The vascular fingerprint of non-balanced BOLD SSFP coherence pathways: gradient echoes show spin echo behavior

The S2-SSFP echo (the echo before the RF pulse in non-balanced SSFP sequences, or F-0, PSIF, CE-FAST, T2-FFE) is a refocused echo and has thus been proposed for BOLD imaging to suppress larger vessels, similar to the classical spin echo. Here we demonstrate in Monte Carlo simulations that the primary S1-SSFP gradient echo shows nearly identical properties as the S2-SSFP echo. Both echoes of this non-balanced SSFP sequence can be used for BOLD imaging exhibiting a pure spin echo behavior, i.e suppression of larger vessels