Spin echoes

One excitation and one refocusing pulse per repetition, with the acquisition centred on the spin echo. The readout trajectories are those of the gradient echoes, with a refocusing pulse between the excitation and the readout.

Example	Scope
2D Cartesian spin echo	One phase-encode line per excitation.
3D Cartesian spin echo	One (line, partition) view per excitation.
2D radial spin echo	One full radial spoke per excitation.
3D stack-of-stars spin echo	One spoke at one Cartesian partition per excitation.
2D spiral spin echo	One spiral interleaf per excitation.
3D stack-of-spirals spin echo	One interleaf at one Cartesian partition per excitation.
2D PROPELLER spin echo	One line of one rotating blade per excitation.
2D PROPELLER spin echo with echo-planar blades	One whole blade per excitation, read as an echo-planar train.
3D stack-of-blades spin echo	One blade line at one Cartesian partition per excitation.