NONSUSCEPTIBILITY ARTIFACTS DUE TO METALLIC OBJECTS IN MR-IMAGING
NONSUSCEPTIBILITY ARTIFACTS DUE TO METALLIC OBJECTS IN MR-IMAGING
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DOI：
10.1002/jmri.1880050115
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发表时间：
1995-01-01
期刊：
影响因子：
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通讯作者：
HENKELMAN, RM
中科院分区：
文献类型：
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作者：
CAMACHO, CR;PLEWES, DB;HENKELMAN, RM
作者研究了磁共振成像场中金属物体引起的涡流伪影。通过使用圆形铜环作为金属植入物中存在的更复杂涡流路径的模型，简化了问题。通过这种简单的几何形状，作者表明，金属中的射频（RF）感应涡流产生了显著的局部伪影，但是，没有观察到由于切换磁场梯度而引起的明显伪影。对铜环引起的RF感应涡流伪影的机制进行了详细的定量分析。实验证明伪影是由RF线圈的发射和接收灵敏度的扰动引起的。这些微扰的理论计算结果与实验结果吻合得很好。在了解伪影机制的基础上，应用了校正RF感应涡流伪影的方法。
The authors investigated eddy current artifacts due to metallic objects within the magnetic resonance imaging field. The problem was simplified by using a circular copper loop as a model for the more complex eddy current pathways present in a metallic implant. With this simple geometry, the authors show that radio-frequency (RF)-induced eddy currents in the metal produce a significant local artifact, However, no appreciable artifacts due to the switching magnetic field gradients were observed. A detailed quantitative analysis of the mechanism of RF-induced eddy current artifact due to the the copper loop was performed. The artifact was demonstrated experimentally to result from perturbations of the transmit and receive sensitivities of the RF coil. Theoretical calculations of these perturbations showed excellent agreement with experimental results. With an understanding of the artifact mechanism, methods for correcting the RF-induced eddy current artifact were applied.