The concept of traveling-wave
MRI has been introduced for ultra-high fields, enabling large field-of-view excitation
and physical separation between the antenna and the subject. Several studies have
shown that introducing additional materials/structures into the magnet bore or
surrounding the subject can improve the efficiency. In this work we explore the
use of high permittivity material placed behind the region of interest and show
that it can be beneficial for traveling wave efficiency. Separating the region
of improved efficiency from that of the dielectric allow positioning of a
receive array in the close proximity to the region of interest, physically
separate from the dielectric material.
