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Elimination of spatial interference in PRESS‐localized editing spectroscopy
Author(s) -
Kaiser Lana G.,
Young Karl,
Matson Gerald B.
Publication year - 2007
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.21407
Subject(s) - signal (programming language) , artifact (error) , nuclear magnetic resonance , chemistry , compartment (ship) , noise (video) , butyric acid , imaging phantom , signal to noise ratio (imaging) , interference (communication) , biophysics , computer science , biological system , physics , optics , artificial intelligence , biochemistry , image (mathematics) , telecommunications , biology , geology , oceanography , channel (broadcasting) , programming language
Unambiguous detection of γ‐amino butyric acid (GABA) in the human brain is hindered by low concentration and spectral overlap with other metabolites. The popular MEGA‐PRESS (PRESS: point‐resolved spectroscopic sequence) method allows spectral separation of GABA from other metabolites, but suffers from a significant signal‐to‐noise ratio (SNR) reduction due to the 4‐compartment artifact. An alternative PRESS localization technique (PRESS+4) was investigated and compared to MEGA‐PRESS using numerical simulations, phantom, and in vivo experiments. It was shown that while the MEGA‐PRESS method suffers significant signal loss (≈20% for the difference spectrum), GABA signal intensity in PRESS+4 is reduced by only 2% compared to the nonlocalized condition at 4T. The improved method retains important features of the popular MEGA‐PRESS such as additional water suppression and macromolecular elimination as demonstrated in human brain experiments. This method is not limited to GABA J‐difference editing, but can be applied in any PRESS‐based experiments. It should prove particularly useful at higher field, where the 4‐compartment artifact is especially detrimental. Magn Reson Med 58:813–818, 2007. © 2007 Wiley‐Liss, Inc.