[Numerical calculation of HF antennas and their interaction with dielectric media in MRI]

At high field MRI the wavelength within the object under investigation is comparable to the dimensions of the human head or body. The development of MR coils, under notice of all safety aspects, can be speed up dramatically by the use of numerical analysis instead of experimental methods. We use the commercially available software packages CONCEPT and MAFIA. We developed new methods for calculating the rf-fields in given structures driven by current, voltage or power sources. With the use of new NMR-methods the amplitude- and phase distribution of the magnetic rf-field and the distribution of the SAR inside the rf-coils, loaded with phantoms, are measured and compared with simulations. The results of the measurements and the simulations of the magnetic rf-field distribution and SAR distribution show a good correspondence.