体外深脑刺激导线对 9.4T（400.2MHz）射频加热的影响。
Effect of the extracranial deep brain stimulation lead on radiofrequency heating at 9.4 Tesla (400.2 MHz).
机构信息
Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA.
出版信息
J Magn Reson Imaging. 2010 Sep;32(3):600-7. doi: 10.1002/jmri.22292.
PURPOSE
To study the effect of the extracranial portion of a deep brain stimulation (DBS) lead on radiofrequency (RF) heating with a transmit and receive 9.4 Tesla head coil.
MATERIALS AND METHODS
The RF heating was studied in four excised porcine heads (mean animal head weight = 5.46 +/- 0.14 kg) for each of the following two extracranial DBS lead orientations: one, parallel to the coil axial direction; two, perpendicular to the coil axial direction (i.e., azimuthal). Temperatures were measured using fluoroptic probes at four locations: one, scalp; two, near the second DBS lead electrode-brain contact; three, near the distal tip of the DBS lead; and four, air surrounding the head. A continuous wave RF power was delivered to each head for 15 min using the coil. Net, delivered RF power was measured at the coil (mean whole head average specific absorption rate = 2.94 +/- 0.08 W/kg).
RESULTS
RF heating was significantly reduced when the extracranial DBS lead was placed in the axial direction (temperature change = 0-5 degrees C) compared with the azimuthal direction (temperature change = 1-27 degrees C).
CONCLUSION
Development of protocols seems feasible to keep RF heating near DBS electrodes clinically safe during ultra-high field head imaging.
目的
研究使用发射和接收 9.4 特斯拉头部线圈时，深部脑刺激（DBS）导线颅外部分对射频（RF）加热的影响。
材料和方法
在四个离体猪头上（平均动物头部重量=5.46 +/- 0.14 公斤），对以下两种颅外 DBS 导线方向进行了 RF 加热研究：一是与线圈轴向平行；二是与线圈轴向垂直（即方位角）。在四个位置使用荧光光纤探头测量温度：一是头皮；二是靠近第二个 DBS 导线电极-脑接触处；三是靠近 DBS 导线远端尖端；四是头部周围的空气。使用线圈向每个头部连续 15 分钟输送连续波 RF 功率。测量线圈的净输送 RF 功率（整个头部平均比吸收率=2.94 +/- 0.08 W/kg）。
结果
当将颅外 DBS 导线放置在轴向方向时，RF 加热显著降低（温度变化=0-5 摄氏度），而当导线放置在方位角方向时，RF 加热显著增加（温度变化=1-27 摄氏度）。
结论
似乎可以制定方案，在超高场头部成像期间使 DBS 电极附近的 RF 加热保持临床安全。
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