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11. 发明授权

US5418462A Method for determining shim placement on tubular magnet 失效
标题翻译：确定管状磁铁上垫片放置的方法
公开(公告)号：US5418462A
公开(公告)日：1995-05-23
申请号：US237256
申请日：1994-05-02
申请人： Bruce C. Breneman , Yen-Hwa Hsu , Jang-Yu Hsu
发明人： Bruce C. Breneman , Yen-Hwa Hsu , Jang-Yu Hsu
IPC分类号： A61B5/055 , G01R33/24 , G01R33/3873 , G01V3/00
CPC分类号： G01R33/3873 , G01R33/24
摘要： A method for using ferromagnetic shims to reduce the inhomogeneity of the magnetic field in a Diameter Spherical Volume (DSV) in the bore of a Magnetic Resonance Imaging (MRI) device is provided. More specifically, a magnetic field is established within the bore of the MRI device. An operator defines the DSV. The strength of the magnetic field is measured at the surface of the DSV. A Legendre polynomial is derived to model the inhomogeneity in the magnetic field in the DSV. A set of coefficients for the harmonic terms of the polynomial is calculated from the field strength measurements and segregated into three separate groups for evaluation. Each group of terms expresses field inhomogeneity in a unique set of spatial dimensions. Ferromagnetic shims are attached to the surface of the bore in individual dipole, linear bar, and ring arrangements to separately reduce the first, second, and third groups of harmonic coefficients to acceptable levels corresponding to a predetermined peak-to-peak inhomogeneity range.
摘要翻译：提供了一种使用铁磁垫片来减少磁共振成像（MRI）装置的孔中的直径球体积（DSV）中的磁场的不均匀性的方法。更具体地，在MRI装置的孔内建立磁场。操作员定义DSV。在DSV的表面测量磁场的强度。导出勒让德多项式来模拟DSV中磁场的不均匀性。从场强测量中计算出多项式谐波项的一组系数，并将其分离为三个独立的组进行评估。每一组术语在一组独特的空间维度中表现出场不均匀性。铁磁垫片以单独的偶极子，线性杆和环形布置附接到孔的表面，以将第一，第二和第三组谐波系数分别地减小到对应于预定的峰 - 峰不均匀性范围的可接受的水平。

12. 发明授权

US5414399A Open access superconducting MRI magnet having an apparatus for reducing magnetic hysteresis in superconducting MRI systems 失效
标题翻译：具有用于降低超导MRI系统中磁滞的设备的开放式超导MRI磁体
公开(公告)号：US5414399A
公开(公告)日：1995-05-09
申请号：US812080
申请日：1991-12-19
申请人： Bruce C. Breneman , Raymond E. Sarwinski , Yen-Hwa L. Hsu
发明人： Bruce C. Breneman , Raymond E. Sarwinski , Yen-Hwa L. Hsu
IPC分类号： G01R33/385 , G01R33/3873 , H01F7/20 , G01R33/28
CPC分类号： G01R33/3806 , G01R33/385 , G01R33/3873
摘要： A MRI superconducting magnet having an open access frame with spaced parallel end plates, a superconducting coil assembly associated with each end plate, and gradient coils associated with each end plate includes an apparatus for minimizing hysteresis. The apparatus for minimizing hysteresis comprises a layer of nonferromagnetic conducting material interposed between the gradient coils and end plates. The interposed layer carries eddy currents induced by time varying magnetic fields produced by the gradient coils, thereby minimizing AC eddy current hysteresis from the end plates. The layer preferably has a thickness of at least one skin depth at the frequency associated with the time varying magnetic field. In another embodiment, each end plate has a plurality of slits formed therein for eliminating eddy currents in the end plates.
摘要翻译： MRI超导磁体具有带有间隔开的平行端板的开放式进入框架，与每个端板相关联的超导线圈组件以及与每个端板相关联的梯度线圈包括用于最小化滞后的装置。用于最小化滞后的装置包括介于梯度线圈和端板之间的非铁磁导电材料层。插入的层承载由梯度线圈产生的时变磁场引起的涡流，从而最小化来自端板的交流涡流滞后。该层优选地具有与时变磁场相关联的频率处的至少一个皮肤深度的厚度。在另一个实施例中，每个端板具有形成在其中的多个狭缝，用于消除端板中的涡流。

13. 发明授权

US5134374A Magnetic field control apparatus 失效
标题翻译：磁场控制装置
公开(公告)号：US5134374A
公开(公告)日：1992-07-28
申请号：US555269
申请日：1990-07-18
申请人： Bruce C. Breneman , J. Wesley Parker , Raymond E. Sarwinski
发明人： Bruce C. Breneman , J. Wesley Parker , Raymond E. Sarwinski
IPC分类号： G01R33/383 , G01R33/3873 , H01F7/02
CPC分类号： G01R33/383 , G01R33/3873 , H01F7/0278
摘要： A magnetic field control apparatus for establishing a uniform field of flux for use in magnetic resonance imaging has a pair of opposed magnetic poles mounted on end plates of variable thickness. A pair of substantially flat parallel pole faces are attached to the facing surfaces of the magnetic poles. The end plates are supported by connecting members. In addition, there is included a plurality of segments movably mounted to the periphery of the pole face for adjusting the density of the magnetic field. The top and bottom end plates may have substantially identical concave portions on the opposite outside surfaces thereof. The magnetic poles and pole faces are preferably in the shape of thin, flat, circular plates. In one embodiment, there is included one or more inner segmented concentric rings for further adjustably controlling the homogeneity of the uniform magnetic flux in the air gap between the opposing pole faces into which a patient can be inserted for magnetic resonance imaging. In another embodiment, the end plates are shaped so that the aggregate cross-sectional area taken in any plane perpendicular to the direction of the return flow of flux is substantially constant.
摘要翻译：用于建立用于磁共振成像的通量的均匀磁场的磁场控制装置具有安装在可变厚度的端板上的一对相对的磁极。一对基本上平坦的平行极面附接到磁极的相对表面。端板由连接构件支撑。此外，还包括可移动地安装到极面的周边的多个段，用于调节磁场的密度。顶端板和底端板可以在其相对的外表面上具有基本上相同的凹部。磁极和极面的形状优选为薄，平的圆形板。在一个实施例中，包括一个或多个内部分段的同心环，用于进一步可调节地控制可插入患者以用于磁共振成像的相对极面之间的气隙中的均匀磁通的均匀性。在另一个实施例中，端板被成形为使得在垂直于焊剂回流方向的任何平面中取得的骨截面面积基本上是恒定的。

14. 发明授权

US4931759A Magnetic resonance imaging magnet having minimally symmetric ferromagnetic shield 失效
标题翻译：具有最小对称铁磁屏蔽的磁共振成像磁体
公开(公告)号：US4931759A
公开(公告)日：1990-06-05
申请号：US334291
申请日：1989-04-06
申请人： Bruce C. Breneman , John R. Purcell , Raymond E. Sarwinski
发明人： Bruce C. Breneman , John R. Purcell , Raymond E. Sarwinski
IPC分类号： G01R33/387 , A61B5/055 , G01R33/3815 , G01R33/3873 , G01R33/421
CPC分类号： G01R33/421 , G01R33/3815 , G01R33/3873
摘要： A magnetic resonance imaging magnet has a solenoidal superconducting winding producing a magnetic field and defining an examination region within a bore thereof. The examination region receives a body to be examined. The solenoidal superconducting winding generates a quasi-static magnetic field for aligning atomic nuclei in the body being examined. A two-fold or minimally symmetric ferromagnetic shield has a pair of magnetic flux return paths positioned on opposite sides of the solenoidal superconducting winding for reducing the magnetic field intensity in a region proximate to and outside of the solenoidal superconducting winding. A magnetic field inhomogeneity compensating system reduces magnetic field inhomogeneities introduced into the magnetic field within the examination region by the minimally symmetric ferromagnetic shield to provide a highly uniform quasi-static magnetic field within the examination region.
摘要翻译：磁共振成像磁体具有产生磁场的螺线管超导绕组并且在其孔内限定检查区域。检查区域接受检查的身体。螺线管超导绕组产生准静态磁场，用于对准被检体内的原子核。双重或最小对称的铁磁屏蔽具有位于螺线管超导绕组的相对侧上的一对磁通返回路径，用于减小靠近和超出螺线管超导绕组的区域内的磁场强度。磁场不均匀性补偿系统通过最小对称的铁磁屏蔽减小引入到检查区域内的磁场的磁场不均匀性，以在检查区域内提供高度均匀的准静态磁场。

15. 发明授权

US06438967B1 Cryocooler interface sleeve for a superconducting magnet and method of use 有权
标题翻译：用于超导磁体的冷却器接口套管及其使用方法
公开(公告)号：US06438967B1
公开(公告)日：2002-08-27
申请号：US09915916
申请日：2001-07-26
申请人： Raymond E. Sarwinski , William E. Stonecipher , Bruce C. Breneman
发明人： Raymond E. Sarwinski , William E. Stonecipher , Bruce C. Breneman
IPC分类号： F25B900
CPC分类号： F25D19/006 , F25B9/10 , H01F6/04
摘要： A method for cooling a superconducting device by using a sleeve assembly which thermally interconnects a two stage cryocooler with the device. In operation, the cryocooler is moveable relative to the sleeve assembly between a first configuration wherein the cryocooler is engaged with the sleeve assembly, and a second configuration wherein the cryocooler is disengaged from the sleeve assembly. The cryocooler is disposed in the sleeve assembly with the cooling element of the cryocooler positioned at a distance from the cylinder of the sleeve assembly to establish thermal communication therebetween. Also, the cooling probe of the cryocooler is in contact with the receptacle of the sleeve assembly and is urged against the receptacle to establish thermal communication therebetween. A bellows joins the cryocooler with the sleeve assembly to create an enclosed chamber therebetween and helium is pumped into the sleeve assembly to maintain an operational pressure in the sleeve assembly.
摘要翻译：一种通过使用将两级制冷器与设备热互连的套筒组件来冷却超导装置的方法。在操作中，低温冷却器可相对于套筒组件在第一构型和第二构造之间移动，第一配置是低温冷却器与套筒组件接合，以及第二构造，其中低温冷却器与套筒组件脱离接合。低温冷却器设置在套筒组件中，低温冷却器的冷却元件位于与套筒组件的气缸一定距离处，以在它们之间建立热连通。此外，低温冷却器的冷却探针与套筒组件的容器接触并且被推靠在容器上以在它们之间建立热连通。波纹管将低温冷却器与套筒组件连接以在其间形成封闭的腔室，并且将氦泵送到套筒组件中以保持套筒组件中的操作压力。

16. 发明授权

US4980641A Method and apparatus of reducing magnetic hysteresis in MRI systems 失效
标题翻译：降低MRI系统磁滞的方法和装置
公开(公告)号：US4980641A
公开(公告)日：1990-12-25
申请号：US393400
申请日：1989-08-11
申请人： Bruce C. Breneman , Raymond E. Sarwinski , Yen-Hwa L. Hsu
发明人： Bruce C. Breneman , Raymond E. Sarwinski , Yen-Hwa L. Hsu
IPC分类号： G01R33/38 , G01R33/383 , G01R33/385 , G01R33/421
CPC分类号： G01R33/421 , G01R33/3806 , G01R33/383 , G01R33/385
摘要： An apparatus for minimizing hysteresis in a magnetic resonance imaging device of the type utilizing a pair of oppositely charged parallel pole faces forming a magnetic field therebetween, and gradient coils spaced apart from each pole face for producing time varying magnetic fields, comprises a layer of nonferromagnetic conducting material interposed between the pole face and the gradient coil. The interposed layer carries eddy currents induced by time varying magnetic fields produced by the gradient coils, thereby minimizing AC induced eddy current hysteresis from the pole faces. The layer preferably has a thickness of at least one skin depth at the frequency associated with the time varying magnetic field. The layer is preferably contiguous with the pole face, and comprises copper or aluminum. In another embodiment, each pole face has a plurality of slits therethrough radiating inward from the circumference for eliminating the eddy currents in the pole face. The slits in one pole face are preferably symmetrical to those in the other. There are preferably twenty-four (24) slits spaced fifteen degrees (15.degree.) apart. There is also disclosed the method for accomplishing the same.
摘要翻译：一种用于最小化磁共振成像装置中的磁滞的装置，该磁共振成像装置利用在它们之间形成磁场的一对相反电荷的平行极面以及与每个极面间隔开的用于产生时变磁场的梯度线圈，包括非铁磁层介于极面和梯度线圈之间的导电材料。插入层承载由梯度线圈产生的由时变磁场引起的涡流，从而最小化从极面引起的AC感应涡流滞后。该层优选地具有与时变磁场相关联的频率处的至少一个皮肤深度的厚度。该层优选与极面相邻，并且包括铜或铝。在另一个实施例中，每个极面具有从圆周向内辐射的多个狭缝，以消除极面中的涡流。一个极面中的狭缝优选地与另一个极面对应。优选分开间隔十五度（15°）的二十四（24）个狭缝。还公开了实现该方法的方法。

17. 发明授权

US4943774A Magnetic field control apparatus 失效
标题翻译：磁场控制装置
公开(公告)号：US4943774A
公开(公告)日：1990-07-24
申请号：US360028
申请日：1989-06-01
申请人： Bruce C. Breneman , J. Wesley Parker , Raymond E. Sarwinski
发明人： Bruce C. Breneman , J. Wesley Parker , Raymond E. Sarwinski
IPC分类号： G01R33/383 , G01R33/3873 , H01F7/02
CPC分类号： H01F7/0278 , G01R33/383 , G01R33/3873
摘要： A magnetic field control apparatus for establishing a uniform field of flux for use in magnetic resonance imaging comprises a pair of opposed magnetic poles mounted on end plates of variable thickness. A pair of substantially flat parallel pole faces are attached to the facing surfaces of the magnetic poles. The end plates are supported by connecting members. In addition, there is included a plurality of segments movably mounted to the periphery of the pole face for adjusting the density of the magnetic field. The top and bottom end plates may have substantially identical concave portions on the opposite outside surfaces thereof. The magnetic poles and pole faces are preferably in the shape of thin, flat, circular plates. In one embodiment, there is included one or more inner concentric rings for further adjustably controlling the homogeneity of the uniform magnetic flux in the air gap between the opposing pole faces into which a patient can be inserted for magnetic resonance imaging. In another embodiment, the end plates are shaped so that the aggregate cross-sectional area taken in any plane perpendicular to the direction of the return flow of flux is substantially constant.
摘要翻译：用于建立用于磁共振成像的通量的均匀磁场的磁场控制装置包括安装在可变厚度的端板上的一对相对的磁极。一对基本上平坦的平行极面附接到磁极的相对表面。端板由连接构件支撑。此外，还包括可移动地安装到极面的周边的多个段，用于调节磁场的密度。顶端板和底端板可以在其相对的外表面上具有基本上相同的凹部。磁极和极面的形状优选为薄，平的圆形板。在一个实施例中，包括一个或多个内同心环，用于进一步可调节地控制可插入患者以用于磁共振成像的相对极面之间的气隙中的均匀磁通的均匀性。在另一个实施例中，端板被成形为使得在垂直于焊剂回流方向的任何平面中取得的骨截面面积基本上是恒定的。

18. 发明授权

US4768008A MRI magnet system with vessel having composite first wall 失效
标题翻译： MRI磁体系统，具有复合第一壁的容器
公开(公告)号：US4768008A
公开(公告)日：1988-08-30
申请号：US80020
申请日：1987-07-31
申请人： John R. Purcell , Bruce C. Breneman , Sibley C. Burnett
发明人： John R. Purcell , Bruce C. Breneman , Sibley C. Burnett
IPC分类号： A61B10/00 , A61B5/055 , G01R33/381 , G01R33/3815 , H01F7/20 , H01F7/22
CPC分类号： G01R33/3815
摘要： A magnet system for use in magnetic resonance imaging. The system includes a vacuum vessel having a first wall assembly defining a bore for receiving the subject of the imaging and a pair of spaced metallic end plates welded to the ends of the first wall assembly. The system further includes a cryogenic containment vessel supported within the vacuum vessel and a coil disposed within the containment vessel for providing the magnetic field. The first wall assembly includes a weldable metallic cylindrical shell positioned intermediate the end plates and having a thickness insufficient without reinforcement to provide structural integrity during operation of the vacuum vessel. This first wall assembly further includes a reinforcement layer of a non-metallic material disposed about the metallic shell so that signals provided by gradient coils disposed inside the bore can more quickly penetrate the first wall assembly than if the metallic shell had sufficient thickness, without reinforcement to provide the necessary structural integrity.

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