal direction of the top plate 18.

[0031] The MRI apparatus 10 includes a drive mechanism (not shown) that moves the top plate 18 in the Z direction to enter and exit the examination space 14. By moving the top plate 18 within the examination space 14, the MRI apparatus 10 sets the examination target region of the subject 20 to be imaged, placed on the top plate 18, at the center of the static magnetic field within the examination space 14.

[0032] A multi-channel RF coil array (not shown) consisting of a plurality of RF coils for receiving magnetic resonance signals generated in the subject 20 is fixed to the examination target region of the subject 20 by a fixing belt 22. In the example shown in FIG. 1, the abdomen of the subject 20 is the examination target region, and the RF coil array is attached to the abdomen of the subject 20.

[0033] A receiving cable (not shown) that outputs magnetic resonance signals received by the RF coil is connected to the RF coil array. A receiving connector (not shown) is connected to an end of this receiving cable. The receiving connector is connected to a bed-side connector of a bed-side cable (not shown). This allows the receiving cable and the bed-side cable to be connected so as to be able to communicate with each other via their respective connectors.

[0034] The bed-side cable is stored in a cable storage unit (not shown) of the bed 16. Magnetic resonance signals of the subject 20 received by the RF coil are transmitted to a signal processing unit (not shown) via the receiving-side cable and the bed-side cable. The signal processing unit processes the received magnetic resonance signals and converts them into image signals.

[0035] [Task 1] Fig. 2 is a schematic cross-sectional view taken along line 2-2 in Fig. 1. As shown in Fig. 2, a spine coil 24 including a plurality of RF coils (not shown) is disposed on the surface of the tabletop 18 on which the subject 20 is placed. In addition, an upper abdomen coil 26 fixed by a fixing belt 22 (not shown in Fig. 2) is disposed on the abdomen of the subject 20 placed on the tabletop 18. The spine coil 24 and the upper abdomen coil 26 correspond to an RF coil array.

[0036] It is preferable that the RF coil array be arranged close to the subject 20 with no gaps. However, a one-piece RF coil array with a fixed size, such as the upper abdomen coil 26, cannot cover variations in the size of the subject 20, and a sufficient SNR may not be obtained in the range that cannot be covered by the RF coil. In the example shown in Fig. 2, there is an area on the side of the subject 20 (the left and right surfaces of the subject 20 in Fig. 2) that is not covered by either the back coil 24 or the upper abdomen coil 26.

[0037] [Task 2] On the other hand, the MR coil described in Patent Document 1 uses a plastic cover filled with a high-quality conductive fluid to form an expandable conductor, making it possible to adjust the length and maintain close contact even when the size of the subject changes. However, it has the problem of being more expensive than conventional conductive materials.

[0038] [Configuration of the device of the present disclosure] 3 is a perspective view showing an example of an MRI apparatus 10A according to the present disclosure. As shown in FIG. 3, the MRI apparatus 10A includes an RF coil array 100 for an MRI apparatus. The RF coil array 100 includes a first coil unit 102 and a second coil unit 122.

[0039] The first coil unit 102 includes a first fixing belt 104. The first fixing belt 104 has a base end 104R disposed on the first end 18A side of the tabletop 18 in the X direction (the front side of the tabletop 18 in FIG. 3), and a tip end 104T which is a free end.

[0040] The second coil unit 122 includes a second fixing belt 124. The second fixing belt 124 has a base end 124R disposed on the second end 18B side (the far side of the tabletop 18 in FIG. 3) opposite the first end 18A side in the X direction of the tabletop 18, and a tip end 124T as a free end.

[0041] The first fixing belt 104 is made of a first stretchable material that is stretchable in a stretching direction in which the base end 104R and the tip 104T move apart (an example of a "first direction"; the X direction in the state of FIG. 7). The second fixing belt 124 is made of a second stretchable material that is stretchable in a stretching direction in which the base end 124R and the tip 124T move apart.

[0042] A stretch material is a polyurethane-based elastic fiber that maintains a non-stretched state when no tensile force is applied, and when a tensile force is applied in the stretching direction, it stretches in the stretching direction in response to the tensile force, deforming into a stretched state, and then attempts to return to its original non-stretched state due to a restoring force. Alternatively, the stretch material is a polyester-based fiber material with a mechanical structure in the way the fiber is folded. When the tensile force is released from the stretched state and the material is returned to an unloaded state, the restoring force restores the stretch material to its non-stretched state. The stretch percentage [%] in the stretching direction of the stretch material is preferably 20% or more, and more preferably 30% or more. In this specification, the stretch percentage is a value measured according to JIS-L-1096 Method B.

[0043] Furthermore, the stretch material is preferably a one-way material that stretches easily in only one direction (an asymmetric material that does not stretch in the non-stretch direction perpendicular to the stretch direction). The stretch material is preferably structured so that the stretch rate in at least the non-stretch direction is relatively smaller than the stretch rate in the stretch direction. For example, the one-way material may have a structure in which a band-like non-stretchable material is partially arranged in the non-stretch direction of the stretch material.

[0044] The stretch rate in the extension direction of the first stretch material and the stretch rate in the extension direction of the second stretch material are preferably equal. The first stretch material and the second stretch material may be the same material.

[0045] The base end 104R of the first fixing belt 104 and the base end 124R of the second fixing belt 124 are arranged at the same Z-direction coordinate position on the tabletop 18. The first fixing belt 104 and the second fixing belt 124 are configured to have the same length in the Z direction. Furthermore, the first fixing belt 104 and the second fixing belt 124 are configured to have the same length from the base end 104R to the tip 104T and the same length from the base end 124R to the tip 124T. In other words, the first fixing belt 104 and the second fixing belt 124 have the same shape and are arranged symmetrically with respect to the tabletop 18.

[0046] The first fixing belt 104 and the second fixing belt 124 are provided with a first surface (surface A) 106 and a second surface (surface B) 126 of a hook and loop fastener, respectively, at positions that overlap each other when the RF coil array 100 is attached to the subject 20 (not shown in FIG. 3). A hook and loop fastener is a joining member in which a pair of hook and loop surfaces engage with each other. For example, the first surface 106 is the hook surface, and the second surface 126 is the loop surface.

[0047] Fig. 4 is a plan view of the first coil unit 102 and the second coil unit 122. F4A in Fig. 4 shows the first coil unit 102 placed flat on the top plate 18 (not shown in Fig. 4). F4B in Fig. 4 shows the second coil unit 122 placed flat on the top plate 18. As shown in F4A, the first surface 106 of the hook-and-loop fastener is arranged in a strip shape in a direction perpendicular to the extension direction at the tip 104T of the surface of the first fixing belt 104 that comes into contact with the second fixing belt 124. Furthermore, the second surface 126 of the hook-and-loop fastener is arranged on the same surface.

[0048] As shown in F4B, second surface 126 of the hook and loop fastener is arranged in a strip shape in a direction perpendicular to the extension direction at tip 124T of the surface of second fixing belt 124 that comes into contact with first fixing belt 104. Furthermore, second surface 126 of the hook and loop fastener is arranged on the same surface.

[0049] At least the second surface 126 of the hook-and-loop fastener is made of a stretch material. When a pulling force is generated in the direction in which the first fixing belt 104 and the second fixing belt 124 extend, the second surface 126 of the hook-and-loop fastener stretches together with the stretching of the first fixing belt 104 and the second fixing belt 124 in response to the pulling force.

[0050] 5 is a perspective view showing an example of an MRI apparatus 10A, showing a state in which an RF coil array 100 is attached to a subject 20 placed on a tabletop 18. Also, FIG. 6 is a cross-sectional view taken along line 6-4 in FIG.

[0051] To attach the RF coil array 100 to the subject 20, the user first places the subject 20 on the tabletop 18, and places the first coil unit 102 on the region to be examined (the abdomen in this case) of the subject 20. That is, the first coil unit 102 is attached to the subject 20 with the tip 104T of the first fixing belt 104 directed from a first end 18A side (an example of "one side in the first direction") in the X direction of the tabletop 18 to a second end 18B side (an example of "the other side in the first direction") in the X direction.

[0052] Next, the user places the second coil unit 122 over the first coil unit 102 attached to the subject 20. At this time, the user connects the first surface 106 of the hook-and-loop fastener of the first fixing belt 104 to the second surface 126 of the hook-and-loop fastener of the second fixing belt 124, and the first surface 106 of the hook-and-loop fastener of the second fixing belt 124 to the second surface 126 of the hook-and-loop fastener of the first fixing belt 104. That is, the second coil unit 122 is attached to the subject 20 with at least a portion thereof overlapping the first coil unit 102, with the tip 124T of the second fixing belt 124 facing from the second end 18B side to the first end 18A side of the top board 18.

[0053] By attaching the RF coil array 100 to the subject 20 in this manner, the subject 20 is fixed to the tabletop 18. The second coil unit 122 may be attached to the subject 20 first, and the first surface 106 and the second surface 126 of the hook-and-loop fastener may be arranged so that the first coil unit 102 is attached on top of the second coil unit 122.

[0054] Fig. 7 is a planar perspective view of the first coil unit 102 and the second coil unit 122. F7A in Fig. 7 shows the first coil unit 102 placed flat on the top plate 18 (not shown in Fig. 7). In F7A, the first fixing belt 104 is in an unstretched state where no tensile force is applied in the X direction. The length of the first fixing belt 104 in the unstretched state in the X direction is L1.

[0055] As shown in F7A, the first coil unit 102 includes a plurality of planar RF coils 108-1, 108-2, 108-3, 108-4, 108-11, 108-12, 108-13, and 108-14 that are two-dimensionally arranged on the first fixing belt 104. The RF coils 108-1 to 108-4 and 108-11 to 108-14 each have a circular shape in a plan view (as viewed in the Y direction in FIG. 7).

[0056] The RF coils 108-1 to 108-4 and 108-11 to 108-14 are disposed on independent flexible substrates (not shown), and each flexible substrate is independently fixed to the first fixing belt 104 at fixing points located at the centers (shown by crosses in FIG. 7) of the RF coils 108-1 to 108-4 and 108-11 to 108-14.

[0057] The RF coils 108-1 to 108-4 partially overlap each other when viewed from above the first fixing belt 104, and their centers are arranged on a straight line 110 (an example of a "first straight line"). For example, the RF coils 108-1 and 108-2 partially overlap each other, the RF coils 108-2 and 108-3 partially overlap each other, and the RF coils 108-3 and 108-4 partially overlap each other.

[0058] Here, the straight line 110 is parallel to the X direction, which is the extension direction of the first fixing belt 104. In this specification, "parallel" may mean completely parallel or substantially parallel. "Substantially parallel" means that the direction of the straight line 110 is angled with respect to the X direction to such an extent that the object of the present disclosure of obtaining relatively high sensitivity even for a subject having a relatively large size can be achieved.

[0059] Moreover, the diameter of each of the RF coils 108-1 to 108-4 becomes smaller as it is relatively closer to the tip 104T of the first fixing belt 104. That is, the diameters of the RF coils 108-1, 108-2, 108-3, and 108-4 become smaller in this order.

[0060] Similarly, the RF coils 108-11 to 108-14 partially overlap one another when viewed from above the first fixing belt 104, and their centers are arranged on a straight line 112 parallel to the X direction. The RF coils 108-11 to 108-14 each have a smaller diameter as they are closer to the tip 104T of the first fixing belt 104.

[0061] F7B in Fig. 7 shows a state in which the second coil unit 122 is placed flat on the top plate 18. In F7B, the second fixing belt 124 is in an unstretched state in which no tensile force is applied in the X direction. The length of the second fixing belt 124 in the unstretched state in the X direction is L2. It is preferable that L2 be equal to L1.

[0062] As shown in F7B, the second coil unit 122 includes a plurality of planar RF coils 128-1, 128-2, 128-3, 128-4, 128-11, 128-12, 128-13, and 128-14 that are two-dimensionally arranged on the second fixing belt 124. The RF coils 128-1 to 128-4 and 128-11 to 128-14 each have a circular shape in plan view.

[0063] The RF coils 128-1 to 128-4 and 128-11 to 128-14 are disposed on independent flexible substrates (not shown). Each flexible substrate is independently fixed to the second fixing belt 124 at fixing points located at the center of the RF coils 128-1 to 128-4 and 128-11 to 128-14.

[0064] The RF coils 128-1 to 128-4 partially overlap each other when viewed from above the second fixing belt 124, and their centers are arranged on a straight line 130 (an example of a "second straight line") that is parallel to the X direction, which is the extension direction of the second fixing belt 124. Here, the RF coils 128-1 and 128-2 partially overlap each other, the RF coils 128-2 and 128-3 partially overlap each other, and the RF coils 128-3 and 128-4 partially overlap each other.

[0065] Moreover, the diameter of each of the RF coils 128-1 to 128-4 becomes smaller as it is relatively closer to the tip 124T of the second fixing belt 124. That is, the diameters of the RF coils 128-1, 128-2, 128-3, and 128-4 become smaller in this order.

[0066] Similarly, RF coils 128-11 to 128-14 partially overlap one another when viewed from above in second fixing belt 124, and their centers are arranged on line 132 parallel to the X direction. Furthermore, RF coils 128-11 to 128-14 each have a smaller diameter as they are closer to tip 124T of second fixing belt 124.

[0067] In the following, when there is no need to distinguish between the RF coils 108-1 to 108-4 and 108-11 to 108-14, they may be simply referred to as RF coils 108. Similarly, when there is no need to distinguish between the RF coils 128-1 to 128-4 and 128-11 to 128-14, they may be simply referred to as RF coils 128. The number and arrangement of the RF coils 108 of the first coil unit 102 and the RF coils 128 of the second coil unit 122 are not limited to the example shown in FIG.

[0068] The straight lines 110 and 112 of the first coil unit 102 and the straight lines 130 and 132 of the second coil unit 122 are arranged offset from each other in the Z direction (an example of a "second direction") perpendicular to (an example of "intersecting") the extension direction of the first fixing belt 104 and the second fixing belt 124. "Aligned from each other" means that they are not arranged on the same straight line. For example, the straight lines 110 and 112 of the first coil unit 102 and the straight lines 130 and 132 of the second coil unit 122 are arranged alternately along the Z direction. In the example shown in FIG. 7, the straight lines 110, 130, 112, and 132 are arranged alternately from top to bottom in this order. In this way, the straight line 110 is not arranged on the same straight line as the straight lines 130 and 132, and the straight line 112 is not arranged on the same straight line as the straight lines 130 and 132.

[0069] In this way, the RF coil 108 of the first coil unit 102 and the RF coil 128 of the second coil unit 122 are arranged point-symmetrically with respect to a point on a line that bisects the top plate 18 (not shown in FIG. 7, see FIG. 3) in the X direction.

[0070] The RF coil array 100 may output the magnetic resonance signals received by each RF coil 108 and each RF coil 128 via a signal processing circuit (not shown in FIG. 7) including a signal amplifier, via a cable or wirelessly.

[0071] [Subject size and RF coil placement] 8 to 10 are diagrams for explaining the relationship between the size of the subject and the arrangement of the RF coils. F8A in Fig. 8, F9A in Fig. 9, and F10A in Fig. 10 are cross-sectional views similar to Fig. 6 showing a state in which the RF coil array 100 is attached to the subject 20. F8B in Fig. 8, F9B in Fig. 9, and F10B in Fig. 10 are planar perspective views showing the arrangement of the RF coils as seen from the Z direction side in the states of F8A, F9A, and F10A, respectively, and are views showing the first fixing belt 104 and the second fixing belt 124 expanded in the X direction. Note that hook-and-loop fasteners are not shown in Figs. 8 to 10.

[0072] 8 shows a state in which the RF coil array 100 is attached to a subject 20 who is relatively small in size (body type). In the state shown in Fig. 8, the first fixing belt 104 and the second fixing belt 124 are both in a non-stretched state.

[0073] As shown in F8B, the RF coil array 100 tightly covers the periphery of the region to be examined of the subject 20 with RF coils 108-1 to 108-4, RF coils 108-11 to 108-14, RF coils 128-1 to 128-4, and RF coils 128-11 to 128-14.

[0074] 9 shows a state in which the RF coil array 100 is attached to a relatively medium-sized subject 20. In the state shown in FIG. 9, the first fixing belt 104 and the second fixing belt 124 are both in a non-stretched state.

[0075] 8 and 9, the overlapping length of the first fixing belt 104 and the second fixing belt 124 changes depending on the size of the subject 20. That is, the sizes of the first coil unit 102 and the second coil unit 122 in the circumferential direction of the subject 20 change in a gradation depending on the size of the subject 20.

[0076] As shown in F9B, the RF coil array 100 tightly covers the periphery of the examination target region of the subject 20 with RF coils 108-1 to 108-4, RF coils 108-11 to 108-14, RF coils 128-1 to 128-4, and RF coils 128-11 to 128-14. In this way, even if the overlapping length of the first fixing belt 104 and the second fixing belt 124 changes, the RF coils are arranged with an equal density.

[0077] 10 shows a state in which the RF coil array 100 is attached to a relatively large subject 20. The first coil unit 102 is attached to the subject 20 with the first fixing belt 104 stretched, and the second coil unit 122 is attached to the subject 20 with the second fixing belt 124 stretched. In the state shown in FIG. 10, the first fixing belt 104 and the second fixing belt 124 are in an extended state in which they are extended by α1 and α2, respectively.

[0078] If the RF coil array 100 is attached to a relatively large subject 20 while the first fixing belt 104 and the second fixing belt 124 are in an unextended state, the RF coil cannot be positioned to cover the region to be examined. In contrast, by attaching the RF coil array 100 with the first fixing belt 104 and the second fixing belt 124 in an extended state, the RF coil is positioned to cover the region to be examined.

[0079] To attach the RF coil array 100 to a subject 20 that is relatively large in size, the user places the first coil unit 102 on the area to be examined of the subject 20 placed on the tabletop 18, and then pulls the first coil unit 102 toward the second end 18B of the tabletop 18, thereby stretching the first fixing belt 104 by α1.

[0080] Next, while keeping the first fixing belt 104 in an extended state, the user pulls the second coil unit 122 above the first coil unit 102 toward the first end 18A of the tabletop 18, thereby extending the second fixing belt 124 by α2. It is preferable that α2 is equal to α1. In other words, it is preferable that the first fixing belt 104 and the second fixing belt 124 are extended equally.

[0081] Finally, the user places the second coil unit 122, whose second fixing belt 124 is in an extended state, over the first coil unit 102, whose first fixing belt 104 is in an extended state, and joins the first surface 106 and the second surface 126 of the hook-and-loop fastener together.

[0082] In the RF coil array 100 worn in this manner, the distance between the centers of the multiple RF coils 108-1, 108-2, 108-3, and 108-4 arranged on a straight line 110 of the first fixing belt 104 is relatively wider than when the first fixing belt 104 is in an unstretched state. Also, the distance between the centers of the multiple RF coils 108-11, 108-12, 108-13, and 108-14 arranged on a straight line 112 of the first fixing belt 104 is relatively wider than when the first fixing belt 104 is in an unstretched state. The same is true for the distance between the centers of the RF coils 128-1 to 128-4 and 128-11 to 128-14 arranged on the second fixing belt 124.

[0083] In this way, by extending the first fixing belt 104 and the second fixing belt 124, the length in which the RF coils exist in the X direction is extended, and the RF coils are arranged with an even density. This makes it possible to obtain relatively high sensitivity even for a subject that is relatively large in size and cannot be covered if the first fixing belt 104 and the second fixing belt 124 do not extend.

[0084] [RF coil placement restrictions] When the first coil unit 102 and the second coil unit 122 are attached to the subject 20, even if the first fixing belt 104 and the second fixing belt 124 are in an extended state, it is preferable that the multiple RF coils 108 of the first coil unit 102 overlap with the adjacent RF coils 108, and the multiple RF coils 128 of the second coil unit 122 overlap with the adjacent RF coils 128. If there is a region where the adjacent RF coils do not overlap with each other, the sensitivity of the RF coils will be relatively low.

[0085] When the first coil unit 102 and the second coil unit 122 are attached to the subject 20, it is preferable that any one of the RF coils 108 of the first coil unit 102 and any one of the RF coils 108 of the second coil unit 122 at least partially overlap each other when viewed from a direction perpendicular to the surfaces of the first fixing belt 104 and the second fixing belt 124 (i.e., a direction perpendicular to the circumferential direction of the subject 20). This makes it possible to image subjects of various sizes.

[0086] Furthermore, when the first coil unit 102 and the second coil unit 122 are attached to the subject 20, it is preferable that the RF coil 108 with the largest diameter (e.g., RF coil 108-1) among the multiple RF coils 108 of the first coil unit 102 and the RF coil 108 with the smallest diameter (e.g., RF coil 128-4) among the multiple RF coils 108 of the second coil unit 122 at least partially overlap each other when viewed from a direction perpendicular to the surfaces of the first fixing belt 104 and the second fixing belt 124. This makes it possible to image subjects of various sizes.

[0087] Similarly, when the first coil unit 102 and the second coil unit 122 are attached to the subject 20, it is preferable that the RF coil 108 with the smallest diameter among the multiple RF coils 108 of the first coil unit 102 (e.g., RF coil 108-4) and the RF coil 108 with the largest diameter among the multiple RF coils 108 of the second coil unit 122 (e.g., RF coil 128-1) at least partially overlap each other.

[0088] [RF coil array extension limit] A portion of the first fixing belt may be made of a non-stretch material having a relatively smaller stretch rate than the first stretch material.

[0089] 11 is a planar perspective view of the first coil unit 102A. The first coil unit 102A includes a first fixing belt 104A. The first fixing belt 104A includes a stretch section 140 made of a stretch material and a non-stretch section 142 made of a non-stretch material.

[0090] The stretch section 140 is made of a first stretch material that is stretchable in the X direction, which is the extension direction. The non-stretch section 142 is made of a non-stretch material that has a relatively smaller stretch rate in the X direction than the first stretch material. The stretch rate of the non-stretch material is preferably less than 5%, and more preferably less than 1%.

[0091] 11A shows the unstretched state of first fixing belt 104A, and F11B shows the stretched state in which first fixing belt 104A is stretched by α3 from the unstretched state. In either state, the centers of RF coils 108-1 to 108-4 are located on line 110, and the centers of RF coils 108-11 to 108-14 are located on line 112. As shown in F11B, in the stretched state, stretch section 140 stretches, increasing the distance between RF coil 108-1 and RF coil 108-2 and the distance between RF coil 108-2 and RF coil 108-3. On the other hand, non-stretch section 142 does not stretch, and the distance between RF coil 108-3 and RF coil 108-4 does not change.

[0092] In this way, first fixing belt 104A can limit the stretchable portion, thereby forming a portion that stabilizes the performance of RF coil 108. The position and length in the X direction that constitutes non-stretch portion 142 are not limited to the example shown in Fig. 11, and may be determined appropriately depending on the length of first fixing belt 104A in the X direction, the size of RF coil 108, etc.

[0093] Here, an example has been described in which a portion of the first fixing belt 104A is made of a non-stretch material, but a portion of the second fixing belt may be made of a non-stretch material having a relatively smaller elongation rate than the second stretch material, or a portion of the first fixing belt and a portion of the second fixing belt may each be made of a non-stretch material.

[0094] In this embodiment, the non-stretch material is provided in one location, but this is not limited to this. Two or more strips of non-stretch material may be provided in a direction perpendicular to the stretch direction. This allows for more precise control of stretch.

[0095] The first coil unit and the second coil unit may also be provided with a stopper structure that restricts the extension amount of the first fixing belt and the second fixing belt in the extension direction from exceeding a certain amount.

[0096] FIG. 12 is a planar perspective view of the first coil unit 102B. The first coil unit 102B includes a stopper band 150 as a stopper structure. The stopper band 150 is made of a non-stretch material with a relatively smaller stretch rate in the stretch direction than the first stretch material, and has a length L2 in the X direction. The length of the stopper band 150 in the X direction may be determined appropriately depending on the length of the first fixing belt 104A in the X direction, the size of the RF coil 108, and the like. The length of the stopper band 150 in the Z direction may be determined appropriately depending on the strength of the stopper band 150, and the like. When the first fixing belt 104 is in an unstretched state, the end portions 150A and 150B of the stopper band 150 are pre-flexed at a certain distance L3 in the X direction and fixed to the first fixing belt 104. In other words, L3 is smaller than L2.

[0097] 12, F12A shows the unstretched state of the first fixing belt 104, and F12B shows the stretched state in which it has stretched by α4 from the unstretched state. In the unstretched state shown in F12A, the stopper band 150 is bent in the X direction. On the other hand, in the stretched state shown in F12B, the stopper band 150 is in an unstretched state, and the first fixing belt 104 does not stretch any further in the X direction.

[0098] As shown in F12B, the multiple RF coils 108 of the first coil unit 102B overlap each other with the adjacent RF coils 108. Therefore, the first fixing belt 104 will not be stretched any further and the overlapping of the RF coils 108 will not disappear.

[0099] In this way, the first coil unit 102B equipped with the stopper bands 150 can reduce the insensitive region even for a relatively large subject, thereby achieving relatively high sensitivity. The position at which the stopper bands 150 are placed may be determined as appropriate. Furthermore, the maximum extension amount of the first fixing belts 104 restricted by the stopper bands 150 is preferably the maximum extension amount that allows the overlap of adjacent RF coils to be maintained. In order for the RF coil array 100 to achieve appropriate performance, it is preferable that the adjacent RF coils overlap by approximately 5% to 15%.

[0100] Here, an example has been described in which the first coil unit 102B has a stopper band 150 as a stopper structure, but the second coil unit may also have a stopper structure, or the first coil unit and the second coil unit may each have a stopper structure.

[0101] [RF coil array fixing structure] The first coil unit and the second coil unit may have a structure in which the ends opposite to the distal ends of the first fixing belt and the second fixing belt can be connected to the tabletop, and may be connected to the tabletop of the MRI apparatus.

[0102] Fig. 13 is a diagram showing the RF coil array 100A. F13A in Fig. 13 is a cross-sectional view similar to Fig. 6. F13B in Fig. 13 is a planar perspective view showing the arrangement of the RF coils when the state of F13A is viewed from the Z direction side, and is shown expanded in the X direction. In F13B, the first fixing belt 104 and the second fixing belt 124 are in a non-stretched state.

[0103] 13, the RF coil array 100A includes a first coil unit 102C and a second coil unit 122C. The first coil unit 102C includes a plurality of rail hooks 160 at the base end 104R of the first fixing belt 104. The second coil unit 122C includes a plurality of rail hooks 162 at the base end 124R of the second fixing belt 124.

[0104] The top plate 18 also has a rail groove 164 along the Z direction on the first end 18A side, and a rail groove 166 along the Z direction on the second end 18B side.

[0105] The first coil unit 102C is connected to the top plate 18 by engaging the multiple rail hooks 160 with the rail grooves 164. The second coil unit 122C is connected to the top plate 18 by engaging the multiple rail hooks 162 with the rail grooves 166.

[0106] This allows the RF coil array 100A to be attached in close contact with the subject 20, and the subject 20 to be fixed to the top board .

[0107] Additionally, the rail hooks 160 are movable along the rail grooves 164. Additionally, the rail hooks 162 are movable along the rail grooves 166.

[0108] This allows the RF coil array 100A to move to a position in the Z direction according to the region of the subject 20 to be examined.

[0109] [RF coil array tightening structure] The RF coil array may include a tightening mechanism for adjusting the amount of extension in the extension direction of at least one of the first fixing belt and the second fixing belt after being attached to the subject.

[0110] Fig. 14 is a diagram showing an RF coil array 100B. F14A in Fig. 14 is a cross-sectional view similar to Fig. 6. F14B in Fig. 14 is a diagram showing the state of F14A as seen from the Z direction side, and is expanded in the X direction.

[0111] 14, the RF coil array 100B includes a first coil unit 102D and a second coil unit 122D. The first coil unit 102D includes a first fixing belt 104A, a third fixing belt 170, and a square ring 172 (an example of an "annular member") as a tightening mechanism.

[0112] The first fixing belt 104A has a first surface 180 and a second surface 182 of the hook and loop fastener provided on the same surface on which the first surface 106 and the second surface 126 (not shown in FIG. 14, see FIG. 6) of the hook and loop fastener are arranged, at positions relatively close to the base end 104R. For example, the first surface 180 is a loop surface, and the second surface 182 is a hook surface. The second surface 182 may be integral with the first surface 106.

[0113] The first fixing belt 104A is connected to the square ring 172 by having the base end 104R pass through the opening of the square ring 172 and then folded back, and by joining the first surface 180 and the second surface 182 of the hook-and-loop fastener.

[0114] The third fixing belt 170 is passed through an opening (an example of the "inside") of the square ring 172 and folded back, with both ends connected to each other. The connected ends of the third fixing belt 170 are provided with a plurality of rail hooks 160A.

[0115] The top plate 18 has a rail groove 164 along the Z direction on the first end 18A side. The first coil unit 102D is connected to the top plate 18 by engaging the rail hooks 160A with the rail groove 164.

[0116] The second coil unit 122D includes a second fixing belt 124A, a fourth fixing belt 174, and a square ring 176 as a tightening mechanism.

[0117] Second fixing belt 124A has first surface 184 and second surface 186 of the hook and loop fastener provided on the surface opposite to the surface on which first surface 106 and second surface 126 (not shown in FIG. 14, see FIG. 6) of the hook and loop fastener are arranged, at positions relatively close to base end 124R. For example, first surface 184 is a loop surface, and second surface 186 is a hook surface.

[0118] The second fixing belt 124A is connected to the square ring 176 by having the base end 124R pass through the opening of the square ring 176 and then folded back, and by joining the first surface 184 and the second surface 186 of the hook-and-loop fastener.

[0119] The fourth fixing belt 174 is passed through the opening of the square ring 176 and folded back, with both ends connected to each other. The connected ends of the fourth fixing belt 174 are provided with a plurality of rail hooks 162A.

[0120] The top plate 18 has a rail groove 166 on the second end 18B side along the Z direction. The second coil unit 122D is connected to the top plate 18 by engaging the rail hooks 162A with the rail groove 166.

[0121] To attach the RF coil array 100B to the subject 20, the user first connects the first coil unit 102D and the second coil unit 122D to the tabletop 18.

[0122] Next, the user places the first coil unit 102 on the region to be examined of the subject 20 placed on the top board 18. The user then places the second coil unit 122 on the first coil unit 102 attached to the subject 20, and couples the first surface 106 of the hook-and-loop fastener of the first fixing belt 104 to the second surface 126 of the hook-and-loop fastener of the second fixing belt 124, and the first surface 106 of the hook-and-loop fastener of the second fixing belt 124 to the second surface 126 of the hook-and-loop fastener of the first fixing belt 104 (not shown in FIG. 14 , see FIG. 6 ). If the size of the subject 20 is relatively large, the user stretches the first fixing belt 104 and the second fixing belt 124 before coupling the first surface 106 and the second surface 126 of the hook-and-loop fasteners.

[0123] In the RF coil array 100 thus attached to the subject 20, the first fixing belt 104A and the second fixing belt 124A can be tightened.

[0124] To further tighten the first fixing belt 104A, the user releases the connection between the first surface 180 and the second surface 182 of the hook-and-loop fastener of the first fixing belt 104A, pulls the base end 104R of the first fixing belt 104A in a direction away from the square ring 172 (for example, in the Y direction), and reconnects the first surface 180 and the second surface 182 of the hook-and-loop fastener.

[0125] To further tighten the second fixing belt 124A, the user releases the connection between the first surface 184 and the second surface 186 of the hook-and-loop fastener of the second fixing belt 124A, pulls the base end 124R of the second fixing belt 124A in a direction away from the square ring 176, and reconnects the first surface 184 and the second surface 186 of the hook-and-loop fastener.

[0126] This allows the extension of the RF coil array to be adjusted appropriately, resulting in stable image quality.

[0127] Here, an example has been described in which first fixing belt 104A and second fixing belt 124A can be retightened, but only one of them may be retightened.

[0128] [Integrated structure of first coil unit and second coil unit] The first coil unit and the second coil unit may be integrally configured by being connected to a connection unit, respectively.

[0129] 15 is a diagram showing an RF coil array 100C. F15A in Fig. 15 is a planar perspective view of the RF coil array 100C, and F15B in Fig. 15 is a cross-sectional view similar to Fig. 6.

[0130] 15, the RF coil array 100C includes a first coil unit 102, a second coil unit 122, and a connection unit 190. The connection unit 190 is made of a non-stretch material. The connection unit 190 is rectangular, and one end is connected to the base end 104R of the first fixing belt 104, and the other end is connected to the base end 124R of the second fixing belt 124. The length of the connection unit 190 in the X direction may be determined appropriately depending on the lengths of the first fixing belt 104 and the second fixing belt 124 in the X direction, etc.

[0131] To attach the RF coil array 100C to the subject 20, the user wraps the RF coil array 100C around the region to be examined of the subject 20, and couples the first surface 106 of the hook-and-loop fastener of the first fixing belt 104 with the second surface 126 of the hook-and-loop fastener of the second fixing belt 124, and the first surface 106 of the hook-and-loop fastener of the second fixing belt 124 with the second surface 126 of the hook-and-loop fastener of the first fixing belt 104 (not shown in FIG. 15, see FIG. 6). If the subject 20 is relatively large, the user stretches the first fixing belt 104 and the second fixing belt 124 before coupling the first surface 106 and the second surface 126 of the hook-and-loop fasteners.

[0132] In this way, the user can use the RF coil array 100C by wrapping it around the region to be examined. The subject 20 fitted with the RF coil array 100C can be fixed to the top board 18 using a separate member.

[0133] [RF coil of connection unit] The connection unit may include multiple RF coils.

[0134] 16 is a diagram showing an RF coil array 100D. The RF coil array 100D includes a connection unit 190A. The connection unit 190A includes RF coils 192-1, 192-2, 192-3, and 192-4. When there is no need to distinguish between the RF coils 192-1 to 192-4, they may be simply referred to as RF coils 192.

[0135] The center of the RF coil 192-1 (shown by a cross in FIG. 16) is placed on a line 110 parallel to the X direction. The RF coil 192-1 and the RF coil 108-1 partially overlap each other.

[0136] The center of the RF coil 192-2 is arranged on a line 130 parallel to the X direction. The RF coil 192-2 and the RF coil 128-1 partially overlap each other.

[0137] The center of the RF coil 192-3 is arranged on a line 112 parallel to the X direction. The RF coil 192-3 and the RF coil 108-11 partially overlap each other.

[0138] The center of the RF coil 192-4 is arranged on a line 132 parallel to the X direction. The RF coil 192-4 and the RF coil 128-11 partially overlap each other.

[0139] The RF coil array 100D may output the magnetic resonance signals received by the RF coils 192-1, 192-2, 192-3, and 192-4 via a cable or wireless communication via a signal processing circuit (not shown in FIG. 16) including a signal amplifier.

[0140] The RF coil array 100D eliminates the need for the back coil 24 of the tabletop 18. The number and arrangement of the RF coils 192 of the connection unit 190A are not limited to the example shown in FIG.

[0141] [Retightening mechanism for integrated RF coil array] The RF coil array of the integral structure may include a tightening mechanism for adjusting the amount of extension in the extension direction of at least one of the first fixing belt and the second fixing belt after being attached to the subject.

[0142] Fig. 17 is a diagram showing an RF coil array 100E, and is a cross-sectional view similar to Fig. 6. As shown in Fig. 17, the RF coil array 100E includes a first fixing belt 104B and a second fixing belt 124B. The RF coil array 100E also includes a square ring 200, a first tightening belt 202, a square ring 208, and a second tightening belt 210 as a tightening mechanism.

[0143] The square ring 200 is fixed to the surface of the connection unit 190 opposite to the surface that comes into contact with the subject 20. The square ring 200 may also be fixed to the surface of the first fixing belt 104B opposite to the surface that comes into contact with the subject 20.

[0144] One end 202R of the first tightening belt 202 is fixed to the surface of the first fixing belt 104B opposite to the surface that comes into contact with the subject 20. The position where the end 202R of the first tightening belt 202 is fixed is between the tip 104T of the first fixing belt 104B and the square ring 200.

[0145] The first tightening belt 202 has a first surface 204 of a hook-and-loop fastener provided on the other end 202T side. Also, the second fixing belt 124B has a second surface 206 of a hook-and-loop fastener provided on the surface opposite to the surface that comes into contact with the subject 20.

[0146] The square ring 208 is fixed to the surface of the connection unit 190 opposite to the surface that comes into contact with the subject 20. The square ring 200 may be fixed to the surface of the second fixing belt 124B opposite to the surface that comes into contact with the subject 20.

[0147] One end 210R of the second tightening belt 210 is fixed to the surface of the second fixing belt 124B opposite to the surface that comes into contact with the subject 20. The position where the end 210R of the second tightening belt 210 is fixed is between the tip 104T and the square ring 208 of the second fixing belt 124B.

[0148] The second tightening belt 210 has a first surface 212 of a hook-and-loop fastener provided on the other end 210T side. Also, a second surface 214 of a hook-and-loop fastener is provided on the surface of the second fixing belt 124B opposite to the surface that comes into contact with the subject 20.

[0149] To attach the RF coil array 100E to the subject 20, the first and second surfaces 204 and 206 of the hook-and-loop fastener, and the first and second surfaces 212 and 214 of the hook-and-loop fastener may be left unattached in the same manner as in the case of the RF coil array 100C.

[0150] Thereafter, to tighten the first fixing belt 104B of the RF coil array 100E attached to the subject 20, the user passes the first tightening belt 202 through the opening of the square ring 200 and folds it back, and pulls the end 202T of the first tightening belt 202 in a direction away from the square ring 200 (for example, in the Y direction), thereby connecting the first surface 204 of the hook-and-loop fastener to the second surface 206.

[0151] Furthermore, to tighten the second fastening belt 124B, the user passes the second tightening belt 210 through the opening of the square ring 208 and folds it back, then pulls the end 210T of the second tightening belt 210 in a direction away from the square ring 208, thereby connecting the first surface 212 of the hook-and-loop fastener to the second surface 214.

[0152] As a result, the RF coil array 100E is firmly fixed to the subject 20, and no displacement occurs between the RF coil array 100E and the subject 20.

[0153] 〔others〕 The technical scope of the present invention is not limited to the scope described in the above embodiments. The configurations and the like in each embodiment can be appropriately combined with each other within the scope that does not deviate from the spirit of the present invention. [Explanation of symbols]

[0154] 10...MRI device 10A...MRI device 12...Magnet 14...Examination space 16...Bed 18...Tabletop 18A…1st end 18B…Second end 20...Subject 22...Fixed belt 24...Rear coil 26...Epigastric coil 100...RF coil array 100A...RF coil array 100B...RF coil array 100C...RF coil array 100D...RF coil array 100E…RF coil array 102...First coil unit 102A...First coil unit 102B...First coil unit 102C...1st coil unit 102D...First coil unit 104...First fixed belt 104A...First fixed belt 104B...First fixed belt 104R…Proximal end 104T...tip 106...Side 1 108...RF coil 108-1...RF coil 108-2...RF coil 108-3...RF coil 108-4...RF coil 108-11...RF coil 108-12...RF coil 108-13...RF coil 108-14...RF coil 110…straight line 112…straight line 122...Second coil unit 122C...Second coil unit 122D...Second coil unit 124...Second fixing belt 124A...Second fixed belt 124B...Second fixed belt 124R…Proximal end 124T...tip 126…Second side 128...RF coil 128-1...RF coil 128-2...RF coil 128-3...RF coil 128-4...RF coil 128-11...RF coil 128-12...RF coil 128-13...RF coil 128-14...RF coil 130…straight line 132…straight line 140...Stretching section 142...Non-stretch section 150...Stopper band 150A...end 150B...end 160...Rail hook 160A...Rail hook 162...Rail hook 162A...Rail hook 164...Rail groove 166...Rail groove 170...Third fixed belt 172...Square ring 174...Fourth fixed belt 176...Square ring 180...Side 1 182…Second side 184...Side 1 186…Second side 190...Connection unit 190A...Connection unit 192...RF coil 192-1...RF coil 192-2...RF coil 192-3...RF coil 192-4...RF coil 200...Square ring 202...Belt 202R…end 202T…end 204...Side 1 206…Second side 208...Square ring 210...Belt 210R…end 210T...end 212...Side 1 214…Second side

Claims

1. An RF (Radio Frequency) coil array for a magnetic resonance imaging apparatus, a first coil unit including a first fixing belt made of a first stretch material stretchable in a first direction and a plurality of RF coils independently arranged on the first fixing belt; a second coil unit including a second fixing belt made of a second stretch material stretchable in the first direction and a plurality of RF coils independently arranged on the second fixing belt; Equipped with the plurality of RF coils of the first coil unit are arranged such that their centers are on a first straight line, and the RF coils that are closer to the tip of the first fixing belt have smaller diameters; the plurality of RF coils of the second coil unit have respective centers arranged on a second straight line, and the RF coils that are relatively closer to the tip of the second fixing belt have relatively smaller diameters; the first straight line and the second straight line are arranged to be shifted from each other in a second direction intersecting the first direction, the first coil unit is attached to the subject with a tip of the first fixing belt facing from one side to the other side in the first direction of the subject, the second coil unit is attached to the subject such that at least a portion of the second fixing belt is overlapped with the first coil unit and the tip of the second fixing belt faces from the other side to the one side in the first direction of the subject; RF coil array.

2. the first straight line and the second straight line are each parallel to the first direction; The RF coil array of claim 1 .

3. when the first coil unit and the second coil unit are attached to the subject, any one of the plurality of RF coils of the first coil unit and any one of the plurality of RF coils of the second coil unit at least partially overlap each other. The RF coil array of claim 1 .

4. When the first coil unit and the second coil unit are attached to the subject, the RF coil of the first coil unit having the largest diameter and the RF coil of the second coil unit having the smallest diameter at least partially overlap each other. The RF coil array of claim 1 .

5. At least one of the first fixing belt and the second fixing belt is partially made of a non-stretch material having a relatively smaller elongation rate in the first direction than the first stretch material and the second stretch material. The RF coil array of claim 1 .

6. a stopper structure that restricts the first fixing belt and the second fixing belt from extending beyond a certain level in the first direction; The RF coil array of claim 1 .

7. the stopper structure is made of a non-stretch material having a relatively smaller elongation rate in the first direction than the first stretch material and the second stretch material, and includes stopper bands provided on the first fixing belt and the second fixing belt, the stopper bands being pre-flexed in the first direction, 7. The RF coil array of claim 6.

8. the first coil unit and the second coil unit are connected at their ends opposite to the tips of the first fixing belt and the second fixing belt to a tabletop on which the subject is placed; The RF coil array of claim 1 .

9. The first fixing belt and the second fixing belt each have a rail hook at the opposite end, the rail hook being engageable with a rail groove provided in the top plate and movable along the rail groove.

9. The RF coil array of claim 8.

10. a tightening mechanism for adjusting an amount of extension of at least one of the first fixing belt and the second fixing belt in the first direction after the fixing belt is attached to the subject; 9. The RF coil array of claim 8.

11. the tightening mechanism includes an annular member connected to the top plate; At least one of the first fixing belt and the second fixing belt has an end opposite to the tip passed through the inside of the annular member and folded back and fixed. The RF coil array of claim 10.

12. The first coil unit and the second coil unit are each connected to a connection unit and integrally configured. The RF coil array of claim 1 .

13. the connection unit includes a plurality of RF coils; 13. The RF coil array of claim 12.

14. a tightening mechanism for adjusting an amount of extension of at least one of the first fixing belt and the second fixing belt in the first direction after the fixing belt is attached to the subject; 13. The RF coil array of claim 12.

15. The tightening mechanism includes a tightening belt connected to at least one of the first fixing belt and the second fixing belt, and an annular member, The tightening belt is passed through the inside of the annular member and folded back to be fixed.

15. The RF coil array of claim 14.

16. the plurality of RF coils of the first coil unit overlap with adjacent RF coils, the plurality of RF coils of the second coil unit overlap with adjacent RF coils, The RF coil array of claim 1 .

17. the first fixing belt and the second fixing belt are provided with a pair of hook-and-loop fasteners, the first surface and the second surface of which engage with each other at positions where the first coil unit and the second coil unit come into contact with each other when the first coil unit and the second coil unit are attached to the subject in a stacked manner; The RF coil array of claim 1 .

18. the first coil unit is attached to the subject by stretching the first fixing belt; the second coil unit is attached to the subject by stretching the second fixing belt; The RF coil array of claim 1 .

Images