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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
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。
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公开(公告)号：EP0918229A3
公开(公告)日：2000-04-19
申请号：EP98308282.7
申请日：1998-10-12
发明人： Ehnholm, Gosta Jakob , Kinanen, Llmari , Gylling, Robert G. , Young, Ian R. , Demeester, Gordon D.
IPC分类号： G01R33/38
CPC分类号： G01R33/421 , G01R33/3806
摘要： A magnetic resonance imaging suite is sheathed with plates ( 32, 34, 36 ) of iron or other ferrous material. The plates define projections ( 42, 44 ) in alignment with each other on opposite ceiling and floor or wall surfaces. A pair of magnetic pole pieces ( 10, 10' ) are surrounded by superconducting electromagnetic coils ( 12, 12' ). The pole pieces are positioned between the ferrous plates in axial alignment. When current flows through the electromagnetic coils, magnetic flux flows between the pole pieces. The ferrous wall sheathing or other ferrous constructions define a flux return path. The pole pieces are magnetically attracted toward each other and are each magnetically mirrored in and attracted toward the adjacent ferrous flux return path. The pole pieces are positioned relative to each other and the ferrous flux return path such that the attraction between the pole pieces is balanced by the attraction between each pole piece and its magnetically mirrored image in the adjacent ferrous material of the flux return path. Optionally, the magnets are selectively extinguished and one or both pole pieces are moved for better access to the patient.
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公开(公告)号：EP0943929A3
公开(公告)日：2000-04-19
申请号：EP99302075.9
申请日：1999-03-18
IPC分类号： G01R33/38
CPC分类号： G01R33/3806
摘要： A magnetic resonance imaging apparatus ( 10 ) includes a couch ( 54 ) for supporting a region of interest of a subject ( 44 ) being examined in an examination region. In one form, a main magnet for generating a substantially uniform temporally constant main magnetic field through the examination region includes a stationary pole piece ( 24 ), a movable pole piece ( 22 ), a ferrous flux return path ( 26 ), and a magnetic flux generator that selectively generates magnetic flux that flows between the pole pieces ( 22, 24 ) through the examination region and through the ferrous flux return path ( 26 ) which connects the pole pieces ( 22, 24 ). The stationary pole piece ( 24 ) is arranged adjacent a first side of the examination region. The movable pole piece ( 22 ) is arranged to be selectively moved between a first position adjacent a second side of the examination region opposite the stationary pole piece ( 24 ) so that the stationary and movable pole pieces ( 24, 22 ) define the examination region therebetween, and a second position remote from the examination region. In other forms, the entire magnet is movable away from the examination region.
摘要翻译： 磁共振成像装置（10）包括用于支撑在检查区域中检查的被检体（44）的感兴趣区域的沙发（54）。 在一种形式中，用于通过检查区域产生基本上均匀的时间常数的主磁场的主磁体包括静止极片（24），可动极片（22），亚铁磁通返回路径（26）和磁性 磁通发生器，其选择性地产生通过检查区域在极片（22,24）之间流动并通过连接极片（22,24）的铁质磁通返回路径（26）的磁通量。 固定极片（24）布置成与检查区域的第一侧相邻。 所述可动极片（22）被布置成选择性地在与所述静止极片（24）相对的所述检查区域的第二侧附近的第一位置之间移动，使得所述固定和可动极片（24,22）限定所述检查区域 并且远离检查区域的第二位置。 在其他形式中，整个磁体可移动离开检查区域。
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公开(公告)号：EP0943929A2
公开(公告)日：1999-09-22
申请号：EP99302075.9
申请日：1999-03-18
IPC分类号： G01R33/38
CPC分类号： G01R33/3806
摘要： A magnetic resonance imaging apparatus ( 10 ) includes a couch ( 54 ) for supporting a region of interest of a subject ( 44 ) being examined in an examination region. In one form, a main magnet for generating a substantially uniform temporally constant main magnetic field through the examination region includes a stationary pole piece ( 24 ), a movable pole piece ( 22 ), a ferrous flux return path ( 26 ), and a magnetic flux generator that selectively generates magnetic flux that flows between the pole pieces ( 22, 24 ) through the examination region and through the ferrous flux return path ( 26 ) which connects the pole pieces ( 22, 24 ). The stationary pole piece ( 24 ) is arranged adjacent a first side of the examination region. The movable pole piece ( 22 ) is arranged to be selectively moved between a first position adjacent a second side of the examination region opposite the stationary pole piece ( 24 ) so that the stationary and movable pole pieces ( 24, 22 ) define the examination region therebetween, and a second position remote from the examination region. In other forms, the entire magnet is movable away from the examination region.
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公开(公告)号：EP0918229A2
公开(公告)日：1999-05-26
申请号：EP98308282.7
申请日：1998-10-12
发明人： Ehnholm, Gosta Jakob , Kinanen, Llmari , Gylling, Robert G. , Young, Ian R. , Demeester, Gordon D.
IPC分类号： G01R33/38
CPC分类号： G01R33/421 , G01R33/3806
摘要： A magnetic resonance imaging suite is sheathed with plates ( 32, 34, 36 ) of iron or other ferrous material. The plates define projections ( 42, 44 ) in alignment with each other on opposite ceiling and floor or wall surfaces. A pair of magnetic pole pieces ( 10, 10' ) are surrounded by superconducting electromagnetic coils ( 12, 12' ). The pole pieces are positioned between the ferrous plates in axial alignment. When current flows through the electromagnetic coils, magnetic flux flows between the pole pieces. The ferrous wall sheathing or other ferrous constructions define a flux return path. The pole pieces are magnetically attracted toward each other and are each magnetically mirrored in and attracted toward the adjacent ferrous flux return path. The pole pieces are positioned relative to each other and the ferrous flux return path such that the attraction between the pole pieces is balanced by the attraction between each pole piece and its magnetically mirrored image in the adjacent ferrous material of the flux return path. Optionally, the magnets are selectively extinguished and one or both pole pieces are moved for better access to the patient.
摘要翻译： 磁共振成像套件包含铁或其他含铁材料的板（32,34,36）。 板在相对的天花板和地板或墙壁表面上限定了彼此对准的突起（42,44）。 一对磁极片（10,10'）被超导电磁线圈（12,12'）包围。 极片以轴向对准的方式定位在铁质板之间。 当电流流过电磁线圈时，磁通量在极片之间流动。 含铁壁护套或其他铁质结构限定了通量返回路径。 极片彼此磁吸引，并且各自磁性镜像并被吸引到相邻的铁流量返回路径。 极靴相对于彼此定位，并且铁质磁通返回路径使得磁极片之间的吸引力通过磁通返回路径的相邻铁质材料中的每个极片与其磁反射图像之间的吸引力平衡。 可选地，磁体被选择性地熄灭，并且一个或两个极片移动以更好地接近患者。
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