JPH02271833A - Magnetic resonance diagnostic device - Google Patents

Abstract

PURPOSE:To collect a magnetic resonance signal in a photographing part with a high S/N by providing an annular member to form one part of a high frequency coil and a connecting member to connect the plural annular members, which are mounted to a supporting member, as one coil. CONSTITUTION:An annular member 21 is composed of a conductive body such as copper, etc. In a support part 27, an adapter 23 is provided to freely attach and detach both end parts 21a and 21b of the annular member 21 and a pair of non-conductive guide members 35 are provided along the lengthwise direction of an enclosure 33 in the support part 27 to guide the adapter 23 to be slid in right and left direction. Then, a connecting member 25 is provided to electrically connect the respective annular members 21 as one coil when the plural annular members 21 are mounted. Further, a tuning circuit part 37 is provided. In a reception coil part 3 having the above mentioned configuration, when the annular member 21 of a suitable diameter corresponding the size and shape, etc., of a head part PH of a reagent P to be the part, which is scheduled to be photographed, is selected and mounted on the adapter 23 at an angle to be suitably set, the coil can be formed to be closed to the surface of the head part PH. Thus, the MR signal of this head part PH can be collected with high S/N.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a magnetic resonance system that collects magnetic resonance signals (hereinafter referred to as MR multiplied signals) from various parts of a subject and utilizes them for diagnosis. The present invention relates to a diagnostic device, and particularly to an improvement in a high frequency coil (hereinafter referred to as an RF coil) for transmitting or receiving the MR multiplied signal.

(Prior Art) A typical example of this type of magnetic resonance diagnostic apparatus is a magnetic resonance imaging apparatus (hereinafter referred to as an MRT apparatus). In this MRI apparatus, an arbitrary part of a subject such as a patient is set as the imaging part, MR multiplied signals are collected from this imaging part, and the collected signals are subjected to signal processing such as image reconstruction processing. It is possible to obtain a cross-sectional image of the photographed region.

This type of MRI apparatus is required to collect MR signals with as high an S/N ratio as possible in order to obtain clear image information of the imaging site. In other words, the spins of the imaging area are excited with an RF pulse as planned, and from there a minute amount of MR
Therefore, in principle, the RF coil for collecting the MR multiplied signal should be wound as close as possible to the imaged area of the subject; in reality, It is necessary to wind the RF coil as close to the surface of the imaging site as possible.

In view of the second need, for example, a bobbin that can be divided into two parts (upper and lower) and configured to form an RF coil when combined is put into practical use. With this configuration, since the two bodies can be attached to the imaging site such as the head from a separated state,
Compared to a cylindrical bobbin, which has a size that allows the head to be inserted freely from the beginning, it can be used closer to the surface of the imaging site.

(Problem to be Solved by the Invention) However, preparing multiple types of RF coils corresponding to various parts of the subject, such as the torso, nine legs, and arms, in addition to the head increases the number of attached parts. In addition, by preparing an RF coil with a certain amount of leeway in size, it is possible to avoid not being able to obtain a high S/N ratio, and to accommodate various sizes even for the same imaging site, making the sizes available in multiple stages. If this is attempted, the number of RF coils to be prepared will inevitably increase.

The present invention has been made in view of the above-mentioned problems of the prior art, and aims to provide a magnetic resonance diagnostic apparatus that can collect magnetic resonance signals of an imaging region at least as high a S/N ratio as possible. purpose.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems and achieve the objects, in the present invention, in order to extract magnetic resonance signals from the imaging region of the subject, a high frequency coil is disposed near the imaging region. In the magnetic resonance diagnostic apparatus, the high-frequency coil includes an annular member forming a part of the high-frequency coil, a support member that removably supports the annular member, and a plurality of annular members attached to the support member. The gist of the present invention is to include a connecting member that can electrically connect the members together as one coil.

(Function) According to the configuration that takes such measures, the following effects are achieved. That is, by preparing a plurality of annular members with various diameters, selecting an annular member with an appropriate diameter depending on the size of the scheduled imaging site, etc., and attaching these annular members to the support member, the connecting member The attached annular members are connected to each other as one high-frequency coil, and the high-frequency coil can be formed to fit the size of the area to be imaged, that is, to be as close to the surface of the area to be imaged as possible, so it can be used for various areas of the subject. The magnetic resonance signals of the imaging site can be collected with as high a S/N ratio as possible without having to prepare many high-frequency coils.

(Example) Hereinafter, an example in which the magnetic resonance diagnostic apparatus according to the present invention is applied to an MR1 apparatus will be described with reference to FIGS. 1 to 5.

FIG. 1 shows a schematic configuration of the MHI device.

This MHI apparatus is a magnet assembly configured to accommodate the subject P therein, and may include a static magnetic field coil (a static magnetic field correction shim coil may be added) using a normal conduction or superconducting method.

)l, a gradient magnetic field coil 2 that generates a gradient magnetic field for providing positional information of the MR multiplied signal inducing site, a transmitter coil (not shown) that transmits a rotating high frequency magnetic field for excitation, and detects the excited MR multiplied signal. It also includes a receiving coil section (high frequency coil) 3, which will be described later.

The electrical system has the following configuration. That is, if the static magnetic field coil 1 is of a superconducting type, it includes a refrigerant supply control system, a static magnetic field control system 4 that mainly controls the energization of the static magnetic field power supply, and a Y-axis, Y-axis, and Z-axis gradient magnetic field power supply. 5, 6, 7, a transmitter 8, a receiver 9, a sequencer 1O1 for executing a predetermined pulse sequence, and a computer system 11 and a display 12 for controlling these and for processing and displaying a detection signal.

The receiving coil section 3, as shown in FIGS. 2(a) and 2(b), roughly consists of an annular member 21 forming an upper part and a support part 27 forming a lower part.

The annular member 21 is made of a pipe made of a conductive material such as copper and has an inner diameter of t, and includes an annular annular portion 21c with a portion cut out, and a direction extending from the end of the cut portion to the outer circumference in one direction. The end portions 21a and 21b are bent at a distance d toward the end portions 21a and 21b. The sizes are the same except that the diameter of the annular portion 21c is different.

A plurality of annular members 21 are prepared.

Further, the support portion 27 includes both ends 21a of the annular member 2I.
.
b) A non-conductor guide member 35 that guides sliding in the left and right direction, and a connecting member 25 that electrically connects each annular member 21 as one coil when a plurality of annular members 21 are attached. and a tuning circuit section 37.

The adapters 23 are electrically conductive, and a plurality of pairs of adapters 23 are provided on the guide member 35. Further, on the upper part of this adapter 23, both ends 21a and 21b of the annular member 21 are provided.
A conductive protrusion 29 is provided that can be inserted into the vibrator and is made of twisted steel wire or the like and can be bent in any direction.

Furthermore, two openings 31 are provided on the upper surface of the casing 33 of the support section 27 at a portion above the guide member 35 . Note that the housing 33 is designed to accommodate, for example, the head P of the subject.
When H is used as a haunting site, it is preferable to configure it so that it can be attached to and detached from a bed top plate attachment member (not shown) or the like.

Further, the connecting member 25 is conductive, and for example, assuming that the annular member 21 is attached to all adapters 23, all the annular members attached in this state electrically become one solenoid coil. As such, different guide members 35
The adapters 23 disposed in the adapters 23 are electrically connected to each other. Note that, instead of assuming that the annular members 21 are attached to all the adapters 23 as described above, the configuration may be such that an appropriately set number of annular members 21 can be attached to the adapters 23. That is, the connection member 25
is an adapter 2 to which the annular member 21 is attached so that all the attached annular members 21 electrically form one coil.
3, and the number of annular members 21 to be used can be arbitrarily selected depending on the required inductance.

Further, the tuning circuit section 37 includes some components of a tuning circuit as shown in FIG.
It consists of a barrier pull capacitor 41 and the like. The inductance shown in this figure is the annular member 21 attached to the support section 27. Protrusion 29. Adapter 23. Connection member 2
It shows the inductance of a solenoid coil formed by 5 etc. In the barrier pull capacitor 41, since the inductance L changes depending on the distance between the annular members 21, the diameter DilJi, the oblique angle, etc., a capacitor having a capacitance range that can be tuned according to these changes is used. A connector terminal 38 for connection to a cable (not shown) for receiving the MR multiplier signal is provided in the housing 33 near the tuning circuit section 37.

Note that reference numeral 39 indicates a stopper for fixing the guide member 35 of the adapter 23 at an appropriately set position and fixing the appropriately set inclination angle of the annular member 21.

In the receiving coil unit 3 having the above configuration, the size of the head PH of the subject 2, which is the planned shadowing site.

Select annular members 21 with appropriate diameters depending on the shape, etc., and attach these annular members 21 to the adapter 2 at an appropriately set angle.
3, the attached annular members 21 are electrically connected as one coil, and a coil close to the back surface of the head PH can be formed, so that the MR multiplied signal of this head PH is as high as possible. It can be collected by ratio.

Also, for example, Fig. 4 (a), (b), (c)
As shown in (d), by varying the distance P between the annular members 21 and the angle θ formed between them, it is possible to freely set a region from which an MR multiplied signal with higher sensitivity than others is to be obtained.

That is, when it is desired to collect an MR multiplied signal with uniform sensitivity over the entire head PH, as shown in FIG. 4(a), the angle θ
(However, it is only necessary to largely adjust the interval P. When it is desired to collect MR multiplied signals with particularly high sensitivity for a specific region such as ears and eyes, as shown in FIG. 4(b), The annular member 21 may be centrally arranged in the area.

In addition, as shown in FIG. 4(c), by adjusting the annular members 21 to open above the head PH, the MR where the interval P between the annular members 21 is narrower, that is, the occipital area has higher sensitivity. As shown in FIG. 4(d), if all the annular members 21 are tilted toward a specific region on the upper side, the annular members 21 will have a narrower interval P, that is, on the forehead side. It can also function in the same way as a surface coil.

Further, it goes without saying that the above embodiment is not only applied to a coil for head PH imaging; FIG. 4(c),
As shown in (d), this is a method of collecting MR multiplied signals with different intervals P between the upper and lower sides.
), (b), (c).

As shown in (d), knee 43. Joints of the human body, such as elbows 451 and hands 47, or parts where joints gather, etc. can also be imaged parts. At this time, cine photography can be easily performed while moving the joint little by little, which is highly effective.

Therefore 1. By equipping the MR1 device with such a receiving coil section 3, various parts can be imaged with one support part 27, and since a large number of coils are not prepared for each of the various parts, the number of parts can be reduced. This makes it possible to significantly reduce costs, reduce costs, and facilitate coil management. Further, when changing the imaging site and imaging conditions, the effort of preparing a completely different coil body is saved, and the time required to attach the coil to the subject can be shortened. Also fixed size.

Since a shaped bobbin is not used, the comfort of the subject is improved.

〔Effect of the invention〕

As described in detail above, in the present invention, in a magnetic resonance diagnostic apparatus in which a high-frequency coil is disposed near the imaging site in order to extract magnetic resonance signals from the imaging site of a subject, the high-frequency coil: An annular member forming a part of this high-frequency coil, a support member that removably supports this annular member, and a plurality of annular members attached to this support member are electrically connected as one coil. The configuration includes a connection member to obtain the connection member.

Therefore, by preparing a plurality of annular members with various diameters, selecting an annular member with an appropriate diameter depending on the size of the scheduled imaging site, etc., and attaching these to the support member, the support member can Each attached annular member is connected as a single coil, and it is possible to form a high-frequency coil that fits the size of the area to be imaged, that is, to get as close to the surface of the area to be imaged as possible, so it can be used for various areas of the subject. Magnetic resonance signals of the imaging site can be collected with as high a S/N ratio as possible without having to prepare many high-frequency coils.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration explanatory diagram of an MHI device to which the present invention is applied, FIG. 2(a) is a schematic cross-sectional configuration explanatory diagram showing an embodiment of the receiving coil section according to the present invention, and FIG. 2(b) is shown in Figure 2 (
Fig. 3 is a circuit diagram showing an example of a tuning circuit, and Fig. 4 (a) to (d) are explanations showing examples of arrangement of variously adjusted coils. 5A and 5B are explanatory diagrams showing examples of arrangement of coils for various imaging regions other than the head. l... - Static magnetic field coil 3... Receiving coil section 23... Adapter 27... Support section 37... Tuning circuit section 2... Gradient magnetic field coil 21... Annular member 25... Connection Member 35...Guide member

Claims (1)

[Claims] (1) In a magnetic resonance diagnostic apparatus in which a high-frequency coil is disposed near the imaging site in order to extract magnetic resonance signals from the imaging site of the subject, the high-frequency coil is an annular member forming a part of the high-frequency coil. and a support member that detachably supports this annular member, and a connecting member that can electrically connect a plurality of annular members attached to this support member as one coil. Magnetic resonance diagnostic equipment.