JPH08191809A - Mat for magnetic resonance imaging apparatus - Google Patents
Mat for magnetic resonance imaging apparatusInfo
- Publication number
- JPH08191809A JPH08191809A JP7005971A JP597195A JPH08191809A JP H08191809 A JPH08191809 A JP H08191809A JP 7005971 A JP7005971 A JP 7005971A JP 597195 A JP597195 A JP 597195A JP H08191809 A JPH08191809 A JP H08191809A
- Authority
- JP
- Japan
- Prior art keywords
- mat
- subject
- fluid
- top plate
- magnetic resonance
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、被検体の居住性を良く
するために天板上に配置される磁気共鳴イメージング装
置用マットに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic resonance imaging apparatus mat which is placed on a top plate to improve the habitability of a subject.
【０００２】[0002]
【従来の技術】一般に、磁気共鳴イメージング装置で
は、被検体を磁石内部に搬送するのに移動可能な天板を
用いている。この天板は、湾曲防止のために強化プラス
ティックのような硬質樹脂が使われているため、被検体
の居住性や安定性を考えて天板上に、ウレタンに代表さ
れる発泡性の多孔質樹脂等の柔軟なマットを配備し、こ
の上に被検体を載置するようにしている。磁気共鳴イメ
ージング、特に近年のエコープラナー法等の高速イメー
ジング法では、静磁場や高周波磁場の均一性が画質向上
の重要な要素となっており、マットには磁場を乱さない
仕様が要求される。したがって、マットの材質として
は、柔軟性（居住性）が良いことの他に、比透磁率が１
に近く、電気伝導率が０に近く、比誘電率が空気のよう
に小さく、しかも誘電体損失が少ないという電気特性が
要求される。上述したウレタンはこのような電気特性を
比較的満足しており、マット材として広く使われてい
る。2. Description of the Related Art Generally, a magnetic resonance imaging apparatus uses a movable top plate to convey an object to be examined into a magnet. This top plate uses a hard resin such as reinforced plastic to prevent bending, so considering the habitability and stability of the subject, a foamable porous material such as urethane is used on the top plate. A flexible mat made of resin or the like is provided, and the subject is placed on it. In magnetic resonance imaging, particularly in recent high-speed imaging methods such as the echo planar method, the uniformity of static magnetic fields and high-frequency magnetic fields is an important factor for improving image quality, and mats are required to have specifications that do not disturb magnetic fields. Therefore, in addition to having good flexibility (habitability), the mat has a relative magnetic permeability of 1
, Electrical conductivity is close to 0, relative permittivity is as small as air, and dielectric loss is small. The above-mentioned urethane is relatively satisfied with such electrical characteristics and is widely used as a mat material.
【０００３】ところで、磁気共鳴イメージングにおい
て、水と脂肪との化学的構造の違いによる水素原子核の
共鳴周波数が微妙に装置することを利用して、被検体表
面付近の脂肪層を抑制する特別なパルスシーケンスが存
在する。脂肪と空気との磁化率は劇的に相違する。した
がって、被検体表面とマットとの境界部分では磁化率が
急激に変化し、磁場均一度が乱れて脂肪抑制効果が低下
してしまう、またこの境界部分での画質が劣化するとい
う問題が生じる。By the way, in magnetic resonance imaging, a special pulse for suppressing the fat layer near the surface of the subject is utilized by utilizing the fact that the resonance frequency of hydrogen nuclei due to the difference in chemical structure between water and fat is delicately set. Sequence exists. The magnetic susceptibility of fat and air is dramatically different. Therefore, the magnetic susceptibility rapidly changes at the boundary between the surface of the subject and the mat, the magnetic field homogeneity is disturbed, the fat suppression effect is reduced, and the image quality at this boundary deteriorates.
【０００４】さらに、高速スピンエコー法やエコープラ
ナー法等の高速イメージングでは、高周波磁場のパルス
デューティー比が上昇し、ＳＡＲ（Specific Absorptio
n Rate）が上昇することを考えると、従来のウレタンマ
ットでは放熱効果が不十分であり、逆に保温効果を作用
してしまう。Further, in high-speed imaging such as the high-speed spin echo method and the echo planar method, the pulse duty ratio of the high-frequency magnetic field rises and SAR (Specific Absorptio)
Considering that the n rate) increases, the heat dissipation effect is insufficient with the conventional urethane mat, and on the contrary, the heat retention effect is exerted.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、良好な居住
性及び良好な放熱効果を実現し、しかも被検体表面との
境界付近での磁場の乱れを軽減して脂肪抑制効果の低下
や画質劣化を抑制できる磁場磁気共鳴イメージング装置
用マットを提供することである。DISCLOSURE OF THE INVENTION The present invention realizes good habitability and good heat dissipation effect, and further reduces disturbance of the magnetic field near the boundary with the surface of the subject to reduce the fat suppression effect and image quality. A mat for a magnetic field magnetic resonance imaging apparatus capable of suppressing deterioration.
【０００６】[0006]
【課題を解決するための手段】本発明は、天板上に配置
され被検体が載置される磁気共鳴イメージング装置用マ
ットにおいて、被検体に近似的な磁化率を有し、且つ同
容積の空気より熱容量の大きな流動物を充填したことを
特徴とすることを特徴とする。SUMMARY OF THE INVENTION The present invention provides a magnetic resonance imaging apparatus mat which is placed on a top plate and on which a subject is placed, which has a magnetic susceptibility approximate to that of the subject and has the same volume. It is characterized by being filled with a fluid having a larger heat capacity than air.
【０００７】[0007]
【作用】本発明によると、流動物は被検体に近似的な磁
化率を有するので、被検体表面との境界部分における磁
化率の変化が少なく、この境界部分の磁場均一度の乱れ
が軽減されるので、被検体表面付近の脂肪抑制効果が向
上され、また被検体表面付近の画質の劣化が抑制され
る。また本発明によると、流動物は同容積の空気より熱
容量が大きいので、高い放熱効果を実現できる。さら
に、本発明によると、流動物を充填したので、マットに
被検体が横たわった場合、従来のウレタンマットに比べ
て、被検体が受ける抗力は特定の部位に集中しないで分
散されるため、人間工学的にも良好な居住性を実現し、
比較的長時間の撮影であっても被検体の負担は軽減す
る。According to the present invention, since the fluid has a magnetic susceptibility close to that of the object, the change in magnetic susceptibility at the boundary with the surface of the object is small, and the disturbance of the magnetic field homogeneity at this boundary is reduced. Therefore, the effect of suppressing fat near the surface of the subject is improved, and deterioration of image quality near the surface of the subject is suppressed. Further, according to the present invention, since the fluid has a larger heat capacity than air of the same volume, a high heat dissipation effect can be realized. Furthermore, according to the present invention, since the fluid is filled, when the subject lays on the mat, the drag received by the subject is dispersed rather than concentrated on a specific part, as compared with the conventional urethane mat. Achieving good habitability in terms of engineering,
The burden on the subject is reduced even if the image is taken for a relatively long time.
【０００８】[0008]
【実施例】以下、図面を参照して本発明による磁気共鳴
イメージング装置の天板マットの一実施例を説明する。
図１に磁気共鳴イメージング装置の磁石寝台部の構成を
示す。被検体を収容できるように円筒状の内部空間を有
するガントリ１には、静磁場磁石、Ｘ・Ｙ・Ｚ軸傾斜磁
場コイル、ＲＦコイルが収容されている。永久磁石、常
電導磁石又は超電導磁石である静磁場磁石は、円筒内部
に静磁場を形成する。Ｘ・Ｙ・Ｚ軸傾斜磁場コイルは、
任意に撮影断面を決めたり、磁気共鳴信号に空間的位置
情報を与えるためのＸ、Ｙ、Ｚ各軸の傾斜磁場を作る３
組のコイルから構成されている。ＲＦコイルは、対象原
子核のスピンを励起状態にするために高周波磁場（ＲＦ
パルス）を被検体に送信すると共に、被検体から誘起さ
れる磁気共鳴信号を受信するためのコイルである。ＲＦ
コイルで受信された磁気共鳴信号は受信器で増幅検波さ
れ、さらにアナログ／ディジタル変換されてホストコン
ピュータに取り込まれる。ホストコンピュータは磁気共
鳴信号から磁気共鳴画像を再構成すると共に、傾斜磁
場、ＲＦパルスの各発生タイミングを制御して所定のパ
ルスシーケンスを実行する機能を有している。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a top mat of a magnetic resonance imaging apparatus according to the present invention will be described below with reference to the drawings.
FIG. 1 shows the configuration of the magnet bed of the magnetic resonance imaging apparatus. A gantry 1 having a cylindrical internal space so that a subject can be accommodated therein accommodates a static magnetic field magnet, an X, Y, Z axis gradient magnetic field coil, and an RF coil. The static magnetic field magnet, which is a permanent magnet, a normal conducting magnet or a superconducting magnet, forms a static magnetic field inside the cylinder. The X, Y and Z axis gradient coils are
Create gradient magnetic fields in X, Y, and Z axes to arbitrarily determine the cross-section for imaging and to add spatial position information to magnetic resonance signals 3
It consists of a set of coils. The RF coil is a high frequency magnetic field (RF) in order to bring the spin of the target nucleus into an excited state.
A coil for transmitting a pulse) to the subject and receiving a magnetic resonance signal induced from the subject. RF
The magnetic resonance signal received by the coil is amplified and detected by the receiver, further analog / digital converted, and taken into the host computer. The host computer has a function of reconstructing a magnetic resonance image from a magnetic resonance signal and controlling the timings of generation of the gradient magnetic field and the RF pulse to execute a predetermined pulse sequence.
【０００９】磁気共鳴信号の収集時には、被検体は寝台
２の天板３に載置された状態で、天板３のスライドに伴
ってガントリ１の内部に挿入される。天板３は、静磁場
均一度を乱さないために、また湾曲防止のために、剛性
の強い強化プラスティックのような非磁性体の硬質樹脂
が使われている。At the time of collecting magnetic resonance signals, the subject is placed on the top plate 3 of the bed 2 and inserted into the gantry 1 as the top plate 3 slides. The top plate 3 is made of a non-magnetic hard resin such as reinforced plastic having a high rigidity so as not to disturb the homogeneity of the static magnetic field and to prevent bending.
【００１０】天板３の表面には、本発明のマット４が着
脱自在に配置される。図２（ａ）にマット４の外観図を
示し、図２（ｂ）に横断面図を示す。マット４は、天板
３の平面形状に合わせて縦長矩形の平面形状に形成さ
れ、さらに天板３の表面形状に合わせて、断面円弧凹状
に形成される。マット４は、磁場均一度を乱さないよう
に非磁性体で、しかも衝緩効果を考慮して柔軟な可撓材
で成型された密封性の水袋５と、水袋５の中に充填さ
れ、被検体に近似的な磁化率を有し、また同容積の空気
より熱容量の大きな流動物６とから構成される。On the surface of the top plate 3, the mat 4 of the present invention is detachably arranged. FIG. 2A shows an external view of the mat 4, and FIG. 2B shows a cross-sectional view. The mat 4 is formed in a vertically long rectangular planar shape in conformity with the planar shape of the top plate 3, and is further formed in an arcuate concave sectional shape in conformity with the surface shape of the top plate 3. The mat 4 is made of a non-magnetic material so as not to disturb the magnetic field homogeneity, and has a sealing water bag 5 formed of a flexible material in consideration of the shock absorbing effect. The fluid 6 has a magnetic susceptibility similar to that of the subject and has a larger heat capacity than air of the same volume.
【００１１】流動物６としては、代表的には水である
が、その他、水を溶媒としたゲル、セラミックス、高分
子ゲル、高分子流動性樹脂、水に電解質イオンを溶解さ
せた電解質水溶液等であってもよい。The fluid 6 is typically water, but other than that, a gel containing water as a solvent, a ceramics, a polymer gel, a polymer fluid resin, an electrolyte aqueous solution in which electrolyte ions are dissolved in water, etc. May be
【００１２】上述したマット４は、次のような作用効果
を実現する。 （１）被検体は、被検体に近似的な磁化率の流動物６上
に載置されるので、被検体表面とマット４との境界部分
における磁化率の変化が少ない。したがって、この境界
部分の磁場均一度の乱れが軽減される。これにより、被
検体表面付近の脂肪抑制効果が向上され、また被検体表
面付近の画質の劣化が抑制される。勿論、マット４と天
板３との境界部分では磁化率が急激に変化するので、こ
の部分の画質の劣化は避けられないが、当該画質劣化が
生じる部分が被検体表面からマット４を介して距離的に
隔絶されていることから診断に悪影響を及ぼすものでな
い。 （２）高速スピンエコー法やエコープラナー法等の高速
イメージングでは、高周波磁場のパルスデューティー比
が上昇し、ＳＡＲ（Specific Absorption Rate）が上昇
するので、被検体の熱対策が重要である。空気を多く含
有する従来の発泡性樹脂製のマットに比べ、本発明のマ
ット４は熱容量が圧倒的に大きい。例えば、従来マット
と、本発明のマット４の容積を50cm×100cm ×5cm ＝0.
025m3 で同じとし、従来マットの空気の質量は20g 、マ
ット４の水の質量は25kgとして考えると、空気の比熱は
4.2×0.24J/g ・K 、水の比熱は 4.2×1.00J/g ・K で
与えられているので、従来マットの熱容量、マット４の
熱容量は次の通りである。 本発明のマット４の熱容量：1.05×105 J/K 従来マットの熱容量：2.02×101 J/K したがって、本発明のマット４は従来マットに比べて約
5200倍の熱容量を持つことになり、マット４は従来マッ
トに比べて圧倒的に高い放熱効果を実現できる。なお、
マット４は流動物６を含有しているので、放熱効果をさ
らに高めるために、マット４と外部冷却装置との間でポ
ンプにより流動物６を循環させるような構成を採用する
ことも容易である。 （３）マット４は水袋５に流動物６を充填した構造であ
るので、従来のウレタンマットに比べて良好な居住性を
実現する。つまり、流動物６を水袋５に充填したマット
４に被検体が横たわった場合、従来のウレタンマットに
比べて、被検体が受ける抗力は特定の部位に集中しない
で分散されるため、人間工学的にも良好な居住性を実現
し、比較的長時間の撮影であっても被検体の負担は軽減
する。The mat 4 described above realizes the following operational effects. (1) Since the subject is placed on the fluid 6 having a magnetic susceptibility similar to that of the subject, the change in magnetic susceptibility at the boundary between the surface of the subject and the mat 4 is small. Therefore, the disturbance of the magnetic field homogeneity at the boundary portion is reduced. As a result, the fat suppression effect near the surface of the subject is improved, and the deterioration of image quality near the surface of the subject is suppressed. Of course, since the magnetic susceptibility suddenly changes at the boundary between the mat 4 and the top plate 3, deterioration of the image quality at this part is unavoidable, but the part where the image quality deterioration occurs is from the surface of the subject through the mat 4. Since they are separated by distance, they do not adversely affect the diagnosis. (2) In high-speed imaging such as the high-speed spin echo method or the echo planar method, the pulse duty ratio of the high-frequency magnetic field rises and the SAR (Specific Absorption Rate) rises, so it is important to take measures against the heat of the subject. The mat 4 of the present invention has an overwhelmingly large heat capacity as compared with the conventional mat made of a foaming resin containing a large amount of air. For example, the volume of the conventional mat and the volume of the mat 4 of the present invention are 50 cm × 100 cm × 5 cm = 0.
Assuming the same for 025 m 3 , assuming that the mass of air in the conventional mat is 20 g and the mass of water in mat 4 is 25 kg, the specific heat of air is
Since the specific heat of water is 4.2 × 0.24 J / g · K and the specific heat of water is 4.2 × 1.00 J / g · K, the heat capacity of the conventional mat and the heat capacity of the mat 4 are as follows. Heat capacity of the mat 4 of the present invention: 1.05 × 10 5 J / K Heat capacity of the conventional mat: 2.02 × 10 1 J / K Therefore, the mat 4 of the present invention is approximately the same as the conventional mat.
Since it has a heat capacity of 5200 times, the mat 4 can achieve an overwhelmingly high heat dissipation effect compared to the conventional mat. In addition,
Since the mat 4 contains the fluid 6, the structure in which the fluid 6 is circulated by a pump between the mat 4 and the external cooling device can be easily adopted in order to further enhance the heat dissipation effect. . (3) Since the mat 4 has a structure in which the fluid 6 is filled in the water bag 5, a better habitability is realized as compared with the conventional urethane mat. That is, when the subject lies on the mat 4 in which the fluid 6 is filled in the water bag 5, the drag force received by the subject is dispersed rather than concentrated on a specific part, as compared with the conventional urethane mat, so that ergonomics From the viewpoint of good habitability, the burden on the subject is reduced even if the image is taken for a relatively long time.
【００１３】さらに本発明では、次のような効果も期待
できる。磁気共鳴信号は静磁場の２乗に比例するので、
ＳＮ比向上のためには高磁場が好ましい。しかし、高磁
場になるほど、 larmor （ラーモア）周波数が高くな
り、核スピンを励起するために使用される高周波磁場の
波長が短くなる。例えば、比誘電率の高い水を考える
と、1.5Teslaの静磁場強度では、波長λ´は、次の
（１）式で与えられる。なお、水の比誘電率εr を８
０、媒質内伝搬速度ｃを 3.0×108 、高周波磁場の周波
数ｆを63.9×106 とする。Further, according to the present invention, the following effects can be expected. Since the magnetic resonance signal is proportional to the square of the static magnetic field,
A high magnetic field is preferable for improving the SN ratio. However, the higher the magnetic field, the higher the larmor frequency and the shorter the wavelength of the high-frequency magnetic field used to excite nuclear spins. For example, considering water having a high relative permittivity, at a static magnetic field strength of 1.5 Tesla, the wavelength λ'is given by the following equation (1). Note that the relative permittivity ε r of water is 8
0, the propagation velocity c in the medium is 3.0 × 10 8 , and the frequency f of the high-frequency magnetic field is 63.9 × 10 6 .
【００１４】[0014]
【数１】 [Equation 1]
【００１５】また、 Bottomleyらによるラットの各種組
織に対する比誘電率の周波数測定などによると、比誘電
率が 200を越えるものも見られ、その場合、波長が20cm
にまで短縮されることが確認されている。被検体の一般
的なサイズが直径40cmとして考えると、波長の効果が無
視できなくなる。したがって、本発明のマット４の比較
的高い比誘電率を持つ流動物（水）６や高誘電率で低誘
電損率を有するセラミックや高分子化合物などを用い
て、マット４内部の流動物６の比誘電率と流動物６の層
の厚さとの少なくとも一方を空間的に変化させること
で、高周波磁場の磁場分布を積極的にコントロールし
て、高周波磁場を均一度を向上させるいわゆるシム機能
を実現できる。なお、誘電損率が大きいと送受信時のこ
の誘電体部分での損失が無視できなくなり、送受信効率
が低下してしまうので、効率を重視する場合には、流動
物６の誘電損率は低いことが好ましい。In addition, according to the frequency measurement of the relative permittivity of various tissues of rat by Bottomley et al., Some have a relative permittivity of more than 200, in which case the wavelength is 20 cm.
It has been confirmed to be shortened to. Considering the general size of the object as 40 cm in diameter, the effect of wavelength cannot be ignored. Therefore, using the fluid (water) 6 having a relatively high relative dielectric constant of the mat 4 of the present invention, or the ceramic or polymer compound having a high dielectric constant and a low dielectric loss factor, the fluid 6 inside the mat 4 is used. By spatially varying at least one of the relative permittivity and the thickness of the layer of the fluid 6, a so-called shim function of positively controlling the magnetic field distribution of the high frequency magnetic field to improve the uniformity of the high frequency magnetic field is obtained. realizable. Note that if the dielectric loss factor is large, the loss in this dielectric portion during transmission and reception cannot be ignored, and the transmission / reception efficiency will decrease. Therefore, when importance is placed on efficiency, the dielectric loss factor of the fluid 6 should be low. Is preferred.
【００１６】また、流動物６が電解質水溶液であれば、
特にマットエッジ付近の高周波磁場の磁場分布を渦電流
の作用によって変化させることができる。つまり、電解
質水溶液の導電率とその電解質水溶液の層の厚さに依存
して、その層の周辺の磁界の振幅と位相が変化し、磁場
分布が変化するので、マット４内部の電解質水溶液の導
電率と、その電解質水溶液の層の厚さの少なくとも一方
を空間的に変化させることで、マット４に高周波磁場の
均一度を向上させるいわゆるシム機能を実現する。If the fluid 6 is an aqueous electrolyte solution,
In particular, the magnetic field distribution of the high frequency magnetic field near the mat edge can be changed by the action of the eddy current. That is, depending on the conductivity of the electrolyte aqueous solution and the thickness of the layer of the electrolyte aqueous solution, the amplitude and phase of the magnetic field around the layer change, and the magnetic field distribution changes, so that the conductivity of the electrolyte aqueous solution inside the mat 4 changes. By spatially varying at least one of the rate and the thickness of the electrolyte aqueous solution layer, a so-called shim function for improving the uniformity of the high-frequency magnetic field is realized in the mat 4.
【００１７】マット４内部の流動物６の比誘電率、導電
率、流動物６の層の厚さを変化させるには、例えば以下
の方法を用いる。第１の方法としては、比誘電率、導電
率、流動物６の層の厚さの異なる複数のマットを用意
し、条件に応じて複数のマットから選出し、且つ選出し
たマットの配置を変える。第２の方法としては、流動物
６を外部タンクとの間でかん流させ、マットに注入する
流動物６の比誘電率、導電率を制御し、また、注入ポン
プの出力（圧力）を変化させて、流動物６の層の厚さを
変化させる。In order to change the relative permittivity and conductivity of the fluid 6 inside the mat 4 and the layer thickness of the fluid 6, for example, the following method is used. As a first method, a plurality of mats having different dielectric constants, electric conductivities, and layer thicknesses of the fluid 6 are prepared, selected from the plurality of mats according to the conditions, and the arrangement of the selected mats is changed. . As a second method, the fluid 6 is perfused with an external tank to control the relative permittivity and conductivity of the fluid 6 injected into the mat, and the output (pressure) of the injection pump is changed. Then, the thickness of the layer of the fluid 6 is changed.
【００１８】なお本実施例の応用例として、図３に示す
ように、マット４と同様の流動物６を水袋５に充填した
構造を毛布状（布団状）に加工した毛布マット７を提供
する。撮影のときには、この毛布マット７を被検体Ｐに
上掛したり、巻き付けたりすることが可能となる。本発
明は上述の実施例に限定されることなく種々変形して実
施可能である。As an application example of the present embodiment, as shown in FIG. 3, a blanket mat 7 is provided in which a structure in which a fluid 6 similar to the mat 4 is filled in a water bag 5 is processed into a blanket (futon) shape. To do. At the time of photographing, this blanket mat 7 can be hung on or wrapped around the subject P. The present invention is not limited to the above-mentioned embodiments and can be modified in various ways.
【００１９】[0019]
【発明の効果】本発明によると、流動物は被検体に近似
的な磁化率を有するので、被検体表面との境界部分にお
ける磁化率の変化が少なく、この境界部分の磁場均一度
の乱れが軽減されるので、被検体表面付近の脂肪抑制効
果が向上され、また被検体表面付近の画質の劣化が抑制
される。また本発明によると、流動物は同容積の空気よ
り熱容量が大きいので、高い放熱効果を実現できる。さ
らに、本発明によると、流動物を充填したので、マット
に被検体が横たわった場合、従来のウレタンマットに比
べて、被検体が受ける抗力は特定の部位に集中しないで
分散されるため、人間工学的にも良好な居住性を実現
し、比較的長時間の撮影であっても被検体の負担は軽減
する。According to the present invention, since the fluid has a magnetic susceptibility close to that of the subject, the change in magnetic susceptibility at the boundary with the surface of the subject is small, and the magnetic field homogeneity at the boundary is not disturbed. Since it is reduced, the fat suppressing effect near the surface of the subject is improved, and the deterioration of the image quality near the surface of the subject is suppressed. Further, according to the present invention, since the fluid has a larger heat capacity than air of the same volume, a high heat dissipation effect can be realized. Furthermore, according to the present invention, since the fluid is filled, when the subject lays on the mat, the drag received by the subject is dispersed rather than concentrated on a specific part, as compared with the conventional urethane mat. Good habitability is achieved from an engineering point of view, and the burden on the subject is reduced even when imaging is performed for a relatively long time.
【図１】本発明の一実施例によるマットを採用した磁気
共鳴イメージング装置の外観図。FIG. 1 is an external view of a magnetic resonance imaging apparatus using a mat according to an embodiment of the present invention.
【図２】図１のマットの構造図。FIG. 2 is a structural diagram of the mat shown in FIG.
【図３】マット及び毛布マットの使用状況を示す図。FIG. 3 is a diagram showing a usage situation of a mat and a blanket mat.
１…ガントリ、 ２…寝台、３…天板、 ４…マッ
ト、５…水袋 ６…流動物。1 ... Gantry, 2 ... Sleeper, 3 ... Top plate, 4 ... Mat, 5 ... Water bag 6 ... Fluid.
Claims (2)
気共鳴イメージング装置用マットにおいて、被検体に近
似的な磁化率を有し、且つ同容積の空気より熱容量の大
きな流動物を充填したことを特徴とする磁気共鳴イメー
ジング装置用マット。1. A magnetic resonance imaging apparatus mat, which is placed on a top plate and on which a subject is placed, wherein a fluid having a magnetic susceptibility similar to that of the subject and having a larger heat capacity than air of the same volume is used. A mat for a magnetic resonance imaging apparatus, which is filled.
請求項１記載の磁気共鳴イメージング装置用マット。2. The mat for magnetic resonance imaging apparatus according to claim 1, wherein the fluid is water.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7005971A JPH08191809A (en) | 1995-01-18 | 1995-01-18 | Mat for magnetic resonance imaging apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7005971A JPH08191809A (en) | 1995-01-18 | 1995-01-18 | Mat for magnetic resonance imaging apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08191809A true JPH08191809A (en) | 1996-07-30 |
Family
ID=11625749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7005971A Pending JPH08191809A (en) | 1995-01-18 | 1995-01-18 | Mat for magnetic resonance imaging apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08191809A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007530204A (en) * | 2004-03-29 | 2007-11-01 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | System for magnetic resonance imaging |
| JP2013094362A (en) * | 2011-10-31 | 2013-05-20 | Ge Medical Systems Global Technology Co Llc | Nursing device |
| JP2013545573A (en) * | 2010-12-16 | 2013-12-26 | コーニンクレッカ フィリップス エヌ ヴェ | Passive B1 field shimming |
| JP2018510685A (en) * | 2015-03-04 | 2018-04-19 | コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ． | Patient table assembly |
| EP3361276A1 (en) * | 2017-02-14 | 2018-08-15 | Koninklijke Philips N.V. | A bridge member for a magnetic resonance examination system |
-
1995
- 1995-01-18 JP JP7005971A patent/JPH08191809A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007530204A (en) * | 2004-03-29 | 2007-11-01 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | System for magnetic resonance imaging |
| JP2013545573A (en) * | 2010-12-16 | 2013-12-26 | コーニンクレッカ フィリップス エヌ ヴェ | Passive B1 field shimming |
| US9689941B2 (en) | 2010-12-16 | 2017-06-27 | Koninklijke Philips Electronics N.V. | Passive B1 field shimming |
| JP2013094362A (en) * | 2011-10-31 | 2013-05-20 | Ge Medical Systems Global Technology Co Llc | Nursing device |
| JP2018510685A (en) * | 2015-03-04 | 2018-04-19 | コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ． | Patient table assembly |
| EP3361276A1 (en) * | 2017-02-14 | 2018-08-15 | Koninklijke Philips N.V. | A bridge member for a magnetic resonance examination system |
| WO2018149683A1 (en) * | 2017-02-14 | 2018-08-23 | Koninklijke Philips N.V. | A bridge member for a magnetic resonance examination system |
| US11029379B2 (en) | 2017-02-14 | 2021-06-08 | Koninklijke Philips N.V. | Bridge member for a magnetic resonance examination system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2871384C (en) | Acoustic noise reducing rf coil for magnetic resonance imaging | |
| Hoult et al. | The sensitivity of the zeugmatographic experiment involving human samples | |
| JP5209842B2 (en) | Multi-winding element RF coil array for multi-channel MRI and method of manufacturing an RF coil assembly | |
| US5865177A (en) | Magnetic resonance imaging (MRI) diagnostic apparatus capable of optimally controlling radio-frequency magnetic field by providing flexible material interposed between RF coil and body | |
| US7816918B2 (en) | Optimized MRI strip array detectors and apparatus, systems and methods related thereto | |
| US20110152670A1 (en) | Method of Utilization of High Dielectric Constant (HDC) Materials for Reducing SAR and Enhancing SNR in MRI | |
| EP1087234A2 (en) | Birdcage RF transmitter coil for magnetic resonance apparatus | |
| US6850065B1 (en) | MRI coil system for breast imaging | |
| WO2005052622A1 (en) | Zoom phased array knee coil for mri | |
| JPH0693009B2 (en) | Dielectric loaded NMR radio frequency coil for improved magnetic field homogeneity | |
| WO2010045457A2 (en) | Coil element decoupling for mri | |
| Kathiravan et al. | A review on potential issues and challenges in MR imaging | |
| Wen et al. | The evaluation of dielectric resonators containing H2O or D2O as RF coils for high-field MR imaging and spectroscopy | |
| US4841249A (en) | Truncated cone shaped surface resonator for nuclear magnetic resonance tomography | |
| WO2016157063A1 (en) | Magnetic resonance volume coil with multiple independent transmit receive channels and method of operation thereof | |
| EP2521924B1 (en) | Rf transmit and/or receive antenna for a hybrid mri / hifu system | |
| Moussu et al. | Systematic analysis of the improvements in magnetic resonance microscopy with ferroelectric composite ceramics | |
| JPH08191809A (en) | Mat for magnetic resonance imaging apparatus | |
| US7733091B2 (en) | Probe, system and method suitable for unilateral nuclear magnetic resonance | |
| US7250764B2 (en) | Shielded dome resonator for MR scanning of a cerebrum | |
| KR20160033980A (en) | Receiving coil for magnetic resonance imaging device | |
| JPH0816694B2 (en) | NMR radio frequency coil with dielectric for improved operating efficiency | |
| JP2007530204A (en) | System for magnetic resonance imaging | |
| Wang | Hardware of MRI System | |
| Ilić et al. | RF excitation in 7 Tesla MRI systems using monofilar axial-mode helical antenna |