Comparison of magnetic properties of MRI contrast media solutions at different magnetic field strengths
Comparison of magnetic properties of MRI contrast media solutions at different magnetic field strengths
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DOI：
10.1097/01.rli.0000184756.66360.d3
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发表时间：
2005-11-01
影响因子：
6.7
通讯作者：
Weinmann, HJ
中科院分区：
文献类型：
--
作者：
Rohrer, M;Bauer, H;Weinmann, HJ
基本原理和目的：表征和比较市售的磁共振成像造影剂（CM）在水和等离子体中生理温度下磁场强度为0.47 T至4.7 T时的弛豫度。方法：分别采用核磁共振（NMR）波谱法测定在0.47 T时MRI- cm的弛豫度，以及在1.5 T、3 T和4.7 T时MRI模态测量。采用适当的自旋回波序列测量了纵向弛豫时间（T-1）和横向弛豫时间（T-2）。核磁共振色散（NMRD）谱也测定了所有药剂在水和血浆中的分布。结果：测定了松驰度对场强和溶剂的依赖性。蛋白质结合导致磁场强度和溶剂依赖性增加，因此在较高的磁场强度下，T松弛度值显著改变。结论：了解与松弛度数据相关的场强和溶剂对松弛度值的比较和评价至关重要。因此，在0.47 T下观察到的数据可能具有误导性，应该用生理温度下在1.5 T和3t下测量到的等离子体弛豫度来代替。
Rationale and Objectives: To characterize and compare commercially available contrast media (CM) for magnetic resonance imaging (MRI) in terms of their relaxivity at magnetic field strengths ranging from 0.47 T to 4.7 T at physiological temperatures in water and in plasma. Relaxivities also were quantified in whole blood at 1.5 T.Methods: Relaxivities of MRI-CM were determined by nuclear magnetic resonance (NMR) spectroscopy at 0.47 T and MRI phantom measurements at 1.5 T, 3 T, and 4.7 T, respectively. Both longitudinal (T-1) and transverse relaxation times (T-2) were measured by appropriate spin-echo sequences. Nuclear magnetic resonance dispersion (NMRD) profiles were also determined for all agents in water and in plasma.Results: Significant dependencies of relaxivities on the field strength and solvents were quantified. Protein binding leads to both increased field strength and solvent dependencies and hence to significantly altered T, relaxivity values at higher magnetic field strengths.Conclusions: Awareness of the field strength and solvent associated with relaxivity data is crucial for the comparison and evaluation of relaxivity values. Data observed at 0.47 T can thus be misleading and should be replaced by relaxivities measured at 1.5 T and at 3 T in plasma at physiological temperature.