公开(公告)号：US5258710A

公开(公告)日：1993-11-02

申请号：US858924

申请日：1992-03-27

申请人： Robert D. Black ,  Peter B. Roemer ,  Antonio A. Mogro-Campero ,  Larry G. Turner

发明人： Robert D. Black ,  Peter B. Roemer ,  Antonio A. Mogro-Campero ,  Larry G. Turner

IPC分类号： F17C13/00 ,  G01R33/31 ,  G01R33/34 ,  G01R33/20

CPC分类号： G01R33/34053 ,  G01R33/31 ,  G01R33/34061 ,  G01R33/341 ,  G01R33/34007 ,  G01R33/34023 ,  G01R33/3403

摘要： An apparatus for microscopic imaging employing nuclear magnetic resonance is constructed from a cryogenic probe which is situated in a conventional magnetic resonance imaging system. The cryogenic probe employs a number of chambers and cryogenic liquids which cool a superconductor resonator to very low temperatures. A sample tube for containing a small specimen is heated to a temperature above its freezing point by flowing nitrogen gas over the specimen. A secondary resonant circuit is inductively coupled to the superconducting resonator. A transceiver passes RF signals to be transmitted into the specimen through the secondary resonant circuit causing the superconducting resonator to transmit the RF signal into the specimen. The resonator then acts as a receive coil and receives a signal from the specimen which is inductively passed to the secondary resonator circuit from which an image is generated. The use of superconductors having low resistance and low temperatures causes noise to be significantly reduced, and the signal-to-noise ratio to be substantially increased.

摘要翻译： 使用核磁共振的微观成像装置由位于常规磁共振成像系统中的低温探针构成。 低温探针采用多个室和低温液体，将超导体谐振器冷却到非常低的温度。 用于容纳小样本的样品管通过将氮气流过样品而被加热到高于其凝固点的温度。 次级谐振电路感应耦合到超导谐振器。 收发器将RF信号通过次级谐振电路传输到样品中，使超导谐振器将RF信号传输到样品中。 谐振器然后用作接收线圈并且接收来自样品的信号，其被感应地传递到从其产生图像的次级谐振器电路。 使用具有低电阻和低温度的超导体使得噪声显着降低，并且信噪比将显着增加。

公开(公告)号：US4961054A

公开(公告)日：1990-10-02

申请号：US376074

申请日：1989-07-06

申请人： John N. Park ,  Otward M. Mueller ,  Peter B. Roemer

发明人： John N. Park ,  Otward M. Mueller ,  Peter B. Roemer

IPC分类号： G01R33/20 ,  A61B5/055 ,  G01R33/38 ,  G01R33/385 ,  G01R33/48 ,  H03K17/567

CPC分类号： G01R33/3852 ,  H03K17/567

摘要： A gradient current speed-up circuit, for use in a higher-speed NMR imaging system with a gradient power amplifier and an associated gradient coil, has an energy-storage element, with an inductance typically between 5 and 20 times the inductance of the associated gradient coil. A plurality of semiconductor switching elements receive the current output of the energy-storage element; and the associated gradient coil is connected between selected ones of these semiconductors devices. The semiconductor devices are turned on and off in selected patterns, to cause the energy-storage element current to be suddenly applied to and removed from flow through the associated gradient coil.

公开(公告)号：US4926125A

公开(公告)日：1990-05-15

申请号：US234729

申请日：1988-08-22

申请人： Peter B. Roemer

发明人： Peter B. Roemer

IPC分类号： G01R33/20 ,  A61B5/055 ,  G01R33/38 ,  G01R33/385 ,  G01R33/422 ,  G01R33/48

CPC分类号： G01R33/422 ,  G01R33/385

摘要： A novel surface gradient assembly for high-speed, high-resolution NMR imaging has at least one substantially planar gradient coil. Each of the planar coils is disposed substantially parallel to any other planar coil of the assembly, and in a chosen plane of two selected Cartesian coordinates. Thus, one or more, planar coils lying in, say, the XZ plane can provide a magnetic gradient field in 1, 2 or all 3 of the X, Y and/or Z directions. Each coil can be formed of 1, 2, 4 or more windings, each of which is a "fingerprint" coil of configuration established by current-flow stream functions. An RF shield can be placed between the substantially planar gradient coil(s) and a RF antenna, to prevent interaction between the antenna and gradient coils, so that the quality factor (Q) of the RF antenna is not appreciable lowered.

公开(公告)号：US4887039A

公开(公告)日：1989-12-12

申请号：US288668

申请日：1988-12-22

申请人： Peter B. Roemer ,  William A. Edelstein ,  Cecil E. Hayes ,  Matthew G. Eash

发明人： Peter B. Roemer ,  William A. Edelstein ,  Cecil E. Hayes ,  Matthew G. Eash

IPC分类号： H01Q1/50 ,  A61B5/055 ,  G01R33/34 ,  G01R33/36

CPC分类号： G01R33/34046 ,  G01R33/3628

摘要： A method for providing plural coaxial cable connections, each to a different portion of a single radio-frequency (RF) antenna without requiring the use of isolation means at any RF connection, determines at least a point within the antenna having a desired common potential adjacent to each of the different portions to which one of the coaxial cable connections is to be made; Then forms a separate segment of each different portion which is located substantially at the common potential and is reactively separated from adjacent segments of the associated portion; and connects a shield conductor of an associated coaxial cable to the separate segment, while connecting a center conductor of that same associated coaxial cable to a selected one of the adjacent segments of that different portion.

公开(公告)号：US4871969A

公开(公告)日：1989-10-03

申请号：US288605

申请日：1988-12-22

申请人： Peter B. Roemer ,  William A. Edelstein

发明人： Peter B. Roemer ,  William A. Edelstein

IPC分类号： G01R33/385 ,  G01R33/422

CPC分类号： G01R33/422 ,  G01R33/385

摘要： An RF shield, for use between a set of gradient coils and an RF coil, is hollow formed of a single conductor sheet divided into first and second opposed halves, each having a set of conductive streamline portions with a series of nonconductive cut lines formed therebetween. Each of the cut lines is parallel to the RF current and is of a generally oval shape. Each of the shield conductor loops is further separated into a "C"-shaped conductive portion, along at least one radial line, and the C portions are then connected so as to continue shielding the RF current, yet pass gradient magnetic fields in all three mutually orthogonal directions of a Cartesian coordinate system.

摘要翻译： 在一组梯度线圈和RF线圈之间使用的RF屏蔽件由分成第一和第二相对半部的单个导体片形成，其中每个具有一组导电流线部分，其间形成有一系列不导电的切割线 。 每个切割线平行于RF电流并且具有大致椭圆形的形状。 每个屏蔽导体环路沿着至少一个径向线进一步分成“C”形导电部分，然后将C部分连接，以便继续屏蔽RF电流，然后在所有三个方向通过梯度磁场 笛卡尔坐标系的相互正交方向。