发明名称 |
Gradient and polarizing field compensation. |
摘要 |
<p>A method is provided for characterizing the spurious, time dependent magnetic field gradient response and for compensating therefor. In accordance with the method, two small sample objects are placed at two positions with respect to the system isocenter where the gradient to be compensated has different values. A magnetic field gradient pulse is applied to the sample, followed by the application after a variable time of a 90 DEG radio frequency pulse. The phase of the resulting free induction decay (FID) signal is monitored as a function of total time since the end of the gradient pulse. These data are related to the impulse response of the gradient and are employed to construct compensation filters for both the gradient coils and the polarizing field shim coil.</p> |
申请公布号 |
EP0332383(A2) |
申请公布日期 |
1989.09.13 |
申请号 |
EP19890302236 |
申请日期 |
1989.03.06 |
申请人 |
GENERAL ELECTRIC COMPANY |
发明人 |
GLOVER, GARY HAROLD;PELC, NORBERT JOSEPH;BRADSHAW, KENNETH MAREL |
分类号 |
G01R33/48;A61B5/055;G01R33/32;G01R33/385;G01R33/3875;G01R33/54 |
主分类号 |
G01R33/48 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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