Christopher M. Collins1, Chienping Kao1,
Andrew G. Webb2
As
shown in both animations of B1 field magnitude through time and Poynting
vector analysis, travelling waves have significantly shorter length and
slower speed in human tissues than in the surrounding air, and thus
experience significant refraction at the surface of the body, resulting in a
direction of travel within the body that is fairly independent of the
original source. Nevertheless, how these waves interfere within the body to
create B1 and E1 field patterns relevant to MRI depends very much on the
position, geometry, and orientation of the source(s).