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126 条记录 (耗时 0.017 秒)

    FOCUSED POINT OVERSAMPLING FOR TEMPORALLY AND SPATIALLY RESOLVING DYNAMIC MR STUDIES
    101.
    发明公开
    FOCUSED POINT OVERSAMPLING FOR TEMPORALLY AND SPATIALLY RESOLVING DYNAMIC MR STUDIES 审中-公开
    时间和空间分辨率动态MR调查的数据点的重复记录

    公开(公告)号：EP1337869A1

    公开(公告)日：2003-08-27

    申请号：EP01995304.1

    申请日：2001-10-31

    申请人： Marconi Medical Systems, Inc.

    发明人： LIU, Kecheng ,  HALAMEK, James, A.

    IPC分类号： G01R33/563 ,  G01R33/28

    CPC分类号： G01R33/563 ,  G01R33/281

    摘要： A contrast material (70) is injected into the subject in a magnetic resonance imaging apparatus. An operator initiates a series of fast scan imaging sequences to track the position for entry of the contrast material, into a region of interest. A trajectory through a k-space is selected for the fast scan imaging sequences that both generates data lines for the fast scan images and oversamples a common data point (76). A peak intensity of the oversampled common point (76) indicates that the bolus of contrast agent (70) has arrived. A sequence controller (40) initiates a diagnostic imaging sequence (80). The operator views the fast scan image, aborting the diagnostic sequence (80) if the fast scan image does not verify that the contrast agent has arrived in the region of interest.

    Birdcage RF transmitter coil for magnetic resonance apparatus
    102.
    发明公开
    Birdcage RF transmitter coil for magnetic resonance apparatus 审中-公开
    用于磁共振装置鸟笼RF发射线圈

    公开(公告)号：EP1087234A3

    公开(公告)日：2003-05-28

    申请号：EP00307138.8

    申请日：2000-08-21

    申请人： Marconi Medical Systems, Inc.

    发明人： Burl, Michael ,  Gauss, Robert C.

    IPC分类号： G01R33/34 ,  G01R33/36

    CPC分类号： G01R33/34046

    摘要： A tunable radio frequency birdcage coil (26, 34) has an improved tuning range for use with a magnetic resonance apparatus. The coil includes a pair of end ring conductors which are connected by a plurality of spaced leg conductors to form a generally cylindrical volume. Both the end rings and the leg conductors contain reactive elements, preferably capacitors. The radio frequency coil also includes a pair of tuning rings (100) for tuning the reactive elements, which each include a non-conductive support cylinder and a plurality of tuning bands which extend axially along the outer surface of the support cylinder. The tuning rings (100) are rotated or translated with respect to the leg conductors in order to vary capacitance and inductance of the coil (26, 34) to tune the (26, 34) coil to the desired resonant frequency.

    RF coil for magnetic resonance apparatus
    103.
    发明公开
    RF coil for magnetic resonance apparatus 审中-公开
    用于磁共振装置的射频线圈

    公开(公告)号：EP1128188A3

    公开(公告)日：2003-05-21

    申请号：EP01301564.9

    申请日：2001-02-21

    申请人： Marconi Medical Systems, Inc.

    发明人： Fujita, Hiroyuki ,  Demeester, Gordon D. ,  Braum, William O.

    IPC分类号： G01R33/34

    CPC分类号： G01R33/34046

    摘要： A tunable radio frequency birdcage coil (30) is oriented vertically in a bore-type magnetic resonance apparatus. The birdcage coil (30) includes a pair of end rings (60, 62) disposed in parallel planes along a coil axis which is orthogonal to the main magnetic field. A plurality of rungs (64) electrically interconnect the end rings (60, 62) to form a generally cylindrical volume. The end rings (60, 62) and rungs (64) are mounted on a hinged (68) dielectric former (66). Conductive connectors (70) releasably fasten the end rings (60, 62) so that the coil (30) may be opened and closed to receive a portion of a subject to be examined. A conductive loop (80) is inductively coupled and positioned parallel to the end rings (60, 62). The conductive loop (80) is slidably adjustable along the coil axis for matching and tuning end-ring modes of the coil. The coil is oriented to provide a subject disposed therein with an open view for fMRI applications. Means for stimulating the visual senses (100) is mounted adjacent the examination region (14) to facilitate fMRI applications.

    Shielded gradient coil assembly for magnetic resonance imaging
    107.
    发明公开
    Shielded gradient coil assembly for magnetic resonance imaging 审中-公开
    用于磁共振成像的屏蔽梯度线圈

    公开(公告)号：EP1004890A3

    公开(公告)日：2003-01-22

    申请号：EP99308959.8

    申请日：1999-11-10

    申请人： Marconi Medical Systems, Inc.

    发明人： Petropoulos, Labros S.

    IPC分类号： G01R33/421

    CPC分类号： G01R33/4215 ,  G01R33/421

    摘要： A method of designing a shielded gradient coil assembly ( 22 ) for magnetic resonance imaging systems is provided. The gradient coil structure comprises two sets of primary gradient coils ( 60, 62 ) and a single set of a shielded (screening) coils ( 64 ). This configuration is suitable for MR applications utilizing a double-duty gradient configuration including a high-efficiency primary coil set that enhances the performance of ultra fast MR sequencing while minimizing the dB/dt and eddy current effects, and including a low-efficiency primary coil set having a high-quality gradient field that is suitable for conventional imaging applications with inherently low dB/dt and eddy current levels. In addition, a minimum inductance/energy algorithm assists in the design of the two primary and the one secondary gradient sets.