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PubMed · 12768588

Increased diffusion sensitivity with hyperechos.

Lawrence R Frank·Eric C Wong·Thomas T Liu·Richard B Buxton
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Abstract

It is shown that the introduction of a 180 degrees refocusing pulse into a standard diffusion weighted stimulated echo sequence is equivalent to the simplest hyperecho sequence with identical diffusion weighting but equal or greater signal-to-noise (SNR) and thus equal or greater diffusion contrast. For high b-value imaging, the hyperecho sequence thus possesses the high diffusion contrast in the presence of small T(1)/T(2) ratios characteristic of stimulated echo sequences but with less than the 50% loss in SNR that is associated with the stimulated echo. For low b-value imaging, the hyperecho signal converges to that of the standard spin echo. The advantages of the two-pulse diffusion weighted hyperecho sequence are demonstrated theoretically. Experimental results are shown in the application to high angular resolution diffusion encoding (HARD) in normal human brain.

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AnisotropyBrainDiffusion Magnetic Resonance ImagingHumansModels, TheoreticalJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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Lawrence R Frank, Eric C Wong, Thomas T Liu, Richard B Buxton. 2003. Increased diffusion sensitivity with hyperechos.. https://doi.org/10.1002/mrm.10457

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