Counting echoes: Application of a complete reciprocal‐space description of NMR spin dynamics

Multiple echo NMR velocimetry: Fast and localized measurements of steady and pulsatile flows in small channels

“…1; pulse and delay timings are defined in this schematic. The sequence is based on the fact that multiple RF pulses in the presence of a constant gradient generate independently evolving coherence pathways giving rise to multiple echoes [17]. In the present implementation, we use four rectangular RF pulses, which generate 13 echoes.…”

“…Therefore these echoes are not used in our velocity analysis. In order to remedy this situation and use all 13 echoes, the RF pulses would need to be replaced with multidimensional spatially selective RF pulses [17,18]. Alternatively, the unwanted echoes can be removed by adequate phase cycling, with the disadvantage that this will require repetitive scans and thus increase the acquisition time.…”

Ultrafast 3D spin-echo acquisition improves Gadolinium-enhanced MRI signal contrast enhancement

“…To increase the ratio of spin-echoes to RF pulses per repetition, several techniques have been developed by splitting the position of echo formation from the multiple coherence pathways generated by a relatively small number of RF pulses 23 24 25 26 27 28 29 30 31 32 . The Multiple-Modulation-Multiple-Echoe (MMME) sequence 33 34 35 36 , which maximizes the number of echoes (57) for 5 RF pulses ([54°–71°–71°–71°–110°]) within 30 ms ~ 50 ms of the total echo train time, provides an unique opportunity to reduce the necessary repetitions and RF irradiations with minimized susceptibility-induced decays during the spin-echo train.…”

A one-shot method for measurement of diffusion

“…a total of 3 ðN À1Þ À 1 2 þ 1 coherence pathways generate observable signals [17]. Each coherence pathway may provide a different modulation (k).…”