Hanson Lars G, Lund Torben E, Hanson Christian G
Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark.
J Magn Reson Imaging. 2007 May;25(5):1059-66. doi: 10.1002/jmri.20906.
To develop a gradient insensitive, generic technique for recording of non-MR signals by use of surplus scanner bandwidth.
Relatively simple battery driven hardware is used to transform one or more signals into radio waves detectable by the MR scanner. Similar to the "magstripe" technique used for encoding of soundtracks in motion pictures, the electrical signals are in this way encoded as artifacts appearing in the MR images or spectra outside the region of interest. The encoded signals are subsequently reconstructed from the signal recorded by the scanner.
Electrophysiological (EP) eye and heart muscular recording (electrooculography [EOG] and electrocardiography [ECG]) during fast echo planar imaging (EPI) is demonstrated with an expandable, modular 8-channel prototype implementation. The gradient artifacts that would normally be dominating EOG are largely eliminated.
The method provides relatively inexpensive sampling with inherent microsecond synchronization and it reduces gradient artifacts in physiological recordings significantly. When oversampling is employed, the method is compatible with all MR reconstruction and postprocessing techniques.
利用剩余扫描仪带宽开发一种对梯度不敏感的通用技术，用于记录非磁共振信号。
使用相对简单的电池驱动硬件将一个或多个信号转换为磁共振扫描仪可检测到的无线电波。类似于用于电影声带编码的“磁条”技术，电信号以这种方式编码为出现在感兴趣区域之外的磁共振图像或频谱中的伪影。随后从扫描仪记录的信号中重建编码信号。
通过一个可扩展的模块化8通道原型实现，展示了在快速回波平面成像（EPI）期间的电生理（EP）眼和心脏肌肉记录（眼电图[EOG]和心电图[ECG]）。通常会主导EOG的梯度伪影在很大程度上被消除。
该方法提供了相对廉价的采样，具有固有的微秒同步，并且显著减少了生理记录中的梯度伪影。当采用过采样时，该方法与所有磁共振重建和后处理技术兼容。
