The use of MR B+1 imaging for validation of FDTD electromagnetic simulations of human anatomies

In this study, MR B+1 imaging is employed to experimentally verify the validity of FDTD simulations of electromagnetic field patterns in human anatomies. Measurements and FDTD simulations of the B+1 field induced by a 3 T MR body coil in a human corpse were performed. It was found that MR B+1 imaging is a sensitive method to measure the radiofrequency (RF) magnetic field inside a human anatomy with a precision of approximately 3.5%. A good correlation was found between the B+1 measurements and FDTD simulations. The measured B+1 pattern for a human pelvis consisted of a global, diagonal modulation pattern plus local B+1 heterogeneties. It is believed that these local B+1 field variations are the result of peaks in the induced electric currents, which could not be resolved by the FDTD simulations on a 5 mm3 simulation grid. The findings from this study demonstrate that B+1 imaging is a valuable experimental technique to gain more knowledge about the dielectric interaction of RF fields with the human anatomy. For more information on this article, see medicalphysicsweb.org