Formulations of the
two-component spoiled gradient recalled echo (SPGR) and balanced steady-state
free precession (bSSFP) models that incorporate nonzero echo time (TE) effects
are presented in the context of mcDESPOT and compared with the conventionally
used SPGR and bSSFP models which ignore nonzero TEs. Relative errors in derived
parameter estimates from conventional mcDESPOT, omitting TE effects, are
assessed using simulations over a wide range of experimental and sample
parameters. The neglect of nonzero TE leads to an overestimate of the SPGR and an
underestimate of the bSSFP signals. These effects introduce large errors in
parameter estimates derived from conventional mcDESPOT.