The principal advantage of MRI at ultra-high field is the concomitant increase in signal-to-noise ratio (SNR), which can be traded for higher resolution. The TW MRI is naturally associated with the propagation effects in media that offer several advantages to RF manipulations. Specifically, propagating TW can be the most effective way to deliver RF power at ultra-high fields to a large FOV and it can naturally provide variety of modes. The propagation of waves inside an electrodynamics system with cylindrical geometry of an MR scanner may be implemented by using a hollow metal waveguide, either by using the bore of the scanner, its shield or a specially constructed and dedicated waveguide. The new regimes depend critically on transmitting and receiving RF waves, specifically, by utilizing far-field excitation instead of the conventional near-field operation normally used in MRI. In my computational and experimental research with various collaborators I study the ways to overcome the constraints of various scanner geometries in order to effectively excite and couple TW RF into a subject. Among the systems of interests are small-bore ultra-high MRI systems (16.4T, 21.1T), which are normally not suitable for waves propagation; and human bore ultra-high MRI (7T, 10.5T).