%0 Journal Article
%T Concurrent J-evolving refocusing pulses.
%A Ehni S
%A Koos MRM
%A Reinsperger T
%A Haller JD
%A Goodwin DL
%A Luy B
%J J Magn Reson
%V 336
%N 0
%D 03 2022
%M 35189510
%F 2.734
%R 10.1016/j.jmr.2022.107152
%X Conventional refocusing pulses are optimised for a single spin without considering any type of coupling. However, despite the fact that most couplings will result in undesired distortions, refocusing in delay-pulse-delay-type sequences with desired heteronuclear coherence transfer might be enhanced considerably by including coupling evolution into pulse design. We provide a proof of principle study for a Hydrogen-Carbon refocusing pulse sandwich with inherent J-evolution following the previously reported ICEBERG-principle with improved performance in terms of refocusing performance and/or overall effective coherence transfer time. Pulses are optimised using optimal control theory with a newly derived quality factor and z-controls as an efficient tool to speed up calculations. Pulses are characterised in theory and experiment and compared to conventional concurrent refocusing pulses, clearly showing an improvement for the J-evolving pulse sandwich. As a side-product, also efficient J-compensated resfocusing pulse sandwiches - termed BUBU pulses following the nomenclature of previous J-compensated BUBI and BEBEtr pulse sandwiches - have been optimised.