JPS63264051A - Nuclear magnetic resonance diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a medical nuclear magnetic resonance diagnostic apparatus, and relates to the structure of a receiving coil that catches nuclear magnetic resonance signals obtained from a subject. .

(q Conventional technologyNuclear 4a Various types of receiving coils are used for nuclear magnetic resonance (NMR) signals in air resonance diagnostic equipment depending on the diagnostic image to be obtained.These receiving coils are There are two types of coils: a coil that receives 4g signals from a wide range of subject areas with good uniformity, and a so-called surface coil that receives only signals from a narrow subject area with high sensitivity. We can separate.

Is the coil with a narrow sensitivity range the HU surface coil? It is used in a dense layer over the area of the subject to be diagnosed, and can efficiently receive signals from that area, making it possible to obtain diagnostic images with a high S/N ratio and high resolution. On the other hand, the sensitivity region where the S/N ratio is excellent is limited to a narrow area, so if the position where the surface coil is brought into close contact with the subject area to be diagnosed is out of sync with the subject area to be diagnosed, There is a problem that the S/N ratio of the area decreases.Therefore, when a surface coil is used, it is necessary to accurately position the surface coil in the subject area to be diagnosed.

Conventionally, the surface coil (102) is placed between the subject (101) placed on the movable top plate (100) and the movable top plate (100) as shown in FIG. , once the body (101) is movable and the surface coil (100) on
102), it was very difficult to make fine adjustments to the position of the surface coil (102) because the position of the surface coil (102) could not be changed without changing the subject's (101) ffi power. Once again, the subject (101
) and surface coil (102) in fixed positions! ! J
' After taking the F image, change the position of the surface coil (102) and take the next diagnostic image 1#! 2, the subject (1) is required to change the position of the surface coil (102).
01) would be necessary to move, and even if it were possible to move,
When the subject (101) is placed on the surface coil (102) again, a shift occurs in the relative positions of the two, making it difficult to finely adjust the position of the surface coil.

(c) Problems to be solved by the present invention The problems to be solved by the present invention are to move the position of only the coil relative to the subject without moving the position of the subject relative to the movable top plate. The goal is to develop a structure that can be applied not only to surface coils but also to coils that obtain signals from a wide range of subject areas.

2) Means for solving the problem A silent magnetic gutter generator that forms a uniform magnetic field using a magnet;
a movable top plate for all subjects to enter and leave the static magnetic field generator; a bed adjacent to the static magnetic field generator for placing the movable top plate so as to be movable in the horizontal direction; A non-conductive and non-magnetic coil support is placed on a moving top plate and a part of the subject is placed on it, and it moves freely in the internal space provided in the coil support. 'eJiI-I' with a possible receiving coil.

(E) The relative position between the subject, the movable top plate, and the coil support located between them is maintained in one foot relation to the imaging center of the diagnostic image, but the relative position of the coil to the coil support is Since the position can be freely moved, the position of the coil for the 41 subjects can also be changed freely.

(F) Embodiment A nuclear magnetic resonance diagnostic apparatus according to the invention will be described in detail below with reference to an embodiment of the drawings.

Figure 4 is a front view (-s
(cross-sectional view) is shown. In the same figure, (1) is closed with a static magnetic field generator, surrounded by an outer shell (2) made of FRP resin, a permanent magnet <3&)C3b) facing vertically, and its surroundings. Magnetic yokes (4a) (4b) forming a magnetic circuit
, (4e) (4d), and the magnet (3&) (
3b) and magnetic yoke (4jL) (4b), (4cJ(
4d) to make the magnetic field uniform (51L) (5b) and tatre magnet (35L) (3b)
) and firmly stand on the opposing surface of the pole piece (55k) (5b
) for forming a gradient magnetic field within the uniform magnetic field are disposed on the opposite surface of the gradient coils (6a), (6b)t'', and a cylindrical gantry shield (71t-position) is disposed between these gradient coils (6a) and (6b). The P3 part is used as the insertion space (9) for the subject (8), and the opening at one end is used as the insertion port αQ for the subject (8).And in order to suppress the shadow # of the formed magnetic field due to external temperature changes. A movable top plate of the same curved shape is placed in the concave portion (12JL) so that J can move. an external shield movable in the direction of the test subject (9) placed in the insertion space (9);
The static magnetic field generator (8) is made of a conductive metal that is electrically connected to the end of the gantry shield (7) in order to cover the outside protruding portion (t).

119/fi # A coil support body made of a non-conductive and non-magnetic material that is installed at any position on the large excitable plate +13, and has a space (15 &) inside.

If the coil support 151 is made of vinyl chloride with a thickness of 5 mm or Ff (P resin) with a thickness of 1 to 311 II, it is light in terms of intensity.

σe is a surface coil installed in a circle that can move freely in the internal space (15&) of the coil support 4, for example, a circular coil with one loop in Fig. 5 or a circular coil with one loop in Fig. 6. A rectangular coil, and moreover, a circular or rectangular coil having two or more loops as shown in FIG. 7 is used.

There are 2 nuclear magnetic resonance diagnostic devices with the above configuration! 3
As shown in V, the coil support is sandwiched between the subject (8) and the movable top plate L3, and
The relative positions of the top plate αJ and the coil support remain unchanged during the imaging of the diagnostic image.

- 10,000 coils (15 and 15) can be freely moved to various locations within the internal space (15&) of the coil support (151), and can be set at positions corresponding to the diagnostic region of the subject (8).

At this time, the coil support (151) is curved, but the coil 1t9 itself is flexible and does not interfere with movement if it is about 1 loop or 2 loops.Furthermore, the coil σ
It is appropriate to confirm the position of e in the <'b''y-coordinate system as shown in Figure 4. In this case, the position of the coil (1 mark @'tX
This is convenient for automatic movement as a composite movement in both the direction and the y direction.

In addition, the coil support σ5 has a thickness of 1 to 5 degrees, which has less effect on the S/N ratio than when the coil is installed directly under the subject (87), and improves the resolution of diagnostic images by 2 degrees. There is almost no decrease in

In addition, NMR from a wide range of subject areas shown in Figure 8
signal? It goes without saying that by locating a part of the obtained coil (171) in the l'3 space (15&) circle of the coil support a9, it is possible to freely move only in the adjacent backward direction. do not have.

(G) Effects of the Invention As explained above, the present invention includes a static magnetic field generator that forms a uniform magnetic field using a magnet, and a movable top plate for moving a subject into and out of the static magnetic field generator. , 14 beds are installed in the static magnetic field generator to place the oJ excitation sheet metal movably in the horizontal direction, and a part of the subject is placed on the movable top plate. A non-conductive and non-magnetic coil support body placed on the coil support body and a G n7
Equipped with a receiving coil that can be moved freely in the 1CP3 space, the position of the coil can be adjusted without moving the entire subject, making it possible to make very accurate adjustments.

Further, even if the position of the coil is changed several times depending on the imaging region, the adjustment can be made within the internal space of the coil support without moving the subject, which has a great practical effect.

[Brief explanation of drawings]

FIG. 4 is a front view (partially sectional view) of the nuclear magnetic resonance diagnostic apparatus of the present invention, FIG. FIG. 4 is a perspective view of the main part of FIG. 1 showing the positional relationship, FIG. 4 is a diagonal view 4J1 of the coil support body showing the moving direction of the receiving coil, and FIGS. 5 to M7 are plane views showing different aspects of the receiving surface coil. 8 is a front perspective view of the main part showing the relationship between another coil and the coil support, and FIG. 9 is a perspective view of the main part of the conventional example corresponding to FIG. 3. C3 & B3b)...・Magnet, (υ... Static magnetic field generator, (8)... Subject, σ... Movable top plate, low bed, (L5... Carp O layer support, (151)... Inside Space, 161 (17)
...Receiving coil.

Claims (3)

[Claims] (1) A static magnetic field generator that forms a uniform magnetic field using a magnet, a movable top plate for moving the subject into and out of the static magnetic field generator, and a movable top plate that is mounted so as to be movable in the horizontal direction. a bed adjacent to the static magnetic field generator for placing the
a non-conductive and non-magnetic coil support placed on the movable top plate and on which a part of the subject is placed; and a receiver movable freely in an internal space provided in the coil support. A nuclear magnetic resonance diagnostic apparatus comprising a coil. (2) The nuclear magnetic resonance diagnostic apparatus according to claim 1, wherein the receiving coil is entirely located within the internal space of the coil support. (3) The nuclear magnetic resonance diagnostic apparatus according to claim 1, wherein a portion of the receiving coil is located within the internal space of the coil support.