JPS60242350A - Nuclear magnetic resonance image pickup device - Google Patents

Nuclear magnetic resonance image pickup device

Info

Publication number
JPS60242350A
JPS60242350A JP59097736A JP9773684A JPS60242350A JP S60242350 A JPS60242350 A JP S60242350A JP 59097736 A JP59097736 A JP 59097736A JP 9773684 A JP9773684 A JP 9773684A JP S60242350 A JPS60242350 A JP S60242350A
Authority
JP
Japan
Prior art keywords
yoke
wire gauze
generating means
magnetic field
couple
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP59097736A
Other languages
Japanese (ja)
Inventor
Kimio Matsumoto
松本　公雄
Kenji Oyamada
小山田　健二
Junichi Hatta
純一 八田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sanyo Electric Co Ltd
Sanyo Denki Co Ltd
Original Assignee
Sanyo Electric Co Ltd
Sanyo Denki Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sanyo Electric Co Ltd, Sanyo Denki Co Ltd filed Critical Sanyo Electric Co Ltd
Priority to JP59097736A priority Critical patent/JPS60242350A/en
Publication of JPS60242350A publication Critical patent/JPS60242350A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42—Screening
    • G01R33/422—Screening of the radio frequency field
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/383—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using permanent magnets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42—Screening
    • G01R33/421—Screening of main or gradient magnetic field

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Epidemiology (AREA)
  • Details Of Measuring And Other Instruments (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)

Abstract

PURPOSE:To attain electrostatic and radio-wave shielding so as to stabilize measurement by using a conductive member to enclose a magnetostatic field generating means made of magnetic yokes which couple with a couple of permanent magnets magnetically and form a nearly sealed space. CONSTITUTION:The magnetostatic field generating means consisting of the couple of discoid permanent magnets 2, upper yoke 3, lower yoke 4, a cylindrical side yoke 5, and a couple of ball pieces 8 is covered with an insulating sheet 11, the 1st metallic wire gauze 12, lids 13 which are opened and closed freely to block openings of the 1st wire gauze 12, and the 2nd wire gauze 14 to attain radio wave shielding. The wire gauze 12 is formed cylindrically and welded in contact with the entire periphery of each opening 6, the sheet 11 has a small hole opposite the small hole of the yoke 5 and covers the whole of the generating means 1 and wire gauze 12, and the wire gauze 14 is arranged thereupon. Further, the wire gauze 14 and yoke 5 are connected together electrically at one point and grounded through an earth wire 15. Then, each lid 13 is made of a discoid sheet of the same material with the sheet 11 between discoid sheets of wire gauze 13a and 13b.

Description

【発明の詳細な説明】 （イ）産業上の利用分野 本発明は、核磁気共鳴撮像装置（以下、ＮＭＲ−ＣＴと
称す）に関する。DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a nuclear magnetic resonance imaging apparatus (hereinafter referred to as NMR-CT).

（ロ）　従来技術 ＮＭＲ−ＣＴにおいて、均一度の高い静磁界を形成する
ことが必要となる。こうした静磁界を形成する静磁界発
生装置には、一般に、日本臨床４１巻７号（７、１９８
３＞のＰ２５４〜Ｐ２５７に見られるように、常伝導磁
石、超伝導磁石もしくは永久磁石が使用きれる。(b) In conventional NMR-CT, it is necessary to form a highly uniform static magnetic field. In general, the static magnetic field generating device that forms such a static magnetic field is
As seen in P254 to P257 of 3>, normal conducting magnets, superconducting magnets, or permanent magnets can be used.

常伝導磁石を使用したものにおいては、消費電力が大き
く、更に大電流を印加するために発熱を生し、これによ
る温度上昇を防止するための冷却装置必要となり、装置
が大型となる。また、超伝導磁石を使用したものにおい
ては、超伝導状態を保持するために液体ヘリウム、液体
窒素を定期的に補充しなければならず、維持することに
問題がある。A device using a normal conduction magnet consumes a large amount of power, and also generates heat due to the application of a large current, and requires a cooling device to prevent the temperature from rising due to this, resulting in a large device. Furthermore, in those using superconducting magnets, liquid helium or liquid nitrogen must be regularly replenished to maintain the superconducting state, which poses a problem in maintaining the superconducting state.

これらの各問題点を解消するものが永久磁石を使用する
ものである。斯る場合、冷却装置及び液体ヘリウム等の
補充が全く不要となり、維持する面で非常に経済的なも
のとなる。The solution to these problems is to use permanent magnets. In such a case, there is no need for a cooling device or replenishment of liquid helium, etc., making it extremely economical to maintain.

ところで、静磁界発生装置に最も要求されるのは、漏洩
磁束を／Ｊ＝ａくすることによって外部からの影響を防
止し、均一度の高い静磁界を形成することである。更に
、ＮＭＲ−ＣＴは、核磁気共鳴により得られる電波信号
を測定するものであるため、外部電波の影響を低減しな
ければならない。By the way, what is most required of a static magnetic field generator is to prevent external influences by setting the leakage magnetic flux to /J=a, and to form a highly uniform static magnetic field. Furthermore, since NMR-CT measures radio wave signals obtained by nuclear magnetic resonance, the influence of external radio waves must be reduced.

（ハ）発明の目的 本発明の目的は、簡単な構成により静磁界発生装置に静
電及び電波シールドを施し、安定した測定を行ない得る
核磁気共Ｑ％撮像装置を提供することにある。(C) Object of the Invention An object of the present invention is to provide a nuclear magnetic co-Q% imaging device that can perform stable measurements by applying electrostatic and radio wave shielding to a static magnetic field generator with a simple configuration.

（二〉　発明の構成 本発明は、一対の永久磁石及び該磁石を磁気的に結合シ
ーると共に、はぼ密閉された空間を形成する磁気ヨーク
からなる静磁界発生手段により上記空間に一様な静磁界
を形成し、上記磁気ヨークに設けた被測定物ｔΦ入用の
開口より被測定物を上記靜磁界中に設置することにより
、」−２被測定物の原子核分布を画像表示する核磁気共
鳴撮像装置であって、上記靜磁界発生手段を導電性部材
により囲繞したことを特徴とする。(2) Structure of the Invention The present invention provides a means for generating a static magnetic field consisting of a pair of permanent magnets and a magnetic yoke that magnetically couples the magnets and forms a nearly sealed space. By forming a static magnetic field and placing the object to be measured in the static magnetic field through the opening provided in the magnetic yoke for receiving the object to be measured, "-2 Nuclear magnetism that displays an image of the nuclear distribution of the object to be measured. The resonance imaging device is characterized in that the silent magnetic field generating means is surrounded by a conductive member.

くホ）実施例 第１図乃至第３図は本発明の実施例を示し、第１図（ａ
）及び（ｂ）はＮＭＲ−ＣＴにおける静磁界発生手段の
夫々一部破断して示す部分上面図及び側面図、第２区及
び第３図は電磁シールドを施こした状態を示す斜視図及
び側面断面図である。なお、各図において、同一部分に
は同一番号を付している。(h) Embodiment Figures 1 to 3 show embodiments of the present invention, and Figure 1 (a) shows an embodiment of the present invention.
) and (b) are partially cutaway top and side views of the static magnetic field generating means in NMR-CT, respectively, and Figures 2 and 3 are perspective views and side views showing the state with electromagnetic shielding applied. FIG. In addition, in each figure, the same number is attached to the same part.

第１図に示す静磁界発生手段（１）において、（２）は
希土類磁石材料から成る一対の円板状永久磁石、（３）
（４）は該永久磁石の各々の一面に接して配きれる磁石
材料力・ら成る円板状の上部ヨーク及び下部ヨーク、（
５）は該上部ヨーク及び下部ヨークと電磁気的に接続さ
れる磁石材料から成る円筒状のサイドヨークで、この開
口を密閉するように上部ヨーク（３ン及び下部ヨーク（
４）が配きれることによって、これらの各ヨークにて磁
気回路を構成し、一対の永久磁石（２）の対向間に静磁
界が形成される。また、サイドヨーク（５）は、上記靜
磁界中への被測定物の設置用に対向配置で設けられた一
対の円形開口（６）及び採光用の複数の／Ｊ＼孔（７）
を有する。（８）は永久磁石（２）の各々の他面に対向
配置で設けられ、上記静磁界の均一度を向上させる一対
のポールピース、（９）はサイドヨーり（５）の上部内
面に突出して設けられ、上部ヨークく３）を支持する受
座リング、（１０）＜１０）は一端が各ポールピース（
８）の側面に接して配され、例えば」二部ヨーク（３）
及び下部ヨーク（４）にねじ止めされる断面り字状のサ
イドリングで、各永久磁石（２〉は各サイドリング（１
０）により位置決めされる２井に、上部ヨーク（３）も
しくは下部ヨーク（４）と各サイドリング（１０〉とに
よって挾持固定される。In the static magnetic field generating means (1) shown in FIG. 1, (2) is a pair of disc-shaped permanent magnets made of rare earth magnet material, (3)
(4) is a disc-shaped upper yoke and a lower yoke made of magnetic material arranged in contact with one surface of each of the permanent magnets;
5) is a cylindrical side yoke made of magnetic material that is electromagnetically connected to the upper yoke and the lower yoke;
4), each of these yokes constitutes a magnetic circuit, and a static magnetic field is formed between the pair of opposing permanent magnets (2). The side yoke (5) also includes a pair of circular openings (6) arranged opposite each other for installing the object to be measured in the above-mentioned quiet magnetic field, and a plurality of /J\ holes (7) for letting in light.
has. (8) is a pair of pole pieces that are arranged opposite to each other on the other surface of each permanent magnet (2) and improve the uniformity of the static magnetic field, and (9) is a pair of pole pieces that protrudes from the upper inner surface of the side yaw (5). A catch ring (10
8), for example, a two-part yoke (3).
and a side ring with an orthogonal cross section screwed to the lower yoke (4), each permanent magnet (2) is attached to each side ring (1).
The upper yoke (3) or the lower yoke (4) and each side ring (10>) are clamped and fixed to the two wells positioned by the upper yoke (3) or the lower yoke (4).

而して、開口（６〉の大きさを被測定物の設置に支障を
来たすことがない程度に小さくすることによって、サイ
ドヨーク（５）による磁気シールド効果を最大にする事
ができ、従って、静磁界の均一度を外部に影響されずに
保持することができる。By making the size of the opening (6) small enough to not interfere with the installation of the object to be measured, the magnetic shielding effect of the side yoke (5) can be maximized, and therefore, The uniformity of the static magnetic field can be maintained without being influenced by the outside.

小孔（７）は、その大きさが非常に小さいため、磁気シ
ールドの上でほとんど影響がない。Since the small hole (7) is very small in size, it has almost no effect on the magnetic shield.

ここで、靜磁界発生手段（１）の各主要部の具体的な太
ききについて説明すると、上部ヨーク（３）及び下部ヨ
ーク（４）の厚さは約１００、サイドヨーク（５）の厚
きは約５ｃｌ′１１１内径は約１．８ｍ、各永久磁石（
２）の厚さは１５ｃＴｎ、径は約１．５ｍ、ポールピー
ス（８）の径は約１．１ｍ、サイドヨーク（５）に設け
られている開口（６）の径は７０ＣＴＩｌであり、磁束
密度的３０００Ｇａｕｓｓの靜磁界が形成きれている。Here, to explain the specific thickness of each main part of the silent magnetic field generating means (1), the thickness of the upper yoke (3) and the lower yoke (4) is approximately 100 mm, and the thickness of the side yoke (5) is approximately 100 mm. is about 5cl'111, the inner diameter is about 1.8m, each permanent magnet (
2) has a thickness of 15 cTn and a diameter of approximately 1.5 m, the diameter of the pole piece (8) is approximately 1.1 m, the diameter of the opening (6) provided in the side yoke (5) is 70 CTIl, and the magnetic flux A quiet magnetic field of 3000 Gauss density has been formed.

ところで、本実施例において、靜磁界発生手段（１）は
更に電波シールドが施こきれている。第２図及び第３図
におい１、（１１〉はゴム、樹脂等の非磁性かつ絶縁性
を有するシーｌ、（１２）は開口（６）と電気的に結合
された第１金網、（１３）は該第１金網の開口を塑ぐ開
閉自在な蓋、（１４）は第２金網、〈１５）はアース線
である。By the way, in this embodiment, the silent magnetic field generating means (1) is further provided with a radio wave shield. In FIGS. 2 and 3, 1, (11>) is a non-magnetic and insulating seal made of rubber or resin, (12) is a first wire mesh electrically connected to the opening (6), (13) ) is an openable and closable lid that covers the opening of the first wire mesh, (14) is a second wire mesh, and (15) is a ground wire.

而し、て、第１金網（１２）は円筒状に形成されて、各
開口（６〉の全周と接するように溶接もしくはねし止め
により固着される。シートク１１）はサイドヨーク（５
）のノ」）孔（７）と対向して同様の小孔を有しており
、静磁界発生手段（１）及び各第１金網（１２）の全体
を包むように配置れ、その上に靜磁界発生手段（ｉ）及
び第１金網（１２）と絶縁的に第２金網（１４）が配設
キれる。そして、サイドヨーク（５）と第２金網（１４
）とは一点において電気的に接続され、アース線（１５
）を介して接地される。更に、蓋（１３）は第１金網（
１２）の開口と同一形状であり、２枚の円板状金網（１
３ａ）（１３ｂ）の間にシート（１１）と同一材料の円
板状シート（１３ｃ）をサンドイッチ状に挾んで構成さ
れたものであって、内側の金網（１３ａ　）が第１金Ｆ
Ｊ（１２）と、また外側の金網（１３ｂ）が第２金網〈
１４）と夫々電気的に連なるように取り付けられる。そ
して、蓋（１３）が開かれ、被測定物（１６）が静磁界
発生手段（１）内へ挿入されると冬着（１３）は閉しら
れる。Therefore, the first wire mesh (12) is formed into a cylindrical shape and is fixed by welding or screwing so as to be in contact with the entire circumference of each opening (6).
) has a similar small hole facing the hole (7), and is arranged so as to entirely envelop the static magnetic field generating means (1) and each first wire mesh (12), and a A second wire mesh (14) is disposed insulatingly from the magnetic field generating means (i) and the first wire mesh (12). Then, the side yoke (5) and the second wire mesh (14)
) is electrically connected at one point to the ground wire (15
). Furthermore, the lid (13) is attached to the first wire mesh (
It has the same shape as the opening of 12), and has two disc-shaped wire meshes (1
It is constructed by sandwiching a disc-shaped sheet (13c) made of the same material as the sheet (11) between 3a) and 13b, and the inner wire mesh (13a) is made of the first metal F.
J (12) and the outer wire mesh (13b) are the second wire mesh.
14) so as to be electrically connected to each other. Then, when the lid (13) is opened and the object to be measured (16) is inserted into the static magnetic field generating means (1), the winter jacket (13) is closed.

従って、静磁界発生手段（１）内は、第２金網（１４）
及び冬着（１３）により完全に電波シールドが施こ詐れ
ることとなり、外部の影響を受けることなく被測定物（
１６）の核磁気共鳴から得られる電波信号を得ることが
できる。Therefore, inside the static magnetic field generating means (1), the second wire mesh (14)
And winter clothing (13) completely prevents radio wave shielding, allowing the object to be measured (
16) Radio wave signals obtained from nuclear magnetic resonance can be obtained.

ここで、第１金網（１２）の長さは、被測定物＜１６）
を完全に靜磁界発生手段（１〉内に収容できるもの→　
であればよく、特に限定されるものではない。Here, the length of the first wire mesh (12) is the object to be measured < 16)
Completely silent magnetic field generating means (1) that can accommodate
It is not particularly limited as long as it is suitable.

なお、各金網に代えて金属箔を使用することもできる。Note that metal foil can also be used instead of each wire mesh.

更に、サイドヨークの形状も円筒状に限らず、角柱形状
とし、これに伴ない上部ヨーク及び下部ヨークも多角形
状にしてもよい。また、各ヨークにより球形状の静磁界
発生手段を形成してもよい。Further, the shape of the side yoke is not limited to a cylindrical shape, but may be a prismatic shape, and the upper yoke and the lower yoke may also be polygonal. Further, each yoke may form a spherical static magnetic field generating means.

くべ）　発明の効果 本発明によれは、静磁界発生手段は、被測定物挿入用の
開口以外を磁性材料からなるヨークにて密閉した形状で
あると共に、導電性部材により完全に囲繞しているので
、上記ヨークによる磁気シールド効果及び上記導電性部
材による電波シールド効果を奏することとなる。従って
、外部からの影響を受けることなく、安定した測定を行
なうことができる。Effects of the Invention According to the present invention, the static magnetic field generating means has a shape in which the opening for inserting the object to be measured is sealed with a yoke made of a magnetic material, and is completely surrounded by a conductive member. Therefore, the yoke provides a magnetic shielding effect and the conductive member provides a radio wave shielding effect. Therefore, stable measurements can be performed without being affected by external influences.

【図面の簡単な説明】[Brief explanation of drawings]

図は本発明の一実施例を示し、第１図（ａ）及び（ｂン
はＮＭＲ−ＣＴにおける靜磁界発生手段の夫々一部破断
して示す部分上面図及び側面図、第２図及び第３図はシ
ールドを施こした状態を示す一斜視図及び側面断面図で
ある。 （２）・・永久磁石、（３）・　上部ヨーク、（４）　
・下部ヨーク、（５）・　サイドヨーク、（１１）・・
　シート、（１２ン・・・第１金網、〈１４〉　・第２
金網。 出願人　三洋電機株式会社 代理人　弁理士　佐野靜夫 第１図 １ 手　続　補　正　書（自発） 昭和６０年４月２日 昭和５゛９年特許願第９７７５６号 ２゜発明の名称 核磁気共鳴撮偉装置 ６補正をする者 事件との関係　特許出願人 名称　（＋８８）三洋電機株式会社 ４°代　理　人 住所　守口市京阪本通２丁目１８番地The figures show one embodiment of the present invention, and FIGS. 1(a) and (b) are partial top and side views, respectively, partially cut away of a silent magnetic field generating means in NMR-CT, and FIGS. Figure 3 is a perspective view and a side sectional view showing the shielded state. (2) Permanent magnet, (3) Upper yoke, (4)
・Lower yoke, (5)・Side yoke, (11)...
Sheet, (12mm...1st wire mesh, <14> 2nd
wire mesh. Applicant Sanyo Electric Co., Ltd. Agent Patent Attorney Shizuo Sano Figure 1 1 Procedures Amendment (spontaneous) April 2, 1985 Patent Application No. 97756, filed in 1980 2゜ Name of the invention Nuclear magnetic resonance Relationship to the case of person who corrects photographic device 6 Patent applicant name (+88) Sanyo Electric Co., Ltd. 4° Agent Address 2-18 Keihan Hondori, Moriguchi City

Claims (1)

【特許請求の範囲】[Claims] （１）一対の永久磁石及び該磁石を磁気的に結合すると
共にほぼ密閉された空間を形成する磁気ヨークからなる
靜磁界発生手段により上記空間に一様な静磁界を形成し
、上記磁気ヨークに設けた被測゛宝物挿入用の開口より
被測定物を上記靜磁界中に設置することにより、上記被
測定物の原子核分布を画像表示する核磁気共鳴撮像装置
であって、上記静磁界発生手段を導電性部材により囲繞
したことを特徴とする核磁気共鳴撮像装置。(1) A uniform static magnetic field is formed in the space by a static magnetic field generating means consisting of a pair of permanent magnets and a magnetic yoke that magnetically couples the magnets and forms a nearly sealed space, and A nuclear magnetic resonance imaging apparatus that displays an image of the atomic distribution of the object to be measured by placing the object in the quiet magnetic field through a provided opening for inserting the object to be measured, the static magnetic field generating means 1. A nuclear magnetic resonance imaging device characterized in that: is surrounded by a conductive member.
JP59097736A 1984-05-16 1984-05-16 Nuclear magnetic resonance image pickup device Pending JPS60242350A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59097736A JPS60242350A (en) 1984-05-16 1984-05-16 Nuclear magnetic resonance image pickup device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59097736A JPS60242350A (en) 1984-05-16 1984-05-16 Nuclear magnetic resonance image pickup device

Publications (1)

Publication Number Publication Date
JPS60242350A true JPS60242350A (en) 1985-12-02

Family

ID=14200179

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59097736A Pending JPS60242350A (en) 1984-05-16 1984-05-16 Nuclear magnetic resonance image pickup device

Country Status (1)

Country Link
JP (1) JPS60242350A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995010786A3 (en) * 1993-10-11 1995-06-01 Innervision Mri Limited Apparatus for magnetic resonance measurement
US5986531A (en) * 1996-08-22 1999-11-16 Esaote S.P.A. Electromagnetic shielding device for nuclear magnetic resonance apparati

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995010786A3 (en) * 1993-10-11 1995-06-01 Innervision Mri Limited Apparatus for magnetic resonance measurement
US5986531A (en) * 1996-08-22 1999-11-16 Esaote S.P.A. Electromagnetic shielding device for nuclear magnetic resonance apparati

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