BOLD sensitivity in multiecho sequences
Gowland P, Bowtell R
Unversity of Nottingham
This abstract aims to determine the optimal echo times for BOLD sensitivity in a multi-echo sequence and to determine how sensitivity varies between regions of different relaxation rates, taking into account the interaction between imaging bandwidth and echo time. For a single echo acquisition, the bandwidth should be as narrow as possible given the limitation of image distortions, up to a maximum echo time of 1.5 T2*. In a multi-echo sequence if the signals are combined by weighted summation, the optimum echo interval is reduced, and the variation in BOLD sensitivity to the underlying tissue T2* is increased.