Laurent S, Vander Elst L, Muller R N
Department of General Organic and Biomedical Chemistry Laboratory of NMR and Molecular Imaging, University of Mons, Mons, Belgium.
Q J Nucl Med Mol Imaging. 2009 Dec;53(6):586-603.
Lanthanide complexes are more and more used in biomedical imaging as contrast agents (CA). The development of these paramagnetic complexes as CA for medical magnetic resonance imaging (MRI) and luminescent probes for optical imaging is very complementary. Gd complexes are well known as CA for MRI and Eu/Tb complexes are often used in microscopy or fluorescence imaging. Each imaging technique has its limitation: low sensitivity but high spatial resolution for MRI and limited penetration but high sensitivity for optical imaging. A bimodal agent can be used for these two methods and give more informations, they can be visualized simultaneously by light and MR imaging. Such compounds are based on the coordination chemistry of the lanthanide ions with an organic ligand to form a stable complex and on the properties of the lanthanide ions. Gd complexes with a chromophore allows also the luminescent detection. This review describes the properties of the lanthanide ions and of their complexes and gives some typical applications of the complexes. The luminescence properties show high quantum yield and long luminescence lifetimes. The relaxometric data of the Gd complexes are comparable or higher than commercial and clinically Gd-DTPA derivatives.
镧系元素配合物作为造影剂（CA）在生物医学成像中的应用越来越广泛。这些顺磁性配合物作为医学磁共振成像（MRI）的造影剂和光学成像的发光探针的发展具有很强的互补性。钆配合物作为MRI造影剂广为人知，而铕/铽配合物常用于显微镜或荧光成像。每种成像技术都有其局限性：MRI灵敏度低但空间分辨率高，光学成像穿透性有限但灵敏度高。一种双模态试剂可用于这两种方法并提供更多信息，它们可以通过光和磁共振成像同时可视化。这类化合物基于镧系离子与有机配体的配位化学以形成稳定的配合物以及镧系离子的性质。带有发色团的钆配合物也能实现发光检测。本文综述描述了镧系离子及其配合物的性质，并给出了这些配合物的一些典型应用。其发光性质显示出高量子产率和长发光寿命。钆配合物的弛豫测量数据与商业和临床使用的钆-二乙三胺五乙酸衍生物相当或更高。
