发明名称 |
Iterative shimming method for a basic field magnet of a nuclear magnetic resonance tomography apparatus |
摘要 |
To improve the homogeneity of the basic magnetic field generated in a nuclear magnetic resonance tomography unit, an iterative shimming method includes the steps of generating a pulse sequence in the form of a bipolar gradient pulse train in the examination volume, and entering the echo signals which are acquired into a measured matrix. A correlation coefficient of the echo signals of at least a part of the rows of the measurement matrix is formed with respect to a reference row. The shim current through at least one shim coil in the tomography apparatus is then varied in a manner causing the correlation coefficient to increase. These steps are repeated until the correlation coefficient reaches a selected value which is large enough to indicate that an adequate basic field homogeneity has been achieved.
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申请公布号 |
US5391990(A) |
申请公布日期 |
1995.02.21 |
申请号 |
US19930105647 |
申请日期 |
1993.08.13 |
申请人 |
SIEMENS AKTIENGESELLSCHAFT |
发明人 |
SCHMITT, FRANZ;FISCHER, |
分类号 |
G01R33/3875;(IPC1-7):G01V3/00 |
主分类号 |
G01R33/3875 |
代理机构 |
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主权项 |
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地址 |
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