Comparative evaluation of polynomial and Lorentzian lineshape-fitted amine CEST imaging in acute ischemic stroke.
Comparative evaluation of polynomial and Lorentzian lineshape-fitted amine CEST imaging in acute ischemic stroke.
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DOI：
10.1002/mrm.29030
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发表时间：
2022-03
影响因子：
3.3
通讯作者：
Zu, Zhongliang
中科院分区：
文献类型：
--
作者：
Cui, Jing;Afzal, Aqeela;Zu, Zhongliang
胺类化合物的化学交换饱和转移信号对pH很敏感，检测这些信号可以替代酰胺质子转移(APT)的pH成像方法。然而，关于缺血性卒中中2ppm的胺CEST成像的结果是相互矛盾的。在此，我们在动物卒中模型中关联了胺CEST和APT，以评估其对pH的特异性，并通过模拟和样本研究探讨了结果不同的原因。采用三点定量方法对APT进行定量。用多项式拟合法和多池洛伦兹拟合法对胺CEST进行了定量。制备了肌酸和谷氨酸样品，研究了精氨酸胺和快速交换池对CEST的不同影响。制备了不同pH的组织匀浆样品，研究了CEST信号仅因pH变化而发生的变化。在2ppm处，胺CEST的多项式拟合度与APT显著相关，而洛伦兹拟合度则不显著。进一步的研究表明，精氨酸胺对多项式拟合度有贡献，而精氨酸胺和快速交换池对洛伦兹拟合度有贡献，其CEST效应在卒中后呈相反方向变化。来自快速交换池的CEST信号减弱，可能是由于池浓度的降低，而不是由于pH。相反方向的变化导致胺CEST与APT的洛伦兹拟合度相关性不大，在不同的实验条件下得到的结果不同。
Chemical exchange saturation transfer signals from amines are sensitive to pH, and detection of these signals can serve as an alternative pH imaging method to amide proton transfer (APT). However, conflicting results regarding amine CEST imaging at 2 ppm in ischemic stroke have been reported. Here, we correlated amine CEST with APT in animal stroke models to evaluate its specificity to pH, and investigated the reason for the different results through simulations and sample studies. A three‐point quantification method was used to quantify APT. A polynomial fit method and a multiple‐pool Lorentzian fit method were used to quantify amine CEST. Samples of creatine and glutamate were prepared to study the different CEST effects from arginine amine and fast exchanging pools. Samples of tissue homogenates with different pH were prepared to study the variation in CEST signals due only to changes in pH. The polynomial fit of amine CEST at 2 ppm had a significant correlation with APT, whereas the Lorentzian fit did not. Further studies showed that arginine amine contributed to the polynomial fit, whereas both the arginine amine and the fast exchanging pools contributed to the Lorentzian fit with their CEST effects varying in opposite directions after stroke. The CEST signal from the fast exchanging pool decreased, probably due to the reduced pool concentration but not pH. The variation in opposite directions led to an insignificant correlation of the Lorentzian fit of amine CEST with APT and the different results in different experimental conditions.
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影响因子：
2.9
作者：
Xu, Junzhong;Zaiss, Moritz;Zu, Zhongliang;Li, Hua;Xie, Jingping;Gochberg, Daniel F.;Bachert, Peter;Gore, John C.
通讯作者：
Gore, John C.
来自Z频谱拟合的2ppm（CEST@2ppm）处的CEST信号与脑肿瘤中的肌酸分布相关。
影响因子：
2.9
作者：
Cai, Kejia;Singh, Anup;Poptani, Harish;Li, Weiguo;Yang, Shaolin;Lu, Yang;Hariharan, Hari;Zhou, Xiaohong J.;Reddy, Ravinder
通讯作者：
Reddy, Ravinder
影响因子：
6.3
作者：
Sun, Phillip Zhe;Cheung, Jerry S.;Lo, Eng H.
通讯作者：
Lo, Eng H.
影响因子：
2.9
作者：
Zaiss, Moritz;Zu, Zhongliang;Xu, Junzhong;Schuenke, Patrick;Gochberg, Daniel F.;Gore, John C.;Ladd, Mark E.;Bachert, Peter
通讯作者：
Bachert, Peter
影响因子：
3.3
作者：
Kogan, Feliks;Haris, Mohammad;Singh, Anup;Cai, Kejia;Debrosse, Catherine;Nanga, Ravi Prakash Reddy;Hariharan, Hari;Reddy, Ravinder
通讯作者：
Reddy, Ravinder