Relaxometric evaluation of novel manganese(II) complexes for application as contrast agents in magnetic resonance imaging
Relaxometric evaluation of novel manganese(II) complexes for application as contrast agents in magnetic resonance imaging
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DOI：
10.1007/s007750100265
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发表时间：
2002-01-01
影响因子：
3
通讯作者：
Terreno, E
中科院分区：
文献类型：
--
作者：
Aime, S;Anelli, PL;Terreno, E
三个新的锰（II）配合物轴承苄氧基甲基功能的报告和他们的能力，以提高水（H-1和O-17）的弛豫时间进行了详细的研究。其中两种含有一个配位水分子，显示的弛豫率值仅略小于临床上最常用的造影剂（例如[Gd（DTPA）（H2O）]（2-））。此外，在这些Mn（II）螯合物中，配位水的交换速率为约100。如果与先前报道的具有八齿配体的Gd（III）络合物的交换速率相比，高一个数量级。这种快速的交换率的配位水的发生被利用在与人血清白蛋白的大分子加合物的形成中，以获得显示弛豫率值在迄今为止报道的类似Gd（III）系统的上限范围内的系统。这些结果强烈支持这样的观点，即Mn（II）络合物，尽管较低的有效磁矩，可以被认为是目前使用的Gd（III）络合物作为MRI应用的造影剂的可行替代品。
Three novel Mn(II) complexes bearing benzyloxymethyl functionalities are reported and their ability to enhance water (H-1 and O-17) relaxation times is investigated in detail. Two of them contain one coordinated water molecule and display relaxivity values only slightly smaller than those shown by the most clinically used contrast agents (e.g. [Gd(DTPA)(H2O)](2-)). Moreover, in these Mn(II) chelates the exchange rate of the coordinated water is ca. one order of magnitude higher if compared to the exchange rates previously reported for Gd(III) complexes with octadentate ligands. The occurrence of such fast exchange rates of the coordinated water is exploited in the formation of macromolecular adducts with human serum albumin to attain systems displaying relaxivity values in the upper range of those so far reported for analogous Gd(III) systems. These results strongly support the view that Mn(II) complexes, in spite of the lower effective magnetic moment, can be considered as viable alternatives to the currently used Gd(III) complexes as contrast agents for MRI applications.