An Analytical Description of Balanced SSFP with Finite RF Excitation

Oliver Bieri¹

Conceptually, the only flaw in the common SSFP signal theory is the assumption of quasi-instantaneous radio-frequency (RF) pulses. An exact analytical solution for finite RF balanced SSFP will be derived and it will be shown that finite RF effects can be quite significant even for moderate RF pulse durations. Thus care should be taken when interpreting SSFP signal based on the common Freeman-Hill formulae since only recently it was realized that besides finite RF pulses also magnetization transfer effects may induce a significant modulation in the steady state amplitude.