The magnetic field dependence of water T1 in tissues.
The magnetic field dependence of water T1 in tissues.
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DOI：
10.1002/mrm.23229
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发表时间：
2012-07
影响因子：
3.3
通讯作者：
Bryant, Robert G.
中科院分区：
文献类型：
--
作者：
Diakova, Galina;Korb, Jean-Pierre;Bryant, Robert G.
关键词：
复合1H2O NMR信号T1的磁场依赖性测定大鼠肝脏，肌肉和肾脏的切除样品的磁场范围从0.7至7 T（35 MHz至300 MHz）与NMR光谱仪使用样品穿梭方法。基于对简单组件系统的广泛测量，研究的所有组织的T1的磁场依赖性在1 MHz以上的拉莫尔频率处很容易拟合，具有由三个贡献组成的简单弛豫方程：幂律，A * ω − 0.60与水与长寿命蛋白质结合位点的相互作用有关，与大分子界面区水扩散有关的对数项B * τ d * log（1 + 1/（ω τ d）2）和与水-自旋-晶格弛豫的高频极限有关的常数项。参数A和B分别包括浓度和表面积依赖性。对数扩散项在高磁场下变得显著，并且与大分子表面的快速平移动力学一致。对于人脑白色物质，数据与大约15 ps的平移相关时间很好地拟合，但是具有比灰质组织大三倍的B值。这一分析表明，水面平移相关时间大约是灰质的三倍。
The magnetic field dependence of the composite 1H2O NMR signal T1 was measured for excised samples of rat liver, muscle, and kidney over the field range from 0.7 to 7 T (35 MHz to 300 MHz) with a NMR spectrometer using sample-shuttle methods. Based on extensive measurements on simpler component systems, the magnetic field dependence of T1 of all tissues studied are readily fitted at Larmor frequencies above 1 MHz with a simple relaxation equation consisting of three contributions: a power law, A*ω−0.60 related to the interaction of water with long-lived-protein binding sites, a logarithmic term B*τd*log(1+1/(ωτd)2) related to water diffusion at macromolecular interfacial regions, and a constant term associated with the high frequency limit of water-spin-lattice relaxation. The parameters A and B include the concentration and surface area dependences respectively. The logarithmic diffusion term becomes significant at high magnetic fields and is consistent with rapid translational dynamics at macromolecular surfaces. The data are fitted well with translational correlation times of approximately 15 ps for human brain white matter, but with a B value three times larger than gray matter tissues. This analysis suggests that the water-surface translational correlation time is approximately three times longer than gray matter.
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DOI：
10.1021/jp9048082
发表时间：
2009-10-08
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Grebenkov DS;Goddard YA;Diakova G;Korb JP;Bryant RG
通讯作者：
Bryant RG
影响因子：
3.3
作者：
Chavez, Fabian Vaca;Halle, Bertil
通讯作者：
Halle, Bertil
影响因子：
2.8
作者：
ANDREW, ER;BRYANT, DJ;CASHELL, EM
通讯作者：
CASHELL, EM
影响因子：
3.4
作者：
KIMMICH, R;GNEITING, T;SCHNUR, G
通讯作者：
SCHNUR, G
影响因子：
3.3
作者：
Korb, JP;Bryant, RG
通讯作者：
Bryant, RG