JPH0975323A - Probe device for mri system - Google Patents
Probe device for mri systemInfo
- Publication number
- JPH0975323A JPH0975323A JP7236784A JP23678495A JPH0975323A JP H0975323 A JPH0975323 A JP H0975323A JP 7236784 A JP7236784 A JP 7236784A JP 23678495 A JP23678495 A JP 23678495A JP H0975323 A JPH0975323 A JP H0975323A
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- former
- size
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- patient
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、被検体内の原子核
スピンの磁気共鳴現象を利用したＭＲＩ（磁気共鳴イメ
ージング）システムに用いるプローブ装置に係り、とく
に、被検体からのＭＲ信号を受信する複数のコイル素子
の内、少なくとも１個のコイル素子がボリューム（volu
me）コイルである多素子コイルを備えたプローブ装置に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe device used in an MRI (magnetic resonance imaging) system utilizing the magnetic resonance phenomenon of nuclear spins in a subject, and more particularly to a plurality of probe devices for receiving MR signals from the subject. At least one of the coil elements in the volume (volu
me) A probe device having a multi-element coil which is a coil.
【０００２】[0002]
【発明が解決しようする課題】ＭＲＩシステムでは、通
常、高周波磁場を被検体に送信するとともに、被検体か
らのＭＲ信号を受信する必要があり、この機能を担うＲ
Ｆコイルを備えている。このＲＦコイルの一つに、ＱＤ
（直交）コイルやフェーズドアレイ（phasedarray）コ
イルなどにみられる如く、複数のコイル素子（ボリュー
ムコイル又はサーフェースコイルで成る）を使って１つ
のコイルアセンブリとして形成される多素子コイルが在
る。ここで、「ボリュームコイル」は立体的な内部空間
を有するコイルで、その空間に被検体を挿入させるコイ
ルであり、「サーフェースコイル」は平面的に形成され
るコイルで、被検体の体表又はその付近に設置するコイ
ルである。In an MRI system, it is usually necessary to transmit a high-frequency magnetic field to a subject and receive MR signals from the subject.
It has an F coil. One of this RF coil, QD
There are multi-element coils that are formed as a single coil assembly using multiple coil elements (consisting of volume coils or surface coils), as found in (orthogonal) coils and phased array coils. Here, the “volume coil” is a coil having a three-dimensional internal space, and is a coil for inserting a subject into the space, and the “surface coil” is a coil formed in a plane and is a body surface of the subject. Or, it is a coil installed in the vicinity thereof.
【０００３】この多素子コイルでは、コイル素子間に相
互誘導などの磁気的カップリングを生じさせないこと
が、良好なＭＲ画像を得る上で極めて重要である。コイ
ル素子間の相互誘導をほとんど零の状態にするには、コ
イル素子の位置を機構的に移動させて相互誘導が無くな
る位置を決定したり、電気的に逆向きの相互誘導を生じ
させて相殺するなどの対策が採られている。In this multi-element coil, it is extremely important not to cause magnetic coupling such as mutual induction between coil elements in order to obtain a good MR image. To make the mutual induction between coil elements almost zero, the positions of the coil elements are mechanically moved to determine the position where mutual induction disappears, or the opposite mutual electrical induction is generated to cancel the mutual induction. Measures such as doing are taken.
【０００４】一方、多素子コイルにおいても、ＳＮＲ
（Ｓ／Ｎ比）向上などの観点から、各コイル素子を被検
体に極力接近させて配置することが望ましく、被検体の
大きさに合わせて多素子コイルの形状（例えば径）を最
適化したいところである。しかし、単純に多素子コイル
の形状を変えてしまうと、コイル素子間の位置的条件が
変化し、相互誘導が相殺されなくなることが多い。つま
り、相互誘導が残ってしまい、再構成したＭＲ画像の画
質低下を招くことになる。On the other hand, even in a multi-element coil, the SNR
From the viewpoint of improving (S / N ratio) and the like, it is desirable to arrange each coil element as close to the subject as possible, and to optimize the shape (eg diameter) of the multi-element coil according to the size of the subject. By the way. However, if the shape of the multi-element coil is simply changed, the positional condition between the coil elements changes, and mutual induction often does not cancel out. In other words, mutual guidance remains, resulting in deterioration of the image quality of the reconstructed MR image.
【０００５】ただ、相互誘導の相殺条件を変化させない
範囲での多素子コイルの被検体サイズに合わせた形状変
形は従来でも実施されている。この一例を、図１０及び
図１１、１２に示す。図１０は対向型のフェーズドアレ
イコイル１００の例を示し、被検体の体格（サイズ）に
応じて、対向するコイル素子の間隔を例えばｈ１の範囲
で調整するものである。図１１及び１２は腹巻き型のフ
レキシブルなフェーズドアレイ又はリニアのコイル１０
１の例を模式的に示し、図１２（ａ）及び（ｂ）に示す
如く、被検体のサイズに応じて巻き具合に拠りコイル素
子の対向間隔を調整できる（ただし、被検体Ｐの両側の
所定位置ａ，ｂに来るコイル素子位置Ａ，Ｂは常に一定
である）。However, the deformation of the shape of the multi-element coil according to the size of the object to be inspected has been carried out in the prior art within the range in which the condition for canceling out mutual induction is not changed. An example of this is shown in FIG. 10 and FIGS. FIG. 10 shows an example of the opposed phased array coil 100, in which the interval between opposed coil elements is adjusted within the range of h1, for example, according to the physique (size) of the subject. 11 and 12 show a flexible bellows type phased array or linear coil 10
As shown in FIGS. 12A and 12B, the facing distance of the coil elements can be adjusted according to the winding condition according to the size of the subject (provided that both sides of the subject P are The coil element positions A and B that come to the predetermined positions a and b are always constant).
【０００６】しかしながら、上述のようにＲＦコイルの
形状を被検体サイズに応じて変えることができるのは、
表面（surface ）コイルのアレイ又は１素子のみのボリ
ュームコイルに限られており、ＱＤコイルや１個以上の
ボリューム（volume）コイルを含む多素子コイルではそ
のコイル配置の複雑さゆえに、相互誘導を相殺して良好
なＳＮＲを保持した状態でコイル形状を被検体サイズに
応じて変えることは実現されていなかった。However, it is possible to change the shape of the RF coil according to the size of the subject as described above.
It is limited to an array of surface coils or a volume coil with only one element, and in a multi-element coil including a QD coil or one or more volume coils, mutual induction is canceled out due to the complexity of the coil arrangement. Therefore, it has not been realized to change the coil shape according to the size of the subject while maintaining a good SNR.
【０００７】このため、通常、ボリューム型コイルで形
成される多素子コイルの大きさ（開口径）は体格的に大
きい患者に合わせて極力大きく作られ、この大形のコイ
ルで小さい患者もイメージングするのが常であり、その
ような場合には、大きい患者はともなく、小さい患者に
対してはＭＲ画像の画質が低下するという問題があっ
た。Therefore, the size (aperture diameter) of the multi-element coil formed by the volume type coil is usually made as large as possible in accordance with a physically large patient, and this large coil also images a small patient. In such a case, there is a problem that the image quality of the MR image is deteriorated for the small patient and not for the large patient.
【０００８】本発明は、上述した未解決の問題を解決す
べくなされたもので、ＱＤコイルやフェーズドアレイな
どのボリューム型の多素子コイルであっても、コイル素
子間の相互誘導を確実に中和し、かつ被検体サイズ（患
者の体格）に応じて全体のコイル形状を変えることがで
き、被検体サイズの大小に関わらず、各コイル素子を極
力、被検体表面に接近させるようにすることを、その目
的とする。The present invention has been made to solve the above-mentioned unsolved problem, and it is possible to ensure mutual induction between coil elements even in a volume type multi-element coil such as a QD coil or a phased array. The overall coil shape can be changed according to the size of the subject (physical size of the patient), and each coil element should be as close to the subject surface as possible regardless of the size of the subject. Is the purpose.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成させるた
め、請求請１記載の発明では、被検体からのＭＲ信号を
受信する複数のコイル素子を有し且つこの内の少なくと
も１個のコイル素子がボリュームコイルであるフレキシ
ブルな多素子コイルと、前記被検体の周りに前記多素子
コイルを巻装して配置し且つこの被検体のサイズに応じ
て取換え可能なフォーマとを有する。In order to achieve the above object, in the invention described in claim 1, there is provided a plurality of coil elements for receiving MR signals from the subject, and at least one of these coil elements is provided. Has a flexible multi-element coil, which is a volume coil, and a former in which the multi-element coil is wound around the subject and arranged, and which is replaceable according to the size of the subject.
【００１０】また請求請２乃至５記載の発明では、被検
体からのＭＲ信号を受信する複数のコイル素子を有し且
つこの内の少なくとも１個のコイル素子がボリュームコ
イルであるフレキシブルな多素子コイルと、この多素子
コイルに接続され且つ前記複数のコイル素子間の磁気的
な相互誘導を中和する中和回路と、前記被検体の周りに
前記多素子コイルを巻装して配置し且つこの被検体のサ
イズに応じて取換え可能なフォーマと、このフォーマの
内部に埋設され且つこのフォーマの大きさに起因した前
記相互誘導の変化量を補正する補正回路とを有する。In the inventions according to claims 2 to 5, a flexible multi-element coil having a plurality of coil elements for receiving MR signals from the subject and at least one of the coil elements is a volume coil A neutralization circuit connected to the multi-element coil and neutralizing magnetic mutual induction between the plurality of coil elements; and the multi-element coil wound around the subject and arranged. The former includes a former that can be replaced according to the size of the subject, and a correction circuit that is embedded in the former and corrects the amount of change in the mutual induction due to the size of the former.
【００１１】例えば、前記補正回路は前記フォーマの大
きさに応じて変わる前記相互誘導の変化量を相殺する量
を呈する回路であって、この補正回路は予め前記フォー
マに組み込まれている。また例えば、前記補正回路は、
コンデンサと、このコンデンサを介して閉ループを形成
するループコイルとで成る。また例えば、前記フォーマ
は、寝台に寝かせた前記被検体に上から被せることが可
能な略半円筒状を成している。For example, the correction circuit is a circuit that presents an amount that cancels the change amount of the mutual induction that changes according to the size of the former, and the correction circuit is incorporated in the former in advance. Further, for example, the correction circuit is
It is composed of a capacitor and a loop coil that forms a closed loop through the capacitor. Further, for example, the former has a substantially semi-cylindrical shape that can be overlaid on the subject lying on a bed.
【００１２】[0012]
【発明の実施の形態】以下、この発明の実施の形態を説
明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
【００１３】（第１の実施の形態）第１の実施の形態を
図１〜図４に基づいて説明する。(First Embodiment) A first embodiment will be described with reference to FIGS.
【００１４】図１において、符号１０は被検体としての
患者Ｐの例えば胴部に巻かれた、ＭＲＩシステムのプロ
ーブ装置としての多素子コイル（ＲＦコイル）を示す。
この多素子コイル１０は、例えば、サドル型、クロス楕
円型、バードケージ型などのボリュームコイルを複数の
コイル素子として形成してもよいしＱＤコイルであって
もよい。また図４には脊椎用多素子コイル１０の一例を
示し、複数のコイル素子１０1 〜１０4 の内、１つのコ
イル素子１０1 がボリュームコイルで、他のコイル素子
１０2 〜１０4 はサーフェースコイルで形成されるもの
である。In FIG. 1, reference numeral 10 indicates a multi-element coil (RF coil) as a probe device of the MRI system, which is wound around, for example, the body of a patient P as an object.
The multi-element coil 10 may be, for example, a saddle type, a cross ellipse type, a birdcage type volume coil, etc. formed as a plurality of coil elements, or may be a QD coil. In addition, FIG. 4 shows an example of the multi-element coil 10 for the spine. Among the plurality of coil elements 10 1 to 10 4 , one coil element 10 1 is a volume coil and the other coil elements 10 2 to 10 4 are servers. It is formed of a face coil.
【００１５】多素子コイル１０は例えばポリイミドのよ
うなフレキシブルな基板材料中に金属薄膜又はその積層
材で成る多素子のコイルパターンを埋め込んで、全体と
してもフレキシブルに形成されている。このため、図２
（ａ），（ｂ）に示すように、患者Ｐの胴部の太さに関
係無く、体表に極力密着させて巻くことができ、胴部が
細い場合（同図（ａ））と太い場合（同図（ｂ））とで
は、重複して巻装される長さが異なる。The multi-element coil 10 is made flexible as a whole by embedding a multi-element coil pattern made of a metal thin film or a laminated material thereof in a flexible substrate material such as polyimide. Therefore, FIG.
As shown in (a) and (b), regardless of the thickness of the torso of the patient P, it can be wound so as to be in intimate contact with the body surface as much as possible, and it is thick when the torso is thin ((a) in the figure). In this case ((b) in the figure), the length of overlapping winding is different.
【００１６】図３には、多素子コイル１０が２つのコイ
ル素子（ボリュームコイル又はサーフェースコイルを代
表するコイル素子であって、その一方は少なくともボリ
ュームコイル）である場合の等価回路を示す。同図にお
いて、符号１１、１２が２つのコイル素子、符号１３が
コイル素子１１、１２間の相互誘導による結合を等価的
に表わす仮想コイルである。両方のコイル素子１１、１
２はトリマコンデンサ１４から成る中和回路で互いに接
続されており、このトリマコンデンサ１４が相互誘導の
仮想コイル１３に並列に接続されている。FIG. 3 shows an equivalent circuit in the case where the multi-element coil 10 is two coil elements (a coil element representing a volume coil or a surface coil, one of which is at least a volume coil). In the figure, reference numerals 11 and 12 are two coil elements, and reference numeral 13 is a virtual coil equivalently representing coupling between the coil elements 11 and 12 by mutual induction. Both coil elements 11, 1
Reference numeral 2 is a neutralization circuit composed of a trimmer capacitor 14, which are connected to each other, and the trimmer capacitor 14 is connected in parallel to a virtual coil 13 for mutual induction.
【００１７】コイル素子１１、１２はＭＲＩシステム本
体の信号処理回路２０に接続され、受信されたＭＲＩ信
号が処理される。またトリマコンデンサ１４にはＭＲＩ
システム本体の中和制御回路２１から患者の太さ、すな
わち多素子コイル１０の巻装数に応じたキャパシタ制御
信号が送られ、これによりトリマコンデンサ１４のキャ
パシタが患者サイズに応じて自動調整されるようになっ
ている。この自動調整は例えば、特開平４−１４１１４
６号、特開平６−２８５０３６号の公報で周知のものを
採用すればよい。The coil elements 11 and 12 are connected to the signal processing circuit 20 of the main body of the MRI system to process the received MRI signal. Also, the trimmer capacitor 14 has an MRI.
The neutralization control circuit 21 of the system body sends a capacitor control signal according to the thickness of the patient, that is, the number of windings of the multi-element coil 10, whereby the capacitor of the trimmer capacitor 14 is automatically adjusted according to the patient size. It is like this. This automatic adjustment is performed by, for example, Japanese Patent Laid-Open No. 14114/1992.
No. 6 and Japanese Patent Application Laid-Open No. 6-285036 may be used.
【００１８】信号処理回路２０では例えば、多素子コイ
ル１０がＱＤコイルの場合で、コイル素子１２はコイル
素子１１より９０度だけ位相の遅れた信号を受信すると
すると、コイル素子１１の位相を９０度ずらしてから互
いの受信信号を加算する処理を含む受信処理が行われ
る。これにより、加算信号の強度は２倍になるが、多素
子コイル１０の巻装数に応じてトリマコンデンサ１４の
キャパシタが調整されることから、多素子コイル１０の
巻装状態が変わって、コイル素子１１、１２間の幾何学
的位置関係が被検体毎に変化しても、コイル素子１１、
１２間の相互誘導が殆ど零に保持される。この結果、コ
イル素子１１、１２の受信雑音には相関が無く、加算し
たときの信号強度は２1/2 倍にしかならないので、ＳＮ
Ｒは２1/2倍に改善され、ＱＤコイルとしての初期の役
目を果たすことになる。In the signal processing circuit 20, for example, when the multi-element coil 10 is a QD coil and the coil element 12 receives a signal whose phase is delayed by 90 degrees from the coil element 11, the phase of the coil element 11 is 90 degrees. A reception process including a process of adding the reception signals of each other after shifting is performed. As a result, although the strength of the added signal is doubled, the winding state of the multi-element coil 10 is changed because the capacitor of the trimmer capacitor 14 is adjusted according to the number of windings of the multi-element coil 10. Even if the geometrical positional relationship between the elements 11 and 12 changes for each subject, the coil elements 11,
The mutual induction between 12 is kept at almost zero. As a result, the received noises of the coil elements 11 and 12 have no correlation, and the signal strength when added is only 2 1/2 times.
The R is improved by 2 1/2 times, and it will serve the initial role as a QD coil.
【００１９】このようなコイル素子間の相互誘導を殆ど
零に保持することに拠る利点は、多素子コイル１０がサ
ドル型、クロス楕円型、バードケージ型などのボリュー
ムコイルをコイル素子として含む場合でも同様に得ら
れ、ＭＲＩシステム本体側で再構成されたＭＲ画像の画
質劣化を防止することができる。The advantage of keeping the mutual induction between the coil elements at almost zero is that the multi-element coil 10 includes a volume coil of a saddle type, a cross ellipse type, a birdcage type or the like as the coil element. Similarly, it is possible to prevent deterioration of the image quality of the MR image reconstructed on the MRI system main body side.
【００２０】（第２の実施の形態）第２の実施の形態を
図５〜図９に基づいて説明する。(Second Embodiment) A second embodiment will be described with reference to FIGS.
【００２１】図５には、被検体Ｐに装着されたＭＲＩシ
ステムのプローブ装置３０の外観を示す。このプローブ
装置３０は、患者Ｐに直接、被着させたフォーマ３１
と、このフォーマ３１の表面に巻装するフレキシブルな
ボリューム型の多素子コイル（ＲＦコイル）３２と、フ
ォーマ３１の内部に予め埋設された相互誘導の補正回路
３３（図６参照）とを備える。FIG. 5 shows an external view of the probe device 30 of the MRI system mounted on the subject P. The probe device 30 includes a former 31 directly attached to the patient P.
And a flexible volume type multi-element coil (RF coil) 32 wound around the surface of the former 31, and a mutual induction correction circuit 33 (see FIG. 6) embedded in the former 31 in advance.
【００２２】多素子コイル３２は、例えば、サドル型、
クロス楕円型、バードケージ型などのボリュームコイル
をコイル素子として１個以上含むコイルであってもよい
しＱＤコイルであってもよい。多素子コイル３０は例え
ばポリイミドのようなフレキシブルな基板材料中に金属
薄膜又はその積層材で成る複数のコイルパターンを埋め
込んで、全体あるいはその一部がフレキシブルに形成さ
れている。図７には、多素子コイル３２が２つのコイル
素子３２ａ，３２ｂ（ボリュームコイル又はサーフェー
スコイルを代表するコイル素子であって、その一方は少
なくともボリュームコイル）である場合の概念図を示
す。両方のコイル素子３２ａ，３２ｂはコンデンサ３４
から成る中和回路で互いに接続されている。この中和用
のコンデンサ３４は、多素子コイル３２が患者Ｐの体軸
方向に直交する径方向に基準径を成して患者Ｐに被着さ
れたとき、２つのコイル素子３２ａ，３２ｂ間の磁気的
相互誘導をほぼ零の状態に中和できる値に予め設定され
ている。コイル素子３２ａ，３２ｂは図示しないＭＲＩ
システム本体の信号処理回路に接続され、受信されたＭ
ＲＩ信号が処理される。The multi-element coil 32 is, for example, a saddle type coil,
It may be a coil including one or more volume coils such as a cross ellipse type or a birdcage type volume coil, or may be a QD coil. The multi-element coil 30 is entirely or partially formed by embedding a plurality of coil patterns made of a metal thin film or a laminated material thereof in a flexible substrate material such as polyimide. FIG. 7 shows a conceptual diagram when the multi-element coil 32 is two coil elements 32a, 32b (a coil element representing a volume coil or a surface coil, one of which is at least a volume coil). Both coil elements 32a and 32b are capacitors 34
Are connected to each other by a neutralization circuit consisting of. The neutralizing capacitor 34 is provided between the two coil elements 32a and 32b when the multi-element coil 32 is attached to the patient P with a reference diameter in a radial direction orthogonal to the body axis direction of the patient P. It is preset to a value that can neutralize magnetic mutual induction to a state of almost zero. The coil elements 32a and 32b are not shown in the MRI.
M received by connecting to the signal processing circuit of the system body
The RI signal is processed.
【００２３】フォーマ３１は、非磁性の合成樹脂で図６
に示す如く所定肉厚を有する略半円筒状に固体形成さ
れ、寝台上に寝かされた患者Ｐに上から被せることがで
きる形状に成っている。このフォーマ３１は患者Ｐのサ
イズ（体格）を考慮して、径が異なる例えば「大」、
「中」、「小」のものが予め用意されており、患者Ｐに
最もフィットするものが診断のときに選択される。The former 31 is made of non-magnetic synthetic resin.
As shown in (3), the solid body is formed in a substantially semi-cylindrical shape having a predetermined wall thickness so that the patient P lying on the bed can be covered from above. This former 31 has a different diameter in consideration of the size (physique) of the patient P, for example, “large”,
The "medium" and "small" ones are prepared in advance, and the one that best fits the patient P is selected at the time of diagnosis.
【００２４】フォーマ３１の内部には、前記補正回路３
３が図６に示す如く埋設されている。この補正回路３３
は図７に示す如く、コンデンサ３５と、このコンデンサ
３５を介して閉ループを成すループコイル３６とで成
り、電源は有して又は接続されていない。補正回路３３
は前記中和回路（コンデンサ３４）の中和機能を補完す
るものである。つまり補正回路３３は、フォーマ３１の
径が変わると、フォーマ３１の外周に巻き付ける多素子
コイル３２のコイル素子３２ａ，３２ｂの幾何学的位置
関係も変わり、中和条件も変わってしまうので、コイル
素子間の磁気的相互誘導が零にはならずに残ってしまう
ことから、この残った相互誘導を零にするように補正す
る機能を有する。補正回路３３のコンデンサ３５とルー
プコイル３６の回路定数は、フォーマ３１毎に、その径
に対応した相互誘導の零からの変化量を相殺できる値に
予め設定してある。Inside the former 31, the correction circuit 3 is provided.
3 is buried as shown in FIG. This correction circuit 33
As shown in FIG. 7, is composed of a capacitor 35 and a loop coil 36 that forms a closed loop via the capacitor 35, and has or does not have a power source. Correction circuit 33
Is to complement the neutralizing function of the neutralizing circuit (condenser 34). That is, in the correction circuit 33, when the diameter of the former 31 changes, the geometrical positional relationship of the coil elements 32a and 32b of the multi-element coil 32 wound around the outer periphery of the former 31 also changes, and the neutralization condition also changes. Since the magnetic mutual induction between them does not become zero and remains, it has a function of correcting so that the remaining mutual induction becomes zero. The circuit constants of the capacitor 35 and the loop coil 36 of the correction circuit 33 are preset for each former 31 to a value that can cancel out the change amount from zero of the mutual induction corresponding to the diameter thereof.
【００２５】診断の際、最初に図８（ａ）に示すよう
に、寝台Ｂ上にフレキシブルな多素子コイル３２を載
せ、その上に患者Ｐを寝かせる。そして同図（ａ），
（ｂ）に示すように、患者Ｐにフォーマ３１を上から被
せる。フォーマ３１は被検体Ｐのサイズ（体格）に応じ
て極力、体表にフィットする大きさのものが選択され
る。At the time of diagnosis, first, as shown in FIG. 8A, a flexible multi-element coil 32 is placed on a bed B, and a patient P is laid on it. And the same figure (a),
As shown in (b), the patient P is covered with the former 31 from above. The former 31 is selected to have a size that fits the body surface as much as possible according to the size (physique) of the subject P.
【００２６】次いで、患者Ｐの下側になっている多素子
コイル３２をフォーマ３１の外周に巻き付ける。この巻
き付けは患者Ｐのサイズを意識せずに行うことができ、
図８（ｃ）及び図９に示すように、単純にフォーマ３１
上に多素子コイル３２を残さずに巻き付ければよい。Next, the multi-element coil 32 located below the patient P is wound around the outer circumference of the former 31. This winding can be performed without being aware of the size of the patient P,
As shown in FIG. 8C and FIG.
It may be wound without leaving the multi-element coil 32 on the top.
【００２７】この結果、多素子コイル３２のコイル素子
３２ａ，３２ｂと補正回路３３とが図７に示すように近
接して固定配置される。ＭＲ信号の受信時には、選択し
たフォーマ３１の径が基準値とは異なる場合、多素子コ
イル３２の径も基準値からずれて、中和回路（コンデン
サ３４）では中和しきれなくなり、図７のようにコイル
素子３２ａ，３２ｂ間に相互誘導に係る磁力線Ｍが発生
する。補正回路３３の回路定数はこの相互誘導を検知す
るように適宜に選択されているため、補正回路３３のＬ
Ｃ回路は磁力線Ｍを検知して共振し、磁力線Ｍを相殺す
る方向の磁力線Ｍ´が発生する。これにより中和回路
（コンデンサ３４）で中和しきれないで残っていたコイ
ル素子３２ａ，３２ｂ間の相互誘導が相殺され、コンデ
ンサ３４のキャパシタがみかけ上、その機能を適切に発
揮したと等価な状態となり、相互誘導の殆ど零の状態が
保持される。As a result, the coil elements 32a and 32b of the multi-element coil 32 and the correction circuit 33 are fixedly arranged close to each other as shown in FIG. At the time of receiving the MR signal, if the diameter of the selected former 31 is different from the reference value, the diameter of the multi-element coil 32 also deviates from the reference value, and the neutralization circuit (capacitor 34) cannot completely neutralize it. Thus, the magnetic force lines M relating to mutual induction are generated between the coil elements 32a and 32b. Since the circuit constant of the correction circuit 33 is appropriately selected so as to detect this mutual induction, L of the correction circuit 33 is set.
The C circuit detects the magnetic force line M and resonates to generate a magnetic force line M ′ in a direction of canceling the magnetic force line M. As a result, the mutual induction between the coil elements 32a and 32b, which has not been completely neutralized by the neutralization circuit (capacitor 34), is canceled out, and the capacitor of the capacitor 34 is apparently equivalent to exhibiting its function properly. And the almost zero state of mutual induction is maintained.
【００２８】患者Ｐの体格上のサイズ（胴周りのサイズ
など）が異なる場合でも、多素子コイル３２を変えず、
フォーマ３１だけを適切なサイズのものを選択し、上述
したように被検体に被着させればよい。これにより、患
者Ｐの体格が変わっても多素子コイル３２を実質的に体
表にフィットさせて配置できる。また、フォーマ３１の
サイズ（径）が基準値でない場合、多素子コイル３２の
巻き付けの径も変わり、相互誘導の中和も崩れるが、予
めフォーマ３１にそのフォーマ固有の回路定数を持たせ
て補正回路３３を組み込んであるから、補正回路３３が
相互誘導中和の崩れを補正し、常にほぼ完全に中和状態
が保持される。Even when the physical size of the patient P is different (size around the waist, etc.), the multi-element coil 32 is not changed,
Only the former 31 having an appropriate size may be selected and attached to the subject as described above. As a result, even if the physique of the patient P changes, the multi-element coil 32 can be arranged so as to substantially fit the body surface. Further, when the size (diameter) of the former 31 is not the reference value, the winding diameter of the multi-element coil 32 also changes and the neutralization of mutual induction is destroyed, but it is corrected by previously giving the former 31 a circuit constant unique to the former. Since the circuit 33 is incorporated, the correction circuit 33 corrects the collapse of the mutual induction neutralization, and the neutralization state is always maintained almost completely.
【００２９】このため、検査者は患者Ｐの体格上のサイ
ズに応じてフォーマ３１を使い分けるだけでよく、中和
回路の回路定数などは無調整のまま、多素子コイル３２
の大きさ（径）を患者Ｐ毎に変えることができる。しか
もコイル素子間の相互誘導を常にほぼ零の状態に保持で
きるから、最適条件で撮影でき、ＳＮＲが良好で、高画
質を維持できる。Therefore, the examiner only needs to use the former 31 properly according to the physical size of the patient P, and the multi-element coil 32 is left unadjusted while the circuit constants of the neutralization circuit are not adjusted.
The size (diameter) of can be changed for each patient P. In addition, since mutual induction between coil elements can be maintained at a state of almost zero at all times, photographing can be performed under optimum conditions, SNR is good, and high image quality can be maintained.
【００３０】また、フォーマ３１のサイズを適切に選択
すれば、患者Ｐに直接ＲＦコイルを巻き付ける場合に比
べて、患者の負担も軽減できる。また、従来ではＲＦコ
イルに収容しきれなかった大きな体格の患者もフォーマ
３１を介して多素子コイルを巻くことで撮影可能になる
から、撮影できる患者の体格上の幅が広がるという利点
もある。Further, if the size of the former 31 is appropriately selected, the burden on the patient can be reduced as compared with the case where the RF coil is wound directly on the patient P. In addition, since a patient having a large physique, which cannot be accommodated in the RF coil in the past, can be photographed by winding the multi-element coil through the former 31, there is an advantage that the width of the physique of the patient that can be photographed is widened.
【００３１】さらに、本実施の態様に係る補正回路３３
はフォーマ３１内部に組み込まれるだけで、この回路３
３とほかの回路とを繋ぐリード線は不要である。このた
め、フォーマ３１とその外部とがリード線で繋がるよう
なことがなく、患者へのフォーマ３１の被着やその取り
外しが容易であるという優れた利点もある。Further, the correction circuit 33 according to the present embodiment.
Is incorporated into the former 31 and the circuit 3
The lead wire connecting 3 and other circuits is unnecessary. For this reason, the former 31 and the outside thereof are not connected by a lead wire, and there is also an excellent advantage that the former 31 can be easily attached to and removed from the patient.
【００３２】なお、上述した実施の態様ではコイル素子
が２個の場合を例示したが、勿論３個以上の場合も同様
である。３個以上のコイル素子から成り、且つ１個以上
のボリューム型コイルを含む多素子コイルの場合、その
コイル素子の数、位置に応じた適宜な１個以上の適宜な
数の補正回路をフォーマにその周方向に沿って埋設して
おけばよい。In the above-described embodiment, the case where the number of coil elements is two is illustrated, but the same applies to the case where the number of coil elements is three or more. In the case of a multi-element coil composed of three or more coil elements and including one or more volume type coils, a corrector of an appropriate number of one or more depending on the number and position of the coil elements is used as a former. It may be buried along the circumferential direction.
【００３３】またフォーマの形状も必ずしも略半円筒状
に限定されることなく、診断部位に応じた任意の形状で
あってよい。The shape of the former is not necessarily limited to the substantially semi-cylindrical shape, and may be any shape according to the diagnosis site.
【００３４】[0034]
【発明の効果】以上説明したように、請求請１記載のＭ
ＲＩシステムのプローブ装置は、複数のコイル素子を有
し且つこの内の少なくとも１個のコイル素子がボリュー
ムコイルであるフレキシブルな多素子コイルと、被検体
の周りに多素子コイルを巻装して配置しかつこの被検体
のサイズに応じて取換え可能なフォーマとを有するの
で、フォーマのサイズを適宜に選択することで実質的に
多素子コイルの径などの大きさを被検体のサイズに応じ
て調整することができる。As described above, M of claim 1 is described.
A probe device of an RI system includes a flexible multi-element coil having a plurality of coil elements, and at least one of the coil elements is a volume coil, and the multi-element coil is wound around the subject and arranged. In addition, since it has a former that can be replaced according to the size of the subject, by appropriately selecting the size of the former, the size such as the diameter of the multi-element coil can be substantially changed according to the size of the subject. Can be adjusted.
【００３５】また請求請２乃至５記載のＭＲＩシステム
のプローブ装置は、複数のコイル素子を有し且つこの内
の少なくとも１個のコイル素子がボリュームコイルであ
るフレキシブルな多素子コイルと、この多素子コイルに
接続され且つコイル素子間の磁気的な相互誘導を中和す
る中和回路と、被検体の周りに多素子コイルを巻装して
配置し且つこの被検体のサイズに応じて取換え可能なフ
ォーマと、このフォーマの内部に埋設され且つフォーマ
の大きさに起因した相互誘導の変化量を補正する補正回
路とを有するので、フォーマのサイズを適切に選択する
ことでボリューム型コイルを含む多素子コイルの径など
のサイズを被検体サイズに応じて簡単に調整でき、この
調整に因ってくずれた相互誘導の中和状態はフォーマ内
の補正回路に拠って適宜補正できる。このため、従来は
無理とされていたボリューム型コイルを含む多素子コイ
ルの径（サイズ）を被検体サイズに応じて調整できると
同時に、被検体のサイズに無関係に相互誘導を常にほぼ
零の状態に保持でき、高いＳＮＲに拠って、高画質のＭ
Ｒ画像を再構成できる。また、補正回路をコンデンサと
閉ループを形成するループコイルとで形成することで、
そのＬＣ共振を利用した相互誘導の補正ができ、フォー
マからリード線が出ない分フォーマを扱い易くなり、検
査者の操作上の負担が軽いという効果もある。The probe device of the MRI system according to claims 2 to 5 has a flexible multi-element coil having a plurality of coil elements, and at least one of the coil elements is a volume coil, and the multi-element coil. A neutralization circuit that is connected to the coil and neutralizes the magnetic mutual induction between coil elements, and a multi-element coil is wound around the subject and can be replaced according to the size of the subject. And a correction circuit that is embedded inside the former and corrects the amount of change in mutual induction due to the size of the former. Therefore, by appropriately selecting the size of the former, it is possible to include a volume type coil. Sizes such as the element coil diameter can be easily adjusted according to the size of the subject, and the neutralization state of mutual induction that has collapsed due to this adjustment depends on the correction circuit in the former. It can be appropriately corrected. Therefore, the diameter (size) of the multi-element coil including the volume type coil, which has been impossible in the past, can be adjusted according to the size of the subject, and at the same time, the mutual induction is always zero regardless of the size of the subject. And high image quality due to high SNR
The R image can be reconstructed. In addition, by forming the correction circuit with a capacitor and a loop coil that forms a closed loop,
Mutual induction using the LC resonance can be corrected, the former is easy to handle because the lead wire does not come out from the former, and the operator's operational burden is light.
【図１】本発明の第１の実施の態様に係るプローブ装置
の外観図。FIG. 1 is an external view of a probe device according to a first embodiment of the present invention.
【図２】（ａ），（ｂ）はそれぞれ患者の胴部サイズに
応じた多素子コイルの巻き付け状態を示す説明図。2 (a) and 2 (b) are explanatory views showing a winding state of a multi-element coil according to a patient's torso size.
【図３】多素子コイルの一例を示す回路図。FIG. 3 is a circuit diagram showing an example of a multi-element coil.
【図４】多素子コイルの変形態様を示す説明図。FIG. 4 is an explanatory diagram showing a modification of a multi-element coil.
【図５】本発明の第２の実施の態様に係るプローブ装置
の外観図。FIG. 5 is an external view of a probe device according to a second embodiment of the present invention.
【図６】フォーマの一例を示す外観図。FIG. 6 is an external view showing an example of a former.
【図７】多素子コイルと補正回路の一例を示す説明図。FIG. 7 is an explanatory diagram showing an example of a multi-element coil and a correction circuit.
【図８】（ａ）〜（ｂ）はそれぞれフォーマの被着及び
多素子コイルの巻き付けを示す説明図。8A and 8B are explanatory views showing the attachment of a former and the winding of a multi-element coil, respectively.
【図９】フォーマの被着及び多素子コイルの巻き付けを
示す概略断面図。FIG. 9 is a schematic cross-sectional view showing deposition of a former and winding of a multi-element coil.
【図１０】従来の対向型のフェーズドアレイコイルの一
例を示す図。FIG. 10 is a diagram showing an example of a conventional opposed phased array coil.
【図１１】従来の腹巻き型のコイルの一例を示す図。FIG. 11 is a diagram showing an example of a conventional belly-wound coil.
【図１２】（ａ），（ｂ）はそれぞれ図１０のコイルの
被検体サイズに応じた巻き付け状態を示す図。12 (a) and 12 (b) are diagrams showing a winding state according to the object size of the coil of FIG.
１０ 多素子コイル（プローブ装置） １１，１２ コイル素子 ３０ プローブ装置 ３１ フォーマ ３２ 多素子コイル ３２ａ，３２ｂ コイル素子 ３３ 補正回路 ３４ 中和回路（コンデンサ） ３５ コンデンサ ３６ ループコイル Ｐ 患者（被検体） 10 multi-element coil (probe apparatus) 11, 12 coil element 30 probe apparatus 31 former 32 multi-element coil 32a, 32b coil element 33 correction circuit 34 neutralization circuit (capacitor) 35 capacitor 36 loop coil P patient (subject)
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成７年１２月１３日[Submission date] December 13, 1995
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】図面の簡単な説明[Correction target item name] Brief description of drawings
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の第１の実施の態様に係るプローブ装置
の外観図。FIG. 1 is an external view of a probe device according to a first embodiment of the present invention.
【図２】（ａ），（ｂ）はそれぞれ患者の胴部サイズに
応じた多素子コイルの巻き付け状態を示す説明図。2 (a) and 2 (b) are explanatory views showing a winding state of a multi-element coil according to a patient's torso size.
【図３】多素子コイルの一例を示す回路図。FIG. 3 is a circuit diagram showing an example of a multi-element coil.
【図４】多素子コイルの変形態様を示す説明図。FIG. 4 is an explanatory diagram showing a modification of a multi-element coil.
【図５】本発明の第２の実施の態様に係るプローブ装置
の外観図。FIG. 5 is an external view of a probe device according to a second embodiment of the present invention.
【図６】フォーマの一例を示す外観図。FIG. 6 is an external view showing an example of a former.
【図７】多素子コイルと補正回路の一例を示す説明図。FIG. 7 is an explanatory diagram showing an example of a multi-element coil and a correction circuit.
【図８】（ａ）〜（ｃ）はそれぞれフォーマの被着及び
多素子コイルの巻き付けを示す説明図。8A to 8C are explanatory views showing the attachment of the former and the winding of the multi-element coil, respectively.
【図９】フォーマの被着及び多素子コイルの巻き付けを
示す概略断面図。FIG. 9 is a schematic cross-sectional view showing deposition of a former and winding of a multi-element coil.
【図１０】従来の対向型のフェーズドアレイコイルの一
例を示す図。FIG. 10 is a diagram showing an example of a conventional opposed phased array coil.
【図１１】従来の腹巻き型のコイルの一例を示す図。FIG. 11 is a diagram showing an example of a conventional belly-wound coil.
【図１２】（ａ），（ｂ）はそれぞれ図１０のコイルの
被検体サイズに応じた巻き付け状態を示す図。12 (a) and 12 (b) are diagrams showing a winding state according to the object size of the coil of FIG.
【符号の説明】 １０ 多素子コイル（プローブ装置） １１，１２ コイル素子 ３０ プローブ装置 ３１ フォーマ ３２ 多素子コイル ３２ａ，３２ｂ コイル素子 ３３ 補正回路 ３４ 中和回路（コンデンサ） ３５ コンデンサ ３６ ループコイル Ｐ 患者（被検体）[Explanation of Codes] 10 multi-element coil (probe device) 11, 12 coil device 30 probe device 31 former 32 multi-element coil 32a, 32b coil device 33 correction circuit 34 neutralization circuit (capacitor) 35 capacitor 36 loop coil P patient ( Subject)
Claims (5)
コイル素子を有し且つこの内の少なくとも１個のコイル
素子がボリュームコイルであるフレキシブルな多素子コ
イルと、前記被検体の周りに前記多素子コイルを巻装し
て配置し且つこの被検体のサイズに応じて取換え可能な
フォーマとを有することを特徴とするＭＲＩシステムの
プローブ装置。1. A flexible multi-element coil having a plurality of coil elements for receiving MR signals from a subject, at least one of which is a volume coil, and the flexible multi-element coil around the subject. A probe device for an MRI system, comprising: a multi-element coil wound around the coil; and a former that can be replaced according to the size of the subject.
コイル素子を有し且つこの内の少なくとも１個のコイル
素子がボリュームコイルであるフレキシブルな多素子コ
イルと、この多素子コイルに接続され且つ前記複数のコ
イル素子間の磁気的な相互誘導を中和する中和回路と、
前記被検体の周りに前記多素子コイルを巻装して配置し
且つこの被検体のサイズに応じて取換え可能なフォーマ
と、このフォーマの内部に埋設され且つこのフォーマの
大きさに起因した前記相互誘導の変化量を補正する補正
回路とを有することを特徴とするＭＲＩシステムのプロ
ーブ装置。2. A flexible multi-element coil having a plurality of coil elements for receiving MR signals from a subject, at least one of which is a volume coil, and a flexible multi-element coil connected to the multi-element coil. And a neutralization circuit that neutralizes magnetic mutual induction between the plurality of coil elements,
A former, which is arranged by winding the multi-element coil around the subject and is replaceable according to the size of the subject, and which is embedded inside the former and is caused by the size of the former. A probe device for an MRI system, comprising: a correction circuit that corrects a change amount of mutual induction.
応じて変わる前記相互誘導の変化量を相殺する量を呈す
る回路であって、この補正回路は予め前記フォーマに組
み込まれている請求請２記載のＭＲＩシステムのプロー
ブ装置。3. The correction circuit is a circuit that presents an amount that cancels the change amount of the mutual induction that changes according to the size of the former, and the correction circuit is incorporated in the former in advance. A probe device of the described MRI system.
ンデンサを介して閉ループを形成するループコイルとで
成る請求請３記載のＭＲＩシステムのプローブ装置。4. The probe device for an MRI system according to claim 3, wherein the correction circuit includes a capacitor and a loop coil that forms a closed loop via the capacitor.
検体に上から被せることが可能な略半円筒状を成してい
る請求請２乃至４のいずれか１項に記載のＭＲＩシステ
ムのプローブ装置。5. The probe of the MRI system according to claim 2, wherein the former has a substantially semi-cylindrical shape capable of covering the subject lying on a bed from above. apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7236784A JPH0975323A (en) | 1995-09-14 | 1995-09-14 | Probe device for mri system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7236784A JPH0975323A (en) | 1995-09-14 | 1995-09-14 | Probe device for mri system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0975323A true JPH0975323A (en) | 1997-03-25 |
Family
ID=17005749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7236784A Pending JPH0975323A (en) | 1995-09-14 | 1995-09-14 | Probe device for mri system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0975323A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001070277A (en) * | 1999-09-03 | 2001-03-21 | Ge Yokogawa Medical Systems Ltd | Rf coil, magnetic resonance signal mesureming instrument and magnetic resonance image instrument |
| JP2001245867A (en) * | 2000-03-03 | 2001-09-11 | Hitachi Medical Corp | Rf coil for magnetic resonance imaging apparatus |
| WO2005124380A3 (en) * | 2004-06-17 | 2006-03-30 | Koninkl Philips Electronics Nv | Flexible and wearable radio frequency coil garments for magnetic resonance imaging |
| WO2006121949A1 (en) * | 2005-05-06 | 2006-11-16 | Regents Of The University Of Minnesota | Wirelessly coupled magnetic resonance coil |
| JP2015213780A (en) * | 2015-07-13 | 2015-12-03 | 株式会社東芝 | Coil pad and planar coil device |
-
1995
- 1995-09-14 JP JP7236784A patent/JPH0975323A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001070277A (en) * | 1999-09-03 | 2001-03-21 | Ge Yokogawa Medical Systems Ltd | Rf coil, magnetic resonance signal mesureming instrument and magnetic resonance image instrument |
| JP2001245867A (en) * | 2000-03-03 | 2001-09-11 | Hitachi Medical Corp | Rf coil for magnetic resonance imaging apparatus |
| JP4545870B2 (en) * | 2000-03-03 | 2010-09-15 | 株式会社日立メディコ | Receiver coil for magnetic resonance imaging apparatus and magnetic resonance imaging apparatus |
| WO2005124380A3 (en) * | 2004-06-17 | 2006-03-30 | Koninkl Philips Electronics Nv | Flexible and wearable radio frequency coil garments for magnetic resonance imaging |
| WO2006121949A1 (en) * | 2005-05-06 | 2006-11-16 | Regents Of The University Of Minnesota | Wirelessly coupled magnetic resonance coil |
| US9568572B2 (en) | 2005-05-06 | 2017-02-14 | Regents Of The University Of Minnesota | Bandage or garment combined with a wirelessly coupled magnetic resonance coil |
| JP2015213780A (en) * | 2015-07-13 | 2015-12-03 | 株式会社東芝 | Coil pad and planar coil device |
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