Multi-Echo PRESTO: T2* mapping for 3D fMR1

Introduction Last year the Dual-Echo PRESTO [l] technique was introduced to measure I0 and T2* simultaneously. This technique is an extension of the PRESTO [2] technique (TE > TR) and allows for the acquisition of two echoes within each TR. The first echo with a short TE (-7 ms) is acquired directly after RF excitation and is immediately followed by an echo with a long TE (-43 ms) which is echo-shifted. Using the echo shifting technique (TE>TR) for the second echo eliminates the ‘dead-time’ between the two echoes. In this study we extended the technique for multi-echo acquisition. The use of multiple echoes allows a better estimation of T2* and Ia than the dualecho method. A motor cortex activation experiment was performed to explore the applicability of Multi-Echo PRESTO.