JPH0634786B2 - Magnetic resonance imaging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention utilizes the magnetic resonance (MR) phenomenon to obtain morphological information such as a slice image of a subject and spectroscopy. The present invention relates to a magnetic resonance imaging apparatus for obtaining morphological information of

(Prior Art) A magnetic resonance phenomenon is a phenomenon in which an atomic nucleus having a non-zero spin and magnetic moment placed in a static magnetic field resonates and emits only an electromagnetic wave of a specific frequency. Angular frequency ω ₀ (ω ₀ = 2πν ₀ , ν ₀ ;
Resonance at Larmor frequency).

ω ₀ = γH ₀ where γ is the gyromagnetic ratio peculiar to the type of nucleus,
H ₀ is the static magnetic field strength.

The apparatus for performing biomedical diagnosis using the above principle performs signal processing on the electromagnetic wave of the same frequency as that induced after the above-mentioned resonance absorption, to thereby obtain nuclear density, longitudinal relaxation time T ₁ , lateral relaxation time T ₂ , Diagnostic information reflecting information such as flow and chemical shift, such as a slice image of a subject, is obtained non-invasively.

Further, the collection of diagnostic information by magnetic resonance is capable of exciting all the parts of the subject placed in a static magnetic field and collecting signals, but there are restrictions on the device configuration and clinical demands for imaging images. Therefore, in an actual device, excitation and signal acquisition of a specific site are performed.

In this case, the specific region to be imaged is generally a sliced region having a certain thickness,
Echo signals from this sliced part and magnetic resonance signals (MR signals) of FID signals are collected by executing a number of data encoding processes, and these data groups are subjected to image reconstruction processing by, for example, a two-dimensional Fourier transform method. Thus, the image of the specific slice region is generated.

In such a magnetic resonance imaging apparatus, any one of a superconducting magnet, a normal conducting magnet, and a permanent magnet or a combination thereof is used as the static magnetic field generating means. Then, a part of the static magnetic field region generated by the static magnetic field generation means can be a diagnostic possible region where the subject is placed and can be an imageable region. As a static magnetic field region of the diagnosable region, this is inevitable from the principle of the magnetic resonance phenomenon.
This is because it is a high-strength magnetic field of several thousand to tens of thousands of Gauss and the magnetic field uniformity needs to be several ppm.

For example, although the static magnetic field generating means, which is a main component of the gantry, is composed of a superconducting magnet, the superconducting wire and the refrigerant are contained in a container in which both openings of the double cylinder are closed. There is. Then, a high-intensity magnetic field having a magnetic field homogeneity of several ppm is generated at an axially intermediate position of the inner cylindrical space. The axial length of the inner cylindrical space is about 2 meters. That is, the subject
It is introduced along the axial direction into the inner cylindrical space having a length of 2 meters in the axial direction. The region of the subject at the axially intermediate position where the high-intensity magnetic field with the magnetic field homogeneity of several ppm in the inner cylindrical space is generated becomes the imageable region. In the inner cylindrical space, the gradient magnetic field coil unit,
A transmitting / receiving coil unit is arranged.

In the above example, a superconducting magnet is used as the static magnetic field generating means, but in other cases, the subject introduction space has a length in meters. This length is extremely long as compared with an X-ray CT scanner device that is often compared as a tomographic image visualization device. This is because, for example, the necessary magnetic field is obtained as described above.

(Problems to be Solved by the Invention) As described above, in the magnetic resonance imaging apparatus, since the subject introduction space has a length of a unit of meter, it is a dim one, and the subject is dim. Must be stationary during the scan. In this case, since the scan time of the magnetic resonance imaging apparatus extends from several minutes to several tens of minutes, the subject must wait for the scan to finish without knowing when the scan will end, which is very difficult for the subject. It is painful.

Therefore, an object of the present invention is to provide a magnetic resonance imaging apparatus capable of giving a subject a psychological sense of security even during scanning.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a structure in which the following means are provided in order to solve the above problems and achieve the object.

That is, the present invention is capable of generating a static magnetic field, a gradient magnetic field, a transmission signal in a space in which a subject is placed in a subject introducing space formed therein, and magnetic resonance induced from the subject. In a magnetic resonance imaging apparatus capable of collecting signals, which is to be introduced into the space while placing the subject, a top plate having a slide groove formed on a side edge portion in the longitudinal direction thereof, A mirror arm whose one end is slidable in the longitudinal direction of the top plate in the slide groove, and the other end of the mirror arm whose mirror surface is the opening on the side opposite to the subject introduction side of the opening of the space. A mirror provided so as to be tiltable so as to face the direction of the part and a remaining scan time at the time of scanning are displayed, and the display surface faces the inside of the space, and the anti-inspection of the opening of the space is performed. Leading And a time indicator arranged in the opening on the entrance side.

(Operation) According to the above configuration, by appropriately adjusting the mirror arm and the mirror, the subject placed on the top plate can see the display surface of the time display through the mirror. Therefore, by displaying the remaining scan time on the time display, the subject can recognize the remaining scan time during the scan, and can be aware of the purpose of ending the scan, so that the subject feels safe. Can be given.

Further, since the mirror arm is provided in the slide groove formed on the side edge portion in the longitudinal direction of the top plate, the space for mounting the subject on the top plate is not narrowed by the installation of the mirror arm. . Similarly, the range of motion of the subject on the tabletop and the range of motion of the tabletop in the subject introduction space are not restricted.

Embodiment An embodiment of the magnetic resonance imaging apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a top plate for placing a subject, which is an essential part of this embodiment. The top plate 10 is provided on a bed (not shown), and can be moved back and forth in the direction of the arrow shown while the subject (not shown) is placed on the top plate 10. In the forward / backward direction, a subject introduction space of a gantry (not shown) of a magnetic resonance imaging apparatus is opened.

Further, a slide groove 11 is formed on a side edge portion in the longitudinal direction of the top plate 10, and one end of a mirror arm 12 is attached to the slide groove 11 so as to be slidable in a direction 11a in the drawing. At the other end of the mirror arm 12, a mirror 13 such as a plane mirror, a concave mirror, or a convex mirror is provided so as to be tiltable in the direction 13a shown in the figure.

Further, as shown in FIG. 2 which is a cross-sectional view of the magnetic resonance imaging apparatus of the present embodiment, the top plate 10 is provided on the bed 20, and the pedestal 30 has a light emitting diode or the like in the anti-subject introduction opening. The time display 40 made up of is arranged with its display surface facing the inside of the subject introducing space 30A.

Here, the time information displayed by the time display 40 indicates the scan remaining time at the time of scanning, and this is drive-controlled by a scan controller (not shown).

With the above configuration, as shown in FIG. 2, the subject P is placed on the top plate 10 without inserting the top plate 10 into the subject introducing space 30A. Then, the mirror 13 is positioned near the head of the subject P. Then, by adjusting the tilt of the mirror 13, the subject P can view the display surface of the time display 40 through the mirror 13 while keeping his or her back.

This completes the setting, and as shown in FIG.
The top plate 10 is inserted into the subject introduction space 30A, and scanning is started. In this case, the display surface of the time display 40 and the mirror 1
Although the distance in the horizontal direction is different from that of the surface of No. 3, the facing relationship is constant, so that the subject P is in the mirror 13 during this scan.
Since the display surface of the time display 40 can be seen through the, the remaining time of the scan can be recognized, and the aim of the end of the scan can be recognized, it is possible to give the subject a psychological sense of security. In this case, the mirror arm 12 is the top plate 1.
Since it is provided in the slide groove 11 formed on the side edge portion in the longitudinal direction of 0, the space for mounting the subject on the top plate 10 is not narrowed by the installation of the mirror arm 12. Similarly, the range of motion of the subject on the top plate 10 (the region in which the subject can make a motion such as turning over during scanning) and the range of motion of the top plate 10 in the subject introducing space 30A (during scanning). In the above, there is no restriction on the area in which the top plate 10 can move back and forth. Therefore, the scan operation is not hindered by providing the mirror arm 12 and the like.

In addition, by sliding the mirror arm 12, the mirror 1
The position of 3 on the top plate 10 can be changed. This is because the position of the subject P on the top plate 10, especially the position of the eyes, changes depending on the scan region, and the position of the mirror 13 can be changed accordingly.

Further, the mirror 13 can be tilted with respect to the mirror arm 12 so as to correspond to the head angle, that is, the line-of-sight direction. Further, the time indicator 40 may be inverted on the floor using a stand or the like without being attached to the gantry 30. Further, a lens or the like may be arranged on the display surface of the time display 40 so that a magnified image is projected on the mirror 13.

In addition, various modifications can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, the present invention has a static magnetic field, a gradient magnetic field, and a static magnetic field in a space in which a subject is placed in a subject introducing space formed therein.
In a magnetic resonance imaging device capable of generating a transmission signal and collecting a magnetic resonance signal induced from the subject, wherein the subject is introduced into the space while mounting the subject, A top plate having a slide groove formed on the longitudinal side edge, a mirror arm having one end slidable in the slide groove in the longitudinal direction of the top plate, and a mirror surface on the other end of the mirror arm. Is a mirror provided so as to be tiltable so as to face the direction of the opening on the side opposite to the subject introduction side among the openings of the space, and the remaining scanning time during scanning, and its display surface And a time indicator which is arranged in the opening on the side opposite to the subject introduction side among the openings of the space so as to face the space.

According to the present invention having the above-described configuration, by appropriately adjusting the mirror arm and the mirror, the subject placed on the top plate can see the display surface of the time display through the mirror. Therefore, by displaying the remaining scan time on the time display, the subject can recognize the remaining scan time during the scan, and can be aware of the purpose of ending the scan, so that the subject feels safe. Can be given.

Further, since the mirror arm is provided in the slide groove formed on the side edge portion in the longitudinal direction of the top plate, the space for mounting the subject on the top plate is not narrowed by the installation of the mirror arm. . Similarly, the range of motion of the subject on the top plate and the range of motion of the top plate in the subject introduction space are not restricted. Therefore, the scan operation is not hindered by providing the mirror arm and the like.

Therefore, according to the present invention, it is possible to provide a magnetic resonance imaging apparatus capable of giving a subject a psychological sense of security at the time of scanning without hindering the scanning operation.

[Brief description of drawings]

FIG. 1 is a perspective view showing a top plate for placing a subject, which is an essential part of one embodiment of the present invention, and FIGS. 2 and 3 are sectional views of a magnetic resonance imaging apparatus of the same embodiment. . 10 ... Top plate, 11 ... Slide groove, 12 ... Mirror arm, 13 ... Mirror, 20 ... Bed, 30 ... Stand, 30
A: Subject introduction space, 40: Time display.

Claims (1)

[Claims] 1. A static magnetic field, a gradient magnetic field, and a transmission signal can be generated in a space in which a subject is placed in a subject introducing space formed therein, and a magnetic resonance signal induced from the subject. In a magnetic resonance imaging apparatus capable of collecting the, which is to be introduced into the space while placing the subject, a top plate having a slide groove formed in the longitudinal side edge thereof, A mirror arm having one end slidable in the longitudinal direction of the top plate in the slide groove, and the other end of the mirror arm whose mirror surface is the opening of the space opposite to the subject introduction side. A mirror provided so as to be tiltable so as to face the direction, and a scan remaining time at the time of scanning, the display surface facing the inside of the space, and the anti-examinee of the opening of the space. Open on the introduction side A magnetic resonance imaging apparatus comprising: a time indicator arranged at a mouth portion;