Magnetic microparticle aggregation for viscosity determination by MR
Magnetic microparticle aggregation for viscosity determination by MR
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DOI：
10.1002/mrm.21526
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Josephson, Lee
中科院分区：
文献类型：
--
作者：
Hong, Rui;Cima, Michael J.;Josephson, Lee
当微米级的磁性颗粒被置于均匀磁场（如磁共振成像仪和松弛计）中时，它们会被诱导聚集，然后当从磁场中移开时，会自发地恢复到分散状态。与磁性颗粒的聚集和分散相关的是水的自旋-自旋弛豫时间（T-2）随时间的增加和减少。每个颗粒的磁矩要小得多的磁性纳米颗粒不会发生磁致聚集，并且表现出与时间无关的 T-2 值。与磁性微粒聚集相关的 T-2 变化率用于测定液体样品的粘度，提供了一种对于测定小体积的潜在生物危害的血液或血浆样品的粘度特别有利的方法。
Micron-sized magnetic particles were induced to aggregate when placed in homogeneous magnetic fields, like those of MR imagers and relaxometers, and then spontaneously returned to their dispersed state when removed from the field. Associated with the aggregation and dispersion of the magnetic particles were time-dependent increases and decreases in the spin-spin relaxation time (T-2) of the water. Magnetic nanoparticles, with far smaller magnetic moments per particle, did not undergo magnetically induced aggregation and exhibited time-indpendent values of T-2. The rate of T-2 change associated with magnetic microparticle aggregation was used to determine the viscosity of liquid samples, providing a method that can be of particular advantage for determining the viscosity of small volumes of potentially biohazardous samples of blood or blood plasma.