JPH01242056A - Magnetic resonance imaging apparatus - Google Patents

Abstract

PURPOSE:To perform the MR imaging of an examinee in a lying to standing state, by mounting the top plate of a bed tiltable in such a state that the examinee is placed on the top plate. CONSTITUTION:A pair of permanent magnets 1, 2 for forming magnetostatic fields are arranged on a base table 9 in opposed relationship. A support 4 is formed to the base table 9 so as to extend in a vertical direction and a support arm is mounted to said support 4. The open end of a support arm 5 is positioned between the permanent magnets 1, 2 to support the top plate 3 of a bed at this part. The top plate 3 of the bed is moved in a tiltable manner in such a state that the examinee is placed on said top plate 3 in MR imaging.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to magnetic resonance (MR)
The present invention relates to a magnetic resonance imaging apparatus (hereinafter referred to as an MRI apparatus) that obtains morphological information such as slice images of a subject (living body) and functional information such as spectroscopy using the MRI (onance) phenomenon.

(Prior art) Magnetic resonance is a phenomenon in which atomic nuclei with non-zero spin and magnetic moment placed in a static magnetic field resonantly absorb and emit only electromagnetic waves of a specific frequency. It resonates at the angular frequency ω0 (ωo = 2π s 0. s 0 ; Larmor frequency) shown in the formula.

ω0=γHO Here, γ is the gyromagnetic ratio specific to the type of atomic nucleus,
Further, Ha is the static magnetic field strength.

An apparatus that performs biological diagnosis using the above-mentioned principle processes the electromagnetic waves of the same frequency as the above induced after the above-mentioned resonance absorption, and calculates the nuclear density, longitudinal relaxation time T1. Transverse relaxation time T2. Diagnostic information that reflects information such as flow and chemical shift, such as slice images of a subject, can be obtained non-invasively.

FIG. 6 shows the main parts of a conventional MRI apparatus.

21 is a magnet device, and this magnet device 21 has a
2 is provided. 23 is a bed device, and arrow 25
move up and down in the direction. This bed apparatus 23 is provided with a bed top plate 26 on which a subject (not shown) is placed. The bed top plate 26 can be opened in the direction of the arrow 24, and the subject on the bed large plate 26 can be opened in the direction of the arrow 24.
placed within. Inside the magnet device 21, a static magnetic field generation coil, a gradient Ia lift field generation coil, an RF transmission/reception coil, etc. are arranged. The MR imaging of the subject is based on this magnetic 5
This is done within the device 21.

(Problems to be Solved by the Invention) Diagnosis using MR images mainly involves examination of the head and vertebrae, but with the reduction in scan time, the demand for decoy images of internal organs is increasing.

However, in the conventional apparatus, the movement of the bed top is limited to the direction of the subject's body axis (direction of arrow 24), and imaging can only be performed with the subject in a recumbent state.
It was not possible to fully meet the request for the original form of internal organs.

Therefore, the present invention aims to eliminate the above-mentioned drawbacks, and its purpose is to perform MR1 with the subject lying or standing.
The object of the present invention is to provide an MRI apparatus capable of performing a.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the MR system according to the present invention includes a bed top that can be raised and lowered with a subject placed thereon. .

(Function) According to the above-mentioned bed top plate, it is possible to raise and lower the bed with a subject placed thereon, and therefore, in an MRI apparatus having this bed large plate, the Ml. Shadows become possible.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

FIG. 1 shows the main parts of an MRI apparatus according to the present invention.

Reference numeral 1.2 denotes a pair of permanent magnets for forming a static magnetic field, and the permanent magnets 1 and 2 are placed facing each other on the base 9 with a predetermined distance therebetween. A gradient magnetic field coil (not shown) formed in a planar shape is attached to the inner wall surfaces of the permanent magnets 1 and 2. A column 4 is formed extending vertically from the base 9, and a top support arm 5 is attached to this column 4.

The top support arm 5 is made of, for example, FRP (fiber reinforced plastic) and is formed into a substantially U-shape.

The top support arm 5 is rotatable about a fulcrum 8 in the directions of arrows 6 and 7. The rotation of the top support arm 5 is driven by an appropriate means including a motor, a speed change gear, etc. The open end of the top support arm 5 is located between the permanent magnets 1 and 2, and the bed top 3 is supported at this portion. Is this bed large plate 3 an MRIf? i Raise and fall with the subject placed in the shadow. As shown in FIG. 2, a bed device 17 is arranged near the device shown in FIG. 1 and is movable up and down in the direction of the arrow 16. A pair of eternity! The subject P is moved in and out of the space between the a stones 1 and 2 (llfi shadow area) via this bed device 17. That is, the bed top 3 is provided with rollers 13, 14, 15, and can move between the bed support arm 5 and the bed device 17, which are in a horizontal state, in the directions of arrows 19, 20. ing. In order to prevent the large bed plate 3 from falling off, a stopper is provided at the open end of the top plate support arm 5.

FIG. 3 shows a cross section taken along line A-A' in FIG.

As shown in the figure, the open end of the top support arm 5 is bent to have a substantially U-shaped cross section, and the rollers 13, 14, and 15 of the bed top 3 are engaged with this portion. ing.

Although not shown, a surface coil or a saddle-type coil may be used as the RF transmitting/receiving coil.

Next, the operation of the above configuration will be explained.

In FIG. 2, a subject P is placed on the bed top 3 located on the bed 17. Here, the subject P is fixed to the bed top 3 by appropriate means 18 such as a belt. At this time, the top support arm 5 is in a horizontal state. In this state, the bed top 3 is moved in the direction of arrow 19. After the large bed board 3 has completely moved onto the top support arm 5, the stopper 10 is raised as shown by 10' to fix the bed top 3.

Next, as shown in FIGS. 4 and 5, the top plate support arm 5
The bed top is raised and lowered by the rotation, and is fixed at any angular position. By executing a predetermined pulse sequence on the MR1a shadow, an MR multiplied signal of the subject P is collected, and an MR image is formed based on this. The details of the pulse sequence and MR image formation are the same as those of the conventional apparatus, so their explanation will be omitted.

In this way, in the present embodiment apparatus, the bed top plate 3 can be raised and lowered with the subject P placed thereon, so that the subject P can be moved up and down.
MRfi imaging is possible in the lying or standing position. Therefore, it is extremely effective in enlarging the internal image of the subject P.

Furthermore, since the direction of gravity on the affected area can be varied, there is also the advantage that changes in the affected area due to compression can be confirmed in MR imaging.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made.

For example, in the above embodiment, a static magnetic field is formed by a pair of permanent magnets 1 and 2, but the present invention can also be applied to a static magnetic field formed by a superconducting or normal conducting magnet.

Effects of the Invention J As described in detail above, according to the present invention, it is possible to provide an MRI apparatus that can perform MR expansion with the subject lying or standing.

[Brief explanation of the drawing]

FIG. 1 is a diagonal diagram showing an embodiment of the MRIH apparatus according to the present invention, FIG. 2 is an explanatory diagram of the relationship between the bed support arm and the bed device in the device of this embodiment, and FIG. 3 is the A of FIG. -A' sectional view, FIGS. 4 and 5 are illustrations of raising and lowering the bed top, and FIG. 6 is a τ1 scale diagram of the conventional device. 1.2... Permanent magnet, 3... Bed top plate, 5... Top plate support arm, P... Subject.

Claims (1)

[Claims] What is claimed is: 1. A magnetic resonance imaging apparatus for obtaining magnetic resonance information of a subject placed in a static magnetic field, comprising a bed top that can be raised and lowered with the subject placed thereon.