Validation of the presence of fast exchanging amine CEST effect at low saturation powers and its influence on the quantification of APT.
Validation of the presence of fast exchanging amine CEST effect at low saturation powers and its influence on the quantification of APT.
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DOI：
10.1002/mrm.29742
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发表时间：
2023-10
影响因子：
3.3
通讯作者：
Zu, Zhongliang
中科院分区：
文献类型：
--
作者：
Sun, Casey;Zhao, Yu;Zu, Zhongliang
准确地量化酰胺质子转移（APT）的效果和基本的交换参数是至关重要的，其应用，但以前的研究报告相互矛盾的结果。在这些定量中，来自快速交换胺的化学交换饱和转移（CEST）效应总是被忽略，因为它被认为具有低饱和能力。本文旨在评估快速交换胺CEST在低饱和功率下对APT定量的影响。使用具有低和高饱和功率的定量方法来区分APT与快速交换胺CEST效应。进行模拟以评估该方法将APT与快速交换胺CEST效应分离的能力。进行动物实验以评估在3.5ppm下快速交换胺和酰胺对CEST信号的相对贡献。采用三种APT定量方法（每种方法都有不同程度的快速交换胺污染）处理动物数据，以评估胺对APT效应和交换参数定量的影响。快交换胺CEST效应与APT效应的相对大小随着饱和功率的增加而逐渐增加。在9.4T时，它从APT效应的约20%增加到40%，饱和功率从0.25 μT增加到1 μT。快速交换胺CEST效应导致过高估计APT效应、拟合酰胺浓度和酰胺-水交换速率，可能导致先前研究中报告的相互矛盾的结果。
Accurately quantifying the amide proton transfer (APT) effect and the underlying exchange parameters is crucial for its applications, but previous studies have reported conflicting results. In these quantifications, the chemical exchange saturation transfer (CEST) effect from the fast exchange amine was always ignored because it was considered weak with low saturation powers. This paper aims to evaluate the influence of the fast exchange amine CEST on the quantification of APT at low saturation powers. A quantification method with low and high saturation powers was used to distinguish APT from the fast exchange amine CEST effect. Simulations were conducted to assess the method’s capability to separate APT from the fast exchange amine CEST effect. Animal experiments were performed to assess the relative contributions from the fast exchange amine and amide to CEST signals at 3.5ppm. Three APT quantification methods, each with varying degrees of contamination from the fast exchange amine, were employed to process the animal data to assess the influence of the amine on the quantification of APT effect and the exchange parameters. The relative size of the fast exchange amine CEST effect to APT effect gradually increases with increasing saturation power. At 9.4T, it increases from approximately 20% to 40% of APT effect with a saturation power increase from 0.25 μT to 1 μT. The fast exchange amine CEST effect leads overestimation of APT effect, fitted amide concentration, and amide–water exchange rate, potentially contributing to the conflicting results reported in previous studies.
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DOI：
10.1158/1078-0432.ccr-18-1233
发表时间：
2019-01-15
期刊：
Clinical cancer research : an official journal of the American Association for Cancer Research
影响因子：
--
作者：
Jiang S;Eberhart CG;Lim M;Heo HY;Zhang Y;Blair L;Wen Z;Holdhoff M;Lin D;Huang P;Qin H;Quinones-Hinojosa A;Weingart JD;Barker PB;Pomper MG;Laterra J;van Zijl PCM;Blakeley JO;Zhou J
通讯作者：
Zhou J
影响因子：
3.3
作者：
Cui J;Zhao Y;Wang F;Gochberg DF;Zu Z
通讯作者：
Zu Z
影响因子：
3.3
作者：
Heo HY;Zhang Y;Jiang S;Lee DH;Zhou J
通讯作者：
Zhou J
影响因子：
3.3
作者：
Heo HY;Zhang Y;Burton TM;Jiang S;Zhao Y;van Zijl PCM;Leigh R;Zhou J
通讯作者：
Zhou J
影响因子：
5.7
作者：
Kim, Byungjai;Schaer, Michael;Heo, Hye-Young
通讯作者：
Heo, Hye-Young