Wang Bocheng, Li Jin, Jin Hua, Chen Xiang
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:2516-2519. doi: 10.1109/EMBC44109.2020.9176018.
RF heating has severely limited the application of high-field magnetic resonance imaging (MRI) in the patients with active implantable medical devices (AIMDs). Based on the finite element methods (FEMs), we study the RF heating of a lead implanted in the human body under 3.0 T MRI. The coupled simulation of electromagnetic and heat transfer is used to analyze the relationship between several factors, such as the resonance length, the implantation position, the implantation configuration, and the thermal conductivity, and RF heating. Results show that the resonance length of the lead is half of the RF wavelength, and the temperature rise exceeds the acceptable range of human body when the resonance occurs. The electromagnetic field distribution in the phantom is not uniform, so the field density around the wire may vary with different implantation positions and configurations. Temperature rise reduces with the decrease of the field density. In addition, RF heating can be reduced by increasing the thermal conductivity.
射频加热严重限制了高场磁共振成像（MRI）在有源植入式医疗设备（AIMD）患者中的应用。基于有限元方法（FEM），我们研究了3.0 T MRI下植入人体的导线的射频加热情况。采用电磁与热传递的耦合模拟来分析几个因素之间的关系，如共振长度、植入位置、植入构型以及热导率与射频加热的关系。结果表明，导线的共振长度为射频波长的一半，共振发生时温度升高超过人体可接受范围。模型中的电磁场分布不均匀，因此导线周围的场密度可能会因植入位置和构型的不同而变化。温度升高随场密度的降低而减小。此外，通过提高热导率可以减少射频加热。
