JPH1119063A - Rf coil for magnetic resonance diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep an RF coil clean without sterilizing it. SOLUTION: To a flexible base plate 1, a pair of current paths 2A, 2B for loop circuit, eight pieces of current paths 3 for loop connecting circuit, and connectors 7a, 7b, 8a, 8b to connect both ends of the current paths 2A, 2B for loop circuit, are attached, and at the same time, the internal surface of the flexible base plate 1, which is bent into a cylindrical form in order to wind it around a body to be inspected, is covered with a cover 9. The attaching of the cover 9 to the flexible base plate 1 is performed in such a manner that Velcro fasteners which are fixed on the cover 9 are combined with Velcro fasteners M1, M2 on the flexible base plate 1 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic resonance diagnostic apparatus (hereinafter, referred to as an MRI apparatus) for performing imaging and spectroscopy measurement utilizing a nuclear magnetic resonance phenomenon (MR phenomenon). The present invention relates to an RF coil that receives a signal (NMR signal), and more particularly to an RF coil that is used by being wound around a portion to be inspected of a subject, that is, a so-called wrap-around RF coil.

[0002]

2. Description of the Related Art A wrap-around type RF coil is widely used in recent years because it is wound around an imaging part such as the abdomen of a subject, so that it can be in close contact with the subject, and has a high sensitivity and a high S / N ratio. It has become to. As shown in FIG. 7, the wrap-around type RF coil 51 has a coil pattern, for example, formed on a flat flexible substrate 52.
A circular loop circuit 53 and an 8-shaped loop circuit 54 are formed, and coupling members 55 and 56 such as magic fasteners are provided at one end of the flexible substrate. At the time of imaging, as shown in FIG.
Is curved and wound around an imaging site such as the abdomen of the subject, and the magic fasteners 55 and 56 are connected to each other to form a cylindrical (cylindrical) coil, and the circular loop 53 transmits the NMR signal in the vertical direction. Receiving, 8-shaped loop circuit 5
4 receives the NMR signal in a horizontal orientation.

[0003]

In particular, a wrap-around type RF coil is wound around a subject (usually a human body) at the time of examination and comes into direct contact with the body surface. Alternatively, at least the inner surface that comes into contact with the body surface when wrapped around the subject before the examination needs to be cleaned by disinfecting with a disinfectant such as alcohol. In the non-contact type RF coil in which the subject is inserted with the fixed shape such as the cylindrical shape, since the inner surface of the cylindrical RF coil facing the subject is covered with FRP, disinfection work is easy, Does not damage the RF coil. However, the wrap-around type RF coil is not flexible because of its property of being directly wound around a subject.
It cannot be protected by covering with P. Therefore, when disinfecting, it is necessary to take great care and time so as not to damage the RF coil, and there is a problem that the RF coil may be damaged or broken depending on a local load during disinfection work or a disinfectant used. .

[0004] In view of the above, the present invention provides an MR coil that can always be kept clean without disinfecting the RF coil itself.
It is an object to provide an RF coil for an I device.

[0005]

In order to achieve the above object, an RF coil for a magnetic resonance diagnostic apparatus according to the present invention uses a connecting member for removably connecting both ends of a flexible substrate having a predetermined coil pattern. It is characterized in that a replaceable cover is provided on a surface which is at least inside when connected and curved into a cylindrical shape (tubular shape).

According to such a configuration, since the flexible substrate having the predetermined coil pattern has flexibility, the flexible substrate is bent into a cylindrical shape (cylindrical shape) in order to be wound around the subject, or is formed into a planar shape. Can be expanded to. Further, a cover is provided on a surface which is inside when the flexible substrate is curved into a cylindrical shape (tubular shape), that is, an inner surface which comes into contact with the surface of the subject when the flexible substrate is wound around the subject. It is supposed to be replaceable. Therefore, after the inspection,
Alternatively, by removing the cover from the RF coil before the inspection and replacing it with a clean new cover, the RF coil is always clean, and the cleaning operation is simple and quick since only the cover is replaced. Also, the RF coil is not damaged or broken.

[0007] As a material of the cover, a material which can be disinfected and washed and is excellent in waterproofness, for example, a medical fabric such as a nonwoven fabric used for surgical gowns, nurse lab coats and the like is suitable. The nonwoven fabric is excellent in liquid repellency, oil repellency, and durability against blood, chemicals, and the like, and can be cleaned by washing with high-temperature water and disinfection / sterilization with high-temperature steam. The cover may be attached to the RF coil with a magic fastener, or the cover may be covered like a pillow cover.

[0008]

Next, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B are views showing a state in which a connecting member (connector) of an RF coil of an embodiment is released and developed in a planar shape, wherein FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. . FIG. 2 is a sectional view showing the layer structure of the RF coil of the embodiment. As shown in FIG. 1, the RF coil C includes a rectangular sheet-shaped flexible board 1, and in this embodiment, loop circuit electric circuits 2A and 2B and eight loops constituting a birdcage RF coil are provided on the board 1. An RF coil pattern of the electric circuit 3 for the coupling circuit is formed. The loop circuit electric circuits 2A and 2B are provided at both peripheral ends of a surface which is inside when the flexible substrate 1 is curved into a cylindrical shape (tubular shape), that is, the flexible substrate 1
Are electrically conductive paths extending along opposing long sides of the loop circuit.
A, a conductive path provided to connect between A and 2B. Further, in the embodiment, in order to obtain a low-pass filter type birdcage RF coil, each loop-coupling circuit electric path 3 is a conductive path through which a capacitor element 4 for resonance or the like is interposed.

On the other hand, as shown in FIG. 2, the flexible substrate 1 is provided with a polycarbonate layer 1b having a thickness of about 1 mm on the back surface of a polyimide layer 1a having a thickness of about 70 μm.
A buffer material layer 1c is provided on the surface. The loop circuit electric paths 2A and 2B, the loop connection circuit electric path 3 and the capacitor element 4 formed by the printed wiring technique are provided on the polyimide layer 1a. Polycarbonate layer 1b
Is a so-called backing material (shape-stabilizing material) for giving the flexible substrate 1 the necessary stiffness because the polyimide layer 1a alone is too weak. The buffer material layer 1c is for protecting each electric circuit and the capacitor element provided in the polyimide layer 1a. Also, plug-type connectors 7a, 7b and plug-type connectors 7a, 7b are provided on both short sides (two opposing sides which abut each other when curved and cylindrical) of the flexible substrate 1. And socket type connectors 8a and 8b that can be connected and disconnected. The connectors 7a and 7b have connection pins at their ends, the connectors 8a and 8b have sockets for receiving the connection pins, and the connection pins of the connectors 7a and 7b are inserted into the sockets of the connectors 8a and 8b, respectively. It is configured to be in an electrically connected state. On the other hand, the left ends of the loop circuit electric circuits 2A and 2B are connected to the connectors 7a and 7b, respectively, and the right ends are connected to the connectors 8a and 8b, respectively.

Therefore, when the flexible substrate 1 is bent into a cylindrical shape and the connectors 7a and 8a are connected, both ends of the loop circuit electric circuit 2A are short-circuited, so that the loop circuit electric circuit 2A forms a loop circuit. When the connectors 7b and 8b are connected, both ends of the loop circuit electric circuit 2B are short-circuited, so that the loop circuit electric circuit 2B forms a loop circuit. In addition, a cable k for connection between the RF coil of the embodiment and the control console is provided.
1, k2 are also provided as appropriate. Further, as a cover holding means for detachably attaching a cover to an inner surface when the flexible substrate 1 is curved into a cylindrical shape in order to wind the flexible substrate 1 around the subject, that is, a surface that comes into contact with the subject when mounted on the subject. The magic fasteners M1 and M2 are provided at a peripheral end portion which is outside when curved.

FIG. 3 shows a rectangular cover 9 made of a non-woven fabric or the like detachably attached to the flexible substrate 1 of the RF coil C. The magic fasteners M1 and M2 are provided at both ends.
The magic fasteners M3 and M4 that are connected to are fixed by sticking or the like. In order to attach the cover 9 to the flexible substrate 1 of the RF coil C, one of the magic fasteners M3 of the cover 9 is connected to the magic fastener M1 fixed to the flexible substrate 1 as shown in FIG. By winding the cover 9 around the inner surface in the direction indicated by the arrow in the figure and connecting the other magic fastener M4 on the cover 9 side to the fastener M2 on the flexible substrate 1 side,
As shown in FIG. 2B, the cover 9 is attached to the flexible substrate 1.
Can be attached to

Thus, the RF with the cover attached
In order to attach the coil C to a test site of the subject, for example, the abdomen, first, as shown in FIG. 5A, the connection between the connector 7a and the connector 8a and the connection between the connector 7b and the connector 8b are released. Then, the RF coil is placed on the couchtop 10 on which the subject P is placed, with the flexible substrate 1 with the cover attached being spread. Next, as shown in FIG. 5B, the subject P is placed on the top plate 10 so that the abdomen is located on the flexible substrate 1. Next, FIG.
As shown in (2), when the connection between the connector 7a and the connector 8a and the connection between the connector 7b and the connector 8b are performed by winding the abdomen of the subject P on the flexible substrate 1 to which the cover is attached, the mounting of the RF coil is completed. I do. Thus, the RF coil on which the subject P has been mounted is the connector 7a and the connector 8a, and the connector 7b and the connector 8b
However, each of them is in a connected state, and the flexible substrate 1 is a cylindrical body. Since this cylindrical body has flexibility and can be closely attached to the subject P, it can receive NMR signals with high sensitivity.

When the connector 7a and the connector 8a and the connector 7b and the connector 8b are connected to each other, the two loop circuit electric circuits 2 circling along the circumferential direction of the cylindrical body.
A, 2B, and eight low-pass filter birdcage R
Since the F coil is formed in such a manner that the abdomen, which is the imaging site, is on the inside, the birdcage-type RF coil can receive an NMR signal from the abdomen of the subject P from all around the abdomen. After the inspection, to replace the cover, the connectors 7a, 8a, and 7b
And the connector 8b are disconnected and removed from the subject P, and the magic fasteners M1 and M3, the magic fastener M
The cover 9 is removed from the flexible substrate 1 by releasing the connection between 2 and M4. Next, by coupling the magic fasteners M3 and M4 of the new cover to the magic fasteners M1 and M2 of the flexible substrate 1, the new cover is mounted on the flexible substrate 1 and the RF coil C is kept clean. The new cover has been disinfected and sterilized by washing or the like.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) Although the coil pattern of the above-described embodiment is a low-pass filter birdcage RF coil, a high-pass filter birdcage RF coil and a bandpass birdcage RF coil are formed. It may be a coil pattern. In the embodiment,
Although the number of loop-coupling circuit electric circuits connecting the pair of opposing loop-circuit electric circuits is eight, the number of loop-coupling circuit electric circuits is not limited to eight. (2) In the RF coil of the above embodiment, the coil pattern is formed on the flexible substrate by the printed wiring technique, but the coil pattern may be formed by attaching a foil plate to the flexible substrate.

(3) The RF coil of the above embodiment is a birdcage type RF coil.
As illustrated, an RF coil including a circular loop circuit and an 8-shaped loop circuit may be used. In this case, each of the circular loop circuit and the 8-shaped loop circuit forms a closed circuit, and electrical connection is not required unlike a birdcage type RF coil. Therefore, as a detachable connecting member (connector), it is only necessary to connect both ends of the flexible substrate, and it is possible to use a magic fastener, so that connecting and releasing can be easily performed. (4) Although the RF coil of the above embodiment is mounted on the abdomen of the subject, the RF coil of the present invention can be applied to other imaging sites such as the hand, foot, knee, hip, and head of the subject. Can also be applied.

(5) In the above embodiment, the cover covers only the inner surface of the RF coil that comes into contact with the subject when the cover is attached to the subject. However, as shown in FIG. The inside and outside surfaces are covered with magic fasteners M5 and M6 at both ends, and the cover 9 is wound around the flexible substrate 1 as shown in FIG. 6 (b) to form the magic fasteners M5 and M6. May be combined to cover the entire inner and outer surfaces of the flexible substrate 1. Also,
The cover may be formed in a tubular shape like a pillow cover, and the flexible substrate 1 may be inserted into the tubular cover. In this case, there is no need to provide a cover holding means such as a magic fastener on the flexible substrate,
The configuration of the RF coil is simplified. (6) In the above embodiment, the cover is reused after cleaning, but the cover may be disposable.

[0017]

According to the RF coil for a magnetic resonance diagnostic apparatus of the present invention, the RF coil can always be kept clean simply by replacing the cover, and the cleaning operation can be performed easily and in a short time. obtain. Further, since the RF coil itself does not need to be disinfected as in the prior art, it is not damaged or broken.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a state in which a connector of an RF coil of an embodiment is released and developed in a planar shape.

FIG. 2 is a cross-sectional view illustrating a layer structure of an RF coil according to an embodiment.

FIG. 3 is a perspective view showing an embodiment of a cover attached to an RF coil.

FIG. 4 is a diagram showing a procedure for attaching a cover to an RF coil.

FIG. 5 is a perspective view showing a procedure of mounting (setting) the RF coil with cover of the embodiment to a subject.

FIG. 6A is a perspective view showing a cover according to another embodiment, and FIG. 6B is a view showing a state in which the cover is attached to an RF coil.

FIG. 7 is a plan view showing a state where a conventional RF coil is not mounted.

FIG. 8 is a perspective view showing a state when a conventional RF coil is mounted.

[Explanation of symbols]

1: Flexible board 2A, 2B: Loop circuit path 3: Loop connection circuit path 4: Capacitor element 5, 6: Short side 7a, 7b:
Plug type connector 8a, 8b: Socket type connector
9: Cover M1 to M6: Magic fastener

Claims (1)

[Claims] 1. An RF coil for a magnetic resonance diagnostic apparatus, comprising: a flexible board having a predetermined coil pattern; and a connecting member for removably connecting an end of the flexible board when the flexible board is curved into a cylindrical shape. An RF coil for a magnetic resonance diagnostic apparatus, wherein a replaceable cover is provided on at least an inner surface when both ends are connected to each other by the connection member and when the connection member is curved into a cylindrical shape.