The impact of quasi-transverse electric modes excited by dipole antennas on transmit field in in vivo ultrahigh field MRI
AUTHORS: Wenz D, Gruetter R
ISMRM & SMRT Annual Meeting, : , Online, May 2021
This work investigates quasi-transverse electric modes which can be excited within rectangular dielectric blocks which are often used to shorten dipole antennas for MRI at 7T. In simulations we studied different parameters which can affect the performance of a dielectrically-shortened dipole antenna. We showed that an optimal geometry for the case when the block and the sample are physically separated differs significantly from the case when perfect direct contact is achieved. Two prototypes were built and used in an in vivo MRI experiments involving one subject showing how different dielectric modes can affect the image quality.