Improved 3D Spin-Echo Imaging Using Frequency-Swept Pulses
Grhn O, Garwood M, Park J
A.I.Virtanen Institute for Molecular Sciences, University of Kuopio
Adiabatic full-passage (AFP) pulses have desirable properties that are commonly exploited in NMR (eg, insensitivity to B1-inhomogeneity and ability to invert broad bandwidths). Although AFP pulses can produce refocusing in spin-echo MRI sequences, even numbers of AFP pulses are required to compensate the non-linear magnetization phase. Recently, it was shown that phase compensating using an even number of slab-selective AFP pulses is unnecessary when spatial-encoding is performed in the slab-selection direction. Here, phase profiles produced by AFP pulses in spin-echo sequences are analytically described and shown to produce a pseudo-echo. Image reconstruction using a sliding window function is also described.