NUCLEAR MAGNETIC-RESONANCE RELAXATION IN EXPERIMENTAL BRAIN EDEMA - EFFECTS OF WATER CONCENTRATION, PROTEIN-CONCENTRATION, AND TEMPERATURE
NUCLEAR MAGNETIC-RESONANCE RELAXATION IN EXPERIMENTAL BRAIN EDEMA - EFFECTS OF WATER CONCENTRATION, PROTEIN-CONCENTRATION, AND TEMPERATURE
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DOI：
10.1002/mrm.1910060304
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发表时间：
1988-03-01
影响因子：
3.3
通讯作者：
BERENDSEN, HJC
中科院分区：
文献类型：
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作者：
KAMMAN, RL;GO, KG;BERENDSEN, HJC
质子弛豫时间T1和T2的大分子溶液，牛脑组织，和实验猫脑水肿组织进行了研究，作为水浓度，蛋白质浓度和温度的函数。一个线性关系被发现之间的倒数的组织水的重量分数和自旋-晶格弛豫速率，R1，基于一个快速质子交换模型的松弛。这种相关性也被发现的自旋-自旋弛豫速率，R2，灰质样品和高分子溶液在低浓度。蛋白质-水样品的浓缩溶液显示出由于粘度效应而增强的松弛。白色物质的T2随着水浓度的升高而显著延长，但与总组织含水量没有直接关系。所有样品的弛豫时间随温度的增加，支持弛豫模型中的快速质子交换的假设。这在白色物质中没有发现，其中T2随着温度的升高而降低，这表明存在中间或甚至缓慢的交换。弛豫时间与组织含水量之间的关系可用于预测由于水升高过程（例如水肿）而导致的组织水的量和/或增加。
Proton relaxation times T1 and T2 of macromolecular solutions, bovine brain tissues, and experimental cat brain edema tissues were studied as a function of water concentration, protein concentration, and temperature. A linear relation was found between the inverse of the weight fraction of tissue water and the spin-lattice relaxation rate, R1, based on a fast proton exchange model for relaxation. This correlation was also found for the spin-spin relaxation rate, R2, of gray matter samples and macromolecular solutions at low concentrations. Concentrated solutions of protein-water samples showed an enhanced relaxation due to viscosity effects. The T2 of white matter was considerably lengthened with elevated water concentration, but showed no straightforward relation with the total tissue water content. The relaxation times of all samples increased with temperature, supporting the assumption of fast proton exchange in the model for relaxation. This was not found for white matter, in which T2 decreased with increasing temperature, which indicated that intermediate or even slow exchange was present. The relation found between relaxation times and tissue water content can be used to predict the amount of and/or increase in tissue water due to water-elevating processes such as edema.