[en] Optimization of an antenna for magnetic resonance imaging (MRI) requires an acurate analysis of antennas located inside a conducting cylindrical RF shield. A Galerkin-moment method analysis which can be used for an arbitrary shaped shield is employed. Surface current on a conducting plane is expanded using surface patch segments based on the method of Richmond. Numerical results are compared with measured input impedance confirming the validity of the proposed method. Furthermore relation between the dimension of shield and the sensitivity of the antenna is discussed theoretically. (author)

[en] We have previously developed a computer code for obtaining the current distribution on the MRI antenna loaded by a man model with an arbitrary geometry and material properties by incorporating the impedance method into the method of Richmond. Using this method, RF magnetic field penetration in a biological body within an MRI antenna is discussed theoretically. It is found that the RF magnetic field produced by the current in the body does not cancel the incident RF magnetic field produced by the current on the MRI antenna, since the phase difference between these magnetic fields is largely deviated from 180 degrees. (author)

[en] The slotted tube resonator for a magnetic resonance imaging diagnostic equipment was approximated with the line model which was corrected with a concentrated electrostatic capacity, and analyzed by using the moment method of Richmond, in this way, the input impedance characteristics, current distribution and electromagnetic field distribution have been elucidated. Moreover, by comparing with the measured values of the input impedance, the validity of the analysis was shown. Magnetic resonance imaging diagnostic equipment can obtain the tomograms of human bodies in any direction without invasion, and it is superior to X-ray CT and ultrasonic diagnostic equipment in the discrimination capability for the soft tissues of human bodies, accordingly attention has been paid to it as a new medical diagnostic equipment. The role of the resonator for MRI is to irradiate a subject with high frequency magnetic field and to receive the resonance signals that the subject generates, and the required performance is to generate a uniform, strong magnetic field. The analysis model and the method of analysis of a slotted tube resonator and the results are reported. (K.I.)