政大機構典藏-National Chengchi University Institutional Repository(NCCUR):Item 140.119/96996

English | 正體中文 | 简体中文 | Post-Print筆數 : 27 | Items with full text/Total items : 109948/140897 (78%)
Visitors : 46113676 Online Users : 1054

RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.

Home ‧ Login ‧ Upload ‧ Help ‧ About ‧ Administer

政大機構典藏 > 理學院 > 應用物理研究所 > 期刊論文 > Item 140.119/96996

Please use this identifier to cite or link to this item: https://nccur.lib.nccu.edu.tw/handle/140.119/96996

Title:	Effects of Frequency Drift on the Quantification of Gamma-Aminobutyric Acid Using MEGA-PRES
Authors:	蔡尚岳 Tsai, Shang-Yueh;Fang, Chun-Hao;Wu, Thai-Yu;Lin, Yi-Ru
Contributors:	應物所
Date:	2016-04
Issue Date:	2016-05-30 15:23:03 (UTC+8)
Abstract:	The MEGA-PRESS method is the most common method used to measure γ-aminobutyric acid (GABA) in the brain at 3T. It has been shown that the underestimation of the GABA signal due to B0 drift up to 1.22 Hz/min can be reduced by post-frequency alignment. In this study, we show that the underestimation of GABA can still occur even with post frequency alignment when the B0 drift is up to 3.93 Hz/min. The underestimation can be reduced by applying a frequency shift threshold. A total of 23 subjects were scanned twice to assess the short-term reproducibility, and 14 of them were scanned again after 2–8 weeks to evaluate the long-term reproducibility. A linear regression analysis of the quantified GABA versus the frequency shift showed a negative correlation (P < 0.01). Underestimation of the GABA signal was found. When a frequency shift threshold of 0.125 ppm (15.5 Hz or 1.79 Hz/min) was applied, the linear regression showed no statistically significant difference (P > 0.05). Therefore, a frequency shift threshold at 0.125 ppm (15.5 Hz) can be used to reduce underestimation during GABA quantification. For data with a B0 drift up to 3.93 Hz/min, the coefficients of variance of short-term and long-term reproducibility for the GABA quantification were less than 10% when the frequency threshold was applied.
Relation:	Scientific Reports, Vol.6, pp.24564
Data Type:	article
DOI 連結:	http://dx.doi.org/10.1038/srep24564
DOI:	10.1038/srep24564
Appears in Collections:	[應用物理研究所 ] 期刊論文

Files in This Item:

File	Description	Size	Format
410179.pdf		1242Kb	Adobe PDF2	778	View/Open

社群 sharing

著作權政策宣告 Copyright Announcement

1.本網站之數位內容為國立政治大學所收錄之機構典藏，無償提供學術研究與公眾教育等公益性使用，惟仍請適度，合理使用本網站之內容，以尊重著作權人之權益。商業上之利用，則請先取得著作權人之授權。
The digital content of this website is part of National Chengchi University Institutional Repository. It provides free access to academic research and public education for non-commercial use. Please utilize it in a proper and reasonable manner and respect the rights of copyright owners. For commercial use, please obtain authorization from the copyright owner in advance.

2.本網站之製作，已盡力防止侵害著作權人之權益，如仍發現本網站之數位內容有侵害著作權人權益情事者，請權利人通知本網站維護人員(nccur@nccu.edu.tw)，維護人員將立即採取移除該數位著作等補救措施。
NCCU Institutional Repository is made to protect the interests of copyright owners. If you believe that any material on the website infringes copyright, please contact our staff(nccur@nccu.edu.tw). We will remove the work from the repository and investigate your claim.

Loading...