Radiofrequency Fields and SAR for Transverse Electromagnetic (TEM) Surface Coils

The ability to predict transmit characteristics in vivo is an important and necessary tool for the development and understanding of radiofrequency (RF) coils in high-field magnetic resonance imaging systems. Accurate simulation provides the coil developer a means to determine the RF fields produced by the coils and the RF power deposition in the sample/subject. This is especially important currently where arrays of multielement surface coils are proposed to maximize transmitted RF magnetic fields. Finite difference time domain (FDTD) simulations provide detailed RF field information for single and multielement RF coils and on field optimization techniques such as B1+ shimming. Confidence in simulations guides the development of future RF coils and optimization strategies. This article discusses the basics of the FDTD methodology and outlines important details of modeling RF coils. Keywords: RF; surface coil; SAR; TEM; shimming; FDTD; high-field MRI

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