The use of MR B1+ imaging for validation of FDTD electromagnetic simulations of human anatomies
Van Den Berg, Cornelis A.T., Bartels, Lambertus W., Van Den Bergen, Bob, Kroeze, Hugo, De Leeuw, Astrid A.C., Van De Kamer, Jeroen B., Lagendijk, Jan J.W.
DOI: https://doi.org/10.1088/0031-9155/51/19/001
Physics in Medicine and Biology 51 (19), p. 4735-4746
Abstract
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.