Ultrafast T1-T2 relaxometry using FLOP sequences

By periodically flipping the longitudinal magnetisation with a chain of 180° pulses it is possible to establish a steady-state of longitudinal polarisation that effectively stores the information of T1 relaxation. The pulse sequence for achieving this, called steady-state Flipped LOngitudinal Polarisation (FLOP) can be used for the fast acquisition of a two-dimensional T1-T2 relaxation time spectrum in both periodic and a-periodic modes. We have therefore called this new class of sequences periodic or a-periodic FLOP-T1-T2.