JPH0353452Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a nuclear magnetic resonance tomography device (hereinafter referred to as
A radio frequency pulse (RF pulse) is applied to a subject placed within the magnetic field formed by the magnet part of a NMR-CT (NMR-CT), or nuclear magnetic resonance is created within the subject by the application The present invention relates to an RF coil for detecting (NMR) signals, and more particularly to improvements in means for fixing the RF coil to a cradle.

(Prior Art) NMR-CT has been rapidly put into practical use as a method for imaging the distribution of protons ( ¹ H), and is now becoming a powerful method for clinical medical diagnosis. Figure 7 shows the
FIG. 2 is a configuration diagram showing the surroundings of a magnet part of NMR-CT.
The magnet part 1 forms a uniform magnetic field within the cylindrical space 2. The table 3 is installed facing the opening of the space 2 and includes a cradle 4 that can be taken in and out of the cylindrical space 2. The subject 5 is placed on this cradle 4 and installed within the magnet section 1 (space 2). Near the target area (head of subject 5 in FIG. 7),
A cylindrical RF coil 6 is fixed that applies a high frequency pulse to the site and detects an NMR signal generated at the site. The coil fixing means is as shown in Figure 8.
A plate material 7 (a plate provided with fastener holes) integrated into the RF coil 6, a hook portion 8 provided at a position apart from the plate material 7, and a fastener fitting portion 9 and a locking portion formed on the cradle. It is composed of a hole 10 and a fastener (trade name Nairatsuchi) 11.

In the above configuration, the RF coil 6 is attached by locking the hook portion 8 in the locking hole 10 and then inserting (fitting) the fastener 11 into the fastener fitting portion 9 from the fastener hole of the plate material 7 ( fixed). on the other hand,
Removal is performed by reversing the above procedure.

(Problems that the invention attempts to solve) However, in the case of conventional RF coils for NMR,
When installing and removing the coil, it is necessary to insert and remove the fastener at the tip of the cradle, so it is necessary to move the table to secure a working space between the cradle and the magnet section. In addition, if the table is not moved, the cradle must be brought as far to the left side in FIG. 7 as possible (pull it out from the magnet part 1 as much as possible) so that the tip of the cradle can be seen from the side of the table. In the former case, there is a problem that moving the table 3 is cumbersome. Moreover, in the latter case, the insertion/removal operations are performed while looking into the tip from the side of the cradle, which poses the problem of making the operations difficult to perform.

The present invention was devised in view of these points, and its purpose is to provide a coil for NMR that allows easy installation and removal of coils without any troublesome operations.
Our goal is to provide RF coils.

(Means for Solving the Problems) The RF coil for NMR of the present invention that achieves the above object is arranged symmetrically when viewed from the longitudinal direction of the cradle, and is rotated within a predetermined range on the coil cover or coil mechanism. two lever assemblies supported so as to be movable and forcibly held in one rotation restriction position by a spring;
Each lever assembly includes a lever and a hook coupled to each end thereof.

(Function) When installing the coil, the hook is guided to the locking hole provided in the cradle and forms a locked state.
At the time of removal, the hook moves to release the lock by operating the lever.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 5 are configuration diagrams showing one embodiment of the present invention. Figure 1 is an exploded diagram of the RF coil.
Figure 2 is an assembly diagram of the RF coil, Figure 3 is a diagram showing the arrangement of the fixing means, Figure 4 is a diagram showing the positions of the locking hole provided in the cradle and the hole for the guide pin, and Figure 5 is a diagram showing the position of the hole for the guide pin. FIG. 3 is an exploded schematic diagram of the fixing means. The following description will be made mainly with reference to FIG. The RF coil 20 is a split coil for head measurement, and is roughly divided into an upper assembly 21, a lower assembly 22,
It consists of a coil cover (base cover) 23,
When these are combined (integrated), they form a substantially cylindrical shape (see Fig. 2). The mechanism portion of the upper assembly 21 is constructed by connecting a substantially semicircular front frame 24 and a rear frame 25 with a plurality of insulating pipes 26. An element 27 covered with an insulating tube is inserted into each insulating pipe. These elements 27 are electrically connected to copper foil tapes 28 and 29 installed on the front frame 24 and rear frame 25, respectively. The copper foil tapes 28 and 29 are constructed by connecting rectangular copper foil sections with capacitors. Each of these copper foil tapes is covered with a front cover 30 and a rear cover 31. The lower assembly 22 includes a trough-shaped base chassis 32 made of an insulating material, flanges 33, 34, and the like. Lower assembly 2
2 is provided with an element similar to the upper assembly 21. Further, copper foil tapes are installed near the flanges 33 and 34, respectively. Furthermore, a microphone, speaker, etc. for communicating between the subject and the operator are also installed (none of which are shown). In the integrated structure of the upper assembly 21 and the lower assembly 22, the copper foil tape 28 and the copper foil tape on the flange 33 side, and the copper foil tape 29 and the copper foil tape on the flange 34 side are contact points (not shown), respectively. are electrically connected to each other to form a predetermined electric circuit. Two coil fixing means 35 and 36 are installed on the coil cover 23 (36 is omitted in FIG. 1). As shown in FIG. 3, the arrangement of these coil fixing means 35 and 36 is symmetrical when viewed from the longitudinal direction of the cradle when the RF coil is fixed to the cradle. Moreover, the levers 37 and 38 of each coil fixing means (the structure of the coil fixing means will be explained in detail in FIG. 5) are connected to openings 39 and 40 formed in both side walls of the coil cover 23.
exposed to the outside. The hooks 41 and 42 of each coil fixing means are connected to openings 43 and 44 (opening 4 in FIG. 1) formed in the bottom wall of the coil cover 23.
4 is located in an invisible position), and protrudes outward from there. Furthermore, although it is omitted in FIG. 3 and a part of it is shown in FIG. 1, the coil cover 23
Positioning guide pins (convex pins) 45 and 46 are provided outwardly on the bottom wall. On the other hand, as shown in FIG. 4, the cradle 4 is formed with locking holes 47 and 48 into which the hooks of hooks 41 and 42 are locked, and recesses 49 and 50 into which guide pins 45 and 46 are inserted.

Next, the structure of the coil fixing means 35 will be explained with reference to the exploded schematic diagram of FIG. Incidentally, since the coil fixing means 35 and 36 have the same configuration, a description of 36 will be omitted. The lever assembly 51 has pins _53a and 5 that are respectively locked in holes in both walls of the base 52.
_3b , and the range of rotation is regulated by two bars _54a and _54b , which are installed between the two walls at a predetermined distance. The end of the assembly 51 is placed between the two bars). Further, the lever assembly 51 is forcibly pulled toward the bar _54a by springs _55a and _55b (the end of the base 52 and the end of the lever assembly 51 are connected via the springs). A lever 37 and a hook-shaped hook 41 are connected to both ends of the lever assembly 51, respectively, so that the three are integrated. By fixing the base 52 at a predetermined position on the coil cover 23, the lever 37 and the hook 41 are exposed through the opening 39, and the latter is exposed through the opening 4, as described above.
Stands out from 3.

Next, the operation of attaching and detaching the RF coil to the cradle will be explained with reference to FIGS. 6a and 6b. FIGS. 6a and 6b schematically show the installed and removed states of the coil fixing means 35 when viewed from the longitudinal direction of the cradle. Each symbol is used with the same meaning as in FIGS. 1 to 5. In addition, the movement of the hooks, levers, etc. of each coil fixing means during installation and removal operations is as follows:
Almost simultaneous and the same. Moreover,
Since they have the same configuration in the attached state, the coil fixing means 35 will be explained in the following explanation, and the explanation about 36 will be omitted. To install the RF coil 20, align the guide pins 45 and 46 with the recesses 49 and 50 of the cradle 4, respectively.
is pressed against the cradle 4 (the lever 37 is not particularly operated). At this time, the hook 41, which has been pulled toward the bar _54a by the spring _55a , moves while being guided by the locking hole 47 while resisting the force of the spring _55a , and is inserted into the locking hole 47. Ru. When the bottom wall of the coil cover 23 and the cradle 4 are in close contact, the hook 41 is completely locked to the edge of the locking hole 47 by the spring _55a , as shown in FIG. 5a. (The tip of the hook gets caught on the edge of the locking hole). On the other hand, removal is performed by placing a finger on the lever 37 and lifting the RF coil 20. That is, when an attempt is made to lift up the RF coil 20 by placing a hand on the lever 37, a force in the direction of arrow A is applied to the lever 37, as shown in FIG. 5b. With this, lever assembly 5
1 rotates around the pin 53 _a , and the hook 41
moves in the direction of arrow B to release the lock from the locking hole 47. If the lifting operation of the RF coil 20 is continued even after the hook 41 is released, the RF coil 20 is completely removed from the cradle 4.

As described above, the RF coil 20 can be attached by simply inserting the hook 41 into the locking hole 34, and removed by simply lifting the lever 52.
All of these operations can be easily performed by standing next to the cradle 4.

Note that the present invention is not limited to the above embodiments. For example, the coil fixing means may be installed in a coil mechanism section such as a lower assembly instead of the coil cover. Further, positioning guide pins facilitate positioning during installation, but are not always necessary.
Furthermore, the RF coil may perform only either transmission or reception.

(Effect of the invention) As explained above, according to the RF coil for NMR of the invention, when the coil is installed, the hook protruding from the coil cover is guided to the locking hole provided in the cradle to form a locked state. At the time of removal, the hook is released by operating levers exposed on both walls of the coil cover, so the coil can be easily installed and removed without any troublesome operations.

[Brief explanation of the drawing]

FIG. 1 is an exploded schematic diagram showing an embodiment of the present invention, FIG. 2 is an assembled diagram showing an embodiment of the present invention, FIG. 3 is a layout diagram of the coil fixing means in an embodiment of the present invention, and FIG. The figure is an explanatory diagram of the positions of the locking holes and guide pin holes provided in the cradle corresponding to the coil fixing means in an embodiment of the present invention, and FIG. 5 is an exploded view of the coil fixing means in an embodiment of the present invention. Schematic diagrams, Figures 6a and b are operation explanatory diagrams of the coil fixing means in an embodiment of the present invention, and Figure 7 is an NMR diagram.
- A block diagram showing the area around the magnet part of the CT; FIG. 8 is a block diagram showing a conventional example. 1... Magnet part, 2... Cylindrical space, 3... Table, 4... Cradle, 5... Subject, 6, 2
0...RF coil, 21...Upper assembly,...
22... Lower assembly, 23... Coil cover, 24... Front frame, 25... Rare frame, 27... Element, 28, 29... Copper foil table, 30... Front cover, 31...
Rare cover, 32...Base chassis, 33,3
4... Flange, 35, 36... Coil fixing means, 37, 38... Lever, 39, 40, 43,
44...Opening, 41, 42...Hook, 45,
46... Guide pin, 47, 48... Locking hole, 4
9, 50...Hole for guide pin, 51...Lever assembly, 52...Base, 53 _a , 53 _b ...
...pin supporting the lever assembly, 54 _a ,
54 _b ... bar, 55 _a , 55 _b ... spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A subject is placed on a cradle that is installed in the magnet part of a nuclear magnetic resonance tomography apparatus, and a high-frequency pulse is applied to the target area, or by the application of the high-frequency pulse. In the RF coil for detecting nuclear magnetic resonance signals generated within the region, two members are arranged symmetrically when viewed from the longitudinal direction of the cradle, and are arranged in advance on the coil cover or the coil mechanism. a lever assembly supported so as to be rotatable within a range and forcibly held in one rotation restriction position by a spring; a lever coupled to one end of the lever assembly; and the cradle. a member that locks in a locking hole provided in the lever assembly, the hook being coupled to the other end of the lever assembly; when installing the coil, the hook is guided to the locking hole to form a locked state; An RF coil for NMR, characterized in that, when removed, the hook moves to release the lock by operating the lever.