Echoes—how to generate, recognize, use or avoid them in MR‐imaging sequences. Part II: Echoes in imaging sequences

Abstract Part I of this sequence of two papers on spin echoes introduced the echo phenomenon and presented the extended‐phase‐graph algorithm for the description of signals arising in the multi‐pulse sequences. In Part II, pulse sequences that are commonly used in MR imaging are discussed with the use of this algorithm. First, it is shown that phase graphs easily demonstrate how a proper multi‐echo imaging experiment should be designed. Then, they are used to shed some light on the signal behavior of gradient‐echo sequences. Finally, some hints are given about how to avoid or use spurious echoes in more general multi‐pulse sequences.