  Purpose: To develop schemes that deliver faithful 2D slices near field
heterogeneities of the kind arising from non-ferromagnetic metal implants, with
reduced artifacts and shorter scan times.
  Methods: An excitation scheme relying on cross-term spatio-temporal encoding
(xSPEN) was used as basis for developing the new inhomogeneity-insensitive,
slice-selective pulse scheme. The resulting Fully refOCUSED cross-term
SPatiotemporal ENcoding (FOCUSED-xSPEN) approach involved four adiabatic
sweeps. The method was evaluated in silico, in vitro and in vivo using mice
models, and compared against a number of existing and of novel alternatives
based on both conventional and swept RF pulses, including an analogous method
based on LASER's selectivity spatial selectivity.
  Results: Calculations and experiments confirmed that multi-sweep derivatives
of xSPEN and LASER can deliver localized excitation profiles, centered at the
intended positions and endowed with enhanced immunity to B0 and B1 distortions.
This, however, is achieved at the expense of higher SAR than non-swept
counterparts. Furthermore, single-shot FOCUSED-xSPEN and LASER profiles covered
limited off-resonance ranges. This could be extended to bands covering
arbitrary off-resonance values with uniform slice widths, by looping the
experiments over a number of scans possessing suitable transmission and
reception offsets.
  Conclusions: A series of novel approaches were introduced to select slices
near metals, delivering robustness against Bo and B1+ field inhomogeneities.
