Magnetic resonance imaging(MRI) has been used in the clinic widely as an early noninvasive diagnosis technique. According to the theory of MRI, three imaging modes exist, namely, T₁-weighted imaging, T₂-weighted imaging and diffusion weighted imaging. Accordingly, there are two types of exogenous MRI contrast agents, namely T₁ contrast agent and T₂ contrast agent, for improvement in contrast in MR images. Either T₁ or T₂ contrast agents has its own advantages and disadvantages, respectively. Recently, a kind of new contrast agents, T₁-T₂ dual-modal contrast agent, has been designed, which can be used on one machine with an accurate match of spatial and temporal imaging parameters. This article reviews the progress of design and chemical synthesis methods of T₁-T₂ dual-mode contrast agents, and also introduces their biomedical applications.
Contents
1 Introduction
2 The research about dual T₁-T₂ MRI contrast agents
2.1 Nanoparticles with a single metal
2.2 Nanoparticles with two types of MRI contrast agents
2.3 A type of metal doping
3 Conclusion