Minimum echo time PRESS-based proton observed carbon edited (POCE) MRS in rat brain using simultaneous editing and localization pulses.

TitleMinimum echo time PRESS-based proton observed carbon edited (POCE) MRS in rat brain using simultaneous editing and localization pulses.
Publication TypeJournal Article
Year of Publication2018
AuthorsKumaragamage C, Madularu D, Mathieu AP, Lupinsky D, de Graaf RA, Near J
JournalMagn Reson Med
Date Published2018 Feb 09
ISSN1522-2594
Abstract

PURPOSE: Indirect C MRS by proton-observed carbon editing (POCE) is a powerful method to study brain metabolism. The sensitivity of POCE-MRS can be enhanced through the use of short TEs, which primarily minimizes homonuclear J-evolution related losses; previous POCE-MRS implementations use longer than optimal echo times due to sequence limitations, or short TE image selected in vivo spectroscopy-based multi-shot acquisitions for 3D localization. To that end, this paper presents a novel single-shot point resolved spectroscopy (PRESS)-localized POCE-MRS sequence that involves the application of simultaneous editing and localization pulses (SEAL)-PRESS, allowing the TE to be reduced to a theoretically optimal value of ∼ 1/J .METHODS: The optimized SEAL-PRESS sequence was first evaluated in simulation and in phantom; next, the sequence was validated with dynamic in vivo POCE-MRS performed in a rat preparation during a 1,6- C -Glc infusion, and on a microwave fixed rat brain following a 2-hour [1,6- C ]-Glc infusion. POCE spectra from the SEAL-PRESS sequence were compared against a previously described 12.6-ms PRESS-POCE sequence utilizing a classical carbon editing scheme.RESULTS: The SEAL-PRESS sequence provides > 95% editing efficiency, optimal sensitivity, and localization for POCE MRS with an overall sequence TE of 8.1 ms. Signal amplitude of C-labeled metabolites Glu-H4, Gln-H4, Glx-H3, Glc-H6 +Glx-H2, and Asp-H2 were shown to be improved by >17% relative to a 12.6-ms PRESS-POCE sequence in vivo.CONCLUSION: We report for the first time, a single-shot PRESS-localized and edited 8.1-ms TE POCE-MRS sequence with optimal sensitivity, editing efficiency, and localization.

DOI10.1002/mrm.27119
Alternate JournalMagn Reson Med
PubMed ID29427395

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