Multi-vendor standardized sequence for edited magnetic resonance spectroscopy

TitleMulti-vendor standardized sequence for edited magnetic resonance spectroscopy
Publication TypeJournal Article
Year of Publication2019
AuthorsSaleh MG, Rimbault D, Mikkelsen M, Oeltzschner G, Wang AM, Jiang D, Alhamud A, Near J, Schär M, Noeske R, Murdoch JB, Ersland L, Craven AR, Dwyer GEric, Grüner ERenate, Pan L, Ahn S, Edden RAE
JournalNeuroimage
Volume189
Pagination425-431
Date Published2019 Apr 01
ISSN1095-9572
KeywordsAdult, Brain, Female, gamma-Aminobutyric Acid, Glutathione, Humans, Lactic Acid, Magnetic Resonance Spectroscopy, Male
Abstract

Spectral editing allows direct measurement of low-concentration metabolites, such as GABA, glutathione (GSH) and lactate (Lac), relevant for understanding brain (patho)physiology. The most widely used spectral editing technique is MEGA-PRESS, which has been diversely implemented across research sites and vendors, resulting in variations in the final resolved edited signal. In this paper, we describe an effort to develop a new universal MEGA-PRESS sequence with HERMES functionality for the major MR vendor platforms with standardized RF pulse shapes, durations, amplitudes and timings. New RF pulses were generated for the universal sequence. Phantom experiments were conducted on Philips, Siemens, GE and Canon 3 T MRI scanners using 32-channel head coils. In vivo experiments were performed on the same six subjects on Philips and Siemens scanners, and on two additional subjects, one on GE and one on Canon scanners. On each platform, edited MRS experiments were conducted with the vendor-native and universal MEGA-PRESS sequences for GABA (TE = 68 ms) and Lac editing (TE = 140 ms). Additionally, HERMES for GABA and GSH was performed using the universal sequence at TE = 80 ms. The universal sequence improves inter-vendor similarity of GABA-edited and Lac-edited MEGA-PRESS spectra. The universal HERMES sequence yields both GABA- and GSH-edited spectra with negligible levels of crosstalk on all four platforms, and with strong agreement among vendors for both edited spectra. In vivo GABA+/Cr, Lac/Cr and GSH/Cr ratios showed relatively low variation between scanners using the universal sequence. In conclusion, phantom and in vivo experiments demonstrate successful implementation of the universal sequence across all four major vendors, allowing editing of several metabolites across a range of TEs.

DOI10.1016/j.neuroimage.2019.01.056
Alternate JournalNeuroimage
PubMed ID30682536
PubMed Central IDPMC7008948
Grant ListU54 HD079123 / HD / NICHD NIH HHS / United States
R01 EB023963 / EB / NIBIB NIH HHS / United States
P41 EB015909 / EB / NIBIB NIH HHS / United States
S10 OD021648 / OD / NIH HHS / United States
R01 EB016089 / EB / NIBIB NIH HHS / United States