JPH0349737A - Magnetic resonance imaging device - Google Patents

Abstract

PURPOSE:To obtain a magnetic resonance imaging device while reducing the burden of a reagent since it is not necessary to force an unnatural posture to the reagent by arranging a shield member near the side of one coil out of surface detecting coils so as to be freely attached and detached. CONSTITUTION:A shield member 2 is arranged on a bed T in a reversely U-shaped state not to get contact with a patient P. A surface detecting coil 1 is arranged on the shield member 2 and a hand P1, which is the purpose of photographing, is put on the surface detecting coil 1 and fixed to the shield member 2 by a band 3 so that the hand P1 and surface detecting coil 1 can not be moved. Magnetic resonance signals from parts, which exist in a sensitive area S2, to be moved by heartbeats or breathing, etc., are shielded by a shield net 2b of the shield member 2 and the magnetic resonance signal of the hand P1 existing in a sensitive area S1 is detected by the surface detecting coil 1. Then, the part as the purpose of photographing is imaged. Thus, the magnetic resonance imaging device, for which the burden of the reagent P is reduced, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic resonance imaging apparatus that uses a surface detection coil to obtain a magnetic resonance image of a subject (usually a patient).

(Prior art) A surface detection coil is placed near the imaging target area of a subject placed in a static magnetic field, and a high frequency magnetic field is applied in a direction perpendicular to the static magnetic field to cause a magnetic resonance phenomenon in the imaging target area. 2. Description of the Related Art A magnetic resonance imaging apparatus is known in which a gradient magnetic field is superimposed on a static magnetic field, and magnetic resonance signals from the imaging target region are detected and imaged.

FIG. 3 shows a state in which a hand P1 is photographed using a conventional magnetic resonance imaging apparatus.

The surface detection coil 1 has sensitivity regions 81 and 32 on both sides of the coil in which magnetic resonance signals can be detected.

Hand P1. When trying to obtain a magnetic resonance image of an elbow or the like, for example, extend hand P1 above the head so as not to detect magnetic resonance signals from other body moving parts other than hand P1, and hold it for a long time of about 30 minutes. The photo is taken in a horizontal position.

(Problem to be solved by the invention) When detecting a hand, etc. with a surface detection coil as described above,
There was a problem in that the patient was forced into an unreasonable position and suffered for a long period of time.

Therefore, the present invention has been made in view of the above circumstances.
The object of the present invention is to provide a magnetic resonance imaging apparatus that reduces the burden on a subject.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a surface detection coil having sensitivity regions on both sides, which is arranged in the vicinity of the imaging target region of the subject. The present invention is characterized in that a magnetic resonance imaging apparatus that obtains a magnetic resonance image of a region to be imaged by detecting magnetic resonance signals from the magnetic resonance imaging apparatus is characterized in that a shield member is removably disposed near one side of the surface detection coil.

(for production) The operation of the apparatus having the above configuration will be explained below.

If there is body movement of the subject within one sensitivity region of this surface detection coil, a good magnetic resonance image cannot be obtained due to this body movement. In this case, if a shield member is placed near the surface detection coil on the side where the body moves, magnetic resonance signals from the side where the body moves can be prevented from being detected.

(Example) Examples of the present invention will be described in detail below.

FIG. 1 is an external perspective view showing the photographing state of an apparatus according to an embodiment of the present invention, and FIG. 2 is a view from below in the photographing state shown in FIG.

This device includes a shield member 2 placed on the subject P,
It has a surface detection coil 1 disposed on the shield member 2, and a band 3 for disposing the hand P1 on the surface detection coil 1 and fixing the hand P1.

The shield member 2 has a support portion 2a made of resin on the front side.
and a shield net 2b made of mesh-like copper fixed to the back side of the support portion 2a, and the overall cross section is U-shaped. Moreover, the height of this shield member 2 is
When placed on the bed T in an inverted U shape, the height is such that there is a gap between it and the patient P. Since the magnetic resonance signal has a high frequency of several MHz or more, it has a sufficient shielding effect even if the shield net 2b is not grounded, so the shield member 2 is simply placed on the bed T.

The band 3 can be detachably fixed to the shield member 2 by detachable fasteners provided at both ends.

The operation of this device will be explained.

First, the patient P is placed on the bed T in a supine position. Next, the shield member 2 is placed from above so as not to come into contact with this patient P.
Place it on the bed T in an inverted U-shape. Then, a surface detection coil 1 is placed on this shield member 2, and a hand P1, which is a target region to be imaged, is placed on top of this surface detection coil 1. Hand P1゜Fix the surface detection coil 1 to the shield member 2 with the band 3 so that it does not move. Magnetic resonance signals from parts of the body that move due to heartbeat, breathing, etc. within the sensitivity region s2 are shielded by the shield net 2b of the shield member 2, and magnetic resonance signals from the hand P1 located in the sensitivity region S1 are shielded by the surface detection coil 1. This detection target region is imaged.

According to the device configured as described above, since the shield member 2 is disposed near the surface detection coil 1 on the body movement side, detection of magnetic resonance signals from the body movement region can be prevented.

Since the shield member 2 can be placed without contacting the patient P, body movements are not directly transmitted, and therefore body movement artifacts can be prevented from occurring on magnetic resonance images.

Although one embodiment has been described above, the present invention is not limited to this, and various modifications can be made without changing the gist thereof.

[Effects of the Invention] According to the present invention described in detail above, since a shield member that can be detachably placed near the surface detection coil is provided, there is no need to force the subject into an unreasonable posture, thereby reducing the burden on the subject. It is possible to provide a magnetic resonance imaging apparatus with reduced costs.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing a photographing state using an apparatus according to an embodiment of the present invention, FIG. 2 is a view from below in the photographing state shown in FIG. 1, and FIG. 3 is a photographing state using a conventional device. It is an external perspective view showing a state. 1...Surface detection coil, 2...Shield member, P.
...Subject, Pl...Target site for imaging, 81°S2...Sensitivity region.

Claims (1)

[Claims] In a magnetic resonance imaging apparatus, a surface detection coil having sensitivity regions on both sides is placed near the imaging target area of the subject, and magnetic resonance signals from the imaging target area are detected to obtain a magnetic resonance image of the imaging target area. A magnetic resonance imaging apparatus characterized in that a shield member is removably disposed near one side of the surface detection coil.