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    HALBACH-MAGNETANORDNUNG MIT NOTCH
    2.
    发明公开
    HALBACH-MAGNETANORDNUNG MIT NOTCH 审中-公开

    公开(公告)号：EP3657194A1

    公开(公告)日：2020-05-27

    申请号：EP19209473.8

    申请日：2019-11-15

    申请人： Bruker BioSpin GmbH

    发明人： Pietig, Rainer ,  Niemann, Volker ,  Hänichen, Lukas

    IPC分类号： G01R33/383 ,  G01R33/387 ,  H01F7/02

    摘要： Eine Magnetanordnung (1) mit einem aus Magnetsegmenten aufgebauten konzentrisch um die z-Achse angeordneten hohlzylindrischen Magnetelement (2a; 2b; 2c) mit axialer Länge L z,M und Innenradius R in , das eine Halbach-Magnetisierung aufweist, ist dadurch gekennzeichnet, dass mindestens ein ringförmiges Magnetelement eine um die z-Achse umlaufende nutförmige, hohlzylindrische Ausnehmung (3a; 3b) symmetrisch zur Ebene z=0 aufweist, deren axiale Ausdehnung L z,A geringer ist als die axiale Länge L z,M des Magnetelements, wobei die Ausnehmung eine radiale Tiefe T=T A sowie eine axiale Länge L z,A z,M zwischen den z-Positionen z=-z A bis z=+z A , aufweist, und dass die radiale Tiefe T A sowie die axiale Länge L z,A der Ausnehmung so gewählt sind, dass die verbleibende Inhomogenität des homogenen Magnetfeldes B 0 in einem vorgegebenen Messvolumen (0) mit einer axialen Plateaulänge L P im Zentrum der Magnetanordnung 10ppm nicht überschreitet. Damit wird eine ungewöhnlich kompakte und leichtgewichtige Halbachanordnung für eine MR-Vorrichtung bereitgestellt die bei vorgegebener Feldstärke über eine axiale Plateaulänge Lp einen Bereich mit besonders homogener Feldverteilung erzeugt, wobei die äußeren Abmaße der Anordnung sowie deren Gewicht gegenüber bekannten Halbachanordnungen deutlich reduziert sind.

    A BRIDGE MEMBER FOR A MAGNETIC RESONANCE EXAMINATION SYSTEM
    3.
    发明公开
    A BRIDGE MEMBER FOR A MAGNETIC RESONANCE EXAMINATION SYSTEM 审中-公开

    公开(公告)号：EP3361276A1

    公开(公告)日：2018-08-15

    申请号：EP17155986.7

    申请日：2017-02-14

    申请人： Koninklijke Philips N.V.

    发明人： DE WEERDT, Elwin

    IPC分类号： G01R33/387 ,  G01R33/48 ,  G01R33/28 ,  G01R33/56 ,  G01R33/565 ,  A61B5/055

    CPC分类号： G01R33/387 ,  G01R33/28 ,  G01R33/4828 ,  G01R33/5607 ,  G01R33/56527

    摘要： The present invention pertains to magnetic resonance imaging, notably of separate body parts with open space between them. A bridge member (51) containing MR responsive material is provided in the open space to establish a correspondence between the body parts (41, 42). The MR responsive material generates magnetic resonance signals in response the RF excitation, so that between the separate body parts via the bridge member magnetic resonance signal are obtained from positions between which there is at most a limited spatial variation of the main magnetic field, so that phase ambiguities between the signals from these positions are avoided. Thus chemical shift separation, notably water-fat separation though a region-of-interest containing several (both) body parts may rely on a smoothness condition imposed on the spatial distribution of the main magnetic field. This avoids artefacts, such as water-fat swaps when separating water and fat contributions in the reconstructed magnetic resonance image.

    SYSTEM AND METHOD FOR AN EDDY-CURRENT FIELD COMPENSATION IN MAGNETIC RESONANCE IMAGING
    4.
    发明公开
    SYSTEM AND METHOD FOR AN EDDY-CURRENT FIELD COMPENSATION IN MAGNETIC RESONANCE IMAGING 审中-公开
    用于磁共振成像中的涡流补偿的系统和方法

    公开(公告)号：EP3317688A1

    公开(公告)日：2018-05-09

    申请号：EP16838392.5

    申请日：2016-06-07

    申请人： Shanghai United Imaging Healthcare Co., Ltd.

    发明人： LI, Bo ,  JIA, Erwei ,  XING, Xiaocong ,  XU, Kaipin

    IPC分类号： G01R33/387

    摘要： A system and method for acquiring a calibrated eddy-current field model in magnetic resonance imaging (MM) are provided. The method may include one or more of the following operations. An eddy-current field model may be obtained. The eddy-current field model may be transformed by Laplace Transformation. Data of an eddy-current field may be obtained. The data of the eddy-current field may be processed. A calibrated eddy-current field model may be acquired. In addition, the calibrated eddy-current field model may be used to compensate an eddy-current field.

    Magnetic resonance system
    9.
    发明公开
    Magnetic resonance system 有权
    Magnetresonanzsystem mit Shim-Ringen

    公开(公告)号：EP0982598A2

    公开(公告)日：2000-03-01

    申请号：EP99306173.8

    申请日：1999-08-03

    申请人： PICKER INTERNATIONAL, INC.

    发明人： McGinley, John V. M. ,  Young, Ian R. ,  Demeester, Gordon D. ,  Kinanen, Ilmari

    IPC分类号： G01R33/38 ,  G01R33/387

    CPC分类号： G01R33/383 ,  G01R33/3873

    摘要： A pair of annular magnets (10) generate a vertical magnetic flux field through an imaging volume (12) . The flux is focussed by a pair of Rose rings (26) of high cobalt steel. A high order shim set includes a plurality of permanently magnetized or magnetized iron rings (32a, 32b, 32c, 32d) which cooperatively interact with the magnet assembly to optimize the homogeneity of the magnetic flux through the imaging volume. One of the permanent magnetic rings (32d) , is mounted with an opposite polarity relative to the others. The magnetized rings are mounted in a non-ferrous, electrically insulating support structure (34) such that gradient coils (50) can be positioned behind the permanent magnet rings. A flux return path (14, 16, 18, 20, 22, 24) provides a low flux resistant path from adjacent the Rose ring at one side of the imaging volume remotely around the imaging volume to a position adjacent the Rose ring at the other side of the imaging volume.

    摘要翻译： 一对环形磁体（10）通过成像体积（12）产生垂直磁通场。 助焊剂由一对高钴钢的玫瑰环（26）聚焦。 高阶垫片包括多个永久磁化或磁化的铁环（32a，32b，32c，32d），其与磁体组件协作地相互作用以优化通过成像体积的磁通量的均匀性。 永久磁环（32d）中的一个相对于其它永久磁环安装有相反的极性。 磁化环安装在有铁，电绝缘的支撑结构（34）中，使得梯度线圈（50）可以位于永磁体环的后面。 磁通返回路径（14,16,18,20,22,24）在成像体积的远侧围绕成像体积的一侧的玫瑰环附近提供低阻抗路径，使其与另一方的玫瑰环相邻的位置 一侧的成像体积。

    Magnetic resonance methods and apparatus
    10.
    发明公开
    Magnetic resonance methods and apparatus 失效
    用于磁共振的方法和装置

    公开(公告)号：EP0752596A2

    公开(公告)日：1997-01-08

    申请号：EP96304893.9

    申请日：1996-07-03

    申请人： GEC-MARCONI LIMITED

    发明人： Young, Ian Robert

    IPC分类号： G01R33/387 ,  G01R33/565

    CPC分类号： G01R33/383 ,  G01R33/56518

    摘要： A magnetic resonance apparatus including a magnet system incorporating two pole pieces having opposed surfaces which define a gap in which a body to be examined is placed in use of the apparatus, the magnet system producing a static magntic field in the gap which defines an equilibrium axis of magnetic alignment in the body, and the apparatus further including a gradient coil arrangement whereby at least one gradient may be superimposed on the magnetic field in the gap; characterised in that at least the portions of said pole pieces adjacent said surfaces comprise a magnetic material which does not support eddy currents and means is provided for controlling the energising currents supplied to the gradient coil arrangement in such a manner as to avoid significant remanent magnetism in said magnetic material when the gradient coil arrangement is not being supplied with energising current.