Radiofrequency Fields and SAR for Bird Cage Coils

This article provides an overview of computational electromagnetic modeling techniques used for modeling MRI birdcage coils. The article also provides guidance and details on how to accurately and efficiently model birdcage coils. Sample modeling results are presented on topics including magnetic field homogeneity, specific absorption rate, and coil tuning/current distribution behavior, and are discussed at different static MRI field strengths.

Keywords: birdcage coils; B₁ field; SAR; FDTD; high fields; RF shimming; feeding/excitation