公开(公告)号：US06284971B1

公开(公告)日：2001-09-04

申请号：US09449027

申请日：1999-11-24

Applicant: Ergin Atalar ,  Ogan Ocali

Inventor： Ergin Atalar ,  Ogan Ocali

IPC: H01B718

CPC classification number: H01P3/06 ,  A61N1/086 ,  H01B11/1895 ,  H01P1/202

Abstract: A coaxial cable which may be a magnetic resonance imaging coaxial cable is designed for enhanced safety so as to reduce the risk of excessive heating or burns to a user. The cable has an elongated axially oriented inner conductor and an axially oriented outer shield conductor in spaced relationship with respect thereto with a first dielectric material disposed therebetween. The outer shield conductor has an annular inner shield portion and segmented outer shield portions which are electrically connected to the inner shield portion. In certain preferred embodiments, a second dielectric material having a higher dielectric constant than the first dielectric material is disposed between the inner shield portion and the segmented outer shield portions. In one embodiment, an electrically conductive element extends between the segmented outer shield portions and the inner shield portion and terminates in spaced relationship therewith. In another embodiment, a capacitor may be introduced between the inner shield portion and the segmented outer shield portions.

Abstract translation: 可以是磁共振成像同轴电缆的同轴电缆被设计用于增强安全性，以便降低对使用者过度加热或烧伤的风险。 电缆具有细长的轴向取向的内导体和相对于其间隔开的轴向取向的外屏蔽导体，其间设置有第一介电材料。 外屏蔽导体具有环形内屏蔽部分和与内屏蔽部分电连接的分段外屏蔽部分。 在某些优选实施例中，具有比第一介电材料更高的介电常数的第二电介质材料设置在内屏蔽部分和分段的外屏蔽部分之间。 在一个实施例中，导电元件在分段的外屏蔽部分和内屏蔽部分之间延伸并且以间隔开的关系终止。 在另一个实施例中，可以在内屏蔽部分和分段的外屏蔽部分之间引入电容器。

公开(公告)号：US6031375A

公开(公告)日：2000-02-29

申请号：US979121

申请日：1996-11-26

Applicant: Ergin Atalar ,  Ogan Ocali

Inventor： Ergin Atalar ,  Ogan Ocali

IPC: A61B5/055 ,  G01R33/28 ,  G01R33/32 ,  G01R33/34 ,  G01R33/54 ,  G01V3/00

CPC classification number: G01R33/54 ,  G01R33/285 ,  G01R33/34084

Abstract: A method of magnetic resonance imaging employs cylindrical coordinates and in one embodiment has an elongated catheter which is operatively associated with an RF pulse transmitting antenna and an RF pulse transmitting body coil. A main magnetic field is imposed on the region of interest. Circumferential phase encoding is accomplished by applying an initial RF pulse from either the catheter antenna or the body coil and subsequently applying an initial series of RF pulses with the source alternating between the antenna and the body coil. Radial phase encoding is effected by applying a first RF pulse which in a second embodiment is followed by a second RF pulse. A longitudinal gradient magnetic pulse is applied in the region of interest to spatially encode magnetic resonance signals. The cylindrical coordinate imaging is obtained by combining the circumferential phase encoding information the longitudinal magnetic encoding information with or without the radial phase encoding information. Other embodiments not employing catheter antennas employ two antennas with non-uniform phase profiles with the pulse sequences employed with the antennas. Corresponding apparatus is provided.

Abstract translation: 磁共振成像的方法使用圆柱坐标，并且在一个实施例中具有可操作地与RF脉冲发射天线和RF脉冲发射体线圈相关联的细长导管。 主要的磁场被施加在感兴趣的区域上。 通过从导管天线或身体线圈施加初始RF脉冲并随后施加初始的RF脉冲序列来实现周期相位编码，其中源极在天线和体线圈之间交替。 径向相位编码通过施加第一RF脉冲来实现，在第二实施例中，第一RF脉冲之后是第二RF脉冲。 在感兴趣的区域中施加纵向梯度磁脉冲以空间编码磁共振信号。 圆周坐标成像通过将周向相位编码信息与纵向磁编码信息相加或不存在径向相位编码信息来获得。 不采用导管天线的其他实施例采用具有与天线一起使用的脉冲序列的非均匀相位曲线的两个天线。 提供相应的设备。

公开(公告)号：US5512825A

公开(公告)日：1996-04-30

申请号：US346130

申请日：1994-11-25

Applicant: Ergin Atalar ,  Elliot R. McVeigh

Inventor： Ergin Atalar ,  Elliot R. McVeigh

IPC: G01V3/14 ,  A61B5/055 ,  G01R33/385 ,  G01R33/54 ,  G01R33/561 ,  G01V3/00

CPC classification number: G01R33/4833 ,  G01R33/561

Abstract: A method of minimizing dead-periods in magnetic resonance imaging pulse sequences employs a specimen disposed within magnetic field, a source of RF signals, a receiver for receiving signals from the specimen responsive to RF pulses and emitting respective output signals. A computer is provided for receiving the output signals from the receiver and establishing image information which may be displayed. For the dead-period, the minimum and maximum phase encoding step, the scan plane gradient pulse for the slice, phase encoding and readout directions are determined and the moments contained within the dead-period waveform is determined. The values are transformed into gradient amplifier coordinates and the minimum dead-period based on a dead-period waveform is determined. The dead-period is employed in establishing a hardware optimized waveform which may be trapezoidal. The trapezoidal waveform is preferably established by for each phase encoding step determining the starting and ending gradient levels and the moments contained within the dead-period waveform and employing the waveform to design a trapezoidal waveform using the calculated minimum dead-period. The method is particularly advantageous when employed in oblique magnetic resonance imaging. The method may also be employed with velocity-encoded or flow-compensated pulse sequences by employing first gradient moments in the information processing, in addition to the starting and ending gradient levels and the zeroeth moments. For other types of pulse sequences, the zeroeth moment and other higher moments may be employed. Associated apparatus is also disclosed.

Abstract translation: 使磁共振成像脉冲序列中的死区最小化的方法使用设置在磁场内的样本，RF信号源，接收器，用于响应于RF脉冲接收来自样本的信号并发射相应的输出信号。 提供一种计算机，用于从接收器接收输出信号并建立可显示的图像信息。 在死区期间，确定最小和最大相位编码步骤，用于切片，相位编码和读出方向的扫描平面梯度脉冲，并且确定包含在死区波形内的力矩。 将这些值转换为梯度放大器坐标，并确定基于死区波形的最小死区。 死区是用来建立可能是梯形的硬件优化波形。 优选地，对于每个相位编码步骤确定梯形波形，确定起始和结束梯度水平以及包含在死区波形内的力矩，并使用该波形来设计使用所计算的最小死区的梯形波形。 该方法在用于倾斜磁共振成像时是特别有利的。 除了开始和结束梯度水平以及零时刻之外，还可以通过在信息处理中采用第一梯度力矩，使用速度编码或流量补偿脉冲序列。 对于其他类型的脉冲序列，可以采用零时刻和其它更高的时刻。 还公开了相关装置。