Simultaneous multi-region detection of GABA+ and Glx using 3D spatially resolved SLOW-editing and EPSI-readout at 7T.

Autor: Weng G; Institute for Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital and University of Bern, Switzerland; Translational Imaging Center, sitem-insel, Bern, Switzerland. Electronic address: guodong.weng@unibe.ch., Slotboom J; Institute for Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital and University of Bern, Switzerland; Translational Imaging Center, sitem-insel, Bern, Switzerland., Schucht P; Department of Neurosurgery, Inselspital, University Hospital and University of Bern, Switzerland., Ermiş E; Department of Radiation Oncology, Inselspital, University Hospital and University of Bern, Switzerland., Wiest R; Institute for Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital and University of Bern, Switzerland; Translational Imaging Center, sitem-insel, Bern, Switzerland., Klöppel S; University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland., Peter J; University Hospital of Old Age Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland., Zubak I; Department of Neurosurgery, Inselspital, University Hospital and University of Bern, Switzerland., Radojewski P; Institute for Diagnostic and Interventional Neuroradiology, Inselspital, University Hospital and University of Bern, Switzerland; Translational Imaging Center, sitem-insel, Bern, Switzerland.
Jazyk: angličtina
Zdroj: NeuroImage [Neuroimage] 2024 Feb 01; Vol. 286, pp. 120511. Date of Electronic Publication: 2024 Jan 05.
DOI: 10.1016/j.neuroimage.2024.120511
Abstrakt: GABA+ and Glx (glutamate and glutamine) are widely studied metabolites, yet the commonly used magnetic resonance spectroscopy (MRS) techniques have significant limitations, including sensitivity to B 0 and B 1 + -inhomogeneities, limited bandwidth of MEGA-pulses, high SAR which is accentuated at 7T. To address these limitations, we propose SLOW-EPSI method, employing a large 3D MRSI coverage and achieving a high resolution down to 0.26 ml. Simulation results demonstrate the robustness of SLOW-editing for both GABA+ and Glx against B 0 and B 1 + -inhomogeneities within the range of [-0.3, +0.3] ppm and [40 %, 250 %], respectively. Two protocols, both utilizing a 70 mm thick FOV slab, were employed to target distinct brain regions in vivo, differentiated by their orientation: transverse and tilted. Protocol 1 (n = 11) encompassed 5 locations (cortical gray matter, white matter, frontal lobe, parietal lobe, and cingulate gyrus). Protocol 2 (n = 5) involved 9 locations (cortical gray matter, white matter, frontal lobe, occipital lobe, cingulate gyrus, caudate nucleus, hippocampus, putamen, and inferior thalamus). Quantitative analysis of GABA+ and Glx was conducted in a stepwise manner. First, B 1 + /B 1 - -inhomogeneities were corrected using water reference data. Next, GABA+ and Glx values were calculated employing spectral fitting. Finally, the GABA+ level for each selected region was compared to the global Glx within the same subject, generating the GABA+/Glx_global ratio. Our findings from two protocols indicate that the GABA+/Glx_global level in cortical gray matter was approximately 16 % higher than in white matter. Elevated GABA+/Glx_global levels acquired with protocol 2 were observed in specific regions such as the caudate nucleus (0.118±0.067), putamen (0.108±0.023), thalamus (0.092±0.036), and occipital cortex (0.091±0.010), when compared to the cortical gray matter (0.079±0.012). Overall, our results highlight the effectiveness of SLOW-EPSI as a robust and efficient technique for accurate measurements of GABA+ and Glx at 7T. In contrast to previous SVS and 2D-MRSI based editing sequences with which only one or a limited number of brain regions can be measured simultaneously, the method presented here measures GABA+ and Glx from any brain area and any arbitrarily shaped volume that can be flexibly selected after the examination. Quantification of GABA+ and Glx across multiple brain regions through spectral fitting is achievable with a 9-minute acquisition. Additionally, acquisition times of 18-27 min (GABA+) and 9-18 min (Glx) are required to generate 3D maps, which are constructed using Gaussian fitting and peak integration.
Competing Interests: Declaration of competing interest Guodong Weng and Johannes Slotboom disclose that the application of SLOW-editing described in the paper has been filed at the International Bureau of WIPO as a PCT patent application. Patent applicant: Universität Bern. Status of application: published (WO 2022/229728). Inventors: Guodong Weng and Johannes Slotboom
(Copyright © 2024. Published by Elsevier Inc.)
Databáze: MEDLINE
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