Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging

Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging

Chemical exchange saturation transfer (CEST) is an emerging MRI contrast mechanism that is capable of noninvasively imaging dilute CEST agents and local properties such as pH and temperature, augmenting the routine MRI methods. However, the routine CEST MRI includes a long RF saturation pulse follow...

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Main Authors: Dai, Zhuozhi, Ji, Jim, Xiao, Gang, Yan, Gen, Li, Shengkai, Zhang, Guishan, Lin, Yan, Shen, Zhiwei, Wu, Renhua
Format: Online
Language:English
Published: Public Library of Science 2014
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4226502/
id pubmed-4226502
recordtype oai_dc
spelling pubmed-42265022014-11-13 Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging Dai, Zhuozhi Ji, Jim Xiao, Gang Yan, Gen Li, Shengkai Zhang, Guishan Lin, Yan Shen, Zhiwei Wu, Renhua Research Article Chemical exchange saturation transfer (CEST) is an emerging MRI contrast mechanism that is capable of noninvasively imaging dilute CEST agents and local properties such as pH and temperature, augmenting the routine MRI methods. However, the routine CEST MRI includes a long RF saturation pulse followed by fast image readout, which is associated with high specific absorption rate and limited spatial resolution. In addition, echo planar imaging (EPI)-based fast image readout is prone to image distortion, particularly severe at high field. To address these limitations, we evaluated magnetization transfer (MT) prepared gradient echo (GRE) MRI for CEST imaging. We proved the feasibility using numerical simulations and experiments in vitro and in vivo. Then we optimized the sequence by serially evaluating the effects of the number of saturation steps, MT saturation power (B1), GRE readout flip angle (FA), and repetition time (TR) upon the CEST MRI, and further demonstrated the endogenous amide proton CEST imaging in rats brains (n = 5) that underwent permanent middle cerebral artery occlusion. The CEST images can identify ischemic lesions in the first 3 hours after occlusion. In summary, our study demonstrated that the readily available MT-prepared GRE MRI, if optimized, is CEST-sensitive and remains promising for translational CEST imaging. Public Library of Science 2014-11-10 /pmc/articles/PMC4226502/ /pubmed/25384020 http://dx.doi.org/10.1371/journal.pone.0112219 Text en © 2014 Dai et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Dai, Zhuozhi
Ji, Jim
Xiao, Gang
Yan, Gen
Li, Shengkai
Zhang, Guishan
Lin, Yan
Shen, Zhiwei
Wu, Renhua
spellingShingle Dai, Zhuozhi
Ji, Jim
Xiao, Gang
Yan, Gen
Li, Shengkai
Zhang, Guishan
Lin, Yan
Shen, Zhiwei
Wu, Renhua
Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
author_facet Dai, Zhuozhi
Ji, Jim
Xiao, Gang
Yan, Gen
Li, Shengkai
Zhang, Guishan
Lin, Yan
Shen, Zhiwei
Wu, Renhua
author_sort Dai, Zhuozhi
title Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
title_short Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
title_full Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
title_fullStr Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
title_full_unstemmed Magnetization Transfer Prepared Gradient Echo MRI for CEST Imaging
title_sort magnetization transfer prepared gradient echo mri for cest imaging
description Chemical exchange saturation transfer (CEST) is an emerging MRI contrast mechanism that is capable of noninvasively imaging dilute CEST agents and local properties such as pH and temperature, augmenting the routine MRI methods. However, the routine CEST MRI includes a long RF saturation pulse followed by fast image readout, which is associated with high specific absorption rate and limited spatial resolution. In addition, echo planar imaging (EPI)-based fast image readout is prone to image distortion, particularly severe at high field. To address these limitations, we evaluated magnetization transfer (MT) prepared gradient echo (GRE) MRI for CEST imaging. We proved the feasibility using numerical simulations and experiments in vitro and in vivo. Then we optimized the sequence by serially evaluating the effects of the number of saturation steps, MT saturation power (B1), GRE readout flip angle (FA), and repetition time (TR) upon the CEST MRI, and further demonstrated the endogenous amide proton CEST imaging in rats brains (n = 5) that underwent permanent middle cerebral artery occlusion. The CEST images can identify ischemic lesions in the first 3 hours after occlusion. In summary, our study demonstrated that the readily available MT-prepared GRE MRI, if optimized, is CEST-sensitive and remains promising for translational CEST imaging.
publisher Public Library of Science
publishDate 2014
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4226502/
_version_ 1613154480317005824

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